THERMAP : a mid-infrared spectro-imager for the Marco Polo R mission

NASA Astrophysics Data System (ADS)

Groussin, O.; Brageot, E.; Reynaud, J.-L.; Lamy, P.; Jorda, L.; Licandro, J.; Helbert, J.; Knollenberg, J.; Kührt, E.; Delbó, M.

2012-09-01

We present THERMAP, a mid-infrared (8-16 μm) spectro-imager based on uncooled micro-bolometer detector arrays. Due to the recent technological development of these detectors, which have undergone significant improvements in the last decade, we wanted to test their performances for a space mission to small bodies in the inner Solar System. THERMAP was selected by ESA in January 2012 for a one year assessment study, in the framework of a call for declaration of interest in science instrumentation for the Marco Polo R Cosmic Vision mission. In this paper, we present some results of this study and in particular demonstrate that the new generation of uncooled micro-bolometer detectors has all the imaging and spectroscopic capabilities to fulfill the scientific objectives of the Marco Polo R mission. THERMAP scientific objectives - The midinfrared instrument of the Marco Polo R mission must be able i) to determine the surface temperature by mapping the entire surface with an absolute accuracy of at least 5 K (goal 1 K) above 200 K, ii) to determine the thermal inertia with an accuracy of 10% and iii) to determine the surface composition by mapping the entire surface with a spectral resolution of 70 between 8 and 16 μm. The above mappings should be performed with a spatial resolution of 10 m for the entire surface (global characterization) and 10 cm for the sampling sites (local characterization). THERMAP imaging capabilities - In order to test the imaging capabilities of the THERMAP uncooled microbolometer detector, we set up an experiment based on a 640x480 ULIS micro-bolometer array, a germanium objective and a black body. Using the results of this experiment, we show that calibrated radiometric images can be obtained down to at least 258 K (lower limit of our experiment), and that two calibration points are sufficient to determine the absolute scene temperature with an accuracy better than 1.5 K. An extrapolation to lower temperatures provides an accuracy of about 5 K at 180 K, the lowest temperature the detector can measure. THERMAP spectroscopic capabilites - In order to test the spectroscopic performances of the detector, we added flux attenuating neutral density mid-infrared filters (transmittance: 50%, 10%, 1%) to our experiment. Our results show that we can perform spectroscopic measurements with a spectral resolution R=40-80 in the wavelength range 8-16 μm for a scene temperature larger than 300 K, the typical surface temperature of a Near Earth Asteroid at 1 AU from the Sun. THERMAP preliminary design - From the above results, we defined a preliminary design for the instrument. THERMAP is a mid-infrared (8-16 μm) spectro-imager based on two uncooled microbolometer arrays. It is composed of two channels, one for imaging and one for spectroscopy. A flip mirror allows switching between the two channels. Calibration is performed using deep space and two black bodies at known temperature. The design of the THERMAP instrument has a strong heritage from the MERTIS instrument on board Bepi-Colombo [1], which guarantees its feasibility and reliability. Our design is very flexible in term of operations, which is fundamental for a mission to a binary asteroid system (1996 FG3). The THERMAP instrument will be proposed for Marco Polo R and any future space missions to small bodies in the inner solar system.

Wafer-level radiometric performance testing of uncooled microbolometer arrays

NASA Astrophysics Data System (ADS)

Dufour, Denis G.; Topart, Patrice; Tremblay, Bruno; Julien, Christian; Martin, Louis; Vachon, Carl

2014-03-01

A turn-key semi-automated test system was constructed to perform on-wafer testing of microbolometer arrays. The system allows for testing of several performance characteristics of ROIC-fabricated microbolometer arrays including NETD, SiTF, ROIC functionality, noise and matrix operability, both before and after microbolometer fabrication. The system accepts wafers up to 8 inches in diameter and performs automated wafer die mapping using a microscope camera. Once wafer mapping is completed, a custom-designed quick insertion 8-12 μm AR-coated Germanium viewport is placed and the chamber is pumped down to below 10-5 Torr, allowing for the evaluation of package-level focal plane array (FPA) performance. The probe card is electrically connected to an INO IRXCAM camera core, a versatile system that can be adapted to many types of ROICs using custom-built interface printed circuit boards (PCBs). We currently have the capability for testing 384x288, 35 μm pixel size and 160x120, 52 μm pixel size FPAs. For accurate NETD measurements, the system is designed to provide an F/1 view of two rail-mounted blackbodies seen through the Germanium window by the die under test. A master control computer automates the alignment of the probe card to the dies, the positioning of the blackbodies, FPA image frame acquisition using IRXCAM, as well as data analysis and storage. Radiometric measurement precision has been validated by packaging dies measured by the automated probing system and re-measuring the SiTF and Noise using INO's pre-existing benchtop system.

Real-Time Terahertz Imaging Using a Quantum Cascade Laser and Uncooled Microbolometer Focal Plane Array

DTIC Science & Technology

2008-06-01

reverse magnetron ” design (in which the polarity of the magnetron elements are reversed—such that the cathode constitutes the outer ring; the anode ...included as inset frames within Fig. 20. The dual nature of this figure (reporting both voltage and intensity vs. bias current) is useful in that it...tuned micro- magnetrons [60]-[61]. Conventional magnetrons (such as those used to generate microwaves) have physical dimensions which are excessively

Metal silicide/poly-Si Schottky diodes for uncooled microbolometers.

PubMed

Chizh, Kirill V; Chapnin, Valery A; Kalinushkin, Victor P; Resnik, Vladimir Y; Storozhevykh, Mikhail S; Yuryev, Vladimir A

2013-04-17

: Nickel silicide Schottky diodes formed on polycrystalline Si 〈P〉 films are proposed as temperature sensors of monolithic uncooled microbolometer infrared focal plane arrays. The structure and composition of nickel silicide/polycrystalline silicon films synthesized in a low-temperature process are examined by means of transmission electron microscopy. The Ni silicide is identified as a multi-phase compound composed of 20% to 40% of Ni3Si, 30% to 60% of Ni2Si, and 10% to 30% of NiSi with probable minor content of NiSi2 at the silicide/poly-Si interface. Rectification ratios of the Schottky diodes vary from about 100 to about 20 for the temperature increasing from 22â"ƒ to 70â"ƒ; they exceed 1,000 at 80 K. A barrier of around 0.95 eV is found to control the photovoltage spectra at room temperature. A set of barriers is observed in photo-electromotive force spectra at 80 K and attributed to the Ni silicide/poly-Si interface. Absolute values of temperature coefficients of voltage and current are found to vary from 0.3%â"ƒ to 0.6%/â"ƒ for forward bias and around 2.5%/â"ƒ for reverse bias of the diodes.

Uncooled Infrared Microbolometers and Silicon Germanium Oxide (SixGe1-xOy) Infrared Sensitive Material for Long Wavelength Detection

DTIC Science & Technology

2014-10-10

Hooge ’s parameters and 1/f noise at the comer frequency for the four wafers are shown in Table 6. We see in the table that the average value of ywas...voltage noise power spectral densities were analyzed and Hooge’s parameters were determined. UNCOOLED MICROBOLOMETER A thermal detector exhibits a...annealing at 200 °C, 250 °C, and 300 °C for duration from 1 hour to 5 hours using a bias current of 0.07 µA. The corresponding Hooge’s parameters for

Uncooled Cantilever Microbolometer Focal Plane Arrays with mK Temperature Resolution: Engineering Mechanics for the Next Generation

DTIC Science & Technology

2009-11-25

34Nanoindentation Stress-Strain Curves of Plasma Enhanced Chemical Vapor Deposited Silicon Oxide Thin Films," Thin Solid Films, 516 (8) (2008) 1941-1951. 9. S...1604. 5. Z. Cao* and X. Zhang, "Measurement of Stress-Strain Curves of PECVD Silicon Oxide Thin Films by Means of Nanoindentation," in Processing...Microsystems (Transducers 󈧋), Lyon, France, June 10-14, 2007. 9. Z. Cao* and X. Zhang, “Measurement of Stress-strain Curves of PECVD Silicon Oxide

COPPER Students - ELaNa IV

NASA Image and Video Library

2013-07-11

The Close Orbiting Propellant Plume Elemental Recognition (COPPER) was developed by students from St. Louis University as a technology demonstration mission whose objective is to test the suitability of a commercially-available compact uncooled microbolometer (tiny infrared camera) array for scientific imagery of Earth in the long-wave infrared range (LWIR, 7-13 microns). Launched by NASA’s CubeSat Launch Initiative on the ELaNa IV mission as an auxiliary payload aboard the U.S. Air Force-led Operationally Responsive Space (ORS-3) Mission on November 19, 2013.

Solid state temperature-dependent NUC (non-uniformity correction) in uncooled LWIR (long-wave infrared) imaging system

NASA Astrophysics Data System (ADS)

Cao, Yanpeng; Tisse, Christel-Loic

2013-06-01

In uncooled LWIR microbolometer imaging systems, temperature fluctuations of FPA (Focal Plane Array) as well as lens and mechanical components placed along the optical path result in thermal drift and spatial non-uniformity. These non-idealities generate undesirable FPN (Fixed-Pattern-Noise) that is difficult to remove using traditional, individual shutterless and TEC-less (Thermo-Electric Cooling) techniques. In this paper we introduce a novel single-image based processing approach that marries the benefits of both statistical scene-based and calibration-based NUC algorithms, without relying neither on extra temperature reference nor accurate motion estimation, to compensate the resulting temperature-dependent non-uniformities. Our method includes two subsequent image processing steps. Firstly, an empirical behavioral model is derived by calibrations to characterize the spatio-temporal response of the microbolometric FPA to environmental and scene temperature fluctuations. Secondly, we experimentally establish that the FPN component caused by the optics creates a spatio-temporally continuous, low frequency, low-magnitude variation of the image intensity. We propose to make use of this property and learn a prior on the spatial distribution of natural image gradients to infer the correction function for the entire image. The performance and robustness of the proposed temperature-adaptive NUC method are demonstrated by showing results obtained from a 640×512 pixels uncooled LWIR microbolometer imaging system operating over a broad range of temperature and with rapid environmental temperature changes (i.e. from -5°C to 65°C within 10 minutes).

Uncooled radiometric camera performance

NASA Astrophysics Data System (ADS)

Meyer, Bill; Hoelter, T.

1998-07-01

Thermal imaging equipment utilizing microbolometer detectors operating at room temperature has found widespread acceptance in both military and commercial applications. Uncooled camera products are becoming effective solutions to applications currently using traditional, photonic infrared sensors. The reduced power consumption and decreased mechanical complexity offered by uncooled cameras have realized highly reliable, low-cost, hand-held instruments. Initially these instruments displayed only relative temperature differences which limited their usefulness in applications such as Thermography. Radiometrically calibrated microbolometer instruments are now available. The ExplorIR Thermography camera leverages the technology developed for Raytheon Systems Company's first production microbolometer imaging camera, the Sentinel. The ExplorIR camera has a demonstrated temperature measurement accuracy of 4 degrees Celsius or 4% of the measured value (whichever is greater) over scene temperatures ranges of minus 20 degrees Celsius to 300 degrees Celsius (minus 20 degrees Celsius to 900 degrees Celsius for extended range models) and camera environmental temperatures of minus 10 degrees Celsius to 40 degrees Celsius. Direct temperature measurement with high resolution video imaging creates some unique challenges when using uncooled detectors. A temperature controlled, field-of-view limiting aperture (cold shield) is not typically included in the small volume dewars used for uncooled detector packages. The lack of a field-of-view shield allows a significant amount of extraneous radiation from the dewar walls and lens body to affect the sensor operation. In addition, the transmission of the Germanium lens elements is a function of ambient temperature. The ExplorIR camera design compensates for these environmental effects while maintaining the accuracy and dynamic range required by today's predictive maintenance and condition monitoring markets.

Low-cost low-power uncooled a-Si-based micro infrared camera for unattended ground sensor applications

NASA Astrophysics Data System (ADS)

Schimert, Thomas R.; Ratcliff, David D.; Brady, John F., III; Ropson, Steven J.; Gooch, Roland W.; Ritchey, Bobbi; McCardel, P.; Rachels, K.; Wand, Marty; Weinstein, M.; Wynn, John

1999-07-01

Low power and low cost are primary requirements for an imaging infrared camera used in unattended ground sensor arrays. In this paper, an amorphous silicon (a-Si) microbolometer-based uncooled infrared camera technology offering a low cost, low power solution to infrared surveillance for UGS applications is presented. A 15 X 31 micro infrared camera (MIRC) has been demonstrated which exhibits an f/1 noise equivalent temperature difference sensitivity approximately 67 mK. This sensitivity has been achieved without the use of a thermoelectric cooler for array temperature stabilization thereby significantly reducing the power requirements. The chopperless camera is capable of operating from snapshot mode (1 Hz) to video frame rate (30 Hz). Power consumption of 0.4 W without display, and 0.75 W with display, respectively, has been demonstrated at 30 Hz operation. The 15 X 31 camera demonstrated exhibits a 35 mm camera form factor employing a low cost f/1 singlet optic and LED display, as well as low cost vacuum packaging. A larger 120 X 160 version of the MIRC is also in development and will be discussed. The 120 X 160 MIRC exhibits a substantially smaller form factor and incorporates all the low cost, low power features demonstrated in the 15 X 31 MIRC prototype. In this paper, a-Si microbolometer technology for the MIRC will be presented. Also, the key features and performance parameters of the MIRC are presented.

Performance and Results from a Space Borne, Uncooled Microbolometer Array Spectral Radiometric Imager

NASA Technical Reports Server (NTRS)

Spinhirne, James M; Scott, V. Stan; Lancaster, Redgie S.; Manizade, Kathrine; Palm, Steven P.

2000-01-01

The Infrared Spectral Imaging Radiometer experiment was flown on a space shuttle mission as a shuttle hitchhiker experiment in August of 1997. The goals of the experiment were to test uncooled array detectors for infrared spectral imaging from space and to apply for the first time retrieval from space of brightness temperatures of cloud, land and sea along with direct laser measurements of cloud top height. The instrument operates in 3 narrow and one broad spectral band, all between 7 and 13 microns in either stare or time-delay and integration mode. The nominal spatial resolution was 1/4 kilometer. Using onboard calibrations along with periodic views of deep space, radiometric calibration of imagery was carried out and performance analyzed. The noise equivalent temperature difference and absolute accuracy reported here varied with operating mode, spectral band and scene temperature but were within requirements. This paper provides a description of the instrument, its operating modes, the method of brightness temperature retrieval, the method of spectral registration and results from the flight.

Modeling and Compensating Temperature-Dependent Non-Uniformity Noise in IR Microbolometer Cameras

PubMed Central

Wolf, Alejandro; Pezoa, Jorge E.; Figueroa, Miguel

2016-01-01

Images rendered by uncooled microbolometer-based infrared (IR) cameras are severely degraded by the spatial non-uniformity (NU) noise. The NU noise imposes a fixed-pattern over the true images, and the intensity of the pattern changes with time due to the temperature instability of such cameras. In this paper, we present a novel model and a compensation algorithm for the spatial NU noise and its temperature-dependent variations. The model separates the NU noise into two components: a constant term, which corresponds to a set of NU parameters determining the spatial structure of the noise, and a dynamic term, which scales linearly with the fluctuations of the temperature surrounding the array of microbolometers. We use a black-body radiator and samples of the temperature surrounding the IR array to offline characterize both the constant and the temperature-dependent NU noise parameters. Next, the temperature-dependent variations are estimated online using both a spatially uniform Hammerstein-Wiener estimator and a pixelwise least mean squares (LMS) estimator. We compensate for the NU noise in IR images from two long-wave IR cameras. Results show an excellent NU correction performance and a root mean square error of less than 0.25 ∘C, when the array’s temperature varies by approximately 15 ∘C. PMID:27447637

Metal silicide/poly-Si Schottky diodes for uncooled microbolometers

PubMed Central

2013-01-01

Nickel silicide Schottky diodes formed on polycrystalline Si 〈P〉 films are proposed as temperature sensors of monolithic uncooled microbolometer infrared focal plane arrays. The structure and composition of nickel silicide/polycrystalline silicon films synthesized in a low-temperature process are examined by means of transmission electron microscopy. The Ni silicide is identified as a multi-phase compound composed of 20% to 40% of Ni3Si, 30% to 60% of Ni2Si, and 10% to 30% of NiSi with probable minor content of NiSi2 at the silicide/poly-Si interface. Rectification ratios of the Schottky diodes vary from about 100 to about 20 for the temperature increasing from 22℃ to 70℃; they exceed 1,000 at 80 K. A barrier of around 0.95 eV is found to control the photovoltage spectra at room temperature. A set of barriers is observed in photo-electromotive force spectra at 80 K and attributed to the Ni silicide/poly-Si interface. Absolute values of temperature coefficients of voltage and current are found to vary from 0.3%℃ to 0.6%/℃ for forward bias and around 2.5%/℃ for reverse bias of the diodes. PMID:23594606

Uncooled thermal imaging and image analysis

NASA Astrophysics Data System (ADS)

Wang, Shiyun; Chang, Benkang; Yu, Chunyu; Zhang, Junju; Sun, Lianjun

2006-09-01

Thermal imager can transfer difference of temperature to difference of electric signal level, so can be application to medical treatment such as estimation of blood flow speed and vessel 1ocation [1], assess pain [2] and so on. With the technology of un-cooled focal plane array (UFPA) is grown up more and more, some simple medical function can be completed with un-cooled thermal imager, for example, quick warning for fever heat with SARS. It is required that performance of imaging is stabilization and spatial and temperature resolution is high enough. In all performance parameters, noise equivalent temperature difference (NETD) is often used as the criterion of universal performance. 320 x 240 α-Si micro-bolometer UFPA has been applied widely presently for its steady performance and sensitive responsibility. In this paper, NETD of UFPA and the relation between NETD and temperature are researched. several vital parameters that can affect NETD are listed and an universal formula is presented. Last, the images from the kind of thermal imager are analyzed based on the purpose of detection persons with fever heat. An applied thermal image intensification method is introduced.

An improved electrical and thermal model of a microbolometer for electronic circuit simulation

NASA Astrophysics Data System (ADS)

Würfel, D.; Vogt, H.

2012-09-01

The need for uncooled infrared focal plane arrays (IRFPA) for imaging systems has increased since the beginning of the nineties. Examples for the application of IRFPAs are thermography, pedestrian detection for automotives, fire fighting, and infrared spectroscopy. It is very important to have a correct electro-optical model for the simulation of the microbolometer during the development of the readout integrated circuit (ROIC) used for IRFPAs. The microbolometer as the sensing element absorbs infrared radiation which leads to a change of its temperature due to a very good thermal insulation. In conjunction with a high temperature coefficient of resistance (TCR) of the sensing material (typical vanadium oxide or amorphous silicon) this temperature change results in a change of the electrical resistance. During readout, electrical power is dissipated in the microbolometer, which increases the temperature continuously. The standard model for the electro-optical simulation of a microbolometer includes the radiation emitted by an observed blackbody, radiation emitted by the substrate, radiation emitted by the microbolometer itself to the surrounding, a heat loss through the legs which connect the microbolometer electrically and mechanically to the substrate, and the electrical power dissipation during readout of the microbolometer (Wood, 1997). The improved model presented in this paper takes a closer look on additional radiation effects in a real IR camera system, for example the radiation emitted by the casing and the lens. The proposed model will consider that some parts of the radiation that is reflected from the casing and the substrate is also absorbed by the microbolometer. Finally, the proposed model will include that some fraction of the radiation is transmitted through the microbolometer at first and then absorbed after the reflection at the surface of the substrate. Compared to the standard model temperature and resistance of the microbolometer can be modelled more realistically when these higher order effects are taken into account. A Verilog-A model for electronic circuit simulations is developed based on the improved thermal model of the microbolometer. Finally, a simulation result of a simple circuit is presented.

Terahertz holography for imaging amplitude and phase objects.

PubMed

Hack, Erwin; Zolliker, Peter

2014-06-30

A non-monochromatic THz Quantum Cascade Laser and an uncooled micro-bolometer array detector with VGA resolution are used in a beam-splitter free holographic set-up to measure amplitude and phase objects in transmission. Phase maps of the diffraction pattern are retrieved using the Fourier transform carrier fringe method; while a Fresnel-Kirchhoff back propagation algorithm is used to reconstruct the complex object image. A lateral resolution of 280 µm and a relative phase sensitivity of about 0.5 rad are estimated from reconstructed images of a metallic Siemens star and a polypropylene test structure, respectively. Simulations corroborate the experimental results.

Optimization of narrow width effect on titanium thermistor in uncooled antenna-coupled terahertz microbolometer

NASA Astrophysics Data System (ADS)

Banerjee, Amit; Satoh, Hiroaki; Elamaran, Durgadevi; Sharma, Yash; Hiromoto, Norihisa; Inokawa, Hiroshi

2018-04-01

Uncooled antenna-coupled terahertz microbolometer arrays are fabricated with a meander-type Ti thermistor, and design widths (DW) = 0.1 and 0.2 µm, considering the design requirement to miniaturize detectors. Each unit device with DW = 0.1 µm of the thermistor has about 4.7 time higher electrical responsivity (132 V/W) than that with DW = 0.2 µm (28.2 V/W) at 10 µA bias current. For DW = 0.2 µm, the calculated noise equivalent power (NEP) was 2.29 × 10‑9 W/\\sqrt{\\text{Hz}} , whereas the minimum NEP of 4.43 × 10‑10 W/\\sqrt{\\text{Hz}} was obtained for DW = 0.1 µm devices, both at 10 µA bias current. The bulk value of temperature coefficient of resistance (TCR) of the Ti thermistor is markedly compromised in low dimensional devices, still in terms of responsivity and NEP, unit devices with Ti thermistor with the lower DW shows better performance. This is because the narrow width effect is minimized owing to higher resistivity for DW = 0.1 than that for DW = 0.2 µm. In this current report, we highlights the optimization of the narrow width effect on TCR of metal interconnects in nanometer dimensions, which to the best of our knowledge is not available at present.

Monolithic Silicon Microbolometer Materials forUncooled Infrared Detectors

DTIC Science & Technology

2015-05-21

L. Allara, Mark W. Horn. Vanadium Oxide Thin Films Alloyed with Ti, Zr , Nb , and Mo for Uncooled Infrared Imaging Applications, Journal of...entitled "Thin Film Materials and Devices for Resistive Temperature Sensing Applications" by Hitesh Basantani and the other entitled "Reactive...extension. One was entitled "Thin Film Materials and Devices for Resistive Temperature Sensing Applications" by Hitesh Basantani and the other

LWIR NUC using an uncooled microbolometer camera

NASA Astrophysics Data System (ADS)

Laveigne, Joe; Franks, Greg; Sparkman, Kevin; Prewarski, Marcus; Nehring, Brian; McHugh, Steve

2010-04-01

Performing a good non-uniformity correction is a key part of achieving optimal performance from an infrared scene projector. Ideally, NUC will be performed in the same band in which the scene projector will be used. Cooled, large format MWIR cameras are readily available and have been successfully used to perform NUC, however, cooled large format LWIR cameras are not as common and are prohibitively expensive. Large format uncooled cameras are far more available and affordable, but present a range of challenges in practical use for performing NUC on an IRSP. Santa Barbara Infrared, Inc. reports progress on a continuing development program to use a microbolometer camera to perform LWIR NUC on an IRSP. Camera instability and temporal response and thermal resolution are the main difficulties. A discussion of processes developed to mitigate these issues follows.

Latest improvements in microbolometer thin film packaging: paving the way for low-cost consumer applications

NASA Astrophysics Data System (ADS)

Yon, J. J.; Dumont, G.; Goudon, V.; Becker, S.; Arnaud, A.; Cortial, S.; Tisse, C. L.

2014-06-01

Silicon-based vacuum packaging is a key enabling technology for achieving affordable uncooled Infrared Focal Plane Arrays (IRFPA) required by a promising mass market that shows momentum for some extensive consumer applications, such as automotive driving assistance, smart presence localization and building management. Among the various approaches studied worldwide, CEA, LETI in partnership with ULIS is committed to the development of a unique technology referred to as PLP (Pixel Level Packaging). In this PLP technology, each bolometer pixel is sealed under vacuum using a transparent thin film deposition on wafer. PLP operates as an array of hermetic micro caps above the focal plane, each enclosing a single microbolometer. In continuation of our on-going studies on PLP for regular QVGA IRFPAs, this paper emphasizes on the innate scalability of the technology which was successfully demonstrated through the development of an 80 × 80 pixel IRFPA. The relevance of the technology with regard to the two formats is discussed, considering both performance and cost issues. We show that the suboptimal fill factor inherent to the PLP arrangement is not so critical when considering smaller arrays preferably fitted for consumer applications. The discussion is supported with the electro-optical performance measurements of the PLP-based 80×80 demonstrator.

The MIDAS Instrument Design and Characterization

NASA Astrophysics Data System (ADS)

Honniball, C. I.; Wright, R.; Lucey, P. G.

2016-10-01

The Miniaturized Infrared detector of Atmospheric Species (MIDAS) utilizes an uncooled microbolometer coupled with a Sagnac interferometer. MIDAS will be used to detect and quantify atmospheric constituents for a variety of science applications.

AlliedSignal driver's viewer enhancement (DVE) for paramilitary and commercial applications

NASA Astrophysics Data System (ADS)

Emanuel, Michael; Caron, Hubert; Kovacevic, Branislav; Faina-Cherkaoui, Marcela; Wrobel, Leslie; Turcotte, Gilles

1999-07-01

AlliedSignal Driver's Viewer Enhancement (DVE) system is a thermal imager using a 320 X 240 uncooled microbolometer array. This high performance system was initially developed for military combat and tactical wheeled vehicles. It features a very small sensor head remotely mounted from the display, control and processing module. The sensor head has a modular design and is being adapted to various commercial applications such as truck and car-driving aid, using specifically designed low cost optics. Tradeoffs in the system design, system features and test results are discussed in this paper. A short video shows footage of the DVE system while driving at night.

Concept Doped-Silicon Thermopile Detectors for Future Planetary Thermal Imaging Instruments

NASA Astrophysics Data System (ADS)

Lakew, Brook; Barrentine, Emily M.; Aslam, Shahid; Brown, Ari D.

2016-10-01

Presently, uncooled thermopiles are the detectors of choice for thermal mapping in the 4.6-100 μm spectral range. Although cooled detectors like Ge or Si thermistor bolometers, and MgB2 or YBCO superconducting bolometers, have much higher sensitivity, the required active or passive cooling mechanisms add prohibitive cost and mass for long duration missions. Other uncooled detectors, likepyroelectrics, require a motor mechanism to chop against a known reference temperature, which adds unnecessary mission risk. Uncooled vanadium oxide or amorphous Si microbolometer arrays with integrated CMOS readout circuits, not only have lower sensitivity, but also have not been proven to be radiation hard >100 krad (Si) total ionizing dose, and barring additional materials and readout development, their performance has reached a plateau.Uncooled and radiation hard thermopiles with D* ~1x109 cm√Hz/W and time constant τ ~100 ms have been integrated into thermal imaging instruments on several past missions and have extensive flight heritage (Mariner, Voyager, Cassini, LRO, MRO). Thermopile arrays are also on the MERTIS instrument payload on-board the soon to be launched BepiColombo Mission.To date, thermopiles used for spaceflight instrumentation have consisted of either hand assembled "one-off" single thermopile pixels or COTS thermopile pixel arrays both using Bi-Sb or Bi-Te thermoelectric materials. For future high performance imagers, thermal detector arrays with higher D*, lower τ, and high efficiency delineated absorbers are desirable. Existing COTS and other flight thermopile designs require highly specialized and nonstandard processing techniques to fabricate both the Bi-Sb or Bi-Te thermocouples and the gold or silver black absorbers, which put limitations on further development.Our detector arrays will have a D* ≥ 3x109 cm√Hz/W and a thermal time constant ≤ 30 ms at 170 K. They will be produced using proven, standard semiconductor and MEMS fabrication techniques, which will enable the future integration of other ancillary structures like high efficiency broadband absorbers, which will result in D* ≥ 5x109 cm√Hz/W.

Evaluation of Microbolometer-Based Thermography for Gossamer Space Structures

NASA Technical Reports Server (NTRS)

Miles, Jonathan J.; Blandino, Joseph R.; Jenkins, Christopher H.; Pappa, Richard S.; Banik, Jeremy; Brown, Hunter; McEvoy, Kiley

2005-01-01

In August 2003, NASA's In-Space Propulsion Program contracted with our team to develop a prototype on-board Optical Diagnostics System (ODS) for solar sail flight tests. The ODS is intended to monitor sail deployment as well as structural and thermal behavior, and to validate computational models for use in designing future solar sail missions. This paper focuses on the thermography aspects of the ODS. A thermal model was developed to predict local sail temperature variations as a function of sail tilt to the sun, billow depth, and spectral optical properties of front and back sail surfaces. Temperature variations as small as 0.5 C can induce significant thermal strains that compare in magnitude to mechanical strains. These thermally induced strains may result in changes in shape and dynamics. The model also gave insight into the range and sensitivity required for in-flight thermal measurements and supported the development of an ABAQUS-coupled thermo-structural model. The paper also discusses three kinds of tests conducted to 1) determine the optical properties of candidate materials; 2) evaluate uncooled microbolometer-type infrared imagers; and 3) operate a prototype imager with the ODS baseline configuration. (Uncooled bolometers are less sensitive than cooled ones, but may be necessary because of restrictive ODS mass and power limits.) The team measured the spectral properties of several coated polymer samples at various angles of incidence. Two commercially available uncooled microbolometer imagers were compared, and it was found that reliable temperature measurements are feasible for both coated and uncoated sides of typical sail membrane materials.

Optical and electrical characterization of high resistivity semiconductors for constant-bias microbolometer devices

NASA Astrophysics Data System (ADS)

Saint John, David B.

The commercial market for uncooled infrared imaging devices has expanded in the last several decades, following the declassification of pulse-biased microbolometer-based focal plane arrays (FPAs) using vanadium oxide as the sensing material. In addition to uncooled imaging platforms based on vanadium oxide, several constant-bias microbolometer FPAs have been developed using doped hydrogenated amorphous silicon (a-Si:H) as the active sensing material. While a-Si:H and the broader Si1-xGex:H system have been studied within the context of photovoltaic (PV) devices, only recently have these materials been studied with the purpose of qualifying and optimizing them for potential use in microbolometer applications, which demand thinner films deposited onto substrates different than those used in PV. The behavior of Ge:H is of particular interest for microbolometers due to its intrinsically low resistivity without the introduction of dopants, which alter the growth behavior and frustrate any attempt to address the merits of protocrystalline a-Ge:H. This work reports the optical, microstructural, and electrical characterization and qualification of a variety of Si:H, Si1-xGex:H, and Ge:H films deposited using a plasma enhanced chemical vapor deposition (PECVD) process, including a-Ge:H films which exhibit high TCR (4-6 -%/K) and low 1/f noise at resistivities of interest for microbolometers (4000 -- 6000 O cm). Thin film deposition has been performed simultaneously with real-time optical characterization of the growth evolution dynamics, providing measurement of optical properties and surface roughness evolutions relevant to controlling the growth process for deliberate variations in film microstructure. Infrared spectroscopic ellipsometry has been used to characterize the Si-H and Ge-H absorption modes allowing assessment of the hydrogen content and local bonding behavior in thinner films than measured traditionally. This method allows IR absorption analysis of hydrogen bonding and other IR modes to be extended to arbitrary substrates, including absorbing and/or device-like substrate configurations not amenable to traditional methods of assessing hydrogen related absorption using infrared transmission measurements. In addition to novel optical assessments of hydrogen in Si1-xGe x:H films, the role of carrier type in a-Si:H has been studied, with n-type material providing a consistently higher TCR and 1/f noise character than p-type material for films of similar resistivity. As the introduction of dopant gas complicates microstructural growth, assessment of undoped material was performed, finding that only Ge-rich films possess suitable resitivities for electrical measurement. The inclusion of nanocrystalline material into otherwise amorphous films has been explored in both Si:H and Ge:H, finding that decreases in resistivity and TCR were not accompanied by a decrease in the 1/f noise character. This suggests that mixed (a+nc) Si1-xGex:H material may be less suitable for microbolometer applications than optimized amorphous material.

Low resistivity W{sub x}V{sub 1−x}O{sub 2}-based multilayer structure with high temperature coefficient of resistance for microbolometer applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Émond, Nicolas; Hendaoui, Ali; Chaker, Mohamed, E-mail: chaker@emt.inrs.ca

2015-10-05

Materials that exhibit semiconductor-to-metal phase transition (SMT) are commonly used as sensing layers for the fabrication of uncooled microbolometers. The development of highly responsive microbolometers would benefit from using a sensing material that possesses a large thermal coefficient of resistance (TCR) close to room temperature and a resistivity low enough to compromise between noise reduction and high TCR, while it should also satisfies the requirements of current CMOS technology. Moreover, a TCR that remains constant when the IR camera surrounding temperature varies would contribute to achieve reliable temperature measurements without additional corrections steps for TCR temperature dependence. In this paper,more » the characteristics of the SMT occurring in undoped and tungsten-doped vanadium dioxide thin films deposited on LaAlO{sub 3} (100) substrates are investigated. They are further exploited to fabricate a W{sub x}V{sub 1−x}O{sub 2} (0 ≤ x ≤ 2.5) multilayer structure exhibiting a bottom-up gradient of tungsten content. This MLS displays a combination of properties that is promising for application to uncooled microbolometer, such as a large TCR of −10.4%/ °C and low resistivity values ranging from 0.012 to 0.10 Ω-cm over the temperature range 22 °C–42 °C.« less

Development of the compact infrared camera (CIRC) for Earth observation

NASA Astrophysics Data System (ADS)

Naitoh, Masataka; Katayama, Haruyoshi; Harada, Masatomo; Nakamura, Ryoko; Kato, Eri; Tange, Yoshio; Sato, Ryota; Nakau, Koji

2017-11-01

The Compact Infrared Camera (CIRC) is an instrument equipped with an uncooled infrared array detector (microbolometer). We adopted the microbolometer, because it does not require a cooling system such as a mechanical cooler, and athermal optics, which does not require an active thermal control of optics. This can reduce the size, cost, and electrical power consumption of the sensor. The main mission of the CIRC is to demonstrate the technology for detecting wildfire, which are major and chronic disasters affecting many countries in the Asia-Pacific region. It is possible to increase observational frequency of wildfires, if CIRCs are carried on a various satellites by taking advantages of small size and light weight. We have developed two CIRCs. The first will be launched in JFY 2013 onboard Advanced Land Observing Satellite-2 (ALOS- 2), and the second will be launched in JFY 2014 onboard CALorimetric Electron Telescope (CALET) of the Japanese Experiment Module (JEM) at the International Space Station(ISS). We have finished the ground Calibration of the first CIRC onboard ALOS-2. In this paper, we provide an overview of the CIRC and its results of ground calibration.

MT3825BA: a 384×288-25µm ROIC for uncooled microbolometer FPAs

NASA Astrophysics Data System (ADS)

Eminoglu, Selim; Gulden, M. Ali; Bayhan, Nusret; Incedere, O. Samet; Soyer, S. Tuncer; Ustundag, Cem M. B.; Isikhan, Murat; Kocak, Serhat; Turan, Ozge; Yalcin, Cem; Akin, Tayfun

2014-06-01

This paper reports the development of a new microbolometer Readout Integrated Circuit (ROIC) called MT3825BA. It has a format of 384 × 288 and a pixel pitch of 25μm. MT3825BA is Mikro-Tasarim's second microbolometer ROIC product, which is developed specifically for resistive surface micro-machined microbolometer detector arrays using high-TCR pixel materials, such as VOx and a-Si. MT3825BA has a system-on-chip architecture, where all the timing, biasing, and pixel non-uniformity correction (NUC) operations in the ROIC are applied using on-chip circuitry simplifying the use and system integration of this ROIC. The ROIC is designed to support pixel resistance values ranging from 30 KΩ to 100 KΩ. MT3825BA is operated using conventional row based readout method, where pixels in the array are read out in a row-by-row basis, where the applied bias for each pixel in a given row is updated at the beginning of each line period according to the applied line based NUC data. The NUC data is applied continuously in a row-by-row basis using the serial programming interface, which is also used to program user configurable features of the ROIC, such as readout gain, integration time, and number of analog video outputs. MT3825BA has a total of 4 analog video outputs and 2 analog reference outputs, placed at the top and bottom of the ROIC, which can be programmed to operate in the 1, 2, and 4-output modes, supporting frames rates well above 60 fps at a 3 MHz pixel output rate. The pixels in the array are read out with respect to reference pixels implemented above and below actual array pixels. The bias voltage of the pixels can be programmed over a 1.0 V range to compensate for the changes in the detector resistance values due to the variations coming from the manufacturing process or changes in the operating temperature. The ROIC has an on-chip integrated temperature sensor with a sensitivity of better than 5 mV / K, and the output of the temperature sensor can be read out the output as part of the analog video stream. MT3825BA can be used to build a microbolometer FPAs with an NETD value below 100 mK using a microbolometer detector array fabrication technology with a detector resistance value up to 100 KΩ, a high TCR value (< 2 % / K), and a sufficiently low pixel thermal conductance (Gth ≤ 20 nW / K). MT3825BA measures 13.0 mm × 13.5 mm and is fabricated on 200 mm CMOS wafers. The microbolometer ROIC wafers are engineered to have flat surface finish to simplify the wafer level detector fabrication and wafer level vacuum packaging (WLVP). The ROIC runs on 3.3 V analog and 1.8 V digital supplies, and dissipates less than 85 mW in the 2-output mode at 30 fps. Mikro-Tasarim provides tested ROIC wafers and offers compact test electronics and software for its ROIC customers to shorten their FPA and camera development cycles.

Uncooled Tunable LWIR Microbolometer

DTIC Science & Technology

2010-05-05

switches [19], micromirrors in projection displays [20], and tunable thermal detectors [21, 22], etc. In all these devices, contact must be achieved...Failure Mechanisms of the Digital Micromirror Device (DMD)”, Proc. 36th Annual Intl. Reliability Physics Symposium, Reno, NV, pp. 9-16, 1998. [33

Uncooled emissive infrared imagers for CubeSats

NASA Astrophysics Data System (ADS)

Puschell, Jeffery J.; Masini, Paolo

2014-09-01

Raytheon's fourth generation uncooled microbolometer array technology with digital output, High Definition (HD) 1920 × 1200 format and 12 μm cell size enables uncooled thermal infrared (TIR) multispectral imagers with the sensitivity and spatial sampling needed for a variety of Earth observation missions in LEO, GEO and HEO. A powerful combination of small detector cell size, fast optics and high sensitivity achieved without cryogenic cooling leads to instruments that are much smaller than current TIR systems, while still offering the capability to meet challenging measurement requirements for Earth observation missions. To consider how this technology could be implemented for Earth observation missions, we extend our previous studies with visible wavelength CubeSat imagers for environmental observations from LEO and examine whether small thermal infrared imagers based on fourth generation uncooled technology could be made small enough to fit onboard a 3U CubeSat and still meet challenging requirements for legacy missions. We found that moderate spatial resolution (~200 m) high sensitivity cloud and surface temperature observations meeting legacy MODIS/VIIRS requirements could be collected successfully with CubeSat-sized imagers but that multiple imagers are needed to cover the full swath for these missions. Higher spatial resolution land imagers are more challenging to fit into the CubeSat form factor, but it may be possible to do so for systems that require roughly 100 m spatial resolution. Regardless of whether it can fit into a CubeSat or not, uncooled land imagers meeting candidate TIR requirements can be implemented with a much smaller instrument than previous imagers. Even though this technology appears to be very promising, more work is needed to qualify this newly available uncooled infrared technology for use in space. If these new devices prove to be as space worthy as the first generation arrays that Raytheon qualified and built into the THEMIS imager still operating successfully onboard Mars Odyssey 2001, new classes of low cost, uncooled TIR Earth instruments will be enabled that are suitable for use as primary and hosted payloads in LEO, GEO and HEO or in constellations of small satellites as small as CubeSats to support Earth science measurement objectives in weather forecasting, land imaging and climate variability and change.

Innovative on-chip packaging applied to uncooled IRFPA

NASA Astrophysics Data System (ADS)

Dumont, Geoffroy; Arnaud, Agnès; Impérinetti, Pierre; Vialle, Claire; Rabaud, Wilfried; Goudon, Valérie; Yon, Jean-Jacques

2008-04-01

The Laboratoire Infrarouge (LIR) of the Laboratoire d'Electronique et de Technologie de l'Information (LETI) has been involved in the development of microbolometers for over fifteen years. Two generations of technology have been transferred to ULIS and LETI is still working to improve performances of low cost detectors. Simultaneously, packaging still represents a significant part of detectors price. Reducing production costs would contribute to keep on extending applications of uncooled IRFPA to high volume markets like automotive. Therefore LETI is developing an on-chip packaging technology dedicated to microbolometers. This paper presents an original microcap structure that enables the use of IR window materials as sealing layers to maintain the expected vacuum level. The modelling and integration of an IR window suitable for this structure is also presented. This monolithic packaging technology is performed in a standard collective way, in continuation of bolometers' technology. The CEA-LETI, MINATEC presents status of these developments concerning this innovating technology including optical simulations results and SEM views of technical realizations.

Mid-wave Infrared Hyperspectral Imaging of Kilauea's Active Halema'uma'u Pit Crater

NASA Astrophysics Data System (ADS)

Honniball, C. I.; Wright, R.; Lucey, P. G.

2017-12-01

The Mid-Wave InfraRed (MWIR) from 3 to 5 microns carries a wealth of information for both earth and planetary science applications. Molecules like methane and carbon dioxide exhibit prominent spectral features in the MWIR allowing us to detect their presences in the atmosphere after being released from volcanic vents, industrial gas leaks or biomass burning events. Energy released by wildfires at 4 μm is an important measurement for quantifying fire radiative power (FRP); an important climate variable that allows estimates of the amount of carbon liberated into the Earth's atmosphere during a burning event. FRP can also be used to estimate lava flow cooling rates and forecasting lava flow hazards. This spectral region also allows the derivation of temperatures from hot spots like the ones on Jupiter's moon Io, which provide important insights into the formation and evolution of Io. In the MWIR region there is limited signal available to measure for low temperature targets. This presents technical challenges on achieving high signal-to-noise ratios (SNR); therefore, acquiring adequate data in the MWIR is difficult without cryogenically cooling the instrument. Recent improvements to microbolometer technology and emerging interferometric techniques have allowed us to acquire good thermal infrared (TIR) data without the need for cooling. By coupling an uncooled microbolometer with a Sagnac interferometer we have demonstrated in the TIR that high SNR's can be obtained for hyperspectral imaging. To explore if this imaging technique holds in the MWIR, with funding from NASA, we have built, tested and compared two MWIR hyperspectral instruments, an uncooled microbolometer version and a liquid nitrogen cooled photon detector version with the same optical design. We demonstrate that using the aforementioned imaging technique we can achieve good SNR's for hyperspectral MWIR imaging using an uncooled instrument for targets 20°C above ambient. In late July 2017, we field tested the uncooled imager at Kilauea's Halema'uma'u pit crater which has an active lava lake and gas plume. Using the lava lake as the hot background source we present MWIR gas analysis of the Kilauea volcanic plume.

A 1024×768-12μm Digital ROIC for uncooled microbolometer FPAs

NASA Astrophysics Data System (ADS)

Eminoglu, Selim

2017-02-01

This paper reports the development of a new digital microbolometer Readout Integrated Circuit (D-ROIC), called MT10212BD. It has a format of 1024 × 768 (XGA) and a pixel pitch of 12μm. MT10212BD is Mikro Tasarim's second 12μm pitch microbolometer ROIC, which is developed specifically for surface micro machined microbolometer detector arrays with small pixel pitch using high-TCR pixel materials, such as VOx and a Si. MT10212BD has an alldigital system on-chip architecture, which generates programmable timing and biasing, and performs 14-bit analog to digital conversion (ADC). The signal processing chain in the ROIC is composed of pixel bias circuitry, integrator based programmable gain amplifier followed by column parallel ADC circuitry. MT10212BD has a serial programming interface that can be used to configure the programmable ROIC features and to load the Non-Uniformity-Correction (NUC) date to the ROIC. MT10212BD has a total of 8 high-speed serial digital video outputs, which can be programmed to operate in the 2, 4, and 8-output modes and can support frames rates above 60 fps. The high-speed serial digital outputs supports data rates as high as 400 Mega-bits/s, when operated at 50 MHz system clock frequency. There is an on-chip phase-locked-loop (PLL) based timing circuitry to generate the high speed clocks used in the ROIC. The ROIC is designed to support pixel resistance values ranging from 30KΩ to 90kΩ, with a nominal value of 60KΩ. The ROIC has a globally programmable gain in the column readout, which can be adjusted based on the detector resistance value.

Innovative on-chip packaging applied to uncooled IRFPA

NASA Astrophysics Data System (ADS)

Dumont, Geoffroy; Arnaud, Agnès; Imperinetti, Pierre; Mottin, Eric; Simoens, François; Vialle, Claire; Rabaud, Wilfried; Grand, Gilles; Baclet, Nathalie

2008-03-01

The Laboratoire Infrarouge (LIR) of the Laboratoire d'Electronique et de Technologie de l'Information (LETI) has been involved in the development of microbolometers for over fifteen years. Two generations of technology have been transferred to ULIS and LETI is still working to improve performances of low cost detectors. Simultaneously, packaging still represents a significant part of detectors price. Reducing production costs would contribute to keep on extending applications of uncooled IRFPA to high volume markets like automotive. Therefore LETI develops an onchip packaging technology dedicated to microbolometers. The efficiency of a micropackaging technology for microbolometers relies on two major technical specifications. First, it must include an optical window with a high transmittance for the IR band, so as to maximize the detector absorption. Secondly, in order to preserve the thermal insulation of the detector, the micropackaging must be hermetically closed to maintain a vacuum level lower than 10 -3mbar. This paper presents an original microcap structure that enables the use of IR window materials as sealing layers to maintain the expected vacuum level. The modelling and integration of an IR window suitable for this structure is also presented. This zero level packaging technology is performed in a standard collective way, in continuation of bolometers' technology. The CEA-LETI, MINATEC presents status of these developments concerning this innovating technology including optical simulations results and SEM views of technical realizations.

Review of terahertz technology development at INO

NASA Astrophysics Data System (ADS)

Dufour, Denis; Marchese, Linda; Terroux, Marc; Oulachgar, Hassane; Généreux, Francis; Doucet, Michel; Mercier, Luc; Tremblay, Bruno; Alain, Christine; Beaupré, Patrick; Blanchard, Nathalie; Bolduc, Martin; Chevalier, Claude; D'Amato, Dominic; Desroches, Yan; Duchesne, François; Gagnon, Lucie; Ilias, Samir; Jerominek, Hubert; Lagacé, François; Lambert, Julie; Lamontagne, Frédéric; Le Noc, Loïc; Martel, Anne; Pancrati, Ovidiu; Paultre, Jacques-Edmond; Pope, Tim; Provençal, Francis; Topart, Patrice; Vachon, Carl; Verreault, Sonia; Bergeron, Alain

2015-10-01

Over the past decade, INO has leveraged its expertise in the development of uncooled microbolometer detectors for infrared imaging to produce terahertz (THz) imaging systems. By modifying its microbolometer-based focal plane arrays to enhance absorption in the THz bands and by developing custom THz imaging lenses, INO has developed a leading-edge THz imaging system, the IRXCAM-THz-384 camera, capable of exploring novel applications in the emerging field of terahertz imaging and sensing. Using appropriate THz sources, results show that the IRXCAM-THz-384 camera is able to image a variety of concealed objects of interest for applications such as non-destructive testing and weapons detections. By using a longer wavelength (94 GHz) source, it is also capable of sensing the signatures of various objects hidden behind a drywall panel. This article, written as a review of THz research at INO over the past decade, describes the technical components that form the IRXCAM-THz-384 camera and the experimental setup used for active THz imaging. Image results for concealed weapons detection experiments, an exploration of wavelength choice on image quality, and the detection of hidden objects behind drywall are also presented.

Night vision in Thales Angenieux: custom solutions for hand-held devices

NASA Astrophysics Data System (ADS)

Rollin, Joel; Teszner, Jean Louis

2005-01-01

Thales Anenieux has been manufacturing for two decades flexible light intensifier goggles that have been popular over numerous countries: thanks to the advent of uncooled microbolometer arrays, further outlooks are settled. Army Forces can have now at their command a multi-purpose and cost effective set of devices that answer most of the battlefield mission profiles. Thales Angenieux move from light intensifier goggles to low cost infared imagers and this smooth change is sketched out: our erlier experience on compact and user-friendly L.I equipment, especially in the field of the opto-mechanical design, has helped us to push forward the best compromises. Our product line policy is displayed: really, we have made a point of addressing many potential customers demands by singling out a modular approach. Further developments are now going on.

Optimization of a 3.6-THz quantum cascade laser for real-time imaging with a microbolometer focal plane array

NASA Astrophysics Data System (ADS)

Behnken, Barry N.; Karunasiri, Gamani; Chamberlin, Danielle; Robrish, Peter; Faist, Jérôme

2008-02-01

Real-time imaging in the terahertz (THz) spectral range was achieved using a 3.6-THz quantum cascade laser (QCL) and an uncooled, 160×120 pixel microbolometer camera fitted with a picarin lens. Noise equivalent temperature difference of the camera in the 1-5 THz frequency range was calculated to be at least 3 K, confirming the need for external THz illumination when imaging in this frequency regime. After evaluating the effects of various operating parameters on laser performance, the QCL found to perform optimally at 1.9 A in pulsed mode with a 300 kHz repetition rate and 10-20% duty cycle; average output power was approximately 1 mW. Under this scheme, a series of metallic objects were imaged while wrapped in various obscurants. Single-frame and extended video recordings demonstrate strong contrast between metallic materials and those of plastic, cloth, and paper - supporting the viability of this imaging technology in security screening applications. Thermal effects arising from Joule heating of the laser were found to be the dominant issue affecting output power and image quality; these effects were mitigated by limiting laser pulse widths to 670 ns and operating the system under closed-cycle refrigeration at a temperature of 10 K.

Initial Checkout Results of the Compact Infrared Camera (circ) for Earth Observation

NASA Astrophysics Data System (ADS)

Kato, E.; Katayama, H.; Sakai, M.; Nakajima, Y.; Kimura, T.; Nakau, K.; Tonooka, H.

2015-04-01

Compact Infrared Camera (CIRC) is a technology-demonstration instrument equipped with an uncooled infrared array detector (microbolometer) for space application. CIRC is the first microbolometer sensor without a calibration function in orbit, like a shutter system or an onboard blackbody. The main objective of the CIRC is to detect wildfires, which are major and chronic disasters affecting various countries of Southeast Asia, particularly considering the effects of global warming and climate change. The CIRC achieves a small size (approximately 200 mm), light mass (approximately 3 kg), and low electrical power consumption (<20 W) by employing athermal optics and a shutterless system. The CIRC can be consequently mounted on multiple satellites to enable highfrequency observation. Installation of CIRCs on the ALOS-2 and on the JEM/CALET is expected to increase observation frequency. We present the initial check-out results of the CIRC onboard ALOS-2. Since the initial check-out phase (July 4-14, 2014), the CIRC has acquired the images of Earth. CIRC was demonstrated to function according to its intended design. After the early calibration validation phase, which confirmed the temperature accuracy of observed data, CIRC data has been available to the public January 2015 onward. We also introduce a few observational results about wildfire, volcanoes, and heat-island.

Spectroscopic Imaging with an Uncooled Microbolometer Infrared Camera and Step-Scan FTIR

DTIC Science & Technology

2006-12-01

NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public released; distribution is unlimited SPECTROSCOPIC...Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the...STATEMENT Approved for public release; distribution is unlimited 12b. DISTRIBUTION CODE 13. ABSTRACT (maximum 200 words) The purpose of this

Enhanced LWIR NUC using an uncooled microbolometer camera

NASA Astrophysics Data System (ADS)

LaVeigne, Joe; Franks, Greg; Sparkman, Kevin; Prewarski, Marcus; Nehring, Brian

2011-06-01

Performing a good non-uniformity correction is a key part of achieving optimal performance from an infrared scene projector, and the best NUC is performed in the band of interest for the sensor being tested. While cooled, large format MWIR cameras are readily available and have been successfully used to perform NUC, similar cooled, large format LWIR cameras are not as common and are prohibitively expensive. Large format uncooled cameras are far more available and affordable, but present a range of challenges in practical use for performing NUC on an IRSP. Some of these challenges were discussed in a previous paper. In this discussion, we report results from a continuing development program to use a microbolometer camera to perform LWIR NUC on an IRSP. Camera instability and temporal response and thermal resolution were the main problems, and have been solved by the implementation of several compensation strategies as well as hardware used to stabilize the camera. In addition, other processes have been developed to allow iterative improvement as well as supporting changes of the post-NUC lookup table without requiring re-collection of the pre-NUC data with the new LUT in use.

Advanced uncooled infrared focal plane development at CEA/LETI

NASA Astrophysics Data System (ADS)

Tissot, Jean-Luc; Mottin, Eric; Martin, Jean-Luc; Yon, Jean-Jacques; Vilain, Michel

2017-11-01

LETI/LIR has been involved for a few year in the field of uncooled detectors and has chosen amorphous silicon for its microbolometer technology development. Uncooled IR detectors pave the way to reduced weight systems aboard satellites. The silicon compatibility of our thermometer is a key parameter which has enabled a very fast technology development and transfer to industry. This competitive technology is now able to provide a new approach for IR detectors for space applications. This paper presents the main characteristics of the CEA / LETI technology which is based on a monolithically integrated structure over a fully completed readout circuit from a commercially available 0.5 μm design rules CMOS line. The technology maturity will be illustrated by the results obtained at LETI/LIR and SOFRADIR on a 320 x 240 with a pitch of 45 μm. First improvement on device reliability and characterization results will be presented.

La détection infrarouge avec les plans focaux non refroidis : état de l'artUncooled focal plane infrared detectors: the state of the art

NASA Astrophysics Data System (ADS)

Tissot, Jean-Luc

2003-12-01

The emergence of uncooled detectors has opened new opportunities for IR detection for both military and commercial applications. Development of such devices involves a lot of trade-offs between the different parameters that define the technological stack. These trade-offs explain the number of different architectures that are under worldwide development. The key factor is to find a high sensitivity and low noise thermometer material compatible with silicon technology in order to achieve high thermal isolation in the smallest area as possible. Ferroelectric thermometer based hybrid technology and electrical resistive thermometer based (microbolometer) technology are under development. LETI and ULIS have chosen from the very beginning to develop first a monolithic microbolometer technology fully compatible with commercially available CMOS technology and secondly amorphous silicon based thermometer. This silicon approach has the greatest potential for reducing infrared detector manufacturing cost. After the development of the technology, the transfer to industrial facilities has been performed in a short period of time and the production is now ramping up with ULIS team in new facilities. LETI and ULIS are now working to facilitate the IRFPA integration into equipment in order to address a very large market. Achievement of this goal needs the development of smart sensors with on-chip advanced functions and the decrease of manufacturing cost of IRFPA by decreasing the pixel pitch and simplifying the vacuum package. We present in this paper the technology developed by CEA/LETI and its improvement for being able to designs 384×288 and 160×120 arrays with a pitch of 35 μm. Thermographic application needs high stability infrared detector with a precise determination of the amount of absorbed infrared flux. Hence, infrared detector with internal temperature stabilized shield has been developed and characterized. These results will be presented. To cite this article: J.-L. Tissot, C. R. Physique 4 (2003).

Application of infrared uncooled cameras in surveillance systems

NASA Astrophysics Data System (ADS)

Dulski, R.; Bareła, J.; Trzaskawka, P.; PiÄ tkowski, T.

2013-10-01

The recent necessity to protect military bases, convoys and patrols gave serious impact to the development of multisensor security systems for perimeter protection. One of the most important devices used in such systems are IR cameras. The paper discusses technical possibilities and limitations to use uncooled IR camera in a multi-sensor surveillance system for perimeter protection. Effective ranges of detection depend on the class of the sensor used and the observed scene itself. Application of IR camera increases the probability of intruder detection regardless of the time of day or weather conditions. It also simultaneously decreased the false alarm rate produced by the surveillance system. The role of IR cameras in the system was discussed as well as technical possibilities to detect human being. Comparison of commercially available IR cameras, capable to achieve desired ranges was done. The required spatial resolution for detection, recognition and identification was calculated. The simulation of detection ranges was done using a new model for predicting target acquisition performance which uses the Targeting Task Performance (TTP) metric. Like its predecessor, the Johnson criteria, the new model bounds the range performance with image quality. The scope of presented analysis is limited to the estimation of detection, recognition and identification ranges for typical thermal cameras with uncooled microbolometer focal plane arrays. This type of cameras is most widely used in security systems because of competitive price to performance ratio. Detection, recognition and identification range calculations were made, and the appropriate results for the devices with selected technical specifications were compared and discussed.

Combined Infrared Stereo and Laser Ranging Cloud Measurements from Shuttle Mission STS-85

NASA Technical Reports Server (NTRS)

Lancaster, R. S.; Spinhirne, J. D.; Manizade, K. F.

2004-01-01

Multiangle remote sensing provides a wealth of information for earth and climate monitoring, such as the ability to measure the height of cloud tops through stereoscopic imaging. As technology advances so do the options for developing spacecraft instrumentation versatile enough to meet the demands associated with multiangle measurements. One such instrument is the infrared spectral imaging radiometer, which flew as part of mission STS-85 of the space shuttle in 1997 and was the first earth- observing radiometer to incorporate an uncooled microbolometer array detector as its image sensor. Specifically, a method for computing cloud-top height with a precision of +/- 620 m from the multispectral stereo measurements acquired during this flight has been developed, and the results are compared with coincident direct laser ranging measurements from the shuttle laser altimeter. Mission STS-85 was the first space flight to combine laser ranging and thermal IR camera systems for cloud remote sensing.

Radiative Properties of Thin Films of Common Dielectric Materials in the IR Spectral Range of 1.5-14.2 μm: Application to Infrared Imaging

NASA Astrophysics Data System (ADS)

Bañobre, Asahel; Marthi, Sita Rajyalaxmi; Ravindra, N. M.

2018-05-01

To measure, map and control temperature, imaging of materials in a thermal furnace routinely utilizes non-contact sensors, such as pyrometers. These pyrometers require a pre-knowledge of the radiative properties of materials in the desired infrared range of wavelengths. In this study, radiative properties of some commonly used thin films of dielectric materials are investigated within the infrared (IR) spectral range of 1.5-14.2 μm. Radiative properties of aluminum oxide (Al2O3), silicon dioxide (SiO2), aluminum nitride (AlN) and silicon nitride (Si3N4) have been simulated and compared, utilizing a matrix method of representing the optical properties. The simulated results of the radiative properties show that Si3N4 is an excellent choice for the infrared radiation absorbing layer that is currently used in infrared uncooled detectors (microbolometers) because of its optical, mechanical and electrical properties. A case study of the radiative properties of an infrared uncooled microbolometer (Honeywell structure) is presented and discussed in the infrared spectral range of 8-14 μm. The results obtained serve as useful information for the design and fabrication of infrared imaging systems and components such as coatings, detectors, filters, lenses and waveguides.

Uncooled Thermal Camera Calibration and Optimization of the Photogrammetry Process for UAV Applications in Agriculture

PubMed Central

Ballesteros, Rocío

2017-01-01

The acquisition, processing, and interpretation of thermal images from unmanned aerial vehicles (UAVs) is becoming a useful source of information for agronomic applications because of the higher temporal and spatial resolution of these products compared with those obtained from satellites. However, due to the low load capacity of the UAV they need to mount light, uncooled thermal cameras, where the microbolometer is not stabilized to a constant temperature. This makes the camera precision low for many applications. Additionally, the low contrast of the thermal images makes the photogrammetry process inaccurate, which result in large errors in the generation of orthoimages. In this research, we propose the use of new calibration algorithms, based on neural networks, which consider the sensor temperature and the digital response of the microbolometer as input data. In addition, we evaluate the use of the Wallis filter for improving the quality of the photogrammetry process using structure from motion software. With the proposed calibration algorithm, the measurement accuracy increased from 3.55 °C with the original camera configuration to 1.37 °C. The implementation of the Wallis filter increases the number of tie-point from 58,000 to 110,000 and decreases the total positing error from 7.1 m to 1.3 m. PMID:28946606

Uncooled Thermal Camera Calibration and Optimization of the Photogrammetry Process for UAV Applications in Agriculture.

PubMed

Ribeiro-Gomes, Krishna; Hernández-López, David; Ortega, José F; Ballesteros, Rocío; Poblete, Tomás; Moreno, Miguel A

2017-09-23

The acquisition, processing, and interpretation of thermal images from unmanned aerial vehicles (UAVs) is becoming a useful source of information for agronomic applications because of the higher temporal and spatial resolution of these products compared with those obtained from satellites. However, due to the low load capacity of the UAV they need to mount light, uncooled thermal cameras, where the microbolometer is not stabilized to a constant temperature. This makes the camera precision low for many applications. Additionally, the low contrast of the thermal images makes the photogrammetry process inaccurate, which result in large errors in the generation of orthoimages. In this research, we propose the use of new calibration algorithms, based on neural networks, which consider the sensor temperature and the digital response of the microbolometer as input data. In addition, we evaluate the use of the Wallis filter for improving the quality of the photogrammetry process using structure from motion software. With the proposed calibration algorithm, the measurement accuracy increased from 3.55 °C with the original camera configuration to 1.37 °C. The implementation of the Wallis filter increases the number of tie-point from 58,000 to 110,000 and decreases the total positing error from 7.1 m to 1.3 m.

Thermal hyperspectral chemical imaging

NASA Astrophysics Data System (ADS)

Holma, Hannu; Hyvärinen, Timo; Mattila, Antti-Jussi; Kormano, Ilkka

2012-06-01

Several chemical compounds have their strongest spectral signatures in the thermal region. This paper presents three push-broom thermal hyperspectral imagers. The first operates in MWIR (2.8-5 μm) with 35 nm spectral resolution. It consists of uncooled imaging spectrograph and cryogenically cooled InSb camera, with spatial resolution of 320/640 pixels and image rate to 400 Hz. The second imager covers LWIR in 7.6-12 μm with 32 spectral bands. It employs an uncooled microbolometer array and spectrograph. These imagers have been designed for chemical mapping in reflection mode in industry and laboratory. An efficient line-illumination source has been developed, and it makes possible thermal hyperspectral imaging in reflection with much higher signal and SNR than is obtained from room temperature emission. Application demonstrations including sorting of dark plastics and mineralogical mapping of drill cores are presented. The third imager utilizes a cryo-cooled MCT array with precisely temperature stabilized optics. The optics is not cooled, but instrument radiation is suppressed by special filtering and corrected by BMC (Background-Monitoring-on-Chip) method. The approach provides excellent sensitivity in an instrument which is portable and compact enough for installation in UAVs. The imager has been verified in 7.6 to 12.3 μm to provide NESR of 18 mW/(m2 sr μm) at 10 μm for 300 K target with 100 spectral bands and 384 spatial samples. It results in SNR of higher than 500. The performance makes possible various applications from gas detection to mineral exploration and vegetation surveys. Results from outdoor and airborne experiments are shown.

Micromachined poly-SiGe bolometer arrays for infrared imaging and spectroscopy

NASA Astrophysics Data System (ADS)

Leonov, Vladimir N.; Perova, Natalia A.; De Moor, Piet; Du Bois, Bert; Goessens, Claus; Grietens, Bob; Verbist, Agnes; Van Hoof, Chris A.; Vermeiren, Jan P.

2003-03-01

The state-of-the-art characteristics of micromachined polycrystalline SiGe microbolometer arrays are reported. An average NETD of 85 mK at a time constant of 14 ms is already achievable on typical self-supported 50 μm pixels in a linear 64-element array. In order to reach these values, the design optimization was performed based on the performance characteristics of linear 32-, 64- and 128-element arrays of 50-, 60- and 75-μm-pixel bolometers on several detector lots. The infrared and thermal modeling accounting for the read-out properties and self-heating effect in bolometers resulted in improved designs and competitive NETD values of 80 mK on 50 μm pixels in a 160x128 format at standard frame rates and f-number of 1. In parallel, the TCR-to-1/f noise ratio and the mechanical design of the pixels were improved making poly-SiGe a good candidate for a low-cost uncooled thermal array. The technological CMOS-based process possesses an attractive balance between characteristics and price, and allows the micromachining of thin structures, less than 0.2 μm. The resistance and TCR non-uniformity with σ/μ better than 0.2% combined with 99.93% yield are demonstrated. The first lots of fully processed linear arrays have already come from the IMEC process line and the results of characterization are presented. Next year, the first linear and small 2D arrays will be introduced on the market.

Design and fabrication of absorber coupled TES microbolometers on continuous silicon-nitride windows.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, C. L.; Carlstrom, J. E.; Datesman, A.

2008-04-01

The implementation of TES based microbolometer arrays will achieve unprecedented sensitivities for mm and sub-mm astronomy through fabrication of large format arrays and improved linearity and stability arising from strong electro-thermal feedback. We report on progress in developing TES microbolometers using Mo/Au thin films and Au absorbing structures. We present measurements of suppressing the thermal conductance through the etching of features on a continuous Silicon-Nitride window.

Comparison of parameters of modern cooled and uncooled thermal cameras

NASA Astrophysics Data System (ADS)

Bareła, Jarosław; Kastek, Mariusz; Firmanty, Krzysztof; Krupiński, Michał

2017-10-01

During the design of a system employing thermal cameras one always faces a problem of choosing the camera types best suited for the task. In many cases such a choice is far from optimal one, and there are several reasons for that. System designers often favor tried and tested solution they are used to. They do not follow the latest developments in the field of infrared technology and sometimes their choices are based on prejudice and not on facts. The paper presents the results of measurements of basic parameters of MWIR and LWIR thermal cameras, carried out in a specialized testing laboratory. The measured parameters are decisive in terms of image quality generated by thermal cameras. All measurements were conducted according to current procedures and standards. However the camera settings were not optimized for a specific test conditions or parameter measurements. Instead the real settings used in normal camera operations were applied to obtain realistic camera performance figures. For example there were significant differences between measured values of noise parameters and catalogue data provided by manufacturers, due to the application of edge detection filters to increase detection and recognition ranges. The purpose of this paper is to provide help in choosing the optimal thermal camera for particular application, answering the question whether to opt for cheaper microbolometer device or apply slightly better (in terms of specifications) yet more expensive cooled unit. Measurements and analysis were performed by qualified personnel with several dozen years of experience in both designing and testing of thermal camera systems with both cooled and uncooled focal plane arrays. Cameras of similar array sizes and optics were compared, and for each tested group the best performing devices were selected.

Enabling High Spectral Resolution Thermal Imaging from CubeSat and MicroSatellite Platforms Using Uncooled Microbolometers and a Fabry-Perot interferometer

NASA Astrophysics Data System (ADS)

Wright, R.; Lucey, P. G.; Crites, S.; Garbeil, H.; Wood, M.; Pilger, E. J.; Honniball, C.; Gabrieli, A.

2016-12-01

Measurements of reflectance or emittance in tens of narrow, contiguous wavebands, allow for the derivation of laboratory quality spectra remotely, from which the chemical composition and physical properties of targets can be determined. Although spaceborne (e.g. EO-1 Hyperion) hyperspectral data in the 0.4-2.5 micron (VSWIR) region are available, the provision of equivalent data in the log-wave infrared has lagged behind, there being no currently operational high spatial resolution LWIR imaging spectrometer on orbit. This is attributable to two factors. Firstly, earth emits less light than it reflects, reducing the signal available to measure in the TIR, and secondly, instruments designed to measure (and spectrally decompose) this signal are more complex, massive, and expensive than their VSWIR counterparts, largely due to the need to cryogenically cool the detector and optics. However, this measurement gap needs to be filled, as LWIR data provide fundamentally different information than VSWIR measurements. The TIRCIS instrument (Thermal Infra-Red Compact Imaging Spectrometer), developed at the Hawaii Institute of Geophysics and Planetology, uses a Fabry-Perot interferometer, an uncooled microbolometer array, and push-broom scanning to acquire hyperspectral image data in the 8-14 micron spectral range. Radiometric calibration is provided by blackbody targets while spectral calibration is achieved using monochromatic light sources. The instrument has a mass of <15 kg and dimensions of 53 cm × 25 cm × 22 cm, and has been designed to be compatible with integration into a micro-satellite platform. (A precursor to this instrument was launched onboard a 55 kg microsatellite as part of the ORS-4 mission in October 2015). The optical design yields a 120 m ground sample size given an orbit of 500 km. Over the wavelength interval of 7.5 to 14 microns up to 50 spectral samples are possible (the accompanying image shows a quartz spectrum composed of 17 spectral samples). Our performance model indicates signal-to-noise ratios of 400-800:1.

CMOS compatible IR sensors by cytochrome c protein

NASA Astrophysics Data System (ADS)

Liao, Chien-Jen; Su, Guo-Dung

2013-09-01

In recent years, due to the progression of the semiconductor industrial, the uncooled Infrared sensor - microbolometer has opened the opportunity for achieving low cost infrared imaging systems for both military and commercial applications. Therefore, various fabrication processes and different materials based microbolometer have been developed sequentially. The cytochrome c (protein) thin film has be reported high temperature coefficient of resistance (TCR), which is related to the performance of microbolometer directly. Hence the superior TCR value will increase the performance of microbolometer. In this paper, we introduced a novel fabrication process using aluminum which is compatible with the Taiwan Semiconductor Manufacture Company (TSMC) D35 2P4M process as the main structure material, which benefits the device to integrate with readout integrated circuit (ROIC).The aluminum split structure is suspended by sacrificial layer utilizing the standard photolithography technology and chemical etching. The height and thickness of the structure are already considered. Besides, cytochrome c solutions were ink-jetted onto the aluminum structure by using the inkjet printer, applying precise control of the Infrared absorbing layer. In measurement, incident Infrared radiation can be detected and later the heat can be transmitted to adjacent pads to readout the signal. This approach applies an inexpensive and simple fabrication process and makes the device suitable for integration. In addition, the performance can be further improved with low noise readout circuits.

Folded path LWIR system for SWAP constrained platforms

NASA Astrophysics Data System (ADS)

Fleet, Erin F.; Wilson, Michael L.; Linne von Berg, Dale; Giallorenzi, Thomas; Mathieu, Barry

2014-06-01

Folded path reflection and catadioptric optics are of growing interest, especially in the long wave infrared (LWIR), due to continuing demands for reductions in imaging system size, weight and power (SWAP). We present the optical design and laboratory data for a 50 mm focal length low f/# folded-path compact LWIR imaging system. The optical design uses 4 concentric aspheric mirrors, each of which is described by annular aspheric functions well suited to the folded path design space. The 4 mirrors are diamond turned onto two thin air-spaced aluminum plates which can be manually focused onto the uncooled LWIR microbolometer array detector. Stray light analysis will be presented to show how specialized internal baffling can be used to reduce stray light propagation through the folded path optical train. The system achieves near diffraction limited performance across the FOV with a 15 mm long optical train and a 5 mm back focal distance. The completed system is small enough to reside within a 3 inch diameter ball gimbal.

Combined Infrared Stereo and Laser Ranging Cloud Measurements from Shuttle Mission STS-85

NASA Technical Reports Server (NTRS)

Lancaster, Redgie S.; Spinhirne, James D.; OCStarr, David (Technical Monitor)

2001-01-01

Multi-angle remote sensing provides a wealth of information for earth and climate monitoring. And, as technology advances so do the options for developing instrumentation versatile enough to meet the demands associated with these types of measurements. In the current work, the multiangle measurement capability of the Infrared Spectral Imaging Radiometer is demonstrated. This instrument flew as part of mission STS-85 of the space shuttle Columbia in 1997 and was the first earth-observing radiometer to incorporate an uncooled microbolometer array detector as its image sensor. Specifically, a method for computing cloud-top height from the multi-spectral stereo measurements acquired during this flight has been developed and the results demonstrate that a vertical precision of 10.6 km was achieved. Further, the accuracy of these measurements is confirmed by comparison with coincident direct laser ranging measurements from the Shuttle Laser Altimeter. Mission STS-85 was the first space flight to combine laser ranging and thermal IR camera systems for cloud remote sensing.

An instrumentation amplifier based readout circuit for a dual element microbolometer infrared detector

NASA Astrophysics Data System (ADS)

de Waal, D. J.; Schoeman, J.

2014-06-01

The infrared band is widely used in many applications to solve problems stretching over very diverse fields, ranging from medical applications like inflammation detection to military, security and safety applications employing thermal imaging in low light conditions. At the heart of these optoelectrical systems lies a sensor used to detect incident infrared radiation, and in the case of this work our focus is on uncooled microbolometers as thermal detectors. Microbolometer based thermal detectors are limited in sensitivity by various parameters, including the detector layout and design, operating temperature, air pressure and biasing that causes self heating. Traditional microbolometers use the entire membrane surface for a single detector material. This work presents the design of a readout circuit amplifier where a dual detector element microbolometer is used, rather than the traditional single element. The concept to be investigated is based on the principle that both elements will be stimulated with a similar incoming IR signal and experience the same resistive change, thus creating a common mode signal. However, such a common mode signal will be rejected by a differential amplifier, thus one element is placed within a negative resistance converter to create a differential mode signal that is twice the magnitude of the comparable single mode signal of traditional detector designs. An instrumentation amplifier is used for the final stage of the readout amplifier circuit, as it allows for very high common mode rejection with proper trimming of the Wheatstone bridge to compensate for manufacturing tolerance. It was found that by implementing the above, improved sensitivity can be achieved.

Frequency selective infrared optical filters for micro-bolometers

NASA Astrophysics Data System (ADS)

Creazzo, Timothy A.; Zablocki, Mathew J.; Zaman, Lenin; Sharkawy, Ahmed; Mirotznik, Mark S.; Prather, Dennis W.

2017-05-01

Current micro-bolometers are broadband detectors and tend to absorb a broad window of the IR spectrum for thermal imaging. Such systems are limited due to their lack of sensitivity to blackbody radiation, as well as the inability to spectrally discern multiple wavelengths in the field of view for hyperspectral imaging (HSI). As a result, many important applications such as low concentration chemical detection cannot be performed. One solution to this problem is to employ a system with thermoelectrically cooled or liquid nitrogen cooled sensors, which can lead to higher sensitivity in detection. However, one major drawback of these systems is the size, weight and power (SWaP) issue as they tend to be rather bulky and cumbersome, which largely challenges their use in unmanned aerial vehicles. Further, spectral filtering is commonly performed with large hardware and moving gratings, greatly increasing the SWaP of the system. To this point, Lumilant's effort is to develop wavelength selective uncooled IR filters that can be integrated onto a microbolometer, to exceed the sensitivity imposed by the blackbody radiation limit. We have demonstrated narrowband absorbers and electrically tunable filters addressing the need for low-SWaP platforms.

High-performance linear arrays of YBa2Cu3O7 superconducting infrared microbolometers on silicon

NASA Astrophysics Data System (ADS)

Johnson, Burgess R.; Foote, Marc C.; Marsh, Holly A.

1995-06-01

Single detectors and linear arrays of microbolometers utilizing the superconducting transition edge of YBa(subscript 2)Cu(subscript 3)O(subscript 7) have been fabricated by micromachining on silicon wafers. A D* of 8 +/- 2 X 10(superscript 9) cm Hz(superscript 1/2)/watt has been measured on a single detector. This is the highest D* reported on any superconducting microbolometer operating at temperatures higher than about 70 K. The NEP of this device was 1.5 X 10(superscript -12) watts/Hz(superscript HLF) at 2 Hz, at a temperature of 80.7 K. The thermal time constant was 105 msec, and the detector area was 140 micrometers X 105 micrometers . The use of batch silicon processing makes fabrication of linear arrays of these detectors relatively straightforward. The measured responsivity of detectors in one such array varied by less than 20% over the 6 mm length of the 64-element linear array. This measurement shows that good uniformity can be achieved at a single operating temperature in a superconductor microbolometer array, even when the superconducting resistive transition is a sharp function of temperature. The thermal detection mechanism of these devices gives them broadband response. This makes them especially useful at long wavelengths (e.g. (lambda) > 20 micrometers ), where they provide very high sensitivity at relatively high operating temperatures.

Uncooled 17 μm ¼ VGA IRFPA development for compact and low power systems

NASA Astrophysics Data System (ADS)

Robert, P.; Tissot, J.; Pochic, D.; Gravot, V.; Bonnaire, F.; Clerambault, H.; Durand, A.; Tinnes, S.

2012-11-01

The high level of accumulated expertise by ULIS and CEA/LETI on uncooled microbolometers made from amorphous silicon enables ULIS to develop ¼ VGA IRFPA formats with 17μm pixel-pitch to enable the development of small power, small weight (SWAP) and high performance IR systems. ROIC architecture will be described where innovations are widely on-chip implemented to enable an easier operation by the user. The detector configuration (integration time, windowing, gain, scanning direction…), is driven by a standard I²C link. Like most of the visible arrays, the detector adopts the HSYNC/VSYNC free-run mode of operation driven with only one master clock (MC) supplied to the ROIC which feeds back pixel, line and frame synchronizations. On-chip PROM memory for customer operational condition storage is available for detector characteristics. Low power consumption has been taken into account and less than 60 mW is possible in analog mode at 60 Hz and < 175 mW in digital mode (14 bits). A wide electrical dynamic range (2.4V) is maintained despite the use of advanced CMOS node. The specific appeal of this unit lies in the high uniformity and easy operation it provides. The reduction of the pixel-pitch turns this TEC-less ¼ VGA array into a product well adapted for high resolution and compact systems. NETD of 35 mK and thermal time constant of 10 ms have been measured leading to 350 mK.ms figure of merit. We insist on NETD trade-off with wide thermal dynamic range, as well as the high characteristics uniformity and pixel operability, achieved thanks to the mastering of the amorphous silicon technology coupled with the ROIC design. This technology node associated with advanced packaging technique, paves the way to compact low power system.

Easy to use uncooled ¼ VGA 17 µm FPA development for high performance compact and low-power systems

NASA Astrophysics Data System (ADS)

Robert, P.; Tissot, JL.; Pochic, D.; Gravot, V.; Bonnaire, F.; Clerambault, H.; Durand, A.; Tinnes, S.

2012-06-01

The high level of accumulated expertise by ULIS and CEA/LETI on uncooled microbolometers made from amorphous silicon enables ULIS to develop ¼ VGA IRFPA formats with 17μm pixel-pitch to enable the development of small power, small weight (SWAP) and high performance IR systems. ROIC architecture will be described where innovations are widely on-chip implemented to enable an easier operation by the user. The detector configuration (integration time, windowing, gain, scanning direction...), is driven by a standard I²C link. Like most of the visible arrays, the detector adopts the HSYNC/VSYNC free-run mode of operation driven with only one master clock (MC) supplied to the ROIC which feeds back pixel, line and frame synchronizations. On-chip PROM memory for customer operational condition storage is available for detector characteristics. Low power consumption has been taken into account and less than 60 mW is possible in analog mode at 60 Hz and < 175 mW in digital mode (14 bits). A wide electrical dynamic range (2.4V) is maintained despite the use of advanced CMOS node. The specific appeal of this unit lies in the high uniformity and easy operation it provides. The reduction of the pixel-pitch turns this TEC-less ¼ VGA array into a product well adapted for high resolution and compact systems. NETD of 35 mK and thermal time constant of 10 ms have been measured leading to 350 mK.ms figure of merit. We insist on NETD trade-off with wide thermal dynamic range, as well as the high characteristics uniformity and pixel operability, achieved thanks to the mastering of the amorphous silicon technology coupled with the ROIC design. This technology node associated with advanced packaging technique, paves the way to compact low power system.

High-performance ferroelectric and magnetoresistive materials for next-generation thermal detector arrays

NASA Astrophysics Data System (ADS)

Todd, Michael A.; Donohue, Paul P.; Watton, Rex; Williams, Dennis J.; Anthony, Carl J.; Blamire, Mark G.

2002-12-01

This paper discusses the potential thermal imaging performance achievable from thermal detector arrays and concludes that the current generation of thin-film ferroelectric and resistance bolometer based detector arrays are limited by the detector materials used. It is proposed that the next generation of large uncooled focal plane arrays will need to look towards higher performance detector materials - particularly if they aim to approach the fundamental performance limits and compete with cooled photon detector arrays. Two examples of bolometer thin-film materials are described that achieve high performance from operating around phase transitions. The material Lead Scandium Tantalate (PST) has a paraelectric-to-ferroelectric phase transition around room temperature and is used with an applied field in the dielectric bolometer mode for thermal imaging. PST films grown by sputtering and liquid-source CVD have shown merit figures for thermal imaging a factor of 2 to 3 times higher than PZT-based pyroelectric thin films. The material Lanthanum Calcium Manganite (LCMO) has a paramagnetic to ferromagnetic phase transition around -20oC. This paper describes recent measurements of TCR and 1/f noise in pulsed laser-deposited LCMO films on Neodymium Gallate substrates. These results show that LCMO not only has high TCR's - up to 30%/K - but also low 1/f excess noise, with bolometer merit figures at least an order of magnitude higher than Vanadium Oxide, making it ideal for the next generation of microbolometer arrays. These high performance properties come at the expense of processing complexities and novel device designs will need to be introduced to realize the potential of these materials in the next generation of thermal detectors.

Development of infrared scene projectors for testing fire-fighter cameras

NASA Astrophysics Data System (ADS)

Neira, Jorge E.; Rice, Joseph P.; Amon, Francine K.

2008-04-01

We have developed two types of infrared scene projectors for hardware-in-the-loop testing of thermal imaging cameras such as those used by fire-fighters. In one, direct projection, images are projected directly into the camera. In the other, indirect projection, images are projected onto a diffuse screen, which is then viewed by the camera. Both projectors use a digital micromirror array as the spatial light modulator, in the form of a Micromirror Array Projection System (MAPS) engine having resolution of 800 x 600 with mirrors on a 17 micrometer pitch, aluminum-coated mirrors, and a ZnSe protective window. Fire-fighter cameras are often based upon uncooled microbolometer arrays and typically have resolutions of 320 x 240 or lower. For direct projection, we use an argon-arc source, which provides spectral radiance equivalent to a 10,000 Kelvin blackbody over the 7 micrometer to 14 micrometer wavelength range, to illuminate the micromirror array. For indirect projection, an expanded 4 watt CO II laser beam at a wavelength of 10.6 micrometers illuminates the micromirror array and the scene formed by the first-order diffracted light from the array is projected onto a diffuse aluminum screen. In both projectors, a well-calibrated reference camera is used to provide non-uniformity correction and brightness calibration of the projected scenes, and the fire-fighter cameras alternately view the same scenes. In this paper, we compare the two methods for this application and report on our quantitative results. Indirect projection has an advantage of being able to more easily fill the wide field of view of the fire-fighter cameras, which typically is about 50 degrees. Direct projection more efficiently utilizes the available light, which will become important in emerging multispectral and hyperspectral applications.

Generation of strong terahertz fields exceeding 8 MV/cm at 1 kHz and real-time beam profiling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oh, T. I.; Yoo, Y. J.; You, Y. S.

2014-07-28

We demonstrate high-field (>8 MV/cm) terahertz generation at a high-repetition-rate (1 kHz) via two-color laser filamentation. Here, we use a cryogenically cooled femtosecond laser amplifier capable of producing 30 fs, 15 mJ pulses at 1 kHz as a driver, along with a combination of a thin dual-wavelength half-waveplate and a Brewster-angled silicon window to enhance terahertz generation and transmission. We also introduce a cost-effective, uncooled microbolometer camera for real-time terahertz beam profiling with two different modes.

MT3250BA: a 320×256-50µm snapshot microbolometer ROIC for high-resistance detector arrays

NASA Astrophysics Data System (ADS)

Eminoglu, Selim; Akin, Tayfun

2013-06-01

This paper reports the development of a new microbolometer readout integrated circuit (MT3250BA) designed for high-resistance detector arrays. MT3250BA is the first microbolometer readout integrated circuit (ROIC) product from Mikro-Tasarim Ltd., which is a fabless IC design house specialized in the development of monolithic CMOS imaging sensors and ROICs for hybrid photonic imaging sensors and microbolometers. MT3250BA has a format of 320 × 256 and a pixel pitch of 50 µm, developed with a system-on-chip architecture in mind, where all the timing and biasing for this ROIC are generated on-chip without requiring any external inputs. MT3250BA is a highly configurable ROIC, where many of its features can be programmed through a 3-wire serial interface allowing on-the-fly configuration of many ROIC features. MT3250BA has 2 analog video outputs and 1 analog reference output for pseudo-differential operation, and the ROIC can be programmed to operate in the 1 or 2-output modes. A unique feature of MT3250BA is that it performs snapshot readout operation; therefore, the image quality will only be limited by the thermal time constant of the detector pixels, but not by the scanning speed of the ROIC, as commonly found in the conventional microbolometer ROICs performing line-by-line (rolling-line) readout operation. The signal integration is performed at the pixel level in parallel for the whole array, and signal integration time can be programmed from 0.1 µs up to 100 ms in steps of 0.1 µs. The ROIC is designed to work with high-resistance detector arrays with pixel resistance values higher than 250 kΩ. The detector bias voltage can be programmed on-chip over a 2 V range with a resolution of 1 mV. The ROIC has a measured input referred noise of 260 µV rms at 300 K. The ROIC can be used to build a microbolometer infrared sensor with an NETD value below 100 mK using a microbolometer detector array fabrication technology with a high detector resistance value (≥ 250 KΩ), a high TCR value (≥ 2.5 % / K), and a sufficiently low pixel thermal conductance (Gth ≤ 20 nW / K). The ROIC uses a single 3.3 V supply voltage and dissipates less than 75 mW in the 1-output mode at 60 fps. MT3250BA is fabricated using a mixed-signal CMOS process on 200 mm CMOS wafers, and tested wafers are available with test data and wafer map. A USB based compact test electronics and software are available for quick evaluation of this new microbolometer ROIC.

Low-cost uncooled VOx infrared camera development

NASA Astrophysics Data System (ADS)

Li, Chuan; Han, C. J.; Skidmore, George D.; Cook, Grady; Kubala, Kenny; Bates, Robert; Temple, Dorota; Lannon, John; Hilton, Allan; Glukh, Konstantin; Hardy, Busbee

2013-06-01

The DRS Tamarisk® 320 camera, introduced in 2011, is a low cost commercial camera based on the 17 µm pixel pitch 320×240 VOx microbolometer technology. A higher resolution 17 µm pixel pitch 640×480 Tamarisk®640 has also been developed and is now in production serving the commercial markets. Recently, under the DARPA sponsored Low Cost Thermal Imager-Manufacturing (LCTI-M) program and internal project, DRS is leading a team of industrial experts from FiveFocal, RTI International and MEMSCAP to develop a small form factor uncooled infrared camera for the military and commercial markets. The objective of the DARPA LCTI-M program is to develop a low SWaP camera (<3.5 cm3 in volume and <500 mW in power consumption) that costs less than US $500 based on a 10,000 units per month production rate. To meet this challenge, DRS is developing several innovative technologies including a small pixel pitch 640×512 VOx uncooled detector, an advanced digital ROIC and low power miniature camera electronics. In addition, DRS and its partners are developing innovative manufacturing processes to reduce production cycle time and costs including wafer scale optic and vacuum packaging manufacturing and a 3-dimensional integrated camera assembly. This paper provides an overview of the DRS Tamarisk® project and LCTI-M related uncooled technology development activities. Highlights of recent progress and challenges will also be discussed. It should be noted that BAE Systems and Raytheon Vision Systems are also participants of the DARPA LCTI-M program.

Attempt to the detection of small wildfire by the uncooled micro bolometer camera onboard 50 kg class satellite

NASA Astrophysics Data System (ADS)

Fukuhara, T.; Kouyama, T.; Kato, S.; Nakamura, R.

2016-12-01

University International Formation Mission (UNIFORM) in Japan started in 2011 is an ambitious project that specialized to surveillance of small wildfire to contribute to provide fire information for initial suppression. Final aim of the mission is to construct a constellation with several 50 kg class satellites for frequent and exclusive observation. The uncooled micro-bolometer camera with 640 x 480 pixels based on commercial products has been newly developed for the first satellite. It has been successfully launched on 24 May 2014 and injected to the Sun-Synchronous orbit at local time of 12:00 with altitude of 628 km. The camera has been detected considerable hotspots not only wildfire but also volcanoes. Brightness temperature observed on orbit has been verified and scale of observed wildfire has been roughly presumed; the smallest wildfire ever detected has flame zone less than 2 x 103 m2. It is one tenth of initial requirement estimated in design process; our camera has enough ability to discover small wildfire and to provide beneficial information for fire control with low cost and quick fabrication; it would contribute to practical utility especially in developing nations. A next camera is available for new wildfire mission with satellite constellation; it has already developed for flight. Pixel arrays increasing to 1024 x 768, spatial resolution becomes fine to detect smaller wildfire whereas the swath of image is kept. This camera would be applied to the future planetary mission for Mars and Asteroid explore, too. When it observes planetary surface, thermal inertia can be estimated from continuous observation. When it observes atmosphere, cloud-top altitude can be estimated from horizontal temperature distribution.

A compact LWIR hyperspectral system employing a microbolometer array and a variable gap Fabry-Perot interferometer employed as a Fourier transform spectrometer

NASA Astrophysics Data System (ADS)

Lucey, Paul G.; Hinrichs, John L.; Akagi, Jason

2012-06-01

A prototype long wave infrared Fourier transform spectral imaging system using a wedged Fabry-Perot interferometer and a microbolometer array was designed and built. The instrument can be used at both short (cm) and long standoff ranges (infinity focus). Signal to noise ratios are in the several hundred range for 30 C targets. The sensor is compact, fitting in a volume about 12 x12 x 4 inches.

MERTIS: the thermal infrared imaging spectrometer onboard of the Mercury Planetary Orbiter

NASA Astrophysics Data System (ADS)

Zeh, T.; Peter, G.; Walter, I.; Kopp, E.; Knollenberg, J.; Helbert, J.; Gebhardt, A.; Weber, I.; Hiesinger, Harry

2017-11-01

The MERTIS instrument is a thermal infrared imaging spectrometer onboard of ESA's cornerstone mission BepiColombo to Mercury. MERTIS has four goals: the study of Mercury's surface composition, identification of rock-forming minerals, mapping of the surface mineralogy, and the study of the surface temperature variations and thermal inertia. MERTIS will provide detailed information about the mineralogical composition of Mercury's surface layer by measuring the spectral emittance in the spectral range from 7-14 μm at high spatial and spectral resolution. Furthermore MERTIS will obtain radiometric measurements in the spectral range from 7-40 μm to study the thermo-physical properties of the surface material. The MERTIS detector is based on an uncooled micro-bolometer array providing spectral separation and spatial resolution according to its 2-dimensional shape. The operation principle is characterized by intermediate scanning of the planet surface and three different calibration targets - free space view and two on-board black body sources. In the current project phase, the MERTIS Qualification Model (QM) is under a rigorous testing program. Besides a general overview of the instrument principles, the papers addresses major aspects of the instrument design, manufacturing and verification.

Design of the front end electronics for the infrared camera of JEM-EUSO, and manufacturing and verification of the prototype model

NASA Astrophysics Data System (ADS)

Maroto, Oscar; Diez-Merino, Laura; Carbonell, Jordi; Tomàs, Albert; Reyes, Marcos; Joven-Alvarez, Enrique; Martín, Yolanda; Morales de los Ríos, J. A.; del Peral, Luis; Rodríguez-Frías, M. D.

2014-07-01

The Japanese Experiment Module (JEM) Extreme Universe Space Observatory (EUSO) will be launched and attached to the Japanese module of the International Space Station (ISS). Its aim is to observe UV photon tracks produced by ultra-high energy cosmic rays developing in the atmosphere and producing extensive air showers. The key element of the instrument is a very wide-field, very fast, large-lense telescope that can detect extreme energy particles with energy above 1019 eV. The Atmospheric Monitoring System (AMS), comprising, among others, the Infrared Camera (IRCAM), which is the Spanish contribution, plays a fundamental role in the understanding of the atmospheric conditions in the Field of View (FoV) of the telescope. It is used to detect the temperature of clouds and to obtain the cloud coverage and cloud top altitude during the observation period of the JEM-EUSO main instrument. SENER is responsible for the preliminary design of the Front End Electronics (FEE) of the Infrared Camera, based on an uncooled microbolometer, and the manufacturing and verification of the prototype model. This paper describes the flight design drivers and key factors to achieve the target features, namely, detector biasing with electrical noise better than 100μV from 1Hz to 10MHz, temperature control of the microbolometer, from 10°C to 40°C with stability better than 10mK over 4.8hours, low noise high bandwidth amplifier adaptation of the microbolometer output to differential input before analog to digital conversion, housekeeping generation, microbolometer control, and image accumulation for noise reduction. It also shows the modifications implemented in the FEE prototype design to perform a trade-off of different technologies, such as the convenience of using linear or switched regulation for the temperature control, the possibility to check the camera performances when both microbolometer and analog electronics are moved further away from the power and digital electronics, and the addition of switching regulators to demonstrate the design is immune to the electrical noise the switching converters introduce. Finally, the results obtained during the verification phase are presented: FEE limitations, verification results, including FEE noise for each channel and its equivalent NETD and microbolometer temperature stability achieved, technologies trade-off, lessons learnt, and design improvement to implement in future project phases.

Radiometric calibration of an ultra-compact microbolometer thermal imaging module

NASA Astrophysics Data System (ADS)

Riesland, David W.; Nugent, Paul W.; Laurie, Seth; Shaw, Joseph A.

2017-05-01

As microbolometer focal plane array formats are steadily decreasing, new challenges arise in correcting for thermal drift in the calibration coefficients. As the thermal mass of the cameras decrease the focal plane becomes more sensitive to external thermal inputs. This paper shows results from a temperature compensation algorithm for characterizing and radiometrically calibrating a FLIR Lepton camera.

Uncooled infrared focal plane array imaging in China

NASA Astrophysics Data System (ADS)

Lei, Shuyu

2015-06-01

This article reviews the development of uncooled infrared focal plane array (UIFPA) imaging in China in the past decade. Sensors based on optical or electrical read-out mechanism were developed but the latter dominates the market. In resistive bolometers, VOx and amorphous silicon are still the two major thermal-sensing materials. The specifications of the IRFPA made by different manufactures were collected and compared. Currently more than five Chinese companies and institutions design and fabricate uncooled infrared focal plane array. Some devices have sensitivity as high as 30 mK; the largest array for commercial products is 640×512 and the smallest pixel size is 17 μm. Emphasis is given on the pixel MEMS design, ROIC design, fabrication, and packaging of the IRFPA manufactured by GWIC, especially on design for high sensitivities, low noise, better uniformity and linearity, better stabilization for whole working temperature range, full-digital design, etc.

Automated optical testing of LWIR objective lenses using focal plane array sensors

NASA Astrophysics Data System (ADS)

Winters, Daniel; Erichsen, Patrik; Domagalski, Christian; Peter, Frank; Heinisch, Josef; Dumitrescu, Eugen

2012-10-01

The image quality of today's state-of-the-art IR objective lenses is constantly improving while at the same time the market for thermography and vision grows strongly. Because of increasing demands on the quality of IR optics and increasing production volumes, the standards for image quality testing increase and tests need to be performed in shorter time. Most high-precision MTF testing equipment for the IR spectral bands in use today relies on the scanning slit method that scans a 1D detector over a pattern in the image generated by the lens under test, followed by image analysis to extract performance parameters. The disadvantages of this approach are that it is relatively slow, it requires highly trained operators for aligning the sample and the number of parameters that can be extracted is limited. In this paper we present lessons learned from the R and D process on using focal plane array (FPA) sensors for testing of long-wave IR (LWIR, 8-12 m) optics. Factors that need to be taken into account when switching from scanning slit to FPAs are e.g.: the thermal background from the environment, the low scene contrast in the LWIR, the need for advanced image processing algorithms to pre-process camera images for analysis and camera artifacts. Finally, we discuss 2 measurement systems for LWIR lens characterization that we recently developed with different target applications: 1) A fully automated system suitable for production testing and metrology that uses uncooled microbolometer cameras to automatically measure MTF (on-axis and at several o-axis positions) and parameters like EFL, FFL, autofocus curves, image plane tilt, etc. for LWIR objectives with an EFL between 1 and 12mm. The measurement cycle time for one sample is typically between 6 and 8s. 2) A high-precision research-grade system using again an uncooled LWIR camera as detector, that is very simple to align and operate. A wide range of lens parameters (MTF, EFL, astigmatism, distortion, etc.) can be easily and accurately measured with this system.

Environmental evaluation of the ULIS PICO1024 microbolometer

NASA Astrophysics Data System (ADS)

Dartois, Thierry; Manolis, Ilias; Bézy, Jean-Loup; Meynart, Roland; Tisse, Christel-Loïc.

2017-09-01

In recent years the European Space Agency (ESA) has been pursuing studies dedicated to Earth imaging from space in the Long Wave Infrared region for applications ranging from monitoring of evapotranspiration, and water resources management to the development of urban heat island and monitoring of high temperature events. Among the various solutions being studied is also that of a low cost instrument with moderate needs in terms of resources. . One potential enabler for such type of mission could be the technology of microbolometer detectors. The latest generation of microbolometer arrays now available offer large formats (XGA) and small pixel sizes which are favourable for keeping the instrument size within reasonable limit while addressing larger swath compared to VGA format. A major concern however, in using commercial microbolometers in space is their ability to sustain the radiation environment of space but also the harsh mechanical environments. COTS microbolometers are potentially susceptible to SEE (single even effects) because of the use of commercial CMOS technology/libraries and no implementation of specific design rules (i.e. space tailored rad hardened). In the past, and in the context of their national program, CNES has performed a space evaluation of COTS microbolometer arrays of 640x480 with 25 μm pitch[3]. Despite successful gamma irradiations and vibration tests; degradation of the ROIC has been evidenced during the heavy ions tests, which makes the full qualification of COTS microbolometers for future space programmes mandatory. Similar tests have been performed on an even earlier device (384x288 with a pitch of 35 μm) under the ESA EarthCARE programme[2]. ESA and Thales Alenia Space have recently run an activity with the objective to validate a third-generation COTS microbolometer offered by ULIS (France) against the relevant environment for a candidate Thermal InfraRed (TIR) space mission. The micro-bolometer selected is the PICO 1024E[1], which offers 1024x768 pixels of size 17 μm square. The validation sequence included the main types of irradiation tests required by a space application as well as vibration and shock tests. Ageing tests are included and synergetic effects are also investigated. The detector performances were tested before, after and during any test sequence. In this paper, the results of this activity achieved in the beginning of 2017 are reported.

On-orbit performance of the Compact Infrared Camera (CIRC) onboard ALOS-2

NASA Astrophysics Data System (ADS)

Sakai, Michito; Katayama, Haruyoshi; Kato, Eri; Nakajima, Yasuhiro; Kimura, Toshiyoshi; Nakau, Koji

2015-10-01

Compact Infrared Camera (CIRC) is a technology demonstration instrument equipped with an uncooled infrared array detector (microbolometer) for space application. Microbolometers have an advantage of not requiring cooling system such as a mechanical cooler and are suitable for resource-limited sensor systems. Another characteristic of the CIRC is its use of an athermal optical system and a shutterless system. The CIRC is small in size (approximately 200 mm), is light weight (approximately 3 kg), and has low electrical power consumption (<20 W) owing to these characteristics. The main objective of CIRC is to detect wildfires, which are major and chronic disasters affecting various countries of Southeast Asia, particularly considering the effects of global warming and climate change. One of the CIRCs was launched in May 24, 2014 as a technology demonstration payload of the Advanced Land Observation Satellite-2 (ALOS- 2). Since the initial functional verification phase (July 4-14, 2014), the CIRC has demonstrated functions according to its intended design. We also confirmed that the noise equivalent differential temperature of the CIRC observation data is less than 0.2 K, the temperature accuracy is within ±4 K, and the spatial resolution is less than 210 m in the calibration validation phase after the initial functional verification phase. The CIRC also detects wildfires in various areas and observes volcano activities and urban heat islands in the operational phase. The other CIRC will be launched in 2015 onboard the CALorimetric Electron Telescope (CALET) of the Japanese Experiment Module (JEM) of the International Space Station. Installation of the CIRCs on the ALOS-2 and on the JEM/CALET is expected to increase the observation frequency. In this study, we present the on-orbit performance including observational results of the CIRC onboard the ALOS-2 and the current status of the CIRC onboard the JEM/CALET.

Recent advances in high-throughput QCL-based infrared microspectral imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Rowlette, Jeremy A.; Fotheringham, Edeline; Nichols, David; Weida, Miles J.; Kane, Justin; Priest, Allen; Arnone, David B.; Bird, Benjamin; Chapman, William B.; Caffey, David B.; Larson, Paul; Day, Timothy

2017-02-01

The field of infrared spectral imaging and microscopy is advancing rapidly due in large measure to the recent commercialization of the first high-throughput, high-spatial-definition quantum cascade laser (QCL) microscope. Having speed, resolution and noise performance advantages while also eliminating the need for cryogenic cooling, its introduction has established a clear path to translating the well-established diagnostic capability of infrared spectroscopy into clinical and pre-clinical histology, cytology and hematology workflows. Demand for even higher throughput while maintaining high-spectral fidelity and low-noise performance continues to drive innovation in QCL-based spectral imaging instrumentation. In this talk, we will present for the first time, recent technological advances in tunable QCL photonics which have led to an additional 10X enhancement in spectral image data collection speed while preserving the high spectral fidelity and SNR exhibited by the first generation of QCL microscopes. This new approach continues to leverage the benefits of uncooled microbolometer focal plane array cameras, which we find to be essential for ensuring both reproducibility of data across instruments and achieving the high-reliability needed in clinical applications. We will discuss the physics underlying these technological advancements as well as the new biomedical applications these advancements are enabling, including automated whole-slide infrared chemical imaging on clinically relevant timescales.

Fast uncooled module 32×32 array of polycrystalline PbSe used for muzzle flash detection

NASA Astrophysics Data System (ADS)

Kastek, Mariusz; Dulski, Rafał; Trzaskawka, Piotr; Bieszczad, Grzegorz

2011-06-01

The paper presents some aspects of muzzle flash detection using low resolution polycrystalline PbSe uncooled 32×32 detectors array. This system for muzzle flash detection works in MWIR (3 - 5 microns) region and it is based on VPD (Vapor Phase Deposition) technology. The low density uncooled 32×32 array is suitable for being used in low cost IR imagers sensitive in the MWIR band with frame rates exceeding 1.000 Hz. The FPA detector, read-out electronics and processing electronics (allowing the implementation of some algorithms for muzzle flash detection) has been presented. The system has been tested at field test ground. Results of detection range measurement with two types of optical systems (wide and narrow field of view) have been shown. The initial results of testing of some algorithms for muzzle flash detection have been also presented.

Thermopile Detector Arrays for Space Science Applications

NASA Technical Reports Server (NTRS)

Foote, M. C.; Kenyon, M.; Krueger, T. R.; McCann, T. A.; Chacon, R.; Jones, E. W.; Dickie, M. R.; Schofield, J. T.; McCleese, D. J.; Gaalema, S.

2004-01-01

Thermopile detectors are widely used in uncooled applications where small numbers of detectors are required, particularly in low-cost commercial applications or applications requiring accurate radiometry. Arrays of thermopile detectors, however, have not been developed to the extent of uncooled bolometer and pyroelectric/ferroelectric arrays. Efforts at JPL seek to remedy this deficiency by developing high performance thin-film thermopile detectors in both linear and two-dimensional formats. The linear thermopile arrays are produced by bulk micromachining and wire bonded to separate CMOS readout electronic chips. Such arrays are currently being fabricated for the Mars Climate Sounder instrument, scheduled for launch in 2005. Progress is also described towards realizing a two-dimensional thermopile array built over CMOS readout circuitry in the substrate.

Implementation and performance of shutterless uncooled micro-bolometer cameras

NASA Astrophysics Data System (ADS)

Das, J.; de Gaspari, D.; Cornet, P.; Deroo, P.; Vermeiren, J.; Merken, P.

2015-06-01

A shutterless algorithm is implemented into the Xenics LWIR thermal cameras and modules. Based on a calibration set and a global temperature coefficient the optimal non-uniformity correction is calculated onboard of the camera. The limited resources in the camera require a compact algorithm, hence the efficiency of the coding is important. The performance of the shutterless algorithm is studied by a comparison of the residual non-uniformity (RNU) and signal-to-noise ratio (SNR) between the shutterless and shuttered correction algorithm. From this comparison we conclude that the shutterless correction is only slightly less performant compared to the standard shuttered algorithm, making this algorithm very interesting for thermal infrared applications where small weight and size, and continuous operation are important.

Autonomous stress imaging cores: from concept to reality

NASA Astrophysics Data System (ADS)

van der Velden, Stephen; Rajic, Nik; Brooks, Chris; Galea, Steve

2016-04-01

The historical reliance of thermoelastic stress analysis on cooled infrared detection has created significant cost and practical impediments to the widespread use of this powerful full-field stress measurement technique. The emergence of low-cost microbolometers as a practical alternative has allowed for an expansion of the traditional role of thermoelastic stress analysis, and raises the possibility that it may in future become a viable structural health monitoring modality. Experimental results are shown to confirm that high resolution stress imagery can be obtained from an uncooled thermal camera core significantly smaller than any infrared imaging device previously applied to TSA. The paper provides a summary of progress toward the development of an autonomous stress-imaging capability based on this core.

Microbolometer characterization with the electronics prototype of the IRCAM for the JEM-EUSO mission

NASA Astrophysics Data System (ADS)

Martín, Yolanda; Joven, Enrique; Reyes, Marcos; Licandro, Javier; Maroto, Oscar; Díez-Merino, Laura; Tomas, Albert; Carbonell, Jordi; Morales de los Ríos, J. A.; del Peral, Luis; Rodríguez-Frías, M. D.

2014-08-01

JEM-EUSO is a space observatory that will be attached to the Japanese module of the International Space Station (ISS) to observe the UV photon tracks produced by Ultra High Energy Cosmic Rays (UHECR) interacting with atmospheric nuclei. The observatory comprises an Atmospheric Monitoring System (AMS) to gather data about the status of the atmosphere, including an infrared camera (IRCAM) for cloud coverage and cloud top height detection. This paper describes the design and characterization tests of IRCAM, which is the responsibility of the Spanish JEM-EUSO Consortium. The core of IRCAM is a 640x480 microbolometer array, the ULIS 04171, sensitive to radiation in the range 7 to 14 microns. The microbolometer array has been tested using the Front End Electronics Prototype (FEEP). This custom designed electronics corresponds to the Breadboard Model, a design built to verify the camera requirements in the laboratory. The FEEP controls the configuration of the microbolometer, digitizes the detector output, sends data to the Instrument Control Unit (ICU), and controls the microbolometer temperature to a 10 mK stability. Furthermore, the FEEP allows IRCAM to preprocess images by the addition of a powerful FPGA. This prototype has been characterized in the laboratories of Instituto de Astrofisica de Canarias (IAC). Main results, including detector response as a function of the scene temperature, NETD and Non-Uniformity Correction (NUC) are shown. Results about thermal resolution meet the system requirements with a NETD lower than 1K including the narrow band filters which allow us to retrieve the clouds temperature using stereovision algorithms.

Study of performance degradation in Titanium microbolometer IR detectors due to elevated heating

NASA Astrophysics Data System (ADS)

Saxena, Raghvendra Sahai; Bhan, R. K.; Rana, Pratap Singh; Vishwakarma, A. K.; Aggarwal, Anita; Khurana, Kumkum; Gupta, Sudha

2011-07-01

Heating of thermal detectors is a major reliability concern because they are always subjected to heat whenever in operation and while absorbing excessive heat they may get degraded or damaged. In case of microbolometer Infrared (IR) detectors, heating can occur due to the absorbed radiations and also due to the bias current. In metal film microbolometers, wherein high bias current is supplied for improving responsivity, the bias heating is an issue. To study the effects of excessive heating of a Titanium microbolometer, we fabricated a linear array of such microbolometers and performed a destructive experiment of passing high bias current pulses through it and report here that even though the power supplied in pulse mode cannot damage the element physically, it may be sufficient for significant performance degradations. With this experiment we extracted that the maximum power that our Titanium microbolometer element can sustain without performance degradation is 2.25 mW. We have also reported a specific signature of temperature coefficient of resistance (TCR) that, up to the reported safe limit, remains almost constant and when that limit is crossed, reduces rapidly to a much lower value. If we keep increasing the power further it increases slightly and attains a kind of saturation.

Advanced pushbroom hyperspectral LWIR imagers

NASA Astrophysics Data System (ADS)

Holma, Hannu; Hyvärinen, Timo; Lehtomaa, Jarmo; Karjalainen, Harri; Jaskari, Risto

2009-05-01

Performance studies and instrument designs for hyperspectral pushbroom imagers in thermal wavelength region are introduced. The studies involve imaging systems based on both MCT and microbolometer detector. All the systems employ pushbroom imaging spectrograph with transmission grating and on-axis optics. The aim of the work was to design high performance instruments with good image quality and compact size for various application requirements. A big challenge in realizing these goals without considerable cooling of the whole instrument is to control the instrument radiation from all the surfaces of the instrument itself. This challenge is even bigger in hyperspectral instruments, where the optical power from the target is spread spectrally over tens of pixels, but the instrument radiation is not dispersed. Without any suppression, the instrument radiation can overwhelm the radiation from the target by 1000 times. In the first imager design, BMC-technique (background monitoring on-chip), background suppression and temperature stabilization have been combined with cryo-cooled MCT-detector. The performance of a very compact hyperspectral imager with 84 spectral bands and 384 spatial samples has been studied and NESR of 18 mW/(m2srμm) at 10 μm wavelength for 300 K target has been achieved. This leads to SNR of 580. These results are based on a simulation model. The second version of the imager with an uncooled microbolometer detector and optics in ambient temperature aims at imaging targets at higher temperatures or with illumination. Heater rods with ellipsoidal reflectors can be used to illuminate the swath line of the hyperspectral imager on a target or sample, like drill core in mineralogical analysis. Performance characteristics for microbolometer version have been experimentally verified.

MWIR hyperspectral imaging with the MIDAS instrument

NASA Astrophysics Data System (ADS)

Honniball, Casey I.; Wright, Rob; Lucey, Paul G.

2017-02-01

Hyperspectral imaging (HSI) in the Mid-Wave InfraRed (MWIR, 3-5 microns) can provide information on a variety of science applications from determining the chemical composition of lava lakes on Jupiter's moon Io, to investigating the amount of carbon liberated into the Earth's atmosphere during a wildfire. The limited signal available in the MWIR presents technical challenges to achieving high signal-to-noise ratios, and therefore it is typically necessary to cryogenically cool MWIR instruments. With recent improvements in microbolometer technology and emerging interferometric techniques, we have shown that uncooled microbolometers coupled with a Sagnac interferometer can achieve high signal-to-noise ratios for long-wave infrared HSI. To explore if this technique can be applied to the MWIR, this project, with funding from NASA, has built the Miniaturized Infrared Detector of Atmospheric Species (MIDAS). Standard characterization tests are used to compare MIDAS against a cryogenically cooled photon detector to evaluate the MIDAS instruments' ability to quantify gas concentrations. Atmospheric radiative transfer codes are in development to explore the limitations of MIDAS and identify the range of science objectives that MIDAS will most likely excel at. We will simulate science applications with gas cells filled with varying gas concentrations and varying source temperatures to verify our results from lab characterization and our atmospheric modeling code.

Compact LWIR sensors using spatial interferometric technology (Conference Presentation)

NASA Astrophysics Data System (ADS)

Bingham, Adam L.; Lucey, Paul G.; Knobbe, Edward T.

2017-05-01

Recent developments in reducing the cost and mass of hyperspectral sensors have enabled more widespread use for short range compositional imaging applications. HSI in the long wave infrared (LWIR) is of interest because it is sensitive to spectral phenomena not accessible to other wavelengths, and because of its inherent thermal imaging capability. At Spectrum Photonics we have pursued compact LWIR hyperspectral sensors both using microbolometer arrays and compact cryogenic detector cameras. Our microbolometer-based systems are principally aimed at short standoff applications, currently weigh 10-15 lbs and feature sizes approximately 20x20x10 cm, with sensitivity in the 1-2 microflick range, and imaging times on the order of 30 seconds. Our systems that employ cryogenic arrays are aimed at medium standoff ranges such as nadir looking missions from UAVs. Recent work with cooled sensors has focused on Strained Layer Superlattice (SLS) technology, as these detector arrays are undergoing rapid improvements, and have some advantages compared to HgCdTe detectors in terms of calibration stability. These sensors include full on-board processing sensor stabilization so are somewhat larger than the microbolometer systems, but could be adapted to much more compact form factors. We will review our recent progress in both these application areas.

Comparison of Thermal Detector Arrays for Off-Axis THz Holography and Real-Time THz Imaging

PubMed Central

Hack, Erwin; Valzania, Lorenzo; Gäumann, Gregory; Shalaby, Mostafa; Hauri, Christoph P.; Zolliker, Peter

2016-01-01

In terahertz (THz) materials science, imaging by scanning prevails when low power THz sources are used. However, the application of array detectors operating with high power THz sources is increasingly reported. We compare the imaging properties of four different array detectors that are able to record THz radiation directly. Two micro-bolometer arrays are designed for infrared imaging in the 8–14 μm wavelength range, but are based on different absorber materials (i) vanadium oxide; (ii) amorphous silicon; (iii) a micro-bolometer array optimized for recording THz radiation based on silicon nitride; and (iv) a pyroelectric array detector for THz beam profile measurements. THz wavelengths of 96.5 μm, 118.8 μm, and 393.6 μm from a powerful far infrared laser were used to assess the technical performance in terms of signal to noise ratio, detector response and detectivity. The usefulness of the detectors for beam profiling and digital holography is assessed. Finally, the potential and limitation for real-time digital holography are discussed. PMID:26861341

Comparison of Thermal Detector Arrays for Off-Axis THz Holography and Real-Time THz Imaging.

PubMed

Hack, Erwin; Valzania, Lorenzo; Gäumann, Gregory; Shalaby, Mostafa; Hauri, Christoph P; Zolliker, Peter

2016-02-06

In terahertz (THz) materials science, imaging by scanning prevails when low power THz sources are used. However, the application of array detectors operating with high power THz sources is increasingly reported. We compare the imaging properties of four different array detectors that are able to record THz radiation directly. Two micro-bolometer arrays are designed for infrared imaging in the 8-14 μm wavelength range, but are based on different absorber materials (i) vanadium oxide; (ii) amorphous silicon; (iii) a micro-bolometer array optimized for recording THz radiation based on silicon nitride; and (iv) a pyroelectric array detector for THz beam profile measurements. THz wavelengths of 96.5 μm, 118.8 μm, and 393.6 μm from a powerful far infrared laser were used to assess the technical performance in terms of signal to noise ratio, detector response and detectivity. The usefulness of the detectors for beam profiling and digital holography is assessed. Finally, the potential and limitation for real-time digital holography are discussed.

Technology for low-cost PIR security sensors

NASA Astrophysics Data System (ADS)

Liddiard, Kevin C.

2008-03-01

Current passive infrared (PIR) security sensors employing pyroelectric detectors are simple, cheap and reliable, but have several deficiencies. These sensors, developed two decades ago, are essentially short-range moving-target hotspot detectors. They cannot detect slow temperature changes, and thus are unable to respond to radiation stimuli indicating potential danger such as overheating electrical appliances and developing fires. They have a poor optical resolution and limited ability to recognize detected targets. Modern uncooled thermal infrared technology has vastly superior performance but as yet is too costly to challenge the PIR security sensor market. In this paper microbolometer technology will be discussed which can provide enhanced performance at acceptable cost. In addition to security sensing the technology has numerous applications in the military, industrial and domestic markets where target range is short and low cost is paramount.

Modulate chopper technique used in pyroelectric uncooled focal plane array thermal imager

NASA Astrophysics Data System (ADS)

He, Yuqing; Jin, Weiqi; Liu, Guangrong; Gao, Zhiyun; Wang, Xia; Wang, Lingxue

2002-09-01

Pyroelectric uncooled focal plane array (FPA) thermal imager has the advantages of low cost, small size, high responsibility and can work under room temperature, so it has great progress in recent years. As a matched technique, the modulate chopper has become one of the key techniques in uncooled FPA thermal imaging system. Now the Archimedes spiral cord chopper technique is mostly used. When it works, the chopper pushing scans the detector's pixel array, thus makes the pixels being exposed continuously. This paper simulates the shape of this kind of chopper, analyses the exposure time of the detector's every pixel, and also analyses the whole detector pixels' exposure sequence. From the analysis we can get the results: the parameter of Archimedes spiral cord, the detector's thermal time constant, the detector's geometrical dimension, the relative position of the detector to the chopper's spiral cord are the system's important parameters, they will affect the chopper's exposure efficiency and uniformity. We should design the chopper's relevant parameter according to the practical request to achieve the chopper's appropriate structure.

Near-field observation platform

NASA Astrophysics Data System (ADS)

Schlemmer, Harry; Baeurle, Constantin; Vogel, Holger

2008-04-01

A miniaturized near-field observation platform is presented comprising a sensitive daylight camera and an uncooled micro-bolometer thermal imager each equipped with a wide angle lens. Both cameras are optimised for a range between a few meters and 200 m. The platform features a stabilised line of sight and can therefore be used also on a vehicle when it is in motion. The line of sight either can be directed manually or the platform can be used in a panoramic mode. The video output is connected to a control panel where algorithms for moving target indication or tracking can be applied in order to support the observer. The near-field platform also can be netted with the vehicle system and the signals can be utilised, e.g. to designate a new target to the main periscope or the weapon sight.

Polarization measurements made on LFRA and OASIS emitter arrays

NASA Astrophysics Data System (ADS)

Geske, Jon; Sparkman, Kevin; Oleson, Jim; Laveigne, Joe; Sieglinger, Breck; Marlow, Steve; Lowry, Heard; Burns, James

2008-04-01

Polarization is increasingly being considered as a method of discrimination in passive sensing applications. In this paper the degree of polarization of the thermal emission from the emitter arrays of two new Santa Barbara Infrared (SBIR) micro-bolometer resistor array scene projectors was characterized at ambient temperature and at 77 K. The emitter arrays characterized were from the Large Format Resistive Array (LFRA) and the Optimized Arrays for Space-Background Infrared Simulation (OASIS) scene projectors. This paper reports the results of this testing.

Polycrystalline lead selenide: the resurgence of an old infrared detector

NASA Astrophysics Data System (ADS)

Vergara, G.; Montojo, M. T.; Torquemada, M. C.; Rodrigo, M. T.; Sánchez, F. J.; Gómez, L. J.; Almazán, R. M.; Verdú, M.; Rodríguez, P.; Villamayor, V.; Álvarez, M.; Diezhandino, J.; Plaza, J.; Catalán, I.

2007-06-01

The existing technology for uncooled MWIR photon detectors based on polycrystalline lead salts is stigmatized for being a 50-year-old technology. It has been traditionally relegated to single-element detectors and relatively small linear arrays due to the limitations imposed by its standard manufacture process based on a chemical bath deposition technique (CBD) developed more than 40 years ago. Recently, an innovative method for processing detectors, based on a vapour phase deposition (VPD) technique, has allowed manufacturing the first 2D array of polycrystalline PbSe with good electro optical characteristics. The new method of processing PbSe is an all silicon technology and it is compatible with standard CMOS circuitry. In addition to its affordability, VPD PbSe constitutes a perfect candidate to fill the existing gap in the photonic and uncooled IR imaging detectors sensitive to the MWIR photons. The perspectives opened are numerous and very important, converting the old PbSe detector in a serious alternative to others uncooled technologies in the low cost IR detection market. The number of potential applications is huge, some of them with high commercial impact such as personal IR imagers, enhanced vision systems for automotive applications and other not less important in the security/defence domain such as sensors for active protection systems (APS) or low cost seekers. Despite the fact, unanimously accepted, that uncooled will dominate the majority of the future IR detection applications, today, thermal detectors are the unique plausible alternative. There is plenty of room for photonic uncooled and complementary alternatives are needed. This work allocates polycrystalline PbSe in the current panorama of the uncooled IR detectors, underlining its potentiality in two areas of interest, i.e., very low cost imaging IR detectors and MWIR fast uncooled detectors for security and defence applications. The new method of processing again converts PbSe into an emerging technology.

YBa2Cu307 superconducting microbolometer linear arrays

NASA Astrophysics Data System (ADS)

Johnson, Burgess R.; Ohnstein, Thomas R.; Marsh, Holly A.; Dunham, Scott B.; Kruse, Paul W.

1992-09-01

Single pixels and linear arrays of microbolometers employing the high-T(subscript c) superconductor YBa(subscript 2)Cu(subscript 3)O(subscript 7) have been fabricated by silicon micromachining techniques. The substrates are 3 in. diameter silicon wafers upon which buffer layers of Si(subscript 3)N(subscript 4) and yttria-stabilized zirconia (YSZ) have been deposited. The YBa(subscript 2)Cu(subscript 3)O(subscript 7) was deposited by ion beam sputtering upon the yttria-stabilized zirconia (YSZ), then photolithographically patterned into serpentines 4 micrometers wide. Anisotropic etching in KOH removed the silicon underlying each pixel, thereby providing the necessary thermal isolation. When operated at 70 degree(s)K with 1 (mu) A dc bias, the D(superscript *) is 7.5 X 10(superscript 8) cm Hz(superscript 1/2)/Watt with a thermal response time of 24 msec.

Imaging antenna array at 119 microns. [for plasma diagnostics

NASA Technical Reports Server (NTRS)

Neikirk, N. P.; Tong, P. P.; Putledge, D. B.; Park, H.; Young, P. E.

1982-01-01

A focal-plane imaging antenna array has been demonstrated at 119 microns. The array is a line of evaporated silver bow-tie antennas with bismuth microbolometer detectors on a silicon substrate. Radiation is coupled into the array by a lens placed on the back of the substrate. The bolometers are thermally isolated from the silicon substrate with a half-micron layer of polyimide. The array performance is demonstrated by coherent imaging of a series of holes at half the diffraction-limited cut-off frequency.

Advanced uncooled infrared system electronics

NASA Astrophysics Data System (ADS)

Neal, Henry W.

1998-07-01

Over the past two decades, Raytheon Systems Company (RSC), formerly Texas Instruments Defense Systems & Electronics Group, developed a robust family of products based on a low- cost, hybrid ferroelectric (FE) uncooled focal-plane array (FPA) aimed at meeting the needs for thermal imaging products across both military and commercial markets. Over the years, RSC supplied uncooled infrared (IR) sensors for applications such as in combat vehicles, man-portable weaponry, personnel helmets, and installation security. Also, various commercial IR systems for use in automobiles, boats, law enforcement, hand-held applications, building/site security, and fire fighting have been developed. These products resulted in a high degree of success where cooled IR platforms are too bulky and costly, and other uncooled implementations are less reliable or lack significant cost advantage. Proof of this great success is found in the large price reductions, the unprecedented monthly production rates, and the wide diversity of products and customers realized in recent years. The ever- changing needs of these existing and potential customers continue to fuel the advancement of both the primary technologies and the production capabilities of uncooled IR systems at RSC. This paper will describe a development project intended to further advance the system electronics capabilities of future uncooled IR products.

Terahertz Real-Time Imaging Uncooled Arrays Based on Antenna-Coupled Bolometers or FET Developed at CEA-Leti

NASA Astrophysics Data System (ADS)

Simoens, François; Meilhan, Jérôme; Nicolas, Jean-Alain

2015-10-01

Sensitive and large-format terahertz focal plane arrays (FPAs) integrated in compact and hand-held cameras that deliver real-time terahertz (THz) imaging are required for many application fields, such as non-destructive testing (NDT), security, quality control of food, and agricultural products industry. Two technologies of uncooled THz arrays that are being studied at CEA-Leti, i.e., bolometer and complementary metal oxide semiconductor (CMOS) field effect transistors (FET), are able to meet these requirements. This paper reminds the followed technological approaches and focuses on the latest modeling and performance analysis. The capabilities of application of these arrays to NDT and security are then demonstrated with experimental tests. In particular, high technological maturity of the THz bolometer camera is illustrated with fast scanning of large field of view of opaque scenes achieved in a complete body scanner prototype.

High-MTF hybrid ferroelectric IRFPA

NASA Astrophysics Data System (ADS)

Evans, Scott B.; Hayden, Terrence

1998-07-01

Low cost, uncooled hybrid infrared focal plane arrays (IRFPA's) are in full-scale production at Raytheon Systems Company (RSC), formerly Texas Instruments Defense Systems and Electronics Group. Detectors consist of reticulated ceramic barium strontium titanate (BST) arrays of 320 X 240 pixels on 48.5 micrometer pitch. The principal performance shortcoming of the hybrid arrays has been low MTF due to thermal crosstalk between pixels. In the past two years, significant improvements have been made to increase MTF making hybrids more competitive in performance with monolithic arrays. The improvements are (1) the reduction of the thickness of the IR absorbing layer electrode that maintains electrical continuity and increases thermal isolation between pixels, (2) reduction of the electrical crosstalk from the ROIC, and (3) development of a process to increase the thermal path-length between pixels called 'elevated optical coat.' This paper describes all three activities and their efficacy. Also discussed is the uncooled IRFPA production capability at RSC.

Analysis of Volcanic Processes at Kilauea Volcano Using an Airborne Imaging Interferometer

NASA Astrophysics Data System (ADS)

Wright, R.; Lucey, P. G.; Garbeil, H.; Pilger, E. J.; Wood, M.; Honniball, C.; Gabrieli, A.

2017-12-01

Measurements of thermal emittance in tens of narrow, contiguous wavebands, allow for the derivation of laboratory quality spectra remotely, from which the chemical composition and physical properties of targets can be determined. The TIRCIS instrument (Thermal Infra-Red Compact Imaging Spectrometer), developed at the Hawaii Institute of Geophysics and Planetology, uses a Fabry-Perot interferometer, an uncooled microbolometer array, and push-broom scanning to acquire hyperspectral image data in the 8-14 micron spectral range. Radiometric calibration is provided by blackbody targets while spectral calibration is achieved using monochromatic light sources. The instrument has a mass of <15 kg and dimensions of 53 cm × 25 cm × 22 cm, and has been designed to be compatible with integration into a micro-satellite platform. (A precursor to this instrument was launched onboard a 55 kg microsatellite as part of the ORS-4 mission in October 2015.) Over the wavelength interval of up to 50 spectral samples are possible, and signal-to-noise ratios of 200-1600:1 have been measured for targets with temperatures covering those of interest to Earth scientists. In this presentation we will discuss how the instrument works, its spectro-radiometric performance (and performance model), and show laboratory measurements that illustrate how the instrument would be able to quantify thermal emission from active lavas, the mineralogy of volcanic rocks, and the composition of volcanic gas plumes. Finally, we will present data obtained during test flights over Kilauea volcano, Hawaii.

An 80x80 microbolometer type thermal imaging sensor using the LWIR-band CMOS infrared (CIR) technology

NASA Astrophysics Data System (ADS)

Tankut, Firat; Cologlu, Mustafa H.; Askar, Hidir; Ozturk, Hande; Dumanli, Hilal K.; Oruc, Feyza; Tilkioglu, Bilge; Ugur, Beril; Akar, Orhan Sevket; Tepegoz, Murat; Akin, Tayfun

2017-02-01

This paper introduces an 80x80 microbolometer array with a 35 μm pixel pitch operating in the 8-12 μm wavelength range, where the detector is fabricated with the LWIR-band CMOS infrared technology, shortly named as CIR, which is a novel microbolometer implementation technique developed to reduce the detector cost in order to enable the use of microbolometer type sensors in high volume markets, such as the consumer market and IoT. Unlike the widely used conventional surface micromachined microbolometer approaches, MikroSens' CIR detector technology does not require the use of special high TCR materials like VOx or a-Si, instead, it allows to implement microbolometers with standard CMOS layers, where the suspended bulk micromachined structure is obtained by only few consecutive selective MEMS etching steps while protecting the wirebond pads with a simple lithograpy step. This approach not only reduces the fabrication cost but also increases the production yield. In addition, needing simple subtractive post-CMOS fabrication steps allows the CIR technology to be carried out in any CMOS and MEMS foundry in a truly fabless fashion, where industrially mature and Au-free wafer level vacuum packaging technologies can also be carried out, leading to cost advantage, simplicity, scalability, and flexibility. The CIR approach is used to implement an 80x80 FPA with 35 μm pixel pitch, namely MS0835A, using a 0.18 μm CMOS process. The fabricated sensor is measured to provide NETD (Noise Equivalent Temperature Difference) value of 163 mK at 17 fps (frames per second) and 71 mK at 4 fps with F/1.0 optics in a dewar environment. The measurement results of the wafer level vacuum packaged sensors with one side AR coating shows an NETD values of 112 mK at 4 fps with F/1.1 optics, i.e., demonstrates a good performance for high volume low-cost applications like advanced presence detection and human counting applications. The CIR approach of MikroSens is scalable and can be used to reduce the pixel pitch even further while increasing the array size if necessary for various other low-cost, high volume applications.

In situ observation of carbon nanotube layer growth on microbolometers with substrates at ambient temperature

NASA Astrophysics Data System (ADS)

Svatoš, Vojtěch; Gablech, Imrich; Ilic, B. Robert; Pekárek, Jan; Neužil, Pavel

2018-03-01

Carbon nanotubes (CNTs) have near unity infrared (IR) absorption efficiency, making them extremely attractive for IR imaging devices. Since CNT growth occurs at elevated temperatures, the integration of CNTs with IR imaging devices is challenging and has not yet been achieved. Here, we show a strategy for implementing CNTs as IR absorbers using differential heating of thermally isolated microbolometer membranes in a C2H2 environment. During the process, CNTs were catalytically grown on the surface of a locally heated membrane, while the substrate was maintained at an ambient temperature. CNT growth was monitored in situ in real time using optical microscopy. During growth, we measured the intensity of light emission and the reflected light from the heated microbolometer. Our measurements of bolometer performance show that the CNT layer on the surface of the microbolometer membrane increases the IR response by a factor of (2.3 ± 0.1) (mean ± one standard deviation of the least-squares fit parameters). This work opens the door to integrating near unity IR absorption, CNT-based, IR absorbers with hybrid complementary metal-oxide-semiconductor focal plane array architectures.

Helmet-mounted uncooled FPA camera for use in firefighting applications

NASA Astrophysics Data System (ADS)

Wu, Cheng; Feng, Shengrong; Li, Kai; Pan, Shunchen; Su, Junhong; Jin, Weiqi

2000-05-01

From the concept and need background of firefighters to the thermal imager, we discuss how the helmet-mounted camera applied in the bad environment of conflagration, especially at the high temperature, and how the better matching between the thermal imager with the helmet will be put into effect in weight, size, etc. Finally, give a practical helmet- mounted IR camera based on the uncooled focal plane array detector for in firefighting.

Progress on uncooled PbSe detectors for low-cost applications

NASA Astrophysics Data System (ADS)

Vergara, German; Gomez, Luis J.; Villamayor, Victor; Alvarez, M.; Rodrigo, Maria T.; del Carmen Torquemada, Maria; Sanchez, Fernando J.; Verdu, Marina; Diezhandino, Jorge; Rodriguez, Purificacion; Catalan, Irene; Almazan, Rosa; Plaza, Julio; Montojo, Maria T.

2004-08-01

This work reports on progress on development of polycrystalline PbSe infrared detectors at the Centro de Investigacion y Desarrollo de la Armada (CIDA). Since mid nineties, the CIDA owns an innovative technology for processing uncooled MWIR detectors of polycrystalline PbSe. Based on this technology, some applications have been developed. However, future applications demand smarter, more complex, faster yet cheaper detectors. Aiming to open new perspectives to polycrystalline PbSe detectors, we are currently working on different directions: 1) Processing of 2D arrays: a) Designing and processing low density x-y addressed arrays with 16x16 and 32x32 elements, as an extension of our standard technology. b) Trying to make compatible standard CMOS and polycrystalline PbSe technologies in order to process monolithic large format arrays. 2) Adding new features to the detector such as monolithically integrated spectral discrimination.

Polarimetric Imaging System for Automatic Target Detection and Recognition

DTIC Science & Technology

2000-03-01

technique shown in Figure 4(b) can also be used to integrate polarizer arrays with other types of imaging sensors, such as LWIR cameras and uncooled...vertical stripe pattern in this φ image is caused by nonuniformities in the particular polarizer array used. 2. CIRCULAR POLARIZATION IMAGING USING

Modulation transfer function measurement of microbolometer focal plane array by Lloyd's mirror method

NASA Astrophysics Data System (ADS)

Druart, Guillaume; Rommeluere, Sylvain; Viale, Thibault; Guerineau, Nicolas; Ribet-Mohamed, Isabelle; Crastes, Arnaud; Durand, Alain; Taboury, Jean

2014-05-01

Today, both military and civilian applications require miniaturized and cheap optical systems. One way to achieve this trend consists in decreasing the pixel pitch of focal plane arrays (FPA). In order to evaluate the performance of the overall optical systems, it is necessary to measure the modulation transfer function (MTF) of these pixels. However, small pixels lead to higher cut-off frequencies and therefore, original MTF measurements that are able to extract frequencies up to these high cut-off frequencies, are needed. In this paper, we will present a way to extract 1D MTF at high frequencies by projecting fringes on the FPA. The device uses a Lloyd mirror placed near and perpendicular to the focal plane array. Consequently, an interference pattern of fringes can be projected on the detector. By varying the angle of incidence of the light beam, we can tune the period of the interference fringes and, thus, explore a wide range of spatial frequencies, and mainly around the cut-off frequency of the pixel which is one of the most interesting area. Illustration of this method will be applied to a 640×480 microbolometer focal plane array with a pixel pitch of 17µm in the LWIR spectral region.

A low cost thermal infrared hyperspectral imager for small satellites

NASA Astrophysics Data System (ADS)

Crites, S. T.; Lucey, P. G.; Wright, R.; Garbeil, H.; Horton, K. A.

2011-06-01

The traditional model for space-based earth observations involves long mission times, high cost, and long development time. Because of the significant time and monetary investment required, riskier instrument development missions or those with very specific scientific goals are unlikely to successfully obtain funding. However, a niche for earth observations exploiting new technologies in focused, short lifetime missions is opening with the growth of the small satellite market and launch opportunities for these satellites. These low-cost, short-lived missions provide an experimental platform for testing new sensor technologies that may transition to larger, more long-lived platforms. The low costs and short lifetimes also increase acceptable risk to sensors, enabling large decreases in cost using commercial off the shelf (COTS) parts and allowing early-career scientists and engineers to gain experience with these projects. We are building a low-cost long-wave infrared spectral sensor, funded by the NASA Experimental Project to Stimulate Competitive Research program (EPSCOR), to demonstrate the ways in which a university's scientific and instrument development programs can fit into this niche. The sensor is a low-mass, power efficient thermal hyperspectral imager with electronics contained in a pressure vessel to enable the use of COTS electronics, and will be compatible with small satellite platforms. The sensor, called Thermal Hyperspectral Imager (THI), is based on a Sagnac interferometer and uses an uncooled 320x256 microbolometer array. The sensor will collect calibrated radiance data at long-wave infrared (LWIR, 8-14 microns) wavelengths in 230-meter pixels with 20 wavenumber spectral resolution from a 400-km orbit.

An array of antenna-coupled superconducting microbolometers for passive indoors real-time THz imaging

NASA Astrophysics Data System (ADS)

Luukanen, A.; Grönberg, L.; Helistö, P.; Penttilä, J. S.; Seppä, H.; Sipola, H.; Dietlein, C. R.; Grossman, E. N.

2006-05-01

The temperature resolving power (NETD) of millimeter wave imagers based on InP HEMT MMIC radiometers is typically about 1 K (30 ms), but the MMIC technology is limited to operating frequencies below ~ 150 GHz. In this paper we report the first results from a pixel developed for an eight pixel sub-array of superconducting antenna-coupled microbolometers, a first step towards a real-time imaging system, with frequency coverage of 0.2 - 3.6 THz. These detectors have demonstrated video-rate NETDs in the millikelvin range, close to the fundamental photon noise limit, when operated at a bath temperature of ~ 4K. The detectors will be operated within a turn-key cryogen-free pulse tube refrigerator, which allows for continuous operation without the need for liquid cryogens. The outstanding frequency agility of bolometric detectors allows for multi-frequency imaging, which greatly enhances the discrimination of e.g. explosives against innoncuous items concealed underneath clothing.

Uncooled tunneling infrared sensor

NASA Technical Reports Server (NTRS)

Kenny, Thomas W. (Inventor); Kaiser, William J. (Inventor); Podosek, Judith A. (Inventor); Vote, Erika C. (Inventor); Rockstad, Howard K. (Inventor); Reynolds, Joseph K. (Inventor)

1994-01-01

An uncooled infrared tunneling sensor in which the only moving part is a diaphragm which is deflected into contact with a micromachined silicon tip electrode prepared by a novel lithographic process. Similarly prepared deflection electrodes employ electrostatic force to control the deflection of a silicon nitride, flat diaphragm membrane. The diaphragm exhibits a high resonant frequency which reduces the sensor's sensitivity to vibration. A high bandwidth feedback circuit controls the tunneling current by adjusting the deflection voltage to maintain a constant deflection of the membrane which would otherwise change deflection depending upon incident infrared radiation. The resulting infrared sensor will meet or exceed the performance of all other broadband, uncooled, infrared sensors and can be miniaturized to pixel dimensions smaller than 100 .mu.m. The technology is readily implemented as a small-format linear array suitable for commercial and spacecraft applications.

Uncooled infrared imaging using bimaterial microcantilever arrays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grbovic, Dragoslav; Lavrik, Nickolay V; Rajic, Slobodan

2006-01-01

We report on the fabrication and characterization of microcantilever based uncooled focal plane array (FPA) for infrared imaging. By combining a streamlined design of microcantilever thermal transducers with a highly efficient optical readout, we minimized the fabrication complexity while achieving a competitive level of imaging performance. The microcantilever FPAs were fabricated using a straightforward fabrication process that involved only three photolithographic steps (i.e. three masks). A designed and constructed prototype of an IR imager employed a simple optical readout based on a noncoherent low-power light source. The main figures of merit of the IR imager were found to be comparablemore » to those of uncooled MEMS infrared detectors with substantially higher degree of fabrication complexity. In particular, the NETD and the response time of the implemented MEMS IR detector were measured to be as low as 0.5K and 6 ms, respectively. The potential of the implemented designs can also be concluded from the fact that the constructed prototype enabled IR imaging of close to room temperature objects without the use of any advanced data processing. The most unique and practically valuable feature of the implemented FPAs, however, is their scalability to high resolution formats, such as 2000x2000, without progressively growing device complexity and cost.« less

Antenna-coupled transition-edge hot-electron microbolometers

NASA Astrophysics Data System (ADS)

Ali, Shafinaz; Timbie, Peter T.; Malu, Siddharth; McCammon, Dan; Nelms, Kari L.; Pathak, Rashmi; van der Weide, Daniel W.; Allen, Christine A.; Abrahams, J.; Chervenak, James A.; Hsieh, Wen-Ting; Miller, Timothy M.; Moseley, S. H., Jr.; Stevenson, Thomas R.; Wollack, Edward J.

2004-10-01

We are developing a new type of detector for observational cosmology and astrophysical research. Incoming radiation from the sky is coupled to a superconducting microstrip transmission line that terminates in a thin film absorber. At sub-Kelvin temperature, the thermal isolation between the electrons and the lattice makes it possible for the electrons in the small absorber (100's of cubic micro-meter) and superconducting bilayer (Transition Edge Sensor) to heat up by the radiation absorbed by the electrons of the normal absorbing layer. We call this detector a Transition-edge Hot-electron Micro-bolometer (THM). THMs can be fabricated by photo lithography, so it is relatively easy to make matched detectors for a large focal plane array telescope. We report on the thermal properties of Mo/Au THMs with Bi/Au absorbers.

Circuit models applied to the design of a novel uncooled infrared focal plane array structure

NASA Astrophysics Data System (ADS)

Shi, Shali; Chen, Dapeng; Li, Chaobo; Jiao, Binbin; Ou, Yi; Jing, Yupeng; Ye, Tianchun; Guo, Zheying; Zhang, Qingchuan; Wu, Xiaoping

2007-05-01

This paper describes a circuit model applied to the simulation of the thermal response frequency of a novel substrate-free single-layer bi-material cantilever microstructure used as the focal plane array (FPA) in an uncooled opto-mechanical infrared imaging system. In order to obtain a high detection of the IR object, gold (Au) is coated alternately on the silicon nitride (SiNx) cantilevers of the pixels (Shi S et al Sensors and Actuators A at press), whereas the thermal response frequency decreases (Zhao Y 2002 Dissertation University of California, Berkeley). A circuit model for such a cantilever microstructure is proposed to be applied to evaluate the thermal response performance. The pixel's thermal frequency (1/τth) is calculated to be 10 Hz under the optimized design parameters, which is compatible with the response of optical readout systems and human eyes.

Thermal Infrared Imaging Experiments of C-Type Asteroid 162173 Ryugu on Hayabusa2

NASA Astrophysics Data System (ADS)

Okada, Tatsuaki; Fukuhara, Tetsuya; Tanaka, Satoshi; Taguchi, Makoto; Imamura, Takeshi; Arai, Takehiko; Senshu, Hiroki; Ogawa, Yoshiko; Demura, Hirohide; Kitazato, Kohei; Nakamura, Ryosuke; Kouyama, Toru; Sekiguchi, Tomohiko; Hasegawa, Sunao; Matsunaga, Tsuneo; Wada, Takehiko; Takita, Jun; Sakatani, Naoya; Horikawa, Yamato; Endo, Ken; Helbert, Jörn; Müller, Thomas G.; Hagermann, Axel

2017-07-01

The thermal infrared imager TIR onboard Hayabusa2 has been developed to investigate thermo-physical properties of C-type, near-Earth asteroid 162173 Ryugu. TIR is one of the remote science instruments on Hayabusa2 designed to understand the nature of a volatile-rich solar system small body, but it also has significant mission objectives to provide information on surface physical properties and conditions for sampling site selection as well as the assessment of safe landing operations. TIR is based on a two-dimensional uncooled micro-bolometer array inherited from the Longwave Infrared Camera LIR on Akatsuki (Fukuhara et al., 2011). TIR takes images of thermal infrared emission in 8 to 12 μm with a field of view of 16 × 12° and a spatial resolution of 0.05° per pixel. TIR covers the temperature range from 150 to 460 K, including the well calibrated range from 230 to 420 K. Temperature accuracy is within 2 K or better for summed images, and the relative accuracy or noise equivalent temperature difference (NETD) at each of pixels is 0.4 K or lower for the well-calibrated temperature range. TIR takes a couple of images with shutter open and closed, the corresponding dark frame, and provides a true thermal image by dark frame subtraction. Data processing involves summation of multiple images, image processing including the StarPixel compression (Hihara et al., 2014), and transfer to the data recorder in the spacecraft digital electronics (DE). We report the scientific and mission objectives of TIR, the requirements and constraints for the instrument specifications, the designed instrumentation and the pre-flight and in-flight performances of TIR, as well as its observation plan during the Hayabusa2 mission.

Characterizing the Diurnal Cycle of Land Surface Temperature and Evapotranspiration at High Spatial Resolution Using Thermal Observations from sUAS.

NASA Astrophysics Data System (ADS)

Dutta, D.; Drewry, D.; Johnson, W. R.

2017-12-01

The surface temperature of plant canopies is an important indicator of the stomatal regulation of plant water use and the associated water flux from plants to atmosphere (evapotranspiration (ET)). Remotely sensed thermal observations using compact, low-cost, lightweight sensors from small unmanned aerial systems (sUAS) have the potential to provide surface temperature (ST) and ET estimates at unprecedented spatial and temporal resolutions, allowing us to characterize the intra-field diurnal variations in canopy ST and ET for a variety of vegetation systems. However, major challenges exist for obtaining accurate surface temperature estimates from low-cost uncooled microbolometer-type sensors. Here we describe the development of calibration methods using thermal chamber experiments, taking into account the ambient optics and sensor temperatures, and applying simple models of spatial non-uniformity correction to the sensor focal-plane-array. We present a framework that can be used to derive accurate surface temperatures using radiometric observations from low-cost sensors, and demonstrate this framework using a sUAS-mounted sensor across a diverse set of calibration and vegetation targets. Further, we demonstrate the use of the Surface Temperature Initiated Closure (STIC) model for computing spatially explicit, high spatial resolution ET estimates across several well-monitored agricultural systems, as driven by sUAS acquired surface temperatures. STIC provides a physically-based surface energy balance framework for the simultaneous retrieval of the surface and atmospheric vapor conductances and surface energy fluxes, by physically integrating radiometric surface temperature information into the Penman-Monteith equation. Results of our analysis over agricultural systems in Ames, IA and Davis, CA demonstrate the power of this approach for quantifying the intra-field spatial variability in the diurnal cycle of plant water use at sub-meter resolutions.

Design of the SAC-D/NIRST camera module

NASA Astrophysics Data System (ADS)

Gauvin, Jonny; Châteauneuf, François; Marchese, Linda; Coté, Patrice; Leclerc, Mélanie; Chevalier, Claude; Marraco, Hugo; Phong, Linh N.

2007-09-01

Aquarius/SAC-D is a cooperative international mission conducted jointly by the National Aeronautics and Space Administration (NASA) of the United States of America (USA) and the Comisión Nacional de Actividades Espaciales (CONAE) of Argentina. The overall mission targets the understanding of the total Earth system and the consequences of the natural and man-made changes in the environment of the planet. Jointly developed by CONAE and the Canadian Space Agency (CSA), the New IR Sensor Technology (NIRST) instrument will monitor high temperature events on the ground related to fires and volcanic events, and will measure their physical parameters. Furthermore, NIRST will take measurements of sea surface temperatures mainly off the coast of South America as well as other targeted opportunities. NIRST has one band in the mid-wave infrared centered at 3.8 um with a bandwidth of 0.8 um, and two bands in the thermal infrared, centered respectively at 10.85 and 11.85 um with a bandwidth of 0.9 um. The temperature range is from 300 to 600 K with an NEDT < 0.5 K for the mid-infrared band and from 200 to 400 K with an NEDT < 0.4 K for the thermal bands. The baseline design of the NIRST is based on micro-bolometer technology developed jointly by INO and the CSA. Two arrays of 512x3 uncooled bolometric sensors will be used to measure brightness temperatures. The instantaneous field-of-view is 534 microradians corresponding to a ground sampling distance of 350 m at the subsatellite point. A pointing mirror allows a total swath of +/- 500 km. This paper describes the detailed design of the NIRST camera module. Key performance parameters are also presented.

Experimental study on the responsivity enhancement of Mn1.56Co0.96Ni0.48O4 detector under moderate bias field

NASA Astrophysics Data System (ADS)

Zhou, Wei; Hou, Yun; Gao, Yan Qing; Zhang, Leibo; Huang, Zhi Ming

2011-08-01

As a typical thermal sensitive material, Mn1.56Co0.96Ni0.48O4 (MCN) has achieved widely applications in uncooled bolometer. In this paper, we report that a large increase in electrical conductivity of MCN is obtained with moderate electric-field strengths (E~103V/cm) applied at room temperature (about 300K). Great enhancement in the responsivity is observed when operating with a proper electric bias field, which corresponds to a threshold voltage VTh. MCN bulk materials are prepared by using the sintering method. Micro MCN detector is fabricated by scribing the bulk material into pieces sized 200×100×10μm. The detector is clinged to an Al2O3 substrate with some electrical insulated epoxy glue which is mounted onto a Cu sink. The surrounding temperature is controlled precisely by a temperature controller with a precision of 1mK. Voltage-current characteristics at 270-330K are carefully examined. Different sweeping speeds of the bias-voltage are applied in different orders so as to find out a proper scanning rate, in which the electrical measurement is proceeded in a state of quasi-thermal equilibrium. According to quasi-thermal equilibrium and the time dependent nominal D.C. power, the temperature increase during the measurement is estimated. The conduction mechanism can be well explained with small polaron theory. Empirical equations are used to describe the thermal dynamic process in the pulsed mode, and the process is also simply simulated via numerical calculations. The experimental results and simulation works will be of some referential value to future studies in uncooled microbolometer made in transition metal oxides.

Visible and thermal imaging of sea ice and open water from Coast Guard Arctic Domain Awareness flights

NASA Astrophysics Data System (ADS)

Chickadel, C. C.; Lindsay, R. W.; Clark, D.

2014-12-01

An uncooled thermal camera (microbolometer) and RGB camera were mounted in the tail section of a US Coast Guard HC-130 to observe sea ice, open water, and cloud tops through the open rear cargo doors during routine Arctic Domain Awareness (ADA) flights. Recent flights were conducted over the Beaufort Sea in June, July, and August of 2014, with flights planned for September and October. Thermal and visible images were collected at low altitude (100m) during times when the cargo doors were open and recorded high resolution information on ice floes, melt ponds, and surface temperature variability associated with the marginal ice zone (MIZ). These observations of sea ice conditions and surface water temperatures will be used to characterize floe size development and the temperature and albedo of ice ponds and leads. This information will allow for a detailed characterization of sea ice that can be used in process studies and for model evaluation, calibration of satellite remote sensing products, and initialization of sea ice prediction schemes.

Vanadium Oxide Thin Films Alloyed with Ti, Zr, Nb, and Mo for Uncooled Infrared Imaging Applications

NASA Astrophysics Data System (ADS)

Ozcelik, Adem; Cabarcos, Orlando; Allara, David L.; Horn, Mark W.

2013-05-01

Microbolometer-grade vanadium oxide (VO x ) thin films with 1.3 < x < 2.0 were prepared by pulsed direct-current (DC) sputtering using substrate bias in a controlled oxygen and argon environment. These films were systematically alloyed with Ti, Nb, Mo, and Zr using a second gun and radiofrequency (RF) reactive co-sputtering to probe the effects of the transition metals on the film charge transport characteristics. The results reveal that the temperature coefficient of resistance (TCR) and resistivity are unexpectedly similar for alloyed and unalloyed films up to alloy compositions in the ˜20 at.% range. Analysis of the film structures for the case of the 17% Nb-alloyed film by glancing-angle x-ray diffraction and transmission electron microscopy shows that the microstructure remains even with the addition of high concentrations of alloy metal, demonstrating the robust character of the VO x films to maintain favorable electrical transport properties for bolometer applications. Postdeposition thermal annealing of the alloyed VO x films further reveals improvement of electrical properties compared with unalloyed films, indicating a direction for further improvements in the materials.

Portable real-time color night vision

NASA Astrophysics Data System (ADS)

Toet, Alexander; Hogervorst, Maarten A.

2008-03-01

We developed a simple and fast lookup-table based method to derive and apply natural daylight colors to multi-band night-time images. The method deploys an optimal color transformation derived from a set of samples taken from a daytime color reference image. The colors in the resulting colorized multiband night-time images closely resemble the colors in the daytime color reference image. Also, object colors remain invariant under panning operations and are independent of the scene content. Here we describe the implementation of this method in two prototype portable dual band realtime night vision systems. One system provides co-aligned visual and near-infrared bands of two image intensifiers, the other provides co-aligned images from a digital image intensifier and an uncooled longwave infrared microbolometer. The co-aligned images from both systems are further processed by a notebook computer. The color mapping is implemented as a realtime lookup table transform. The resulting colorised video streams can be displayed in realtime on head mounted displays and stored on the hard disk of the notebook computer. Preliminary field trials demonstrate the potential of these systems for applications like surveillance, navigation and target detection.

Real-time, continuous-wave terahertz imaging using a microbolometer focal-plane array

NASA Technical Reports Server (NTRS)

Hu, Qing (Inventor); Min Lee, Alan W. (Inventor)

2010-01-01

The present invention generally provides a terahertz (THz) imaging system that includes a source for generating radiation (e.g., a quantum cascade laser) having one or more frequencies in a range of about 0.1 THz to about 10 THz, and a two-dimensional detector array comprising a plurality of radiation detecting elements that are capable of detecting radiation in that frequency range. An optical system directs radiation from the source to an object to be imaged. The detector array detects at least a portion of the radiation transmitted through the object (or reflected by the object) so as to form a THz image of that object.

Technology of uncooled fast polycrystalline PbSe focal plane arrays in systems for muzzle flash detection

NASA Astrophysics Data System (ADS)

Kastek, Mariusz; PiÄ tkowski, Tadeusz; Polakowski, Henryk; Barela, Jaroslaw; Firmanty, Krzysztof; Trzaskawka, Piotr; Vergara, German; Linares, Rodrigo; Gutierrez, Raul; Fernandez, Carlos; Montojo Supervielle, Maria Teresa

2014-05-01

The paper presents some aspects of muzzle flash detection using low resolution polycrystalline PbSe 32×32 and 80×80 detectors FPA operating at room temperature (uncooled performance). These sensors, which detect in MWIR (3 - 5 microns region) and are manufactured using proprietary technology from New Infrared Technologies (VPD PbSe - Vapor Phase Deposition of polycrystalline PbSe), can be applied to muzzle flash detection. The system based in the uncooled 80×80 FPA monolithically integrated with the CMOS readout circuitry has allowed image recording with frame rates over 2000 Hz (true snapshot acquisition), whereas the lower density, uncooled 32×32 FPA is suitable for being used in low cost infrared imagers sensitive in the MWIR band with frame rates above 1000 Hz. The FPA detector, read-out electronics and processing electronics (allows the implementation of some algorithms for muzzle flash detection) of both systems are presented. The systems have been tested at field test ground. Results of detection range measurement with two types of optical systems (wide and narrow field of view) have been shown. The theoretical analysis of possibility detection of muzzle flash and initial results of testing of some algorithms for muzzle flash detection have been presented too.

Uncooled Micro-Cantilever Infrared Imager Optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panagiotis, Datskos G.

2008-02-05

We report on the development, fabrication and characterization of microcantilever based uncooled focal plane array (FPA) for infrared imaging. By combining a streamlined design of microcantilever thermal transducers with a highly efficient optical readout, we minimized the fabrication complexity while achieving a competitive level of imaging performance. The microcantilever FPAs were fabricated using a straightforward fabrication process that involved only three photolithographic steps (i.e. three masks). A designed and constructed prototype of an IR imager employed a simple optical readout based on a noncoherent low-power light source. The main figures of merit of the IR imager were found to bemore » comparable to those of uncooled MEMS infrared detectors with substantially higher degree of fabrication complexity. In particular, the NETD and the response time of the implemented MEMS IR detector were measured to be as low as 0.5K and 6 ms, respectively. The potential of the implemented designs can also be concluded from the fact that the constructed prototype enabled IR imaging of close to room temperature objects without the use of any advanced data processing. The most unique and practically valuable feature of the implemented FPAs, however, is their scalability to high resolution formats, such as 2000 x 2000, without progressively growing device complexity and cost. The overall technical objective of the proposed work was to develop uncooled infrared arrays based on micromechanical sensors. Currently used miniature sensors use a number of different readout techniques to accomplish the sensing. The use of optical readout techniques sensing require the deposition of thin coatings on the surface of micromechanical thermal detectors. Oak Ridge National Laboratory (ORNL) is uniquely qualified to perform the required research and development (R&D) services that will assist our ongoing activities. Over the past decade ORNL has developed a number of unique methods and techniques that led to improved sensors using a number of different approaches.« less

Nonuniformity correction based on focal plane array temperature in uncooled long-wave infrared cameras without a shutter.

PubMed

Liang, Kun; Yang, Cailan; Peng, Li; Zhou, Bo

2017-02-01

In uncooled long-wave IR camera systems, the temperature of a focal plane array (FPA) is variable along with the environmental temperature as well as the operating time. The spatial nonuniformity of the FPA, which is partly affected by the FPA temperature, obviously changes as well, resulting in reduced image quality. This study presents a real-time nonuniformity correction algorithm based on FPA temperature to compensate for nonuniformity caused by FPA temperature fluctuation. First, gain coefficients are calculated using a two-point correction technique. Then offset parameters at different FPA temperatures are obtained and stored in tables. When the camera operates, the offset tables are called to update the current offset parameters via a temperature-dependent interpolation. Finally, the gain coefficients and offset parameters are used to correct the output of the IR camera in real time. The proposed algorithm is evaluated and compared with two representative shutterless algorithms [minimizing the sum of the squares of errors algorithm (MSSE), template-based solution algorithm (TBS)] using IR images captured by a 384×288 pixel uncooled IR camera with a 17 μm pitch. Experimental results show that this method can quickly trace the response drift of the detector units when the FPA temperature changes. The quality of the proposed algorithm is as good as MSSE, while the processing time is as short as TBS, which means the proposed algorithm is good for real-time control and at the same time has a high correction effect.

Enhancing Microbolometer Performance at Terahertz Frequencies with Metamaterial Absorbers

DTIC Science & Technology

2013-09-01

focal plane arrays (FPAs). Indeed, these sensors naturally evolved in snakes in the form of pit organs leading to a high sensitivity, albeit low...materials. Indeed, they can even have characteristics that are not found in nature , such as a negative refractive index [27]. Absorption in these...modes [44], interference of multiple reflections [45], and transmission lines [46]. However, due to the complex nature of metamaterials, these models

Towards Silicon-Based Longwave Integrated Optoelectronics (LIO)

DTIC Science & Technology

2008-01-21

circuitry. The photonics can use, for example, microbolometers and III-V photodetectors as well as III-V interband cascade and quantum cascade lasers...chips using inputs from several sensors. (4) imaging: focal - plane - array imager with integral readout, infrared-to-visible image converter chip, (5... photodetectors , type II interband cascades and QCLs. I would integrate the cascades in LIO using a technique similar to that developed by John Bower’s

Challenges, constraints, and results of lens design for 17 micron-bolometer focal plane arrays in 8-12 micron waveband

NASA Astrophysics Data System (ADS)

Schuster, Norbert; Franks, John

2011-06-01

In the 8-12 micron waveband Focal Plane Arrays (FPA) are available with a 17 micron pixel pitch in different arrays sizes (e.g. 512 x 480 pixels and 320 x 240 pixels) and with excellent electrical properties. Many applications become possible using this new type of IR-detector which will become the future standard in uncooled technology. Lenses with an f-number faster than f/1.5 minimize the diffraction impact on the spatial resolution and guarantee a high thermal resolution for uncooled cameras. Both effects will be quantified. The distinction between Traditional f-number (TF) and Radiometric f-number (RF) is discussed. Lenses with different focal lengths are required for applications in a variety of markets. They are classified by their Horizontal field of view (HFOV). Respecting the requirements for high volume markets, several two lens solutions will be discussed. A commonly accepted parameter of spatial resolution is the Modulation Transfer Function (MTF)-value at the Nyquist frequency of the detector (here 30cy/mm). This parameter of resolution will be presented versus field of view. Wide Angle and Super Wide Angle lenses are susceptible to low relative illumination in the corner of the detector. Measures to reduce this drop to an acceptable value are presented.

Microminiature rotary Stirling cryocooler for compact, lightweight, and low-power thermal imaging systems

NASA Astrophysics Data System (ADS)

Filis, Avishai; Bar Haim, Zvi; Pundak, Nachman; Broyde, Ramon

2009-05-01

Novel compact and low power consuming cooled infrared thermal imagers as used in gyro-stabilized payloads of miniature unmanned aerial vehicles, Thermal small arms sights and tactical night vision goggles often rely on integral rotary micro-miniature closed cycle Stirling cryogenic engines. Development of EPI Antimonides technology and optimization of MCT technology allowed decreasing in order of magnitudes the level of dark current in infrared detectors thus enabling an increase in the optimal focal plane temperature in excess of 95K while keeping the same radiometric performances as achieved at 77K using regular technologies. Maintaining focal plane temperature in the range of 95K to 110K instead of 77K improves the efficiency of Stirling thermodynamic cycle thus enlarging cooling power and enabling the development of a mini micro cooler similar to RICOR's K562S model which is three times smaller, lighter and more compact than a standard tactical cryocooler like RICOR's K508 model. This cooler also features a new type of ball bearings and internal components which were optimized to fit tight bulk constraints and maintain the required life span, while keeping a low level of vibration and noise signature. Further, the functions of management the brushless DC motor and temperature stabilization are delivered by the newly developed high performance sensorless digital controller. By reducing Dewar Detector thermal losses and increasing the focal plane temperature, longer life time operation is expected as was proved with RICOR's K508 model. Resulting from this development, the RICOR K562S model cryogenic engine consumes 1.2 - 3.0 WDC while operating in the closed loop mode and maintaining the typical focal plane arrays at 200-100K. This makes it compatible with very compact battery packages allowing further reduction of the overall thermal imager weight thus making it comparable with the compatible uncooled infrared thermal imager relying on a microbolometer detector in terms of power consumption and bulk.

Efficient Heat Dissipation of Uncooled 400-Gbps (16×25-Gbps) Optical Transceiver Employing Multimode VCSEL and PD Arrays

NASA Astrophysics Data System (ADS)

Shih, Tien-Tsorng; Chi, Yu-Chieh; Wang, Ruei-Nian; Wu, Chao-Hsin; Huang, Jian-Jang; Jou, Jau-Ji; Lee, Tai-Cheng; Kuo, Hao-Chung; Lin, Gong-Ru; Cheng, Wood-Hi

2017-04-01

An effective heat dissipation of uncooled 400-Gbps (16×25-Gbps) form-factor pluggable (CDFP) optical transceiver module employing chip-on-board multimode 25-Gbps vertical-surface-emitting-laser (VCSEL) and 25-Gbps photodiode (PD) arrays mounted on a brass metal core embedded within a printed circuit board (PCB) is proposed and demonstrated. This new scheme of the hollow PCB filling with thermally-dissipated brass metal core was simulated and used for high temperature and long term stability operation of the proposed 400-Gbps CDFP transceiver. During one-hour testing, a red-shift of central wavelength by 0.4-nm corresponding temperature increment of 6.7 °C was observed with the brass core assisted cooler module. Such a temperature change was significantly lower than that of 28.3 °C for the optical transceiver driven with conventional circuit board. After 100-m distance transmission over a multimode fiber (OM4), the 400-Gbps CDFP transceiver exhibited dispersion penalty of 2.6-dB, power budget of ≧ 3-dB, link loss of ≦ 0.63-dB, mask margin of 20%, and bit error rate (BER) of <10-12 with maintained stability more than one hour. The developed 400-Gbps CDFP transceiver module employing low-power consumption VCSEL and PD arrays, effective coupling lens arrays, and well thermal-dissipation brass metal core is suitable for use in the low-cost and high-performance data center applications.

Fabrication and design of vanadium oxide microbolometer

NASA Astrophysics Data System (ADS)

Abdel-Rahman, M.; Al-Khalli, N.; Zia, M. F.; Alduraibi, M.; Ilahi, B.; Awad, E.; Debbar, N.

2017-02-01

Vanadium oxide (VxOy) multilayer sandwich structures previously studied by our group were found to yield a sensitive thermometer thin film material suitable for microbolometer applications. In this work, we aim to estimate the performance of a proposed air-bridge microbolometer configuration based on VxOy multilayer sandwich structure thermometer thin films. For this purpose, a microbolometer was fabricated on silicon (Si) substrate covered with a silicon nitride (Si3N4) insulating layer using VxOy thermometer thin film material. The fabricated microbolometer was patterned using electron-beam lithography and liftoff techniques and it was characterized in terms of its voltage repsonsivity (Rv), signal to noise ratio (SNR), noise equivalent power (NEP) and detectivity D*. A model was then developed by the aid of numerical optical/thermal simulations and experimentally measured parameters to estimate the performance of the microbolometer when fabricated in an air-bridge configuration. The estimated D* was found to be 1.55×107 cm.√Hz/ W.

Characterization of Terahertz Bi-Material Sensors with Integrated Metamaterial Absorbers

DTIC Science & Technology

2013-09-01

Kumar, Qing Hu, and J. L. Reno, “Real-time imaging using a 4.3-THz quantum cascade laser and a 320x240 microbolometer focal-plane array ,” IEEE...responsivity, the speed of operation and the minimum detected incident power were measured using a quantum cascade laser (QCL), operating at 3.8 THz...of operation and the minimum detected incident power were measured using a quantum cascade laser (QCL), operating at 3.8 THz. The measured

ManTech Affordability for Defense Weapon Systems

DTIC Science & Technology

2009-11-01

the Virginia Class Submarine Development of Friction Stir Welding for Navy Expeditionary Fighting Vehicle (EFV) Hull Components Procurement...Tile 2007 – Translational Friction Stir Welding 2006 – Engine Rotor Life Extension 2006 – Uncooled Focal Plane Array Producibility 2005 – Large...DDG 1000 with Hybrid Laser Arc Welding The Problem: T-Beam stiffeners, used extensively for decks, bulkheads, and other ship structures, are being

Nonuniformity correction algorithm with efficient pixel offset estimation for infrared focal plane arrays.

PubMed

Orżanowski, Tomasz

2016-01-01

This paper presents an infrared focal plane array (IRFPA) response nonuniformity correction (NUC) algorithm which is easy to implement by hardware. The proposed NUC algorithm is based on the linear correction scheme with the useful method of pixel offset correction coefficients update. The new approach to IRFPA response nonuniformity correction consists in the use of pixel response change determined at the actual operating conditions in relation to the reference ones by means of shutter to compensate a pixel offset temporal drift. Moreover, it permits to remove any optics shading effect in the output image as well. To show efficiency of the proposed NUC algorithm some test results for microbolometer IRFPA are presented.

Uncooled Terahertz real-time imaging 2D arrays developed at LETI: present status and perspectives

NASA Astrophysics Data System (ADS)

Simoens, François; Meilhan, Jérôme; Dussopt, Laurent; Nicolas, Jean-Alain; Monnier, Nicolas; Sicard, Gilles; Siligaris, Alexandre; Hiberty, Bruno

2017-05-01

As for other imaging sensor markets, whatever is the technology, the commercial spread of terahertz (THz) cameras has to fulfil simultaneously the criteria of high sensitivity and low cost and SWAP (size, weight and power). Monolithic silicon-based 2D sensors integrated in uncooled THz real-time cameras are good candidates to meet these requirements. Over the past decade, LETI has been studying and developing such arrays with two complimentary technological approaches, i.e. antenna-coupled silicon bolometers and CMOS Field Effect Transistors (FET), both being compatible to standard silicon microelectronics processes. LETI has leveraged its know-how in thermal infrared bolometer sensors in developing a proprietary architecture for THz sensing. High technological maturity has been achieved as illustrated by the demonstration of fast scanning of large field of view and the recent birth of a commercial camera. In the FET-based THz field, recent works have been focused on innovative CMOS read-out-integrated circuit designs. The studied architectures take advantage of the large pixel pitch to enhance the flexibility and the sensitivity: an embedded in-pixel configurable signal processing chain dramatically reduces the noise. Video sequences at 100 frames per second using our 31x31 pixels 2D Focal Plane Arrays (FPA) have been achieved. The authors describe the present status of these developments and perspectives of performance evolutions are discussed. Several experimental imaging tests are also presented in order to illustrate the capabilities of these arrays to address industrial applications such as non-destructive testing (NDT), security or quality control of food.

Leading Edge. Sensors Challenges and Solutions for the 21st Century. Volume 7, Issue Number 2

DTIC Science & Technology

2010-01-01

above, microbolometer technology is not very sen- sitive. To gain sensitivity, one needs to go to IR cam- eras that have cryogenically cooled detector ...QWIP) and detector arrays made from mercury cadmium telluride ( MCT ). Both types can be very sensitive. QWIP cameras have spectral detection bands...commercially available IR camera to meet the needs of CAPTC. One MCT camera was located that had a detection band from 7.7 µ to 11.6 µ and included an

Real Time Imaging Analysis Using a Terahertz Quantum Cascade Laser and a Microbolometer Focal Plane Array

DTIC Science & Technology

2008-12-01

evident from Figure 7 that, if the applied bias is not correct, it is very likely that electrons will not tunnel into their intended energy state...the theoretical laser contrasts sharply to that of semiconductor lasers. Semiconductor lasers rely on electron hole recombination or interband ...the active layer of a forward- biased pn junction [26]. In contrast to this, the QCL is a unipolar device that uses a quantum well (QW) structure

Advanced electro-mechanical micro-shutters for thermal infrared night vision imaging and targeting systems

NASA Astrophysics Data System (ADS)

Durfee, David; Johnson, Walter; McLeod, Scott

2007-04-01

Un-cooled microbolometer sensors used in modern infrared night vision systems such as driver vehicle enhancement (DVE) or thermal weapons sights (TWS) require a mechanical shutter. Although much consideration is given to the performance requirements of the sensor, supporting electronic components and imaging optics, the shutter technology required to survive in combat is typically the last consideration in the system design. Electro-mechanical shutters used in military IR applications must be reliable in temperature extremes from a low temperature of -40°C to a high temperature of +70°C. They must be extremely light weight while having the ability to withstand the high vibration and shock forces associated with systems mounted in military combat vehicles, weapon telescopic sights, or downed unmanned aerial vehicles (UAV). Electro-mechanical shutters must have minimal power consumption and contain circuitry integrated into the shutter to manage battery power while simultaneously adapting to changes in electrical component operating parameters caused by extreme temperature variations. The technology required to produce a miniature electro-mechanical shutter capable of fitting into a rifle scope with these capabilities requires innovations in mechanical design, material science, and electronics. This paper describes a new, miniature electro-mechanical shutter technology with integrated power management electronics designed for extreme service infra-red night vision systems.

Characterization and initial field test of a long wave thermal infrared hyperspectral imager for measuring SO2 in volcanic plumes

NASA Astrophysics Data System (ADS)

Gabrieli, A.; Wright, R.; Porter, J. N.; Lucey, P. G.; Crites, S.; Garbeil, H.; Pilger, E. J.; Wood, M.

2015-12-01

The ability to quantify volcanic SO2 and image the spatial distribution in plumes either by day or by night would be beneficial to volcanologists. In this project, a newly developed remote sensing long-wave thermal infrared imaging hyperspectral sensor, was tested. The system employs a Sagnac interferometer and an uncooled microbolometer in rapid scanning configuration. This instrument is able to collect hyperspectral images of the scene between 8 and 14 and for each pixel a spectrum containing 50 samples can be retrieved. Images are spectrally and radiometrically calibrated using an IR source with a narrow band filter and two black bodies. The sensitivity of the system was studied by using a gas cell containing various known concentrations of SO2, which are representative of those found in volcanic plumes. Measured spectra were compared with theoretical spectra obtained from MODTRAN5 with the same viewing geometry and spectral resolution as the sensor. The MODTRAN5 calculations were carried out using a radiative transfer algorithm which accounts for the transmission and emission both inside and outside of the gas cell. These preliminary results and field measurements at Kīlauea volcano, Hawai'i will be discussed demonstrating the performance of the system and the ability of retrieving SO2 plume concentrations.

ManTech Implementing a Strategy to Deliver Weapon Systems Affordability

DTIC Science & Technology

2010-11-01

Tile 2007 – Translational Friction Stir Welding 2006 – Uncooled Focal Plane Array Producibility 2006 – Engine Rotor Life Extension 2005...compelling ideas will continue to help drive our Department’s innovative engine and ensure our Nation maintains its competitive edge on the...Sheets Composite Vertical Stabilizer Apache AH-64 NAVY The Challenge: Butt welding exterior ship panels produces a weld protrusion that exceeds the

Single-image-based solution for optics temperature-dependent nonuniformity correction in an uncooled long-wave infrared camera.

PubMed

Cao, Yanpeng; Tisse, Christel-Loic

2014-02-01

In this Letter, we propose an efficient and accurate solution to remove temperature-dependent nonuniformity effects introduced by the imaging optics. This single-image-based approach computes optics-related fixed pattern noise (FPN) by fitting the derivatives of correction model to the gradient components, locally computed on an infrared image. A modified bilateral filtering algorithm is applied to local pixel output variations, so that the refined gradients are most likely caused by the nonuniformity associated with optics. The estimated bias field is subtracted from the raw infrared imagery to compensate the intensity variations caused by optics. The proposed method is fundamentally different from the existing nonuniformity correction (NUC) techniques developed for focal plane arrays (FPAs) and provides an essential image processing functionality to achieve completely shutterless NUC for uncooled long-wave infrared (LWIR) imaging systems.

Low-Cost WDM-PON With Colorless Bidirectional Transceivers

NASA Astrophysics Data System (ADS)

Shin, Dong Jae; Keh, Y. C.; Kwon, J. W.; Lee, E. H.; Lee, J. K.; Park, M. K.; Park, J. W.; Oh, Y. K.; Kim, S. W.; Yun, I. K.; Shin, H. C.; Heo, D.; Lee, J. S.; Shin, H. S.; Kim, H. S.; Park, S. B.; Jung, D. K.; Hwang, Seongtaek; Oh, Y. J.; Jang, D. H.; Shim, C. S.

2006-01-01

This paper presents a low-cost bidirectional (BiDi) wavelength-division-multiplexed passive optical network (WDM-PON) employing colorless uncooled BiDi transceivers (TRxs) and superluminescent diode (SLD)-based broadband light sources (BLSs). The C band is allocated for upstream and the E+ band for downstream in consideration of BiDi packaging, SLD development, and wavelength alignment of dual-window arrayed waveguide gratings (AWGs). The BiDi TRx integrates an uncooled Fabry-Pérot laser diode (FP-LD), a p-i-n photodiode (PD), and a 45°-angled thin-film filter in a small-form-factor (SFF) package. The SLD-based BLSs provide 13-dBm amplified spontaneous emissions (ASEs) with spectral ripples of < 3 dB and polarization dependencies of < 1 dB. Colorless operations over 32 100-GHz-spaced channels are demonstrated from -20 to 80°C in 155-Mb/s BiDi transmissions over 25 km.

Variable filter array spectrometer of VPD PbSe

NASA Astrophysics Data System (ADS)

Linares-Herrero, R.; Vergara, G.; Gutiérrez-Álvarez, R.; Fernández-Montojo, C.; Gómez, L. J.; Villamayor, V.; Baldasano-Ramírez, A.; Montojo, M. T.

2012-06-01

MWIR spectroscopy shows a large potential in the current IR devices market, due to its multiple applications (gas detection, chemical analysis, industrial monitoring, combustion and flame characterization, food packaging etc) and its outstanding performance (good sensitivity, NDT method, velocity of response, among others), opening this technique to very diverse fields of application, such as industrial monitoring and control, agriculture, medicine and environmental monitoring. However, even though a big interest on MWIR spectroscopy technique has been present in the last years, two major barriers have held it back from its widespread use outside the laboratory: the complexity and delicateness of some popular techniques such as Fourier-transform IR (FT-IR) spectrometers, and the lack of affordable specific key elements such a MWIR light sources and low cost (real uncooled) detectors. Recent developments in electrooptical components are helping to overcome these drawbacks. The need for simpler solutions for analytical measurements has prompted the development of better and more affordable uncooled MWIR detectors, electronics and optics. In this paper a new MWIR spectrometry device is presented. Based on linear arrays of different geometries (64, 128 and 256 elements), NIT has developed a MWIR Variable Filter Array Spectrometer (VFAS). This compact device, with no moving parts, based on a rugged and affordable detector, is suitable to be used in applications which demand high sensitivity, good spectral discrimination, reliability and compactness, and where an alternative to the traditional scanning instrument is desired. Some measurements carried out for several industries will be also presented.

Superconducting Digital Multiplexers for Sensor Arrays

NASA Technical Reports Server (NTRS)

Kadin, Alan M.; Brock, Darren K.; Gupta, Deepnarayan

2004-01-01

Arrays of cryogenic microbolometers and other cryogenic detectors are being developed for infrared imaging. If the signal from each sensor is amplified, multiplexed, and digitized using superconducting electronics, then this data can be efficiently read out to ambient temperature with a minimum of noise and thermal load. HYPRES is developing an integrated system based on SQUID amplifiers, a high-resolution analog-to-digital converter (ADC) based on RSFQ (rapid single flux quantum) logic, and a clocked RSFQ multiplexer. The ADC and SQUIDs have already been demonstrated for other projects, so this paper will focus on new results of a digital multiplexer. Several test circuits have been fabricated using Nb Josephson technology and are about to be tested at T = 4.2 K, with a more complete prototype in preparation.

Defense Industrial Base Assessment: U.S. Imaging and Sensors Industry

DTIC Science & Technology

2006-10-01

uncooled devices, but provide much higher resolution. The semiconductor material used in the detector is typically mercury cadmium telluride (HgCdTe...The material principally used in the arrays was mercury cadmium telluride (HgCdTe). Generation 2 detectors significantly improved the signal-to...Silicide (PtSi), Gallium Arsenide (GaAs), Aluminum Gallium Arsenide (AlGaAs), Mercury Cadmium Telluride (HgCdTe), Indium Gallium Arsenide (InGaAs

Combined holography and thermography in a single sensor through image-plane holography at thermal infrared wavelengths.

PubMed

Georges, Marc P; Vandenrijt, Jean-François; Thizy, Cédric; Alexeenko, Igor; Pedrini, Giancarlo; Vollheim, Birgit; Lopez, Ion; Jorge, Iagoba; Rochet, Jonathan; Osten, Wolfgang

2014-10-20

Holographic interferometry in the thermal wavelengths range, combining a CO(2) laser and digital hologram recording with a microbolometer array based camera, allows simultaneously capturing temperature and surface shape information about objects. This is due to the fact that the holograms are affected by the thermal background emitted by objects at room temperature. We explain the setup and the processing of data which allows decoupling the two types of information. This natural data fusion can be advantageously used in a variety of nondestructive testing applications.

Materials Research of Perovskite Thin Films for Uncooled Infrared (IR) Detectors

DTIC Science & Technology

2011-07-01

Today April 2010, 5 (2), 99–105. 4. Livingston, F. E.; Helvajian , H . Laser Processing Architecture for Improved Material Processing. in Laser...crystalline final perovskite (BaTiO3) in only 3 h , representing a significantly increased throughput compared to previous results using vapor...Plane Arrays; ARL-TR-5389; U.S. Army Research Laboratory: Adelphi, MD, November 2010. 5. Wemple, S. H . Phys. Rev. B 1970, 2, 2679. 6. Xu, J

Dual band sensitivity enhancements of a VO(x) microbolometer array using a patterned gold black absorber.

PubMed

Smith, Evan M; Panjwani, Deep; Ginn, James; Warren, Andrew P; Long, Christopher; Figuieredo, Pedro; Smith, Christian; Nath, Janardan; Perlstein, Joshua; Walter, Nick; Hirschmugl, Carol; Peale, Robert E; Shelton, David

2016-03-10

Infrared-absorbing gold black has been selectively patterned onto the active surfaces of a vanadium-oxide-based infrared bolometer array. Patterning by metal lift-off relies on protection of the fragile gold black with an evaporated oxide, which preserves much of gold black's high absorptance. This patterned gold black also survives the dry-etch removal of the sacrificial polyimide used to fabricate the air-bridge bolometers. For our fabricated devices, infrared responsivity is improved 22% in the long-wave IR and 70% in the mid-wave IR by the gold black coating, with no significant change in detector noise, using a 300°C blackbody and 80 Hz chopping rate. The increase in the time constant caused by the additional mass of gold black is ∼15%.

High resolution infrared acquisitions droning over the LUSI mud eruption.

NASA Astrophysics Data System (ADS)

Di Felice, Fabio; Romeo, Giovanni; Di Stefano, Giuseppe; Mazzini, Adriano

2016-04-01

The use of low-cost hand-held infrared (IR) thermal cameras based on uncooled micro-bolometer detector arrays became more widespread during the recent years. Thermal cameras have the ability to estimate temperature values without contact and therefore can be used in circumstances where objects are difficult or dangerous to reach such as volcanic eruptions. Since May 2006 the Indonesian LUSI mud eruption continues to spew boiling mud, water, aqueous vapor, CO2, CH4 and covers a surface of nearly 7 km2. At this locality we performed surveys over the unreachable erupting crater. In the framework of the LUSI Lab project (ERC grant n° 308126), in 2014 and 2015, we acquired high resolution infrared images using a specifically equipped remote-controlled drone flying at an altitude of m 100. The drone is equipped with GPS and an autopilot system that allows pre-programming the flying path or designing grids. The mounted thermal camera has peak spectral sensitivity in LW wavelength (μm 10) that is characterized by low water vapor and CO2 absorption. The low distance (high resolution) acquisitions have a temperature detail every cm 40, therefore it is possible to detect and observe physical phenomena such as thermodynamic behavior, hot mud and fluids emissions locations and their time shifts. Despite the harsh logistics and the continuously varying gas concentrations we managed to collect thermal images to estimate the crater zone spatial thermal variations. We applied atmosphere corrections to calculate infrared absorption by high concentration of water vapor. Thousands of images have been stitched together to obtain a mosaic of the crater zone. Regular monitoring with heat variation measurements collected, e.g. every six months, could give important information about the volcano activity estimating its evolution. A future data base of infrared high resolution and visible images stored in a web server could be a useful monitoring tool. An interesting development will be to use a multi-spectral thermal camera to perform a complete near remote sensing to detect, not only temperature, but gas, sensitive to particular wavelengths.

Winter Far InfraRed Measurements in the High Arctic

NASA Astrophysics Data System (ADS)

S Pelletier, L.; Libois, Q.; Laurence, C.; Blanchet, J. P.

2017-12-01

During the polar night the majority of earth emission to space occurs in the Far InfraRed (FIR) (l>15mm). Below 10 mm of column integrated water vapour (WV) the atmosphere becomes partially transparent in this spectral range, extending the atmospheric window to longer wavelength. Small variations of WV content can thus lead to strong variations of the transmittance of the atmosphere, impacting its cooling rate and the water vapor greenhouse effect. This is especially true in the Arctic since more than 50% of atmospheric cooling occurs in the FIR. Furthermore, remote sensing observations from CALIPSO and CloudSat satellites over the Arctic have enlighten the ubiquity of optically thin ice clouds (TIC). Those clouds act as effective radiators through the whole troposphere and their formation process is still poorly understood. Theoretical work has shown the added value of FIR measurements for WV and TIC optical properties retrieval. Even so there is currently no spaceborne instrument performing spectrally resolved measurements in the FIR. The TICFIRE (Thin ice cloud in the far infrared experiment) satellite project aims to fill this gap. Here we present the results of the first ground experiments using a breadboard of the satellite, the Far InfraRed Radiometer (FIRR). It measured downwelling radiance at Eureka, NU (79°59'20″N 085°56'27″W) from 25/02/2016 to 31/05/2016. The FIRR uses an array of uncooled microbolometers to measure radiance in 9 spectral channels spanning from 8 - 50 μm. The emission of the atmosphere in this spectral region is extremely sensitive to its WV content and the effective diameter of TIC ice crystals. By comparing these measurements with the E-AERI, a Fourier transform interferometer which serves as a reference, and a radiative transfers model , we aim to assess the radiative accuracy of this new technology as well as its sensitivity to the state of the atmosphere. Results shows that the in situ radiometric accuracy of the FIRR matches laboratory performances (noise below 0.02 Wm-2sr-1). This paves the way for the development of TIC properties retrieval from ground measurements.

A Readout Integrated Circuit (ROIC) employing self-adaptive background current compensation technique for Infrared Focal Plane Array (IRFPA)

NASA Astrophysics Data System (ADS)

Zhou, Tong; Zhao, Jian; He, Yong; Jiang, Bo; Su, Yan

2018-05-01

A novel self-adaptive background current compensation circuit applied to infrared focal plane array is proposed in this paper, which can compensate the background current generated in different conditions. Designed double-threshold detection strategy is to estimate and eliminate the background currents, which could significantly reduce the hardware overhead and improve the uniformity among different pixels. In addition, the circuit is well compatible to various categories of infrared thermo-sensitive materials. The testing results of a 4 × 4 experimental chip showed that the proposed circuit achieves high precision, wide application and high intelligence. Tape-out of the 320 × 240 readout circuit, as well as the bonding, encapsulation and imaging verification of uncooled infrared focal plane array, have also been completed.

Pyroelectric Materials for Uncooled Infrared Detectors: Processing, Properties, and Applications

NASA Technical Reports Server (NTRS)

Aggarwal, M. D.; Batra, A. K.; Guggilla, P.; Edwards, M. E.; Penn, B. G.; Currie, J. R., Jr.

2010-01-01

Uncooled pyroelectric detectors find applications in diverse and wide areas such as industrial production; automotive; aerospace applications for satellite-borne ozone sensors assembled with an infrared spectrometer; health care; space exploration; imaging systems for ships, cars, and aircraft; and military and security surveillance systems. These detectors are the prime candidates for NASA s thermal infrared detector requirements. In this Technical Memorandum, the physical phenomena underlying the operation and advantages of pyroelectric infrared detectors is introduced. A list and applications of important ferroelectrics is given, which is a subclass of pyroelectrics. The basic concepts of processing of important pyroelectrics in various forms are described: single crystal growth, ceramic processing, polymer-composites preparation, and thin- and thick-film fabrications. The present status of materials and their characteristics and detectors figures-of-merit are presented in detail. In the end, the unique techniques demonstrated for improving/enhancing the performance of pyroelectric detectors are illustrated. Emphasis is placed on recent advances and emerging technologies such as thin-film array devices and novel single crystal sensors.

High temperature coefficient of resistance achieved by ion beam assisted sputtering with no heat treatment in V{sub y}M{sub 1−y}O{sub x} (M = Nb, Hf)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vardi, Naor; Sharoni, Amos, E-mail: amos.sharoni@biu.ac.il

2015-11-15

Thermal imaging based on room temperature bolometer sensors is a growing market, constantly searching for improved sensitivity. One important factor is the temperature coefficient of resistance (TCR), i.e., the sensitivity of the active material. Herein, the authors report the improved TCR properties attainable by the “ion beam assisted deposition” method for room temperature deposition. V{sub y}M{sub 1−y}O{sub x} (M = Nb, Hf) thin-film alloys were fabricated on 1 μm thermal SiO{sub 2} atop Si (100) substrates by reactive magnetron cosputtering at room temperature using a low energy ion source, aimed at the film, to insert dissociated oxygen species and increase film density. Themore » authors studied the influence of deposition parameters such as oxygen partial pressure, V to M ratio, and power of the plasma source, on resistance and TCR. The authors show high TCR (up to −3.7% K{sup −1}) at 300 K, and excellent uniformity, but also an increase in resistance. The authors emphasize that samples were prepared at room temperature with no heat treatment, much simpler than common processes that require annealing at high temperatures. So, this is a promising fabrication route for uncooled microbolometers.« less

Superimpose methods for uncooled infrared camera applied to the micro-scale thermal characterization of composite materials

NASA Astrophysics Data System (ADS)

Morikawa, Junko

2015-05-01

The mobile type apparatus for a quantitative micro-scale thermography using a micro-bolometer was developed based on our original techniques such as an achromatic lens design to capture a micro-scale image in long-wave infrared, a video signal superimposing for the real time emissivity correction, and a pseudo acceleration of a timeframe. The total size of the instrument was designed as it was put in the 17 cm x 28 cm x 26 cm size carrying box. The video signal synthesizer enabled to record a direct digital signal of monitoring temperature or positioning data. The encoded digital signal data embedded in each image was decoded to read out. The protocol to encode/decode the measured data was originally defined. The mixed signals of IR camera and the imposed data were applied to the pixel by pixel emissivity corrections and the pseudo-acceleration of the periodical thermal phenomena. Because the emissivity of industrial materials and biological tissues were usually inhomogeneous, it has the different temperature dependence on each pixel. The time-scale resolution for the periodic thermal event was improved with the algorithm for "pseudoacceleration". It contributes to reduce the noise by integrating the multiple image data, keeping a time resolution. The anisotropic thermal properties of some composite materials such as thermal insulating materials of cellular plastics and the biometric composite materials were analyzed using these techniques.

Mushroom plasmonic metamaterial infrared absorbers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ogawa, Shinpei, E-mail: Ogawa.Shimpei@eb.MitsubishiElectric.co.jp; Fujisawa, Daisuke; Hata, Hisatoshi

2015-01-26

There has been a considerable amount of interest in the development of various types of electromagnetic wave absorbers for use in different wavelength ranges. In particular, infrared (IR) absorbers with wavelength selectivity can be applied to advanced uncooled IR sensors, which would be capable of identifying objects through their radiation spectrum. In the present study, mushroom plasmonic metamaterial absorbers (MPMAs) for the IR wavelength region were designed and fabricated. The MPMAs consist of a periodic array of thin metal micropatches connected to a thin metal plate with narrow silicon (Si) posts. A Si post height of 200 nm was achieved bymore » isotropic XeF{sub 2} etching of a thin Si layer sandwiched between metal plates. This fabrication procedure is relatively simple and is consistent with complementary metal oxide semiconductor technology. The absorption spectra of the fabricated MPMAs were experimentally measured. In addition, theoretical calculations of their absorption properties were conducted using rigorous coupled wave analysis. Both the calculated and measured absorbance results demonstrated that these MPMAs can realize strong selective absorption at wavelengths beyond the period of the array by varying the micropatch width. Absorbance values greater than 90% were achieved. Dual- or single-mode absorption can also be selected by varying the width of the Si posts. Pixel structures using such MPMAs could be used as high responsivity, high resolution and fast uncooled IR sensors.« less

Micromachined Thermoelectric Sensors and Arrays and Process for Producing

NASA Technical Reports Server (NTRS)

Foote, Marc C. (Inventor); Jones, Eric W. (Inventor); Caillat, Thierry (Inventor)

2000-01-01

Linear arrays with up to 63 micromachined thermopile infrared detectors on silicon substrates have been constructed and tested. Each detector consists of a suspended silicon nitride membrane with 11 thermocouples of sputtered Bi-Te and Bi-Sb-Te thermoelectric elements films. At room temperature and under vacuum these detectors exhibit response times of 99 ms, zero frequency D* values of 1.4 x 10(exp 9) cmHz(exp 1/2)/W and responsivity values of 1100 V/W when viewing a 1000 K blackbody source. The only measured source of noise above 20 mHz is Johnson noise from the detector resistance. These results represent the best performance reported to date for an array of thermopile detectors. The arrays are well suited for uncooled dispersive point spectrometers. In another embodiment, also with Bi-Te and Bi-Sb-Te thermoelectric materials on micromachined silicon nitride membranes, detector arrays have been produced with D* values as high as 2.2 x 10(exp 9) cm Hz(exp 1/2)/W for 83 ms response times.

THz holography in reflection using a high resolution microbolometer array.

PubMed

Zolliker, Peter; Hack, Erwin

2015-05-04

We demonstrate a digital holographic setup for Terahertz imaging of surfaces in reflection. The set-up is based on a high-power continuous wave (CW) THz laser and a high-resolution (640 × 480 pixel) bolometer detector array. Wave propagation to non-parallel planes is used to reconstruct the object surface that is rotated relative to the detector plane. In addition we implement synthetic aperture methods for resolution enhancement and compare Fourier transform phase retrieval to phase stepping methods. A lateral resolution of 200 μm and a relative phase sensitivity of about 0.4 rad corresponding to a depth resolution of 6 μm are estimated from reconstructed images of two specially prepared test targets, respectively. We highlight the use of digital THz holography for surface profilometry as well as its potential for video-rate imaging.

Advances in hyperspectral LWIR pushbroom imagers

NASA Astrophysics Data System (ADS)

Holma, Hannu; Mattila, Antti-Jussi; Hyvärinen, Timo; Weatherbee, Oliver

2011-06-01

Two long-wave infrared (LWIR) hyperspectral imagers have been under extensive development. The first one utilizes a microbolometer focal plane array (FPA) and the second one is based on an Mercury Cadmium Telluride (MCT) FPA. Both imagers employ a pushbroom imaging spectrograph with a transmission grating and on-axis optics. The main target has been to develop high performance instruments with good image quality and compact size for various industrial and remote sensing application requirements. A big challenge in realizing these goals without considerable cooling of the whole instrument is to control the instrument radiation. The challenge is much bigger in a hyperspectral instrument than in a broadband camera, because the optical signal from the target is spread spectrally, but the instrument radiation is not dispersed. Without any suppression, the instrument radiation can overwhelm the radiation from the target even by 1000 times. The means to handle the instrument radiation in the MCT imager include precise instrument temperature stabilization (but not cooling), efficient optical background suppression and the use of background-monitoring-on-chip (BMC) method. This approach has made possible the implementation of a high performance, extremely compact spectral imager in the 7.7 to 12.4 μm spectral range. The imager performance with 84 spectral bands and 384 spatial pixels has been experimentally verified and an excellent NESR of 14 mW/(m2srμm) at 10 μm wavelength with a 300 K target has been achieved. This results in SNR of more than 700. The LWIR imager based on a microbolometer detector array, first time introduced in 2009, has been upgraded. The sensitivity of the imager has improved drastically by a factor of 3 and SNR by about 15 %. It provides a rugged hyperspectral camera for chemical imaging applications in reflection mode in laboratory and industry.

SCD's uncooled detectors and video engines for a wide-range of applications

NASA Astrophysics Data System (ADS)

Fraenkel, A.; Mizrahi, U.; Bikov, L.; Giladi, A.; Shiloah, N.; Elkind, S.; Kogan, I.; Maayani, S.; Amsterdam, A.; Vaserman, I.; Duman, O.; Hirsh, Y.; Schapiro, F.; Tuito, A.; Ben-Ezra, M.

2011-06-01

Over the last decade SCD has established a state of the art VOx μ-Bolometer product line. Due to its overall advantages this technology is penetrating a large range of systems. In addition to a large variety of detectors, SCD has also recently introduced modular video engines with an open architecture. In this paper we will describe the versatile applications supported by the products based on 17μm pitch: Low SWaP short range systems, mid range systems based on VGA arrays and high-end systems that will utilize the XGA format. These latter systems have the potential to compete with cooled 2nd Gen scanning LWIR arrays, as will be demonstrated by TRM3 system level calculations.

Verification of the test stand for microbolometer camera in accredited laboratory

NASA Astrophysics Data System (ADS)

Krupiński, Michal; Bareła, Jaroslaw; Chmielewski, Krzysztof; Kastek, Mariusz

2017-10-01

Microbolometer belongs to the group of thermal detectors and consist of temperature sensitive resistor which is exposed to measured radiation flux. Bolometer array employs a pixel structure prepared in silicon technology. The detecting area is defined by a size of thin membrane, usually made of amorphous silicon (a-Si) or vanadium oxide (VOx). FPAs are made of a multitude of detector elements (for example 384 × 288 ), where each individual detector has different sensitivity and offset due to detector-to-detector spread in the FPA fabrication process, and additionally can change with sensor operating temperature, biasing voltage variation or temperature of the observed scene. The difference in sensitivity and offset among detectors (which is called non-uniformity) additionally with its high sensitivity, produces fixed pattern noise (FPN) on produced image. Fixed pattern noise degrades parameters of infrared cameras like sensitivity or NETD. Additionally it degrades image quality, radiometric accuracy and temperature resolution. In order to objectively compare the two infrared cameras ones must measure and compare their parameters on a laboratory test stand. One of the basic parameters for the evaluation of a designed camera is NETD. In order to examine the NETD, parameters such as sensitivity and pixels noise must be measured. To do so, ones should register the output signal from the camera in response to the radiation of black bodies at two different temperatures. The article presets an application and measuring stand for determining the parameters of microbolometers camera. Prepared measurements were compared with the result of the measurements in the Institute of Optoelectronics, MUT on a METS test stand by CI SYSTEM. This test stand consists of IR collimator, IR standard source, rotating wheel with test patterns, a computer with a video grabber card and specialized software. The parameters of thermals cameras were measure according to norms and method described in literature.

A novel readout integrated circuit for ferroelectric FPA detector

NASA Astrophysics Data System (ADS)

Bai, Piji; Li, Lihua; Ji, Yulong; Zhang, Jia; Li, Min; Liang, Yan; Hu, Yanbo; Li, Songying

2017-11-01

Uncooled infrared detectors haves some advantages such as low cost light weight low power consumption, and superior reliability, compared with cryogenically cooled ones Ferroelectric uncooled focal plane array(FPA) are being developed for its AC response and its high reliability As a key part of the ferroelectric assembly the ROIC determines the performance of the assembly. A top-down design model for uncooled ferroelectric readout integrated circuit(ROIC) has been developed. Based on the optical thermal and electrical properties of the ferroelectric detector the RTIA readout integrated circuit is designed. The noise bandwidth of RTIA readout circuit has been developed and analyzed. A novel high gain amplifier, a high pass filter and a low pass filter circuits are designed on the ROIC. In order to improve the ferroelectric FPA package performance and decrease of package cost a temperature sensor is designed on the ROIC chip At last the novel RTIA ROIC is implemented on 0.6μm 2P3M CMOS silicon techniques. According to the experimental chip test results the temporal root mean square(RMS)noise voltage is about 1.4mV the sensitivity of the on chip temperature sensor is 0.6 mV/K from -40°C to 60°C the linearity performance of the ROIC chip is better than 99% Based on the 320×240 RTIA ROIC, a 320×240 infrared ferroelectric FPA is fabricated and tested. Test results shows that the 320×240 RTIA ROIC meets the demand of infrared ferroelectric FPA.

Microbolometer spectrometer opens hoist of new applications

NASA Astrophysics Data System (ADS)

Leijtens, J.; Smorenburg, C.; Escudero, I.; Boslooper, E.; Visser, H.; Helden, W. v.; Breussin, F.

2017-11-01

Current Thermal infra red ( 7..14μm) multispectral imager instruments use cryogenically cooled Mercury Cadmium Telluride (MCT or HgCdTe) detectors. This causes the instruments to be bulky, power hungry and expensive. For systems that have medium NETD (Noise Equivalent Temperature Difference) requirements and can operate with high speed optics (<1.5), room temperature microbolometer performance has increased enough to enable people to design multispectral instruments based on this new detector technology. Because microbolometer technology has been driven by the military need for inexpensive, reliable and small thermal imagers, microbolometer based detectors are almost exclusively available in 2D format, and performance is still increasing. Building a spectrometer for the 7 to 12 μm wavelength region using microbolometers has been discarded until now, based on the expected NETD performance. By optimising the throughput of the optical system, and using the latest improvements in detector performance, TNO TPD has been able to design a spectrometer that is able to provide co-registered measurements in the 7 to 12 μm wavelength region yielding acceptable NETD performance. Apart from the usual multispectral imaging, the concept can be used for several other applications, among which imaging in both the 3 to 5 and 7 to 12 μm atmospheric windows at the same time (forest fire detection and military recognisance) or wideband flame analysis (Nox detection in industrial ovens).

Microbolometer SU-8 photoresist microstructure with cytochrome c protein as a sensing pixel for microbolometer

NASA Astrophysics Data System (ADS)

Lai, Jian-Lun; Su, Guo-Dung J.

2012-08-01

There are two important parts in Microbolometer: the high TCR sensing material and low thermal conductance. The high TCR material cytochrome c protein is a good candidate for infrared detection. Our group already demonstrated cytochrome c thin film has high TCR on the top of SU8 surface that has been published in Proc. of SPIE (2011). Because the very low thermal conductivity of SU-8, we proposed a new concept of SU-8 photoresist thermal insulation desk structure, and used the exposure dose method to establish it. Although exposure dose method is very sensitive to exposure time and PEB time, we successfully investigated the right recipe to create new desk insulation structure which with different height. We also explored the relationship between mask II exposure time and desktop thickness, and how the post-exposure baking (PEB) time influenced our structure. Our SU-8 photoresist insulation structure fabrication process is much easier and cheaper than present SiNx fabrication process. The desk shape structure can have low thermal conductance of 6.681*10-6 W/K. The easy-made SU-8 microstructures and cytochrome c thin films that and can reduce the cost of IR microbolometer. We believe that it is possible to fabricate a new generation of microbolometer based on cytochrome c protein and SU-8 photoresist microstructures.

Axially engineered metal-insulator phase transition by graded doping VO2 nanowires.

PubMed

Lee, Sangwook; Cheng, Chun; Guo, Hua; Hippalgaonkar, Kedar; Wang, Kevin; Suh, Joonki; Liu, Kai; Wu, Junqiao

2013-03-27

The abrupt first-order metal-insulator phase transition in single-crystal vanadium dioxide nanowires (NWs) is engineered to be a gradual transition by axially grading the doping level of tungsten. We also demonstrate the potential of these NWs for thermal sensing and actuation applications. At room temperature, the graded-doped NWs show metal phase on the tips and insulator phase near the center of the NW, and the metal phase grows progressively toward the center when the temperature rises. As such, each individual NW acts as a microthermometer that can be simply read out with an optical microscope. The NW resistance decreases gradually with the temperature rise, eventually reaching 2 orders of magnitude drop, in stark contrast to the abrupt resistance change in undoped VO2 wires. This novel phase transition yields an extremely high temperature coefficient of resistivity ~10%/K, simultaneously with a very low resistivity down to 0.001 Ω·cm, making these NWs promising infrared sensing materials for uncooled microbolometers. Lastly, they form bimorph thermal actuators that bend with an unusually high curvature, ~900 m(-1)·K(-1) over a wide temperature range (35-80 °C), significantly broadening the response temperature range of previous VO2 bimorph actuators. Given that the phase transition responds to a diverse range of stimuli-heat, electric current, strain, focused light, and electric field-the graded-doped NWs may find wide applications in thermo-opto-electro-mechanical sensing and energy conversion.

Advanced uncooled sensor product development

NASA Astrophysics Data System (ADS)

Kennedy, A.; Masini, P.; Lamb, M.; Hamers, J.; Kocian, T.; Gordon, E.; Parrish, W.; Williams, R.; LeBeau, T.

2015-06-01

The partnership between RVS, Seek Thermal and Freescale Semiconductor continues on the path to bring the latest technology and innovation to both military and commercial customers. The partnership has matured the 17μm pixel for volume production on the Thermal Weapon Sight (TWS) program in efforts to bring advanced production capability to produce a low cost, high performance product. The partnership has developed the 12μm pixel and has demonstrated performance across a family of detector sizes ranging from formats as small as 206 x 156 to full high definition formats. Detector pixel sensitivities have been achieved using the RVS double level advanced pixel structure. Transition of the packaging of microbolometers from a traditional die level package to a wafer level package (WLP) in a high volume commercial environment is complete. Innovations in wafer fabrication techniques have been incorporated into this product line to assist in the high yield required for volume production. The WLP seal yield is currently > 95%. Simulated package vacuum lives >> 20 years have been demonstrated through accelerated life testing where the package has been shown to have no degradation after 2,500 hours at 150°C. Additionally the rugged assembly has shown no degradation after mechanical shock and vibration and thermal shock testing. The transition to production effort was successfully completed in 2014 and the WLP design has been integrated into multiple new production products including the TWS and the innovative Seek Thermal commercial product that interfaces directly to an iPhone or android device.

Atomic layer deposition synthesized TiO{sub x} thin films and their application as microbolometer active materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanrikulu, Mahmud Yusuf, E-mail: mytanrikulu@adanabtu.edu.tr; Rasouli, Hamid Reza; Ghaffari, Mohammad

2016-05-15

This paper demonstrates the possible usage of TiO{sub x} thin films synthesized by atomic layer deposition as a microbolometer active material. Thin film electrical resistance is investigated as a function of thermal annealing. It is found that the temperature coefficient of resistance values can be controlled by coating/annealing processes, and the value as high as −9%/K near room temperature is obtained. The noise properties of TiO{sub x} films are characterized. It is shown that TiO{sub x} films grown by atomic layer deposition technique could have a significant potential to be used as a new active material for microbolometer-based applications.

New Thermal Infrared Hyperspectral Imagers

DTIC Science & Technology

2009-10-01

involve imaging systems based on both MCT and microbolometer detector . All the systems base on push-broom imaging spectrograph with transmission grating...application requirements. The studies involve imaging systems based on both MCT and microbolometer detector . All the systems base on push-broom...remote sensing imager utilizes MCT detector combined with BMC-technique (background monitoring on-chip), background suppression and temperature

Shutterless non-uniformity correction for the long-term stability of an uncooled long-wave infrared camera

NASA Astrophysics Data System (ADS)

Liu, Chengwei; Sui, Xiubao; Gu, Guohua; Chen, Qian

2018-02-01

For the uncooled long-wave infrared (LWIR) camera, the infrared (IR) irradiation the focal plane array (FPA) receives is a crucial factor that affects the image quality. Ambient temperature fluctuation as well as system power consumption can result in changes of FPA temperature and radiation characteristics inside the IR camera; these will further degrade the imaging performance. In this paper, we present a novel shutterless non-uniformity correction method to compensate for non-uniformity derived from the variation of ambient temperature. Our method combines a calibration-based method and the properties of a scene-based method to obtain correction parameters at different ambient temperature conditions, so that the IR camera performance can be less influenced by ambient temperature fluctuation or system power consumption. The calibration process is carried out in a temperature chamber with slowly changing ambient temperature and a black body as uniform radiation source. Enough uniform images are captured and the gain coefficients are calculated during this period. Then in practical application, the offset parameters are calculated via the least squares method based on the gain coefficients, the captured uniform images and the actual scene. Thus we can get a corrected output through the gain coefficients and offset parameters. The performance of our proposed method is evaluated on realistic IR images and compared with two existing methods. The images we used in experiments are obtained by a 384× 288 pixels uncooled LWIR camera. Results show that our proposed method can adaptively update correction parameters as the actual target scene changes and is more stable to temperature fluctuation than the other two methods.

Infrared broadband metasurface absorber for reducing the thermal mass of a microbolometer.

PubMed

Jung, Joo-Yun; Song, Kyungjun; Choi, Jun-Hyuk; Lee, Jihye; Choi, Dae-Geun; Jeong, Jun-Ho; Neikirk, Dean P

2017-03-27

We demonstrate an infrared broadband metasurface absorber that is suitable for increasing the response speed of a microbolometer by reducing its thermal mass. A large fraction of holes are made in a periodic pattern on a thin lossy metal layer characterised with a non-dispersive effective surface impedance. This can be used as a non-resonant metasurface that can be integrated with a Salisbury screen absorber to construct an absorbing membrane for a microbolometer that can significantly reduce the thermal mass while maintaining high infrared broadband absorption in the long wavelength infrared (LWIR) band. The non-dispersive effective surface impedance can be matched to the free space by optimising the surface resistance of the thin lossy metal layer depending on the size of the patterned holes by using a dc approximation method. In experiments a high broadband absorption was maintained even when the fill factor of the absorbing area was reduced to 28% (hole area: 72%), and it was theoretically maintained even when the fill factor of the absorbing area was reduced to 19% (hole area: 81%). Therefore, a metasurface with a non-dispersive effective surface impedance is a promising solution for reducing the thermal mass of infrared microbolometer pixels.

Performance enhancement of uncooled infrared focal plane array by integrating metamaterial absorber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, Wei; Wen, Yongzheng; Yu, Xiaomei, E-mail: yuxm@pku.edu.cn

2015-03-16

This letter presents an infrared (IR) focal plane array (FPA) with metamaterial absorber (MMA) integrated to enhance its performance. A glass substrate, on which arrays of bimaterial cantilevers are fabricated as the thermal-sensitive pixels by a polyimide surface sacrificial process, is employed to allow the optical readout from the back side of the substrate. Whereas the IR wave radiates onto the FPA from the front side, which consequently avoids the energy loss caused by the silicon substrate compared with the previous works. This structure also facilitates the integration of MMA by introducing a layer of periodic square resonators atop themore » SiN{sub x} structural layer to form a metal/dielectric/metal stack with the gold mirror functioning as the ground plane. A comparative experiment was carried out on the FPAs that use MMA and ordinary SiN{sub x} as the absorbers, respectively. The performance improvement was verified by the evaluation of the absorbers as well as the imaging results of both FPAs.« less

A Microbolometer System for Radiation Detection in the THz Frequency Range with a Resonating Cavity Fabricated in the CMOS Technology.

PubMed

Sesek, Aleksander; Zemva, Andrej; Trontelj, Janez

2018-02-14

The THz sensors using microbolometers as a sensing element are reported as one of the most sensitive room-temperature THz detectors suitable for THz imaging and spectroscopic applications. Microbolometer detectors are usually fabricated using different types of the MEMS technology. The patent for the detection system presented in this paper describes a method for microbolometer fabrication using a standard CMOS technology with advanced micromachining techniques. The measured sensitivity of the sensors fabricated by the patented method is 1000 V/W at an optimal frequency and is determined by the performance of a double-dipole antenna and quarter-wavelength resonant cavity. The paper presents a patented method for fabrication of a microbolometer system for radiation detection in the THz frequency range (16). The method is divided into several stages regarding the current silicon micromachining process. Main stages are fabrication of supporting structures for micro bridge, creation of micro cavities and fabrication of Aluminum antenna and Titanium microbolometer. Additional method for encapsulation in the vacuum is described which additionally improves the performance of bolometer. The CMOS technology is utilized for fabrication as it is cost effective and provides the possibility of larger sensor systems integration with included amplification. At other wavelengths (e.g. IR region) thermistors are usually also the receivers with the sensor resistance change provoked by self-heating. In the THz region the energy is received by an antenna coupled to a thermistor. Depending on the specific application requirement, two types of the antenna were designed and used; a narrow-band dipole antenna and a wideband log-periodic antenna. With method described in the paper, the microbolometer detector reaches sensitivities up to 500 V/W and noise equivalent power (NEP) down to 10 pW/√Hz. Additional encapsulation in the vacuum improves its performance at least by a factor of 2, therefore the sensitivity reaches approximately 1000 V/W and NEP down to 5 pW/√Hz. The thermal response time of bolometer is 0.5 µs. The thermistor biasing current drops with its resistance (defined by microbolometer active area), but the sensitivity rises. Typical value of biasing current is 300 µA at 680 Ω of resistance, where the sensitivity reaches highest level. Air pressure decrease highly influences the sensitivity due to lower thermal dissipation to surrounding air. The sensitivity is therefore doubled when packaged in the high vacuum (0.1Pa). The main advantage of the presented approach is that the detection devices can be fabricated by a standard silicon micromachining process. Their overall dimension is defined by the receiving antenna and they do not need any additional optic source for the operation. They are robust and appropriate for mass production and can be easily embedded or merged with other vision system in use. The developed microbolometer is highly sensitive, its noise is low and it operates at a room temperature with no additional cooling system at a normal atmospheric pressure. The output of the THz detector connected to a discrete low-noise amplifier increases the total sensitivity up to 106 V/W with no impact on the noise equivalent power of 5 pW/√HZ. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Correction method for stripe nonuniformity.

PubMed

Qian, Weixian; Chen, Qian; Gu, Guohua; Guan, Zhiqiang

2010-04-01

Stripe nonuniformity is very typical in line infrared focal plane arrays (IR-FPA) and uncooled staring IR-FPA. In this paper, the mechanism of the stripe nonuniformity is analyzed, and the gray-scale co-occurrence matrix theory and optimization theory are studied. Through these efforts, the stripe nonuniformity correction problem is translated into the optimization problem. The goal of the optimization is to find the minimal energy of the image's line gradient. After solving the constrained nonlinear optimization equation, the parameters of the stripe nonuniformity correction are obtained and the stripe nonuniformity correction is achieved. The experiments indicate that this algorithm is effective and efficient.

Spectrally resolved far-fields of terahertz quantum cascade lasers.

PubMed

Brandstetter, Martin; Schönhuber, Sebastian; Krall, Michael; Kainz, Martin A; Detz, Hermann; Zederbauer, Tobias; Andrews, Aaron M; Strasser, Gottfried; Unterrainer, Karl

2016-10-31

We demonstrate a convenient and fast method to measure the spectrally resolved far-fields of multimode terahertz quantum cascade lasers by combining a microbolometer focal plane array with an FTIR spectrometer. Far-fields of fundamental TM0 and higher lateral order TM1 modes of multimode Fabry-Pérot type lasers have been distinguished, which very well fit to the results obtained by a 3D finite-element simulation. Furthermore, multimode random laser cavities have been investigated, analyzing the contribution of each single laser mode to the total far-field. The presented method is thus an important tool to gain in-depth knowledge of the emission properties of multimode laser cavities at terahertz frequencies, which become increasingly important for future sensing applications.

Thermal-to-visible transducer (TVT) for thermal-IR imaging

NASA Astrophysics Data System (ADS)

Flusberg, Allen; Swartz, Stephen; Huff, Michael; Gross, Steven

2008-04-01

We have been developing a novel thermal-to-visible transducer (TVT), an uncooled thermal-IR imager that is based on a Fabry-Perot Interferometer (FPI). The FPI-based IR imager can convert a thermal-IR image to a video electronic image. IR radiation that is emitted by an object in the scene is imaged onto an IR-absorbing material that is located within an FPI. Temperature variations generated by the spatial variations in the IR image intensity cause variations in optical thickness, modulating the reflectivity seen by a probe laser beam. The reflected probe is imaged onto a visible array, producing a visible image of the IR scene. This technology can provide low-cost IR cameras with excellent sensitivity, low power consumption, and the potential for self-registered fusion of thermal-IR and visible images. We will describe characteristics of requisite pixelated arrays that we have fabricated.

A LWIR hyperspectral imager using a Sagnac interferometer and cooled HgCdTe detector array

NASA Astrophysics Data System (ADS)

Lucey, Paul G.; Wood, Mark; Crites, Sarah T.; Akagi, Jason

2012-06-01

LWIR hyperspectral imaging has a wide range of civil and military applications with its ability to sense chemical compositions at standoff ranges. Most recent implementations of this technology use spectrographs employing varying degrees of cryogenic cooling to reduce sensor self-emission that can severely limit sensitivity. We have taken an interferometric approach that promises to reduce the need for cooling while preserving high resolution. Reduced cooling has multiple benefits including faster system readiness from a power off state, lower mass, and potentially lower cost owing to lower system complexity. We coupled an uncooled Sagnac interferometer with a 256x320 mercury cadmium telluride array with an 11 micron cutoff to produce a spatial interferometric LWIR hyperspectral imaging system operating from 7.5 to 11 microns. The sensor was tested in ground-ground applications, and from a small aircraft producing spectral imagery including detection of gas emission from high vapor pressure liquids.

Uncooled thin film pyroelectric IR detector with aerogel thermal isolation

DOEpatents

Ruffner, Judith A.; Bullington, Jeff A.; Clem, Paul G.; Warren, William L.; Brinker, C. Jeffrey; Tuttle, Bruce A.; Schwartz, Robert W.

1999-01-01

A monolithic infrared detector structure which allows integration of pyroelectric thin films atop low thermal conductivity aerogel thin films. The structure comprises, from bottom to top, a substrate, an aerogel insulating layer, a lower electrode, a pyroelectric layer, and an upper electrode layer capped by a blacking layer. The aerogel can offer thermal conductivity less than that of air, while providing a much stronger monolithic alternative to cantilevered or suspended air-gap structures for pyroelectric thin film pixel arrays. Pb(Zr.sub.0.4 Ti.sub.0.6)O.sub.3 thin films deposited on these structures displayed viable pyroelectric properties, while processed at 550.degree. C.

Uncooled LWIR imaging: applications and market analysis

NASA Astrophysics Data System (ADS)

Takasawa, Satomi

2015-05-01

The evolution of infrared (IR) imaging sensor technology for defense market has played an important role in developing commercial market, as dual use of the technology has expanded. In particular, technologies of both reduction in pixel pitch and vacuum package have drastically evolved in the area of uncooled Long-Wave IR (LWIR; 8-14 μm wavelength region) imaging sensor, increasing opportunity to create new applications. From the macroscopic point of view, the uncooled LWIR imaging market is divided into two areas. One is a high-end market where uncooled LWIR imaging sensor with sensitivity as close to that of cooled one as possible is required, while the other is a low-end market which is promoted by miniaturization and reduction in price. Especially, in the latter case, approaches towards consumer market have recently appeared, such as applications of uncooled LWIR imaging sensors to night visions for automobiles and smart phones. The appearance of such a kind of commodity surely changes existing business models. Further technological innovation is necessary for creating consumer market, and there will be a room for other companies treating components and materials such as lens materials and getter materials and so on to enter into the consumer market.

Low-cost compact thermal imaging sensors for body temperature measurement

NASA Astrophysics Data System (ADS)

Han, Myung-Soo; Han, Seok Man; Kim, Hyo Jin; Shin, Jae Chul; Ahn, Mi Sook; Kim, Hyung Won; Han, Yong Hee

2013-06-01

This paper presents a 32x32 microbolometer thermal imaging sensor for human body temperature measurement. Waferlevel vacuum packaging technology allows us to get a low cost and compact imaging sensor chip. The microbolometer uses V-W-O film as sensing material and ROIC has been designed 0.35-um CMOS process in UMC. A thermal image of a human face and a hand using f/1 lens convinces that it has a potential of human body temperature for commercial use.

GaN-based THz advanced quantum cascade lasers for manned and unmanned systems

NASA Astrophysics Data System (ADS)

Anwar, A. F. M.; Manzur, Tariq; Lefebvre, Kevin R.; Carapezza, Edward M.

2009-09-01

In recent years the use of Unmanned Autonomous Vehicles (UAV) has seen a wider range of applications. However, their applications are restricted due to (a) advanced integrated sensing and processing electronics and (b) limited energy storage or on-board energy generation to name a few. The availability of a wide variety of sensing elements, operating at room temperatures, provides a great degree of flexibility with an extended application domain. Though sensors responding to a variable spectrum of input excitations ranging from (a) chemical, (b) biological, (c) atmospheric, (d) magnetic and (e) visual/IR imaging have been implemented in UAVs, the use of THz as a technology has not been implemented due to the absence of systems operating at room temperature. The integration of multi-phenomenological onboard sensors on small and miniature unmanned air vehicles will dramatically impact the detection and processing of challenging targets, such as humans carrying weapons or wearing suicide bomb vests. Unmanned air vehicles have the potential of flying over crowds of people and quickly discriminating non-threat humans from treat humans. The state of the art in small and miniature UAV's has progressed to vehicles of less than 1 pound in weight but with payloads of only a fraction of a pound. Uncooled IR sensors, such as amorphous silicon and vanadium oxide microbolometers with MRT's of less than 70mK and requiring power of less than 250mW, are available for integration into small UAV's. These sensors are responsive only up to approximately 14 microns and do not favorably compare with THz imaging systems for remotely detecting and classifying concealed weapons and bombs. In the following we propose the use of THz GaN-based QCL operating at room temperature as a possible alternative.

LWIR passive perception system for stealthy unmanned ground vehicle night operations

NASA Astrophysics Data System (ADS)

Lee, Daren; Rankin, Arturo; Huertas, Andres; Nash, Jeremy; Ahuja, Gaurav; Matthies, Larry

2016-05-01

Resupplying forward-deployed units in rugged terrain in the presence of hostile forces creates a high threat to manned air and ground vehicles. An autonomous unmanned ground vehicle (UGV) capable of navigating stealthily at night in off-road and on-road terrain could significantly increase the safety and success rate of such resupply missions for warfighters. Passive night-time perception of terrain and obstacle features is a vital requirement for such missions. As part of the ONR 30 Autonomy Team, the Jet Propulsion Laboratory developed a passive, low-cost night-time perception system under the ONR Expeditionary Maneuver Warfare and Combating Terrorism Applied Research program. Using a stereo pair of forward looking LWIR uncooled microbolometer cameras, the perception system generates disparity maps using a local window-based stereo correlator to achieve real-time performance while maintaining low power consumption. To overcome the lower signal-to-noise ratio and spatial resolution of LWIR thermal imaging technologies, a series of pre-filters were applied to the input images to increase the image contrast and stereo correlator enhancements were applied to increase the disparity density. To overcome false positives generated by mixed pixels, noisy disparities from repeated textures, and uncertainty in far range measurements, a series of consistency, multi-resolution, and temporal based post-filters were employed to improve the fidelity of the output range measurements. The stereo processing leverages multi-core processors and runs under the Robot Operating System (ROS). The night-time passive perception system was tested and evaluated on fully autonomous testbed ground vehicles at SPAWAR Systems Center Pacific (SSC Pacific) and Marine Corps Base Camp Pendleton, California. This paper describes the challenges, techniques, and experimental results of developing a passive, low-cost perception system for night-time autonomous navigation.

Comparison of the temperature accuracy between smart phone based and high-end thermal cameras using a temperature gradient phantom

NASA Astrophysics Data System (ADS)

Klaessens, John H.; van der Veen, Albert; Verdaasdonk, Rudolf M.

2017-03-01

Recently, low cost smart phone based thermal cameras are being considered to be used in a clinical setting for monitoring physiological temperature responses such as: body temperature change, local inflammations, perfusion changes or (burn) wound healing. These thermal cameras contain uncooled micro-bolometers with an internal calibration check and have a temperature resolution of 0.1 degree. For clinical applications a fast quality measurement before use is required (absolute temperature check) and quality control (stability, repeatability, absolute temperature, absolute temperature differences) should be performed regularly. Therefore, a calibrated temperature phantom has been developed based on thermistor heating on both ends of a black coated metal strip to create a controllable temperature gradient from room temperature 26 °C up to 100 °C. The absolute temperatures on the strip are determined with software controlled 5 PT-1000 sensors using lookup tables. In this study 3 FLIR-ONE cameras and one high end camera were checked with this temperature phantom. The results show a relative good agreement between both low-cost and high-end camera's and the phantom temperature gradient, with temperature differences of 1 degree up to 6 degrees between the camera's and the phantom. The measurements were repeated as to absolute temperature and temperature stability over the sensor area. Both low-cost and high-end thermal cameras measured relative temperature changes with high accuracy and absolute temperatures with constant deviations. Low-cost smart phone based thermal cameras can be a good alternative to high-end thermal cameras for routine clinical measurements, appropriate to the research question, providing regular calibration checks for quality control.

U.S. market for infrared thermography equipment

NASA Astrophysics Data System (ADS)

Fulop, Gabor F.

1995-03-01

The market for infrared thermography is undergoing dramatic changes. Focal plane array technologies previously dominated by the military are being opened up to the commercial sector, new uncooled technologies are advancing rapidly and entirely new applications are emerging. Maxtech International has carried out its second in-depth analysis of these markets within two years. In 1994, the U.S. market for commercial (and dual-use) infrared thermography equipment reached 100 million and is expected to grow to 250 million by 1999. As part of the analysis, a survey of over 3,900 users of infrared thermography equipment has been completed. Included are segmentation by end-user industry and expected spending projections in various market segments.

Thermoelectric bolometers based on silicon membranes

NASA Astrophysics Data System (ADS)

Varpula, Aapo; Timofeev, Andrey V.; Shchepetov, Andrey; Grigoras, Kestutis; Ahopelto, Jouni; Prunnila, Mika

2017-05-01

State-of-the-art high performance IR sensing and imaging systems utilize highly expensive photodetector technology, which requires exotic and toxic materials and cooling. Cost-effective alternatives, uncooled bolometer detectors, are widely used in commercial long-wave IR (LWIR) systems. Compared to the cooled detectors they are much slower and have approximately an order of magnitude lower detectivity in the LWIR. We present uncooled bolometer technology which is foreseen to be capable of narrowing the gap between the cooled and uncooled technologies. The proposed technology is based on ultra-thin silicon membranes, the thermal conductivity and electrical properties of which can be controlled by membrane thickness and doping, respectively. The thermal signal is transduced into electric voltage using thermocouple consisting of highly-doped n and p type Si beams. Reducing the thickness of the Si membrane improves the performance (i.e. sensitivity and speed) as thermal conductivity and thermal mass of Si membrane decreases with decreasing thickness. Based on experimental data we estimate the performance of these uncooled thermoelectric bolometers.

Image processing system design for microcantilever-based optical readout infrared arrays

NASA Astrophysics Data System (ADS)

Tong, Qiang; Dong, Liquan; Zhao, Yuejin; Gong, Cheng; Liu, Xiaohua; Yu, Xiaomei; Yang, Lei; Liu, Weiyu

2012-12-01

Compared with the traditional infrared imaging technology, the new type of optical-readout uncooled infrared imaging technology based on MEMS has many advantages, such as low cost, small size, producing simple. In addition, the theory proves that the technology's high thermal detection sensitivity. So it has a very broad application prospects in the field of high performance infrared detection. The paper mainly focuses on an image capturing and processing system in the new type of optical-readout uncooled infrared imaging technology based on MEMS. The image capturing and processing system consists of software and hardware. We build our image processing core hardware platform based on TI's high performance DSP chip which is the TMS320DM642, and then design our image capturing board based on the MT9P031. MT9P031 is Micron's company high frame rate, low power consumption CMOS chip. Last we use Intel's company network transceiver devices-LXT971A to design the network output board. The software system is built on the real-time operating system DSP/BIOS. We design our video capture driver program based on TI's class-mini driver and network output program based on the NDK kit for image capturing and processing and transmitting. The experiment shows that the system has the advantages of high capturing resolution and fast processing speed. The speed of the network transmission is up to 100Mbps.

Auto-converging stereo cameras for 3D robotic tele-operation

NASA Astrophysics Data System (ADS)

Edmondson, Richard; Aycock, Todd; Chenault, David

2012-06-01

Polaris Sensor Technologies has developed a Stereovision Upgrade Kit for TALON robot to provide enhanced depth perception to the operator. This kit previously required the TALON Operator Control Unit to be equipped with the optional touchscreen interface to allow for operator control of the camera convergence angle adjustment. This adjustment allowed for optimal camera convergence independent of the distance from the camera to the object being viewed. Polaris has recently improved the performance of the stereo camera by implementing an Automatic Convergence algorithm in a field programmable gate array in the camera assembly. This algorithm uses scene content to automatically adjust the camera convergence angle, freeing the operator to focus on the task rather than adjustment of the vision system. The autoconvergence capability has been demonstrated on both visible zoom cameras and longwave infrared microbolometer stereo pairs.

History highlights and future trends of infrared sensors

NASA Astrophysics Data System (ADS)

Corsi, Carlo

2010-10-01

Infrared (IR) technologies (materials, devices and systems) represent an area of excellence in science and technology and, even if they have been generally confined to a selected scientific community, they have achieved technological and scientific highlights constituting 'innovation drivers' for neighbouring disciplines, especially in the sensors field. The development of IR sensors, initially linked to astronomical observations, since World War II and for many years has been fostered essentially by defence applications, particularly thermo-vision and, later on, smart vision and detection, for surveillance and warning. Only in the last few decades, the impact of silicon technology has changed the development of IR detectors dramatically, with the advent of integrated signal read-outs and the opening of civilian markets (EO communications, biomedical, environmental, transport and energy applications). The history of infrared sensors contains examples of real breakthroughs, particularly true in the case of focal plane arrays that first appeared in the late 1970s, when the superiority of bi-dimensional arrays for most applications pushed the development of technologies providing the highest number of pixels. An impressive impulse was given to the development of FPA arrays by integration with charge coupled devices (CCD), with strong competition from different technologies (high-efficiency photon sensors, Schottky diodes, multi-quantum wells and, later on, room temperature microbolometers/cantilevers). This breakthrough allowed the development of high performance IR systems of small size, light weight and low cost - and therefore suitable for civil applications - thanks to the elimination of the mechanical scanning system and the progressive reduction of cooling requirements (up to the advent of microbolometers, capable of working at room temperature). In particular, the elimination of cryogenic cooling allowed the development and commercialisation of IR Smart Sensors; strategic components for important areas like transport, environment, territory control and security. Infrared history is showing oscillations and variations in raw materials, technology processes and in device design and characteristics. Various technologies oscillating between the two main detection techniques (photon and bolometer effects) have been developed and evaluated as the best ones, depending on the system use as well as expectable performances. Analysis of the 'waving change' in the history of IR sensor technologies is given with the fundamental theory of the various approaches. Highlights of the main historical IR developments and their impact and use in civil and military applications is shown and correlated with the leading technology of silicon microelectronics: scientific and economic comparisons are given and emerging technologies and forecasting of future developments are outlined.

Using an SU-8 photoresist structure and cytochrome C thin film sensing material for a microbolometer.

PubMed

Lai, Jian-Lun; Liao, Chien-Jen; Su, Guo-Dung John

2012-11-27

There are two critical parameters for microbolometers: the temperature coefficient of resistance (TCR) of the sensing material, and the thermal conductance of the insulation structure. Cytochrome c protein, having a high TCR, is a good candidate for infrared detection. We can use SU-8 photoresist for the thermal insulation structure, given its low thermal conductance. In this study, we designed a platform structure based on a SU-8 photoresist. We fabricated an infrared sensing pixel and recorded a high TCR for this new structure. The SU-8 photoresist insulation structure was fabricated using the exposure dose method. We experimentally demonstrated high values of TCR from 22%/K to 25.7%/K, and the measured noise was 1.2 × 10(-8) V2/Hz at 60 Hz. When the bias current was 2 μA, the calculated voltage responsivity was 1.16 × 10(5) V/W. This study presents a new kind of microbolometer based on cytochrome c protein on top of an SU-8 photoresist platform that does not require expensive vacuum deposition equipment.

Using an SU-8 Photoresist Structure and Cytochrome C Thin Film Sensing Material for a Microbolometer

PubMed Central

Lai, Jian-Lun; Liao, Chien-Jen; Su, Guo-Dung John

2012-01-01

There are two critical parameters for microbolometers: the temperature coefficient of resistance (TCR) of the sensing material, and the thermal conductance of the insulation structure. Cytochrome c protein, having a high TCR, is a good candidate for infrared detection. We can use SU-8 photoresist for the thermal insulation structure, given its low thermal conductance. In this study, we designed a platform structure based on a SU-8 photoresist. We fabricated an infrared sensing pixel and recorded a high TCR for this new structure. The SU-8 photoresist insulation structure was fabricated using the exposure dose method. We experimentally demonstrated high values of TCR from 22%/K to 25.7%/K, and the measured noise was 1.2 × 10−8 V2/Hz at 60 Hz. When the bias current was 2 μA, the calculated voltage responsivity was 1.16 × 105 V/W. This study presents a new kind of microbolometer based on cytochrome c protein on top of an SU-8 photoresist platform that does not require expensive vacuum deposition equipment. PMID:23443384

An investigation of noise performance in optical lock-in thermography

NASA Astrophysics Data System (ADS)

Rajic, Nik; Antolis, Cedric

2017-12-01

An investigation into the noise performance of optical lock-in thermography (OLT) is described. The study aims to clarify the influence of infrared detector type and key inspection parameters such as illumination strength and lock-in duration on the quality of OLT amplitude and phase imagery. The study compares the performance of a state-of-the-art cooled photon detector with several lower-cost microbolometers. The results reveal a significant noise performance advantage to the photon detector. Under certain inspection regimes the advantage with respect to phase image quality is disproportionately high relative to detector sensitivities. This is shown to result from an explicit dependence in the phase signal variance on the ratio between the signal amplitude and the detector sensitivity. While this finding supports the preferred use of photon detectors for OLT inspections, it does not exclude microbolometers from a useful role. In cases where the significantly lower capital cost and improved practicality of microbolometers provide an advantage it is shown that performance shortfalls can be overcome with a relatively small factorial increase in optical illumination intensity.

Energy efficient engine: High pressure turbine uncooled rig technology report

NASA Technical Reports Server (NTRS)

Gardner, W. B.

1979-01-01

Results obtained from testing five performance builds (three vane cascades and two rotating rigs of the Energy Efficient Engine uncooled rig have established the uncooled aerodynamic efficiency of the high-pressure turbine at 91.1 percent. This efficiency level was attained by increasing the rim speed and annulus area (AN(2)), and by increasing the turbine reaction level. The increase in AN(2) resulted in a performance improvement of 1.15 percent. At the design point pressure ratio, the increased reaction level rig demonstrated an efficiency of 91.1 percent. The results of this program have verified the aerodynamic design assumptions established for the Energy Efficient Engine high-pressure turbine component.

Design and operation of SUCHI: the space ultra-compact hyperspectral imager for a small satellite

NASA Astrophysics Data System (ADS)

Crites, S. T.; Lucey, P. G.; Wright, R.; Chan, J.; Garbeil, H.; Horton, K. A.; Imai, A.; Pilger, E. J.; Wood, M.; Yoneshige, Lance

2014-06-01

The primary payload on the University of Hawaii-built `HiakaSat' micro-satellite will be the Space Ultra Compact Hyperspectral Imager (SUCHI). SUCHI is a low-mass (<9kg), low-volume (10x10x36 cm3) long wave infrared hyperspectral imager designed and built at the University of Hawaii. SUCHI is based on a variable-gap Fabry-Perot interferometer employed as a Fourier transform spectrometer with images collected by a commercial 320x256 microbolometer array. The microbolometer camera and vacuum-sensitive electronics are contained within a sealed vessel at 1 atm. SUCHI will collect spectral radiance data from 8 to 14 microns and demonstrate the potential of this instrument for geological studies from orbit (e.g. mapping of major rock-forming minerals) and volcanic hazard observation and assessment (e.g. quantification of volcanic sulfur dioxide pollution and lava flow cooling rates). The sensor has been integrated with the satellite which will launch on the Office of Responsive Space ORS-4 mission scheduled for 2014. The primary mission will last 6 months, with extended operations anticipated for approximately 2 years. A follow-on mission has been proposed to perform imaging of Earth's surface in the 3-5 micron range with a field of view of 5 km with 5.25 m sampling (from a 350 km orbit). The 19-kg proposed instrument will be a prototype sensor for a constellation of small satellites for Earth imaging. The integrated satellite properties will be incorporated into the Hawaii Space Flight Laboratory's constellation maintenance software environment COSMOS (Comprehensive Openarchitecture Space Mission Operations System) to ease future implementation of the instrument as part of a constellation.

The Development of a Transition-Edge Hot-Electron Microbolometer for Observation of the Cosmic Microwave Background

NASA Astrophysics Data System (ADS)

Barrentine, Emily Margaret

In this thesis the development of a Transition-Edge Hot-Electron Microbolometer (THM) is presented. This detector will have the capacity to make sensitive and broadband astrophysical observations when deployed in large detector arrays in future ground- or space-based instruments, over frequencies ranging from 30-300 GHz (10-1 mm). This thesis focuses on the development of the THM for observations of the Cosmic Microwave Background (CMB), and specifically for observations of the CMB polarization signal. The THM is a micron-sized bolometer that is fabricated photolithographically. It consists of a superconducting Molybdenum/Gold Transition-Edge Sensor (TES) and a thin-film semi-metal Bismuth microwave absorber, both of which are deposited directly on the substrate. The THM employs the decoupling between electrons and phonons at low temperatures (˜100-300 mK) to provide thermal isolation for the bolometer. The devices are read out with Superconducting Quantum Interference Devices (SQUIDs). In this thesis a summary of the thermal and electrical models for the THM detector is presented. The physical processes within the detector, with particular attention to electron-phonon decoupling, and the lateral proximity effect between the superconducting leads and the TES, are also discussed. This understanding of the detector and these models are used to interpret measurements of thermal conductance, noise, responsivity and the transition behaviour of a variety of THM test devices. The optimization of the THM design, based on these models and measurements, is also discussed, and the thesis concludes with a presentation of the recommended THM design for CMB applications. In addition, a planar-microwave circuit design and a quasi-optical scheme for coupling microwave radiation to the THM detector are presented.

A low-power CMOS readout IC design for bolometer applications

NASA Astrophysics Data System (ADS)

Galioglu, Arman; Abbasi, Shahbaz; Shafique, Atia; Ceylan, Ömer; Yazici, Melik; Kaynak, Mehmet; Durmaz, Emre C.; Arsoy, Elif Gul; Gurbuz, Yasar

2017-02-01

A prototype of a readout IC (ROIC) designed for use in high temperature coefficient of resistance (TCR) SiGe microbolometers is presented. The prototype ROIC architecture implemented is based on a bridge with active and blind bolometer pixels with a capacitive transimpedance amplifier (CTIA) input stage and column parallel integration with serial readout. The ROIC is designed for use in high (>= 4 %/K) TCR and high detector resistance Si/SiGe microbolometers with 17x17 μm2 pixel sizes in development. The prototype has been designed and fabricated in 0.25- μm SiGe:C BiCMOS process.

Influence of dielectric substrate on the responsivity of microstrip dipole-antenna-coupled infrared microbolometers.

PubMed

Codreanu, Iulian; Boreman, Glenn D

2002-04-01

We report on the influence of the dielectric substrate on the performance of microstrip dipole-antenna-coupled microbolometers. The location, the width, and the magnitude of the resonance of a printed dipole are altered when the dielectric substrate is backed by a ground plane. A thicker dielectric substrate shifts the antenna resonance toward shorter dipole lengths and leads to a stronger and slower detector response. The incorporation of an air layer into the antenna substrate further increases thermal impedance, leading to an even stronger response and shifting the antenna resonance toward longer dipole lengths.

Effects of internal electrode cooling on irreversible electroporation using a perfused organ model.

PubMed

O'Brien, Timothy J; Bonakdar, Mohammad; Bhonsle, Suyashree; Neal, Robert E; Aardema, Charles H; Robertson, John L; Goldberg, S Nahum; Davalos, Rafael V

2018-05-28

This study evaluates the effects of active electrode cooling, via internal fluid circulation, on the irreversible electroporation (IRE) lesion, deployed electric current and temperature changes using a perfused porcine liver model. A bipolar electrode delivered IRE electric pulses with or without activation of internal cooling to nine porcine mechanically perfused livers. Pulse schemes included a constant voltage, and a preconditioned delivery combined with an arc-mitigation algorithm. After treatment, organs were dissected, and treatment zones were stained using triphenyl-tetrazolium chloride (TTC) to demonstrate viability. Thirty-nine treatments were performed with an internally cooled applicator and 21 with a non-cooled applicator. For the constant voltage scenario, the average final electrical current measured was 26.37 and 29.20 A for the cooled and uncooled electrodes respectively ([Formula: see text]). The average final temperature measured was 33.01 and 42.43 °C for the cooled and uncooled electrodes respectively ([Formula: see text]). The average measured ablations (fixed lesion) were 3.88-by-2.08 cm and 3.86-by-2.12 cm for the cooled and uncooled electrode respectively ([Formula: see text], [Formula: see text]). Similarly, the preconditioned/arc-mitigation scenario yielded an average final electrical current measurement of a 41.07 and 47.20 A for the cooled and uncooled electrodes respectively ([Formula: see text]). The average final temperature measured was 34.93 and 44.90 °C for the cooled and uncooled electrodes respectively ([Formula: see text]). The average measured ablations (fixed lesion) were 3.67-by-2.27 cm and 3.58-by-2.09 cm for the cooled and uncooled applicators ([Formula: see text]). The internally-cooled bipolar applicator offers advantages that could improve clinical outcomes. Thermally mitigating internal perfusion technology reduced tissue temperatures and electric current while maintaining similar lesion sizes.

Noise properties of a corner-cube Michelson interferometer LWIR hyperspectral imager

NASA Astrophysics Data System (ADS)

Bergstrom, D.; Renhorn, I.; Svensson, T.; Persson, R.; Hallberg, T.; Lindell, R.; Boreman, G.

2010-04-01

Interferometric hyperspectral imagers using infrared focal plane array (FPA) sensors have received increasing interest within the field of security and defence. Setups are commonly based upon either the Sagnac or the Michelson configuration, where the former is usually preferred due to its mechanical robustness. However, the Michelson configuration shows advantages in larger FOV due to better vignetting performance and improved signal-to-noise ratio and cost reduction due to relaxation of beamsplitter specifications. Recently, a laboratory prototype of a more robust and easy-to-align corner-cube Michelson hyperspectral imager has been demonstrated. The prototype is based upon an uncooled bolometric FPA in the LWIR (8-14 μm) spectral band and in this paper the noise properties of this hyperspectral imager are discussed.

CIRiS: Compact Infrared Radiometer in Space

NASA Astrophysics Data System (ADS)

Osterman, D. P.; Collins, S.; Ferguson, J.; Good, W.; Kampe, T.; Rohrschneider, R.; Warden, R.

2016-09-01

The Compact Infrared Radiometer in Space (CIRiS) is a thermal infrared radiometric imaging instrument under development by Ball Aerospace for a Low Earth Orbit mission on a CubeSat spacecraft. Funded by the NASA Earth Science Technology Office's In-Space Validation of Earth Science Technology (InVEST) program, the mission objective is technology demonstration for improved on-orbit radiometric calibration. The CIRiS calibration approach uses a scene select mirror to direct three calibration views to the focal plane array and to transfer the resulting calibrated response to earth images. The views to deep space and two blackbody sources, including one at a selectable temperature, provide multiple options for calibration optimization. Two new technologies, carbon nanotube blackbody sources and microbolometer focal plane arrays with reduced pixel sizes, enable improved radiometric performance within the constrained 6U CubeSat volume. The CIRiS instrument's modular design facilitates subsystem modifications as required by future mission requirements. CubeSat constellations of CIRiS and derivative instruments offer an affordable approach to achieving revisit times as short as one day for diverse applications including water resource and drought management, cloud, aerosol, and dust studies, and land use and vegetation monitoring. Launch is planned for 2018.

Large Imaging X-ray MKID Arrays for Astrophysics

NASA Astrophysics Data System (ADS)

Mazin, Benjamin

Microwave Kinetic Inductance Detectors, or MKIDs, are a relatively new type of superconducting detector with built-in frequency domain multiplexing. Like Transition Edge Sensors (TESs) microbolometers, MKIDs can count single X-ray photons over a wide energy range and determine their energy and arrival time. MKIDs allow very large pixel counts with a simple room temperature microwave readout. In this investigation we will develop a new type of detector based on a MKID called the Thermal Kinetic Inductance Detector, or TKID. A TKID changes the basic MKID architecture by placing the inductor of the MKID on a suspended SiN membrane. The capacitor will remain on the bulk Si to reduce noise. Much like a TES, the TKID will sense changes in temperature of the isolated SiN island caused by photon absorption. The advantages of a TKID include lack of positional/geometry dependence, a more tunable pulse decay time, a relaxation of the MKID resonator material requirements, and more. We have already fabricated a TKID with the best energy resolution seen to date in any KID. Here we propose to improve the energy resolution below 10 eV, develop mushroom absorbers compatible with our TKIDs, and integrate these detectors into small arrays.

The Cool vs. The Uncool. Your Middle School Classroom

ERIC Educational Resources Information Center

Barnes, Peter

2005-01-01

Social cliques start around fourth or fifth grade and get worse through middle school and beyond. The cool vs. the uncool. Nerds, jocks, popular kids and outsiders--students are categorized by their peers and excluded by those different from them. Students who are not part of the "cool" crowd feel isolated and lonely and are often subjected to…

Progress in the utilization of an oxide-dispersion-strengthened alloy for small engine turbine blades

NASA Technical Reports Server (NTRS)

Beatty, T. G.; Millan, P. P.

1984-01-01

The conventional means of improving gas turbine engine performance typically involves increasing the turbine inlet temperature; however, at these higher operational temperatures the high pressure turbine blades require air-cooling to maintain durability. Air-cooling imposes design, material, and economic constraints not only on the turbine blades but also on engine performance. The use of uncooled turbine blades at increased operating temperatures can offer significantly improved performance in small gas turbine engines. A program to demonstrate uncooled MA6000 high pressure turbine blades in a GTEC TFE731 turbofan engine is being conducted. The project goals include demonstration of the advantages of using uncooled MA6000 turbine blades as compared with cast directionally solidified MAR-M 247 blades.

Innovative monolithic detector for tri-spectral (THz, IR, Vis) imaging

NASA Astrophysics Data System (ADS)

Pocas, S.; Perenzoni, M.; Massari, N.; Simoens, F.; Meilhan, J.; Rabaud, W.; Martin, S.; Delplanque, B.; Imperinetti, P.; Goudon, V.; Vialle, C.; Arnaud, A.

2012-10-01

Fusion of multispectral images has been explored for many years for security and used in a number of commercial products. CEA-Leti and FBK have developed an innovative sensor technology that gathers monolithically on a unique focal plane arrays, pixels sensitive to radiation in three spectral ranges that are terahertz (THz), infrared (IR) and visible. This technology benefits of many assets for volume market: compactness, full CMOS compatibility on 200mm wafers, advanced functions of the CMOS read-out integrated circuit (ROIC), and operation at room temperature. The ROIC houses visible APS diodes while IR and THz detections are carried out by microbolometers collectively processed above the CMOS substrate. Standard IR bolometric microbridges (160x160 pixels) are surrounding antenna-coupled bolometers (32X32 pixels) built on a resonant cavity customized to THz sensing. This paper presents the different technological challenges achieved in this development and first electrical and sensitivity experimental tests.

Method for detection and imaging over a broad spectral range

DOEpatents

Yefremenko, Volodymyr; Gordiyenko, Eduard; Pishko, legal representative, Olga; Novosad, Valentyn; Pishko, deceased; Vitalii

2007-09-25

A method of controlling the coordinate sensitivity in a superconducting microbolometer employs localized light, heating or magnetic field effects to form normal or mixed state regions on a superconducting film and to control the spatial location. Electron beam lithography and wet chemical etching were applied as pattern transfer processes in epitaxial Y--Ba--Cu--O films. Two different sensor designs were tested: (i) a 3 millimeter long and 40 micrometer wide stripe and (ii) a 1.25 millimeters long, and 50 micron wide meandering-like structure. Scanning the laser beam along the stripe leads to physical displacement of the sensitive area, and, therefore, may be used as a basis for imaging over a broad spectral range. Forming the superconducting film as a meandering structure provides the equivalent of a two-dimensional detector array. Advantages of this approach are simplicity of detector fabrication, and simplicity of the read-out process requiring only two electrical terminals.

Application of Terahertz Field Enhancement Effect in Metal Microstructures

NASA Astrophysics Data System (ADS)

Nakajima, M.; Kurihara, T.; Tadokoro, Y.; Kang, B.; Takano, K.; Yamaguchi, K.; Watanabe, H.; Oto, K.; Suemoto, T.; Hangyo, M.

2016-12-01

Applications of high-field terahertz pulses are attractive in physics and terahertz technology. In this study, two applications related to high-intensity terahertz pulses are demonstrated. The field enhancement effect by subwavelength metallic microstructures is utilized for terahertz excitation measurement. The spin precession dynamics in magnetic materials was induced by a terahertz magnetic field. Spin precession was amplified by one order of magnitude in amplitude by the enhanced magnetic terahertz field in orthoferrite ErFeO3 with metal microstructures. The induced spin dynamics was analyzed and explained by LLG-LCR model. Moreover, a detection method for terahertz pulses was developed using a cholesteric liquid crystal at room temperature without any electronic devices. The beam profile of terahertz pulses was visualized and compared to other methods such as the knife edge method using pyroelectric detector and micro-bolometer array. The liquid crystal terahertz imager is very simple and has good applicability as a portable terahertz-sensing card.

New solutions and technologies for uncooled infrared imaging

NASA Astrophysics Data System (ADS)

Rollin, Joël.; Diaz, Frédéric; Fontaine, Christophe; Loiseaux, Brigitte; Lee, Mane-Si Laure; Clienti, Christophe; Lemonnier, Fabrice; Zhang, Xianghua; Calvez, Laurent

2013-06-01

The military uncooled infrared market is driven by the continued cost reduction of the focal plane arrays whilst maintaining high standards of sensitivity and steering towards smaller pixel sizes. As a consequence, new optical solutions are called for. Two approaches can come into play: the bottom up option consists in allocating improvements to each contributor and the top down process rather relies on an overall optimization of the complete image channel. The University of Rennes I with Thales Angénieux alongside has been working over the past decade through French MOD funding's, on low cost alternatives of infrared materials based upon chalcogenide glasses. A special care has been laid on the enhancement of their mechanical properties and their ability to be moulded according to complex shapes. New manufacturing means developments capable of better yields for the raw materials will be addressed, too. Beyond the mere lenses budget cuts, a wave front coding process can ease a global optimization. This technic gives a way of relaxing optical constraints or upgrading thermal device performances through an increase of the focus depths and desensitization against temperature drifts: it combines image processing and the use of smart optical components. Thales achievements in such topics will be enlightened and the trade-off between image quality correction levels and low consumption/ real time processing, as might be required in hand-free night vision devices, will be emphasized. It is worth mentioning that both approaches are deeply leaning on each other.

Experimental characterization of mm-wave detection by a micro-array of Golay cells

NASA Astrophysics Data System (ADS)

Denison, Douglas R.; Knotts, Michael E.; McConney, Michael E.; Tsukruk, Vladimir V.

2009-05-01

We present experimental results for an uncooled imaging focal plane array technology that consists of a polymer/metal/polymer layered membrane suspended over a micro-fabricated array of cavities. The device operation is Golay-like (heating of air in the cavity causes a detectable deflection of the membrane proportional to incident EM power), but potentially offers both greater sensitivity and more read-out options (optical or electrical) than a traditional Golay cell through tailoring of the membrane properties. The membrane is formed from a layer-by-layer deposition of polymer with one or more monolayers of gold nanoparticles (or other metal) that help control the membrane's elasticity and deformation-dependent optical reflectivity/electrical conductivity. Baseline capabilities of the device have been established through optical measurements of membrane deflection due to incident mm-wave radiation modulated at 30 Hz (corresponding to a video refresh rate). The device demonstrates an NEP of 300 nW/√Hz at 105 GHz for a 19-layer membrane (9 poly/1 Au/9 poly) suspended over an array of 80 μm diameter cavities (depth = 100 μm) etched in a 500 μm thick substrate of Si. Calculations of membrane sensitivity show that this NEP could be reduced to ~ 100 pW/√Hz with enlarged cavity diameters on the order of 600 μm.

A miniature low-cost LWIR camera with a 160×120 microbolometer FPA

NASA Astrophysics Data System (ADS)

Tepegoz, Murat; Kucukkomurler, Alper; Tankut, Firat; Eminoglu, Selim; Akin, Tayfun

2014-06-01

This paper presents the development of a miniature LWIR thermal camera, MSE070D, which targets value performance infrared imaging applications, where a 160x120 CMOS-based microbolometer FPA is utilized. MSE070D features a universal USB interface that can communicate with computers and some particular mobile devices in the market. In addition, it offers high flexibility and mobility with the help of its USB powered nature, eliminating the need for any external power source, thanks to its low-power requirement option. MSE070D provides thermal imaging with its 1.65 inch3 volume with the use of a vacuum packaged CMOS-based microbolometer type thermal sensor MS1670A-VP, achieving moderate performance with a very low production cost. MSE070D allows 30 fps thermal video imaging with the 160x120 FPA size while resulting in an NETD lower than 350 mK with f/1 optics. It is possible to obtain test electronics and software, miniature camera cores, complete Application Programming Interfaces (APIs) and relevant documentation with MSE070D, as MikroSens want to help its customers to evaluate its products and to ensure quick time-to-market for systems manufacturers.

Wideband response of a terahertz-millimeter imager based on a 384x288 pixel uncooled bolometric detector

NASA Astrophysics Data System (ADS)

Terroux, Marc; Marchese, Linda; Bolduc, Martin; Mercier, Luc; Chevalier, Claude; Gagnon, Lucie; Tremblay, Bruno; Généreux, Francis; Paultre, Jacques-Edmond; Provençal, Francis; Beaupré, Patrick; Desroches, Yan; Châteauneuf, François; Bergeron, Alain

2017-11-01

In the past, bolometer-based imagers have been used for earth observation. Uncooled-bolometer based imagers are especially well suited for this due to their low power consumption. NIRST (New Infra-Red Sensor Technology), an example of an imager based on uncooled bolometers, monitors high temperature events on the ground related to fires and volcanic events, and will measure their physical parameters and takes measurements of sea surface temperatures mainly off the coast of South America as well as other targeted opportunities. NIRST has one band in the mid-wave infrared centered at 3.8 um with a bandwidth of 0.8 um, and two bands in the thermal infrared, centered respectively at 10.85 and 11.85 um with a bandwidth of 0.9 um.

Large-format 17μm high-end VOx μ-bolometer infrared detector

NASA Astrophysics Data System (ADS)

Mizrahi, U.; Argaman, N.; Elkind, S.; Giladi, A.; Hirsh, Y.; Labilov, M.; Pivnik, I.; Shiloah, N.; Singer, M.; Tuito, A.; Ben-Ezra, M.; Shtrichman, I.

2013-06-01

Long range sights and targeting systems require a combination of high spatial resolution, low temporal NETD, and wide field of view. For practical electro-optical systems it is hard to support these constraints simultaneously. Moreover, achieving these needs with the relatively low-cost Uncooled μ-Bolometer technology is a major challenge in the design and implementation of both the bolometer pixel and the Readout Integrated Circuit (ROIC). In this work we present measured results from a new, large format (1024×768) detector array, with 17μm pitch. This detector meets the demands of a typical armored vehicle sight with its high resolution and large format, together with low NETD of better than 35mK (at F/1, 30Hz). We estimate a Recognition Range for a NATO target of better than 4 km at all relevant atmospheric conditions, which is better than standard 2nd generation scanning array cooled detector. A new design of the detector package enables improved stability of the Non-Uniformity Correction (NUC) to environmental temperature drifts.

Generalized algebraic scene-based nonuniformity correction algorithm.

PubMed

Ratliff, Bradley M; Hayat, Majeed M; Tyo, J Scott

2005-02-01

A generalization of a recently developed algebraic scene-based nonuniformity correction algorithm for focal plane array (FPA) sensors is presented. The new technique uses pairs of image frames exhibiting arbitrary one- or two-dimensional translational motion to compute compensator quantities that are then used to remove nonuniformity in the bias of the FPA response. Unlike its predecessor, the generalization does not require the use of either a blackbody calibration target or a shutter. The algorithm has a low computational overhead, lending itself to real-time hardware implementation. The high-quality correction ability of this technique is demonstrated through application to real IR data from both cooled and uncooled infrared FPAs. A theoretical and experimental error analysis is performed to study the accuracy of the bias compensator estimates in the presence of two main sources of error.

Performance analysis of panoramic infrared systems

NASA Astrophysics Data System (ADS)

Furxhi, Orges; Driggers, Ronald G.; Holst, Gerald; Krapels, Keith

2014-05-01

Panoramic imagers are becoming more commonplace in the visible part of the spectrum. These imagers are often used in the real estate market, extreme sports, teleconferencing, and security applications. Infrared panoramic imagers, on the other hand, are not as common and only a few have been demonstrated. A panoramic image can be formed in several ways, using pan and stitch, distributed aperture, or omnidirectional optics. When omnidirectional optics are used, the detected image is a warped view of the world that is mapped on the focal plane array in a donut shape. The final image on the display is the mapping of the omnidirectional donut shape image back to the panoramic world view. In this paper we analyze the performance of uncooled thermal panoramic imagers that use omnidirectional optics, focusing on range performance.

TANDIR: projectile warning system using uncooled bolometric technology

NASA Astrophysics Data System (ADS)

Horovitz-Limor, Z.; Zahler, M.

2007-04-01

Following the demand for affordable, various range and light-weight protection against ATGM's, Elisra develops a cost-effective passive IR system for ground vehicles. The system is based on wide FOV uncooled bolometric sensors with full azimuth coverage and a lightweight processing & control unit. The system design is based on the harsh environmental conditions. The basic algorithm discriminates the target from its clutter and predicts the time to impact (TTI) and the target aiming direction with relation to vehicle. The current detector format is 320*240 pixels and frame rate is 60 Hz, Spectral response is on Far Infrared (8-14μ). The digital video output has 14bit resolution & wide dynamic range. Future goal is to enhance detection performance by using large format uncooled detector (640X480) with improved sensitivity and higher frame rates (up to 120HZ).

PIGC™ - A low cost fugitive emissions and methane detection system using advanced gas filter correlation techniques for local and wide area monitoring

NASA Astrophysics Data System (ADS)

Lachance, R. L.; Gordley, L. L.; Marshall, B. T.; Fisher, J.; Paxton, G.; Gubeli, J. F.

2015-12-01

Currently there is no efficient and affordable way to monitor gas releases over small to large areas. We have demonstrated the ability to accurately measure key greenhouse and pollutant gasses with low cost solar observations using the breakthrough sensor technology called the "Pupil Imaging Gas Correlation", PIGC™, which provides size and complexity reduction while providing exceptional resolution and coverage for various gas sensing applications. It is a practical implementation of the well-known Gas Filter Correlation Radiometry (GFCR) technique used for the HALOE and MOPITT satellite instruments that were flown on successful NASA missions in the early 2000s. This strong space heritage brings performance and reliability to the ground instrument design. A methane (CH4) abundance sensitivity of 0.5% or better of ambient column with uncooled microbolometers has been demonstrated with 1 second direct solar observations. These under $10 k sensors can be deployed in precisely balanced autonomous grids to monitor the flow of chosen gasses, and infer their source locations. Measureable gases include CH4, 13CO2, N2O, NO, NH3, CO, H2S, HCN, HCl, HF, HDO and others. A single instrument operates in a dual operation mode, at no additional cost, for continuous (real-time 24/7) local area perimeter monitoring for the detection of leaks for safety & security needs, looking at an artificial light source (for example a simple 60 W light bulb placed 100 m away), while simultaneously allowing solar observation for quasi-continuous wide area total atmospheric column scanning (3-D) for environmental monitoring (fixed and mobile configurations). The second mode of operation continuously quantifies the concentration and flux of specific gases over different ground locations, determined the amount of targeted gas being released from the area or getting into the area from outside locations, allowing better tracking of plumes and identification of sources. This paper reviews the measurement technique, performance demonstration and grid deployment strategy.

Mid-IR Spectral Investigation of Normal and Malignant Breast and Cervical Tissue Samples Using a Quantum Cascade Laser-Based Microscope

NASA Astrophysics Data System (ADS)

Haugen, Paul

Mid-infrared (MIR) spectroscopy has been a tool used to identify specific features of normal and malignant tissue samples by utilizing MIR characteristics, specifically in the "fingerprint" region. The fingerprint region is a biologically significant spectral region typically identified between 1500 and 500 cm-1. MIR spectroscopy can be used to study molecular changes and variations occurring in samples, which can then be used to fingerprint specific spectral characteristics and biomarkers in order to categorize the specimens. The most common instruments currently used in this analysis are Fourier transform infrared (FTIR) spectrometers, although properties inherent in these instruments, such as slow data collection time and an inability to specify sample location for the spectral data collection, have placed a ceiling on the clinical practicality of their use for specimen classification and identification. In this thesis, we use a prototype of an infrared hyperspectral imaging microscopy platform based around tunable quantum cascade laser (QCL) technology that has a spectral coverage from 1800-900 cm-1. The quantum cascade lasers are coupled with a series of MIR refractive objectives and an uncooled microbolometer camera. The speed of spectral imaging improves to 30 frames per second, and the high magnification objective has a 1.34 microm pixel resolution with a 0.70 numerical aperture and 4.3 microm spatial resolution. We are able to specify data collection at specific discrete wavelengths as opposed to the full spectrum, which improves the data collection time and de-clutters the data for analysis expediency. Finally, we perform spectral imaging real-time, which aides in selecting precise regions of interest on the target sample. This thesis demonstrates the advantages of exploiting the capabilities of the QCL microscope to advance MIR spectroscopy in the identification of distinguishing traits of normal and malignant breast and cervical tissue samples.

The TRICLOBS Dynamic Multi-Band Image Data Set for the Development and Evaluation of Image Fusion Methods

PubMed Central

Hogervorst, Maarten A.; Pinkus, Alan R.

2016-01-01

The fusion and enhancement of multiband nighttime imagery for surveillance and navigation has been the subject of extensive research for over two decades. Despite the ongoing efforts in this area there is still only a small number of static multiband test images available for the development and evaluation of new image fusion and enhancement methods. Moreover, dynamic multiband imagery is also currently lacking. To fill this gap we present the TRICLOBS dynamic multi-band image data set containing sixteen registered visual (0.4–0.7μm), near-infrared (NIR, 0.7–1.0μm) and long-wave infrared (LWIR, 8–14μm) motion sequences. They represent different military and civilian surveillance scenarios registered in three different scenes. Scenes include (military and civilian) people that are stationary, walking or running, or carrying various objects. Vehicles, foliage, and buildings or other man-made structures are also included in the scenes. This data set is primarily intended for the development and evaluation of image fusion, enhancement and color mapping algorithms for short-range surveillance applications. The imagery was collected during several field trials with our newly developed TRICLOBS (TRI-band Color Low-light OBServation) all-day all-weather surveillance system. This system registers a scene in the Visual, NIR and LWIR part of the electromagnetic spectrum using three optically aligned sensors (two digital image intensifiers and an uncooled long-wave infrared microbolometer). The three sensor signals are mapped to three individual RGB color channels, digitized, and stored as uncompressed RGB (false) color frames. The TRICLOBS data set enables the development and evaluation of (both static and dynamic) image fusion, enhancement and color mapping algorithms. To allow the development of realistic color remapping procedures, the data set also contains color photographs of each of the three scenes. The color statistics derived from these photographs can be used to define color mappings that give the multi-band imagery a realistic color appearance. PMID:28036328

The TRICLOBS Dynamic Multi-Band Image Data Set for the Development and Evaluation of Image Fusion Methods.

PubMed

Toet, Alexander; Hogervorst, Maarten A; Pinkus, Alan R

2016-01-01

The fusion and enhancement of multiband nighttime imagery for surveillance and navigation has been the subject of extensive research for over two decades. Despite the ongoing efforts in this area there is still only a small number of static multiband test images available for the development and evaluation of new image fusion and enhancement methods. Moreover, dynamic multiband imagery is also currently lacking. To fill this gap we present the TRICLOBS dynamic multi-band image data set containing sixteen registered visual (0.4-0.7μm), near-infrared (NIR, 0.7-1.0μm) and long-wave infrared (LWIR, 8-14μm) motion sequences. They represent different military and civilian surveillance scenarios registered in three different scenes. Scenes include (military and civilian) people that are stationary, walking or running, or carrying various objects. Vehicles, foliage, and buildings or other man-made structures are also included in the scenes. This data set is primarily intended for the development and evaluation of image fusion, enhancement and color mapping algorithms for short-range surveillance applications. The imagery was collected during several field trials with our newly developed TRICLOBS (TRI-band Color Low-light OBServation) all-day all-weather surveillance system. This system registers a scene in the Visual, NIR and LWIR part of the electromagnetic spectrum using three optically aligned sensors (two digital image intensifiers and an uncooled long-wave infrared microbolometer). The three sensor signals are mapped to three individual RGB color channels, digitized, and stored as uncompressed RGB (false) color frames. The TRICLOBS data set enables the development and evaluation of (both static and dynamic) image fusion, enhancement and color mapping algorithms. To allow the development of realistic color remapping procedures, the data set also contains color photographs of each of the three scenes. The color statistics derived from these photographs can be used to define color mappings that give the multi-band imagery a realistic color appearance.

Characterization and initial field test of an 8-14 μm thermal infrared hyperspectral imager for measuring SO2 in volcanic plumes

NASA Astrophysics Data System (ADS)

Gabrieli, Andrea; Wright, Robert; Lucey, Paul G.; Porter, John N.; Garbeil, Harold; Pilger, Eric; Wood, Mark

2016-10-01

The ability to image and quantify SO2 path-concentrations in volcanic plumes, either by day or by night, is beneficial to volcanologists. Gas emission rates are affected by the chemical equilibria in rising magmas and a better understanding of this relationship would be useful for short-term eruption prediction. A newly developed remote sensing long-wave thermal InfraRed (IR) imaging hyperspectral sensor - the Thermal Hyperspectral Imager (THI) - was built and tested. The system employs a Sagnac interferometer and an uncooled microbolometer in rapid scanning configuration to collect hyperspectral images of volcanic plumes. Each pixel in the resulting image yields a spectrum with 50 samples between 8 and 14 μm. Images are spectrally and radiometrically calibrated using an IR source with a narrow band filter and two blackbodies. In this paper, the sensitivity of the instrument for the purpose of quantifying SO2 using well constrained laboratory experiments is evaluated, and initial field results from Kīlauea volcano, Hawai'i, are presented. The sensitivity of THI was determined using gas cells filled with known concentrations of SO2 and using NIST-traceable blackbodies to simulate a range of realistic background conditions. Measurements made by THI were then benchmarked against a high spectral resolution off-the-shelf Michelson FTIR instrument. Theoretical thermal IR spectral radiances were computed with MODTRAN5 for the same optical conditions, to evaluate how well the (known) concentration of SO2 in the gas cells could be retrieved from the resulting THI spectra. Finally, THI was recently field-tested at Kīlauea to evaluate its ability to image the concentration of SO2 in a real volcanic plume. A path-concentration of 7150 ppm m was retrieved from measurements made near the Halema'uma'u vent.

Lightweight uncooled TWS equipped with catadioptric optics and microscan mechanism

NASA Astrophysics Data System (ADS)

Bergeron, A.; Jerominek, H.; Doucet, M.; Lagacé, F.; Desnoyers, N.; Bernier, S.; Mercier, L.; Boucher, M.-A.; Jacob, M.; Alain, C.; Pope, T. D.; Laou, P.

2006-05-01

A rugged lightweight thermal weapon sight (TWS) prototype was developed at INO in collaboration with DRDC-Valcartier. This TWS model is based on uncooled bolometer technology, ultralight catadioptric optics, ruggedized mechanics and electronics, and extensive onboard processing capabilities. The TWS prototype operates in a single 8-12 μm infrared (IR) band. It is equipped with a unique lightweight athermalized catadioptric objective and a bolometric IR imager with an INO focal plane array (FPA). Microscan technology allows the use of a 160 x 120 pixel FPA with a pitch of 50 μm to achieve a 320 × 240 pixel resolution image thereby avoiding the size (larger optics) and cost (expensive IR optical components) penalties associated with the use of larger format arrays. The TWS is equipped with a miniature shutter for automatic offset calibration. Based on the operation of the FPA at 100 frames per second (fps), real-time imaging with 320 x 240 pixel resolution at 25 fps is available. This TWS is also equipped with a high resolution (857 x 600 pixels) OLED color microdisplay and an integrated wireless digital RF link. The sight has an adjustable and selectable electronic reticule or crosshair (five possible reticules) and a manual focus from 5 m to infinity standoff distance. Processing capabilities are added to introduce specific functionalities such as image inversion (black hot and white hot), image enhancement, and pixel smoothing. This TWS prototype is very lightweight (~ 1100 grams) and compact (volume of 93 cubic inches). It offers human size target detection at 800 m and recognition at 200 m (Johnson criteria). With 6 Li AA batteries, it operates continuously for 5 hours and 20 minutes at room temperature. It can operate over the temperature range of -30 °C to +40 °C and its housing is completely sealed. The TWS is adapted to weaver or Picatinny rail mounting. The overall design of the TWS prototype is based on feedbacks of users to achieve improved user-friendly (e.g. no pull-down menus and no electronic focusing) and ergonomic (e.g. locations of buttons) features.

Calibration Assessment of Uncooled Thermal Cameras for Deployment on UAV platforms

NASA Astrophysics Data System (ADS)

Aragon, B.; Parkes, S. D.; Lucieer, A.; Turner, D.; McCabe, M.

2017-12-01

In recent years an array of miniaturized sensors have been developed and deployed on Unmanned Aerial Vehicles (UAVs). Prior to gaining useful data from these integrations, it is vitally important to quantify sensor accuracy, precision and cross-sensitivity of retrieved measurements on environmental variables. Small uncooled thermal frame cameras provide a novel solution to monitoring surface temperatures from UAVs with very high spatial resolution, with retrievals being used to investigate heat stress or evapotranspiration. For these studies, accuracies of a few degrees are generally required. Although radiometrically calibrated thermal cameras have recently become commercially available, confirmation of the accuracy of these sensors is required. Here we detail a system for investigating the accuracy and precision, start up stabilisation time, dependence of retrieved temperatures on ambient temperatures and image vignetting. The calibration system uses a relatively inexpensive blackbody source deployed with the sensor inside an environmental chamber to maintain and control the ambient temperature. Calibration of a number of different thermal sensors commonly used for UAV deployment was investigated. Vignetting was shown to be a major limitation on sensor accuracy, requiring characterization through measuring a spatially uniform temperature target such as the blackbody. Our results also showed that a stabilization period is required after powering on the sensors and before conducting an aerial survey. Through use of the environmental chamber it was shown the ambient temperature influenced the temperatures retrieved by the different sensors. This study illustrates the importance of determining the calibration and cross-sensitivities of thermal sensors to obtain accurate thermal maps that can be used to study crop ecosystems.

Development of low-cost high-performance multispectral camera system at Banpil

NASA Astrophysics Data System (ADS)

Oduor, Patrick; Mizuno, Genki; Olah, Robert; Dutta, Achyut K.

2014-05-01

Banpil Photonics (Banpil) has developed a low-cost high-performance multispectral camera system for Visible to Short- Wave Infrared (VIS-SWIR) imaging for the most demanding high-sensitivity and high-speed military, commercial and industrial applications. The 640x512 pixel InGaAs uncooled camera system is designed to provide a compact, smallform factor to within a cubic inch, high sensitivity needing less than 100 electrons, high dynamic range exceeding 190 dB, high-frame rates greater than 1000 frames per second (FPS) at full resolution, and low power consumption below 1W. This is practically all the feature benefits highly desirable in military imaging applications to expand deployment to every warfighter, while also maintaining a low-cost structure demanded for scaling into commercial markets. This paper describes Banpil's development of the camera system including the features of the image sensor with an innovation integrating advanced digital electronics functionality, which has made the confluence of high-performance capabilities on the same imaging platform practical at low cost. It discusses the strategies employed including innovations of the key components (e.g. focal plane array (FPA) and Read-Out Integrated Circuitry (ROIC)) within our control while maintaining a fabless model, and strategic collaboration with partners to attain additional cost reductions on optics, electronics, and packaging. We highlight the challenges and potential opportunities for further cost reductions to achieve a goal of a sub-$1000 uncooled high-performance camera system. Finally, a brief overview of emerging military, commercial and industrial applications that will benefit from this high performance imaging system and their forecast cost structure is presented.

Bibliography of Research Reports and Publications Issued by the Human Engineering Division, January 1987 - December 1993

DTIC Science & Technology

1994-03-01

cues in an aircraft simulator. AMAA Flight Simulation Technologies Conference, 63- 70. Marasco , P. L., & Dereniak, E. L. (1993). Uncooled infrared...Space Center, TX: National Aeronautics and Space Administration. Task, H. L., Hartman, R. T., Marasco , P. L., & Zobel, A. R. (1993). Methods for...Aerospace VIIJ Conference, 2, 623-644. Marasco , P. L., & Dereniak, E. L. (1993). Uncooled infrared sensor performance. In B. F. Andresen, & F. D

Uncooled infrared sensors: rapid growth and future perspective

NASA Astrophysics Data System (ADS)

Balcerak, Raymond S.

2000-07-01

The uncooled infrared cameras are now available for both the military and commercial markets. The current camera technology incorporates the fruits of many years of development, focusing on the details of pixel design, novel material processing, and low noise read-out electronics. The rapid insertion of cameras into systems is testimony to the successful completion of this 'first phase' of development. In the military market, the first uncooled infrared cameras will be used for weapon sights, driver's viewers and helmet mounted cameras. Major commercial applications include night driving, security, police and fire fighting, and thermography, primarily for preventive maintenance and process control. The technology for the next generation of cameras is even more demanding, but within reach. The paper outlines the technology program planned for the next generation of cameras, and the approaches to further enhance performance, even to the radiation limit of thermal detectors.

Successful Mars remote sensors, MO THEMIS and MER Mini-TES

NASA Astrophysics Data System (ADS)

Silverman, Steven; Christensen, Phil

2006-10-01

This paper describes results of the calibration of the miniature thermal emission spectrometer (Mini-TES) and the thermal emission imaging system (THEMIS) built by Raytheon Santa Barbara Remote Sensing (SBRS) under contract to Arizona State University (ASU). This paper also serves as an update to an earlier paper (Silverman et al., 2003) for mission description and instrument designs (Schueler et al., 2003). A major goal of the Mars exploration program is to help determine whether life ever existed on Mars via detailed in situ studies and surface sample return. It is essential to identify landing sites with the highest probability of containing samples indicative of early pre-biotic or biotic environments. Of particular interest are aqueous and/or hydrothermal environments in which life could have existed, or regions of current near-surface water or heat sources [Exobiology_Working_Group, 1995, An Exobiological Strategy for Mars Exploration, NASA Headquarters]. The search requires detailed geologic mapping and accurate interpretations of site composition and history in a global context. THEMIS and Mini-TES were designed to do this and builds upon a wealth of data from previous experiments. Previous experiments include the Mariner 6/7 Mars infrared radiometer (MIR) and infrared spectrometer [G.C. Pimentel, P.B. Forney, K.C. Herr, Evidence about hydrate and solid water in the martian surface from the 1969 Mariner infrared spectrometer, Journal of Geophysical Research 79(11) (1974) 1623 1634], the Mariner 9 infrared interferometer spectrometer (IRIS) [B. Conrath, R. Curran, R. Hanel, V. Kunde, W. Maguire, J. Pearl, J. Pirraglia, J. Walker, Atmospheric and surface properties of Mars obtained by infrared spectroscopy on Mariner 9, Journal of Geophysical Research 78 (1973) 4267 4278], the Viking infrared thermal mapper (IRTM) [H.H. Kieffer, T.Z. Martin, A.R. Peterfreund, B.M. Jakosky, E.D. Miner, F.D. Palluconi, Thermal and albedo mapping of Mars during the Viking primary mission, Journal of Geophysical Research 82 (1977) 4249 4292], the Phobos Termoscan [A.S. Selivanov, M.K. Naraeva, A.S. Panfilov, Y.M. Gektin, V.D. Kharlamov, A.V. Romanov, D.A. Fomin, Y.Y. Miroshnichenko, Thermal imaging of the surface of Mars, Nature, 341 (1989) 593 595], and the continuing Mars global surveyor (MGS) mission using the Mars orbiter camera (MOC) [M.C. Malin, K.S. Edgett, Mars global surveyor Mars orbiter camera: interplanetary cruise through primary mission, Journal of Geophysical Research 106 (2001) 23, 429 23, 570] and MGS thermal emission spectrometer (TES) [P.R. Christensen, J.L. Bandfield, V.E. Hamilton, S.W. Ruff, H.H. Kieffer, T. Titus, M.C. Malin, R.V. Morris, M.D. Lane, R.N. Clark, B.M. Jakosky, M.T. Mellon, J.C. Pearl, B.J. Conrath, M.D. Smith, R.T. Clancy, R.O. Kuzmin, T. Roush, G.L. Mehall, N. Gorelick, K. Bender, K. Murray, S. Dason, E. Greene, S.H. Silverman, M. Greenfield, The Mars global surveyor thermal emission spectrometer experiment: investigation description and surface science results, Journal of Geophysical Research 106 (2001a) 23, 823 23, 871]. TES has collected hyperspectral images (up to 286 spectral bands from 6 50μm) of the entire martian surface, providing an initial global reconnaissance of mineralogy and thermophysical properties [J.L. Bandfield, Global mineral distributions on Mars, Journal of Geophysical Research 107 (2002) 10.1029/2001JE001510; S.W. Ruff, P.R. Christensen, Bright and dark regions on Mars: particle size and mineralogical characteristics based on thermal emission spectrometer data, Journal of Geophysical Research, 2002, in press]. By covering the key 6.3 15.0μm region in both TES and THEMIS, it is possible to combine TES fine spectral resolution with THEMIS fine spatial resolution to achieve a global mineralogic inventory at the spatial scales necessary for detailed geologic studies within the Odyssey data resources. Mini-TES is a single detector Fourier transform spectrometer (FTS), covering the spectral range 5 29μm at 10cm spectral resolution. Launched in June 2003, one Mini-TES instrument will fly to Mars aboard each of the two missions of NASA's Mars Exploration Rover Project (MER), named Spirit and Opportunity. The first Mini-TES unit was required to meet a two-year development schedule with proven, flight-tested instrumentation. Therefore, SBRS designed Mini-TES based on proven heritage from the successful MGS TES. THEMIS is based on “bolt-together” pushbroom optics and uncooled silicon microbolometer focal plane array (FPA) technology. Sometimes dubbed “Mars Landsat,” THEMIS was launched in 2001 on Mars Odyssey, and provides guidance for future lander missions now in preparation for launch. Advanced materials and optical machining allow THEMIS low-scatter, reflective, wide field-of-view (WFOV) pushbroom optics for relatively long dwell-time compared to narrow FOV optics requiring cross-track scanning for equivalent spatial resolution. This allows uncooled silicon microbolometer FPAs, with less signal sensitivity than cryogenically cooled photo-diode FPAs, to meet the THEMIS sensitivity requirements. Instrument design, performance, integration, as well as details of the calibration are discussed. Full instrument and calibration details are available in the Journal of Geophysical Research Mini-TES and THEMIS papers by Christensen et al.

The infrared imaging radiometer for PICASSO-CENA

NASA Astrophysics Data System (ADS)

Corlay, Gilles; Arnolfo, Marie-Christine; Bret-Dibat, Thierry; Lifferman, Anne; Pelon, Jacques

2017-11-01

Microbolometers are infrared detectors of an emerging technology mainly developed in US and few other countries for few years. The main targets of these developments are low performing and low cost military and civilian applications like survey cameras. Applications in space are now arising thanks to the design simplification and the associated cost reduction allowed by this new technology. Among the four instruments of the payload of PICASSO-CENA, the Imaging Infrared Radiometer (IIR) is based on the microbolometer technology. An infrared camera in development for the IASI instrument is the core of the IIR. The aim of the paper is to recall the PICASSO-CENA mission goal, to describe the IIR instrument architecture and highlight its main features and performances and to give the its development status.

A Scalable Fabrication Process for Liquid Crystal Based Uncooled Thermal Imagers

DTIC Science & Technology

2016-02-12

ll.mit.edu). Phillip Bos, Valerie Finnemeyer, Colin McGinty and Douglas Bryant are with the Liquid Crystal Institute at Kent State University, Kent...Crystal-Based Uncooled Thermal Imagers Shaun Berry, Carl Bozler, Robert Reich, Harry Clark Jr., Phillip Bos, Valerie Finnemeyer, Colin McGinty...was aligned to the die features on the wafer with appropriate weight added (Fig. 5b). We used stainless steel bars to apply the weight to the block

Superimpose signal processing method for micro-scale thermal imaging of solar salts at high temperature

NASA Astrophysics Data System (ADS)

Morikawa, Junko; Zamengo, Massimiliano; Kato, Yukitaka

2016-05-01

The global interest in energy applications activates the advanced study about the molten salts in the usage of fluids in the power cycle, such as for transport and heat storage in solar power facilities. However, the basic properties of molten salts show a general scattering in characterization especially in thermal properties. It is suggested that new studies are required on the measurement of thermal properties of solar salts using recent technologies. In this study, micro-scale heat transfer and phase change in molten salts are presented using our originally developed device: the micro-bolometer Infrared focal plane arrays (IR FPA) measuring system is a portable type instrument, which is re-designed to measure the thermal phenomena in high temperature up to 700 °C or higher. The superimpose system is newly setup adjusted to the signal processing in high temperature to realize the quantitative thermal imaging, simultaneously. The portable type apparatus for a quantitative micro-scale thermography using a micro-bolometer has been proposed based on an achromatic lens design to capture a micro-scale image in the long-wave infrared, a video signal superimposing for the real time emissivity correction, and a pseudo acceleration of a timeframe. Combined with the superimpose technique, the micro-scale thermal imaging in high temperature is achieved and the molten flows of the solar salts, sodium nitrate, and potassium nitrate are successfully observed. The solar salt, the mixture of sodium nitrate and potassium nitrate, shows a different shape of exothermic heat front morphology in the lower phase transition (solidification) temperature than the nitrates on cooling. The proposed measuring technique will be utilized to accelerate the screening step to determine the phase diagram and the eutectics of the multiple mixtures of candidate molten salts, which may be used as heat transport medium from the concentrated solar power to a processing plant for thermal energy storage.

Uncooled detectors optimized for unattended applications

NASA Astrophysics Data System (ADS)

Malkinson, E.; Fraenkel, A.; Mizrahi, U.; Ben-Ezra, M.; Bikov, L.; Adin, A.; Zabar, Y.; Seter, D.; Kopolovich, Z.

2005-10-01

SCD has recently presented an uncooled detector product line based on the high-end VOx bolometer technology. The first FPA launched, named BIRD - short for Bolometer Infra Red Detector, is a 384x288 (or 320x240) configurable format with 25μm pitch. Typical NETD values for these FPAs range at 50mK with an F/1 aperture and 60 Hz frame rate. These detectors also exhibit a relatively fast thermal time constant of approximately 10 msec, as reported previously. In this paper, the special features of BIRD optimized for unattended sensor applications are presented and discussed. Unattended surveillance using sensors on unattended aerial vehicles (UAV's) or micro air vehicles (MAV's) , unattended ground vehicles (UGV's) or unattended ground sensor (UGS) are growing applications for uncooled detectors. This is due to their low power consumption, low weight, negligible acoustic noise and reduced price. On the other hand, uncooled detectors are vulnerable to ambient drift. Even minor temperature fluctuations are manifested as fixed pattern noise (FPN). As a result, frequent, shutter operation must be applied, with the risk of blocking the scenery in critical time frames and loosing information for various scenarios. In order to increase the time span between shutter operations, SCD has incorporated various features within the FPA and supporting algorithms. This paper will discuss these features and present some illustrative examples. Minimum power consumption is another critical issue for unattended applications. SCD has addressed this topic by introducing the "Power Save" concept. For very low power applications or for TEC-less (Thermo-Electric-Cooler) applications, the flexible dilution architecture enables the system to operate the detector at a number of formats. This, together with a smooth frame rate and format transition capability turns SCD's uncooled detector to be well suited for unattended applications. These issues will be described in detail as well.

Improved integrated sniper location system

NASA Astrophysics Data System (ADS)

Figler, Burton D.; Spera, Timothy J.

1999-01-01

In July of 1995, Lockheed Martin IR Imaging Systems, of Lexington, Massachusetts began the development of an integrated sniper location system for the Defense Advanced Research Projects Agency and for the Department of the Navy's Naval Command Control & Ocean Surveillance Center, RDTE Division in San Diego, California. The I-SLS integrates acoustic and uncooled infrared sensing technologies to provide an affordable and highly effective sniper detection and location capability. This system, its performance and results from field tests at Camp Pendleton, California, in October 1996 were described in a paper presented at the November 1996 SPIE Photonics East Symposium1 on Enabling Technologies for Law Enforcement and Security. The I-SLS combines an acoustic warning system with an uncooled infrared warning system. The acoustic warning system has been developed by SenTech, Inc., of Lexington, Massachusetts. This acoustic warning system provides sniper detection and coarse location information based upon the muzzle blast of the sniper's weapon and/or upon the shock wave produced by the sniper's bullet, if the bullet is supersonic. The uncooled infrared warning system provides sniper detection and fine location information based upon the weapon's muzzle flash. In addition, the uncooled infrared warning system can provide thermal imagery that can be used to accurately locate and identify the sniper. Combining these two technologies improves detection probability, reduces false alarm rate and increases utility. In the two years since the last report of the integrated sniper location system, improvements have been made and a second field demonstration was planned. In this paper, we describe the integrated sniper location system modifications in preparation for the new field demonstration. In addition, fundamental improvements in the uncooled infrared sensor technology continue to be made. These improvements include higher sensitivity (lower minimum resolvable temperature), higher spatial resolution, and smaller size. This paper will describe the implementation and status of these improvements.

Very large scale heterogeneous integration (VLSHI) and wafer-level vacuum packaging for infrared bolometer focal plane arrays

NASA Astrophysics Data System (ADS)

Forsberg, Fredrik; Roxhed, Niclas; Fischer, Andreas C.; Samel, Björn; Ericsson, Per; Hoivik, Nils; Lapadatu, Adriana; Bring, Martin; Kittilsland, Gjermund; Stemme, Göran; Niklaus, Frank

2013-09-01

Imaging in the long wavelength infrared (LWIR) range from 8 to 14 μm is an extremely useful tool for non-contact measurement and imaging of temperature in many industrial, automotive and security applications. However, the cost of the infrared (IR) imaging components has to be significantly reduced to make IR imaging a viable technology for many cost-sensitive applications. This paper demonstrates new and improved fabrication and packaging technologies for next-generation IR imaging detectors based on uncooled IR bolometer focal plane arrays. The proposed technologies include very large scale heterogeneous integration for combining high-performance, SiGe quantum-well bolometers with electronic integrated read-out circuits and CMOS compatible wafer-level vacuum packing. The fabrication and characterization of bolometers with a pitch of 25 μm × 25 μm that are arranged on read-out-wafers in arrays with 320 × 240 pixels are presented. The bolometers contain a multi-layer quantum well SiGe thermistor with a temperature coefficient of resistance of -3.0%/K. The proposed CMOS compatible wafer-level vacuum packaging technology uses Cu-Sn solid-liquid interdiffusion (SLID) bonding. The presented technologies are suitable for implementation in cost-efficient fabless business models with the potential to bring about the cost reduction needed to enable low-cost IR imaging products for industrial, security and automotive applications.

The 2-MM Range Receiving Module for Observations of Atmospheric Ozone Emission Line at 142.2 GHz

NASA Astrophysics Data System (ADS)

Piddyachiy, V. I.; Korolev, O. M.; Myshenko, V. V.; Shulga, V. M.

2015-09-01

A low-noise uncooled receiver was designed and constructed for measurements of the atmospheric ozone spectral line at 142.2 GHz. The design has shown the double-sideband (DSB) receiver noise temperature of about 350 K within 130 to 150 GHz. Critical construction features of the basic units (mixer, intermediate frequency amplifier, and diplexer) are described. Noise characteristics showed by the receiver are the best in the class of uncooled heterodyne receivers of the 2-mm wavelengths.

Experimental Results of Ground Disturbance Detection Using Uncooled Infrared Imagers in Wideband and Multispectral Modes

DTIC Science & Technology

2012-02-01

and undisturbed soil. An uncooled IR imager with sufficient sensitivity ( Noise equivalent of temperature difference or NETD) at around 100mK NETD...Imager temperature sensitivity in bandpass mode: NETD is defined as the temperature difference ( T) for which the signal-to- noise ratio (SNR) equals to...1 where the signal is proportional to radiance L (watt/cm2-ster) while noise level is known. The NETD of the imager, however, will degrade when it

Unmanned Ground Vehicle Perception Using Thermal Infrared Cameras

NASA Technical Reports Server (NTRS)

Rankin, Arturo; Huertas, Andres; Matthies, Larry; Bajracharya, Max; Assad, Christopher; Brennan, Shane; Bellut, Paolo; Sherwin, Gary

2011-01-01

TIR cameras can be used for day/night Unmanned Ground Vehicle (UGV) autonomous navigation when stealth is required. The quality of uncooled TIR cameras has significantly improved over the last decade, making them a viable option at low speed Limiting factors for stereo ranging with uncooled LWIR cameras are image blur and low texture scenes TIR perception capabilities JPL has explored includes: (1) single and dual band TIR terrain classification (2) obstacle detection (pedestrian, vehicle, tree trunks, ditches, and water) (3) perception thru obscurants

Stand-off detection of trace explosives by infrared photothermal imaging

NASA Astrophysics Data System (ADS)

Papantonakis, Michael R.; Kendziora, Chris; Furstenberg, Robert; Stepnowski, Stanley V.; Rake, Matthew; Stepnowski, Jennifer; McGill, R. Andrew

2009-05-01

We have developed a technique for the stand-off detection of trace explosives using infrared photothermal imaging. In this approach, infrared quantum cascade lasers tuned to strong vibrational absorption bands of the explosive particles illuminate a surface of interest, preferentially heating the explosives material. An infrared focal plane array is used to image the surface and detect a small increase in the thermal intensity upon laser illumination. We have demonstrated the technique using TNT and RDX residues at several meters of stand-off distance under laboratory conditions, while operating the lasers below the eye-safe intensity limit. Sensitivity to explosives traces as small as a single grain (~100 ng) of TNT has been demonstrated using an uncooled bolometer array. We show the viability of this approach on a variety of surfaces which transmit, reflect or absorb the infrared laser light and have a range of thermal conductivities. By varying the incident wavelength slightly, we demonstrate selectivity between TNT and RDX. Using a sequence of lasers at different wavelengths, we increase both sensitivity and selectivity while reducing the false alarm rate. At higher energy levels we also show it is possible to generate vapor from solid materials with inherently low vapor pressures.

Passive athermalization of doublets in 8-13 micron waveband

NASA Astrophysics Data System (ADS)

Schuster, Norbert

2014-10-01

Passive athermalization of lenses has become a key-technology for automotive and other outdoor applications using modern uncooled 25, 17 and 12 micron pixel pitch bolometer arrays. Typical pixel counts for thermal imaging are 384x288 (qVGA), 640x480 (VGA), and 1024x768 (XGA). Two lens arrangements (called Doublets) represent a cost effective way to satisfy resolution requirements of these detectors with F-numbers 1.4 or faster. Thermal drift of index of refraction and the geometrical changes (in lenses and housing) versus temperature defocus the initial image plane from the detector plane. The passive athermalization restricts this drop of spatial resolution in a wide temperature range (typically -40°C…+80°C) to an acceptable value without any additional external refocus. In particular, lenses with long focal lengths and high apertures claim athermalization. A careful choice of lens and housing materials and a sophistical dimensioning lead to three different principles of passivation: The Passive Mechanical Athermalization (PMA) shifts the complete lens cell, the Passive Optical and Mechanical Athermalization (POMA) shifts only one lens inside the housing, the Passive Optical Athermalization (POA) works without any mechanism. All three principles will be demonstrated for a typical narrow-field lens (HFOV about 12°) with high aperture (aperture based F-number 1.3) for the actual uncooled reference detector (17micron VGA). Six design examples using different combinations of lens materials show the impact on spatial lens resolution, on overall length, and on weight. First order relations are discussed. They give some hints for optimization solutions. Pros and cons of different passive athermalization principles are evaluated in regards of housing design, availability of materials and costing. Examples with a convergent GASIR®1-lens in front distinguish by best resolution, short overall length, and lowest weight.

Vicarious Calibration of sUAS Microbolometer Temperature Imagery for Estimation of Radiometric Land Surface Temperature.

PubMed

Torres-Rua, Alfonso

2017-06-26

In recent years, the availability of lightweight microbolometer thermal cameras compatible with small unmanned aerial systems (sUAS) has allowed their use in diverse scientific and management activities that require sub-meter pixel resolution. Nevertheless, as with sensors already used in temperature remote sensing (e.g., Landsat satellites), a radiance atmospheric correction is necessary to estimate land surface temperature. This is because atmospheric conditions at any sUAS flight elevation will have an adverse impact on the image accuracy, derived calculations, and study replicability using the microbolometer technology. This study presents a vicarious calibration methodology (sUAS-specific, time-specific, flight-specific, and sensor-specific) for sUAS temperature imagery traceable back to NIST-standards and current atmospheric correction methods. For this methodology, a three-year data collection campaign with a sUAS called "AggieAir", developed at Utah State University, was performed for vineyards near Lodi, California, for flights conducted at different times (early morning, Landsat overpass, and mid-afternoon") and seasonal conditions. From the results of this study, it was found that, despite the spectral response of microbolometer cameras (7.0 to 14.0 μm), it was possible to account for the effects of atmospheric and sUAS operational conditions, regardless of time and weather, to acquire accurate surface temperature data. In addition, it was found that the main atmospheric correction parameters (transmissivity and atmospheric radiance) significantly varied over the course of a day. These parameters fluctuated the most in early morning and partially stabilized in Landsat overpass and in mid-afternoon times. In terms of accuracy, estimated atmospheric correction parameters presented adequate statistics (confidence bounds under ±0.1 for transmissivity and ±1.2 W/m²/sr/um for atmospheric radiance, with a range of RMSE below 1.0 W/m²/sr/um) for all sUAS flights. Differences in estimated temperatures between original thermal image and the vicarious calibration procedure reported here were estimated from -5 °C to 10 °C for early morning, and from 0 to 20 °C for Landsat overpass and mid-afternoon times.

Vicarious Calibration of sUAS Microbolometer Temperature Imagery for Estimation of Radiometric Land Surface Temperature

PubMed Central

2017-01-01

In recent years, the availability of lightweight microbolometer thermal cameras compatible with small unmanned aerial systems (sUAS) has allowed their use in diverse scientific and management activities that require sub-meter pixel resolution. Nevertheless, as with sensors already used in temperature remote sensing (e.g., Landsat satellites), a radiance atmospheric correction is necessary to estimate land surface temperature. This is because atmospheric conditions at any sUAS flight elevation will have an adverse impact on the image accuracy, derived calculations, and study replicability using the microbolometer technology. This study presents a vicarious calibration methodology (sUAS-specific, time-specific, flight-specific, and sensor-specific) for sUAS temperature imagery traceable back to NIST-standards and current atmospheric correction methods. For this methodology, a three-year data collection campaign with a sUAS called “AggieAir”, developed at Utah State University, was performed for vineyards near Lodi, California, for flights conducted at different times (early morning, Landsat overpass, and mid-afternoon”) and seasonal conditions. From the results of this study, it was found that, despite the spectral response of microbolometer cameras (7.0 to 14.0 μm), it was possible to account for the effects of atmospheric and sUAS operational conditions, regardless of time and weather, to acquire accurate surface temperature data. In addition, it was found that the main atmospheric correction parameters (transmissivity and atmospheric radiance) significantly varied over the course of a day. These parameters fluctuated the most in early morning and partially stabilized in Landsat overpass and in mid-afternoon times. In terms of accuracy, estimated atmospheric correction parameters presented adequate statistics (confidence bounds under ±0.1 for transmissivity and ±1.2 W/m2/sr/um for atmospheric radiance, with a range of RMSE below 1.0 W/m2/sr/um) for all sUAS flights. Differences in estimated temperatures between original thermal image and the vicarious calibration procedure reported here were estimated from −5 °C to 10 °C for early morning, and from 0 to 20 °C for Landsat overpass and mid-afternoon times. PMID:28672864

Hybrid WDM/TDM-PON With Wavelength-Selection-Free Transmitters

NASA Astrophysics Data System (ADS)

Shin, Dong Jae; Jung, Dae Kwang; Shin, Hong Seok; Kwon, Jin Wook; Hwang, Seongtaek; Oh, Yunje; Shim, Changsup

2005-01-01

A hybrid wavelength-division-multiplexed/time-division-multiplexed passive optical network serving 128 subscribers with wavelength-selection-free transmitters is presented by cascading 1x16 arrayed-waveguide gratings (AWGs) and 1x8 splitters. The wavelength-selection-free transmitter is an uncooled Fabry-Pérot laser diode (FP-LD) wavelength-locked to an externally injected narrow-band amplified spontaneous emission (ASE). Bit-error rates better than 10^-9 over temperature ranging from 0 to 60 °C are achieved in all 16 wavelength channels using a single FP-LD with an ASE injection of about -15 and -2 dBm in 622-Mb/s upstream and 1.25-Gb/s downstream transmissions over a 10-km feeder fiber, respectively. It is also reported that the ASE injection does not exert penalty upon burst-mode operations of the FP-LDs in the upstream.

High-operating temperature MWIR photon detectors based on type II InAs/GaSb superlattice

NASA Astrophysics Data System (ADS)

Razeghi, Manijeh; Nguyen, Binh-Minh; Delaunay, Pierre-Yves; Abdollahi Pour, Siamak; Huang, Edward Kwei-wei; Manukar, Paritosh; Bogdanov, Simeon; Chen, Guanxi

2010-01-01

Recent efforts have been paid to elevate the operating temperature of Type II InAs/GaSb superlattice Mid Infrared photon detectors. Optimized growth parameters and interface engineering technique enable high quality material with a quantum efficiency above 50%. Intensive study on device architecture and doping profile has resulted in almost one order of magnitude of improvement to the electrical performance and lifted up the 300K-background BLIP operation temperature to 166K. At 77K, the ~4.2 μm cut-off devices exhibit a differential resistance area product in excess of the measurement system limit (106 Ohm.cm2) and a detectivity of 3x1013cm.Hz1/2/W. High quality focal plane arrays were demonstrated with a noise equivalent temperature of 10mK at 77K. Uncooled camera is capable to capture hot objects such as soldering iron.

Investigation of antenna-coupled Nb5N6 microbolometer THz detector with substrate resonant cavity.

PubMed

Tu, Xuecou; Jiang, Chengtao; Xiao, Peng; Kang, Lin; Zhai, Shimin; Jiang, Zhou; Feng Su, Run; Jia, Xiaoqing; Zhang, Labao; Chen, Jian; Wu, Peiheng

2018-04-02

Fabricating resonant cavities with conventional methods to improve the coupling efficiency of a detector in the terahertz (THz) region is difficult for the wavelength is too long. Here, we propose a solution by using the substrate cavity effect given that the substrate wavelength and thickness of the preparation device are in the same order. The planar dipole antenna-coupled Nb 5 N 6 microbolometers with different substrate thicknesses were fabricated. The interference effect of the substrate cavity on the optical voltage response of the detector is analyzed experimentally and theoretically. The experimental results show that the optical response of the detector is determined by the length of the substrate cavity. Thus, the THz devices with different detection frequencies can be designed by changing the substrate cavity length. Furthermore, on the basis of this substrate cavity effect, an asymmetric coupled Fabry-Pérot (FP) cavity is constituted by simply placing a movable metallic planar mirror at the backside of the Si substrate. The incident THz radiation on the Nb 5 N 6 microbolometer can be effectively manipulated by changing the substrate-mirror distance to modulate the phase relation between the reflect wave and the incident wave. The distinct radiation control can be observed, and the experiments can be well explained by numerically analyzing the responsivity dynamics that highlights the role of the FP cavity effect during radiation. All of the results discussed here can be extended to a broad range of frequency and other type of THz detectors.

Uncooled infrared sensors for an integrated sniper location system

NASA Astrophysics Data System (ADS)

Spera, Timothy J.; Figler, Burton D.

1997-02-01

Since July of 1995, Lockheed Martin IR Imaging Systems of Lexington, Massachusetts has been developing an integrated sniper location system for the Advanced Research Projects Agency (ARPA) and for the Department of the Navy's Naval Command Control & Ocean Surveillance Center, RDTE Division in San Diego, California. This system integrates two technologies to provide an affordable and highly effective sniper detection and location capability. The integrated sniper location system is being developed for use by the military and by law enforcement agencies. It will be man portable and can be used by individuals, at fixed ground sites, on ground vehicles, and on low flying aircraft. The integrated sniper location system combines an acoustic warning system with an uncooled infrared warning system. The acoustic warner is being developed by SenTech, Inc. of Lexington, Massachusetts. This acoustic warner provides sniper detection and coarse location information based upon the muzzle blast of the sniper's weapon and/or upon the shock wave produced by the sniper's bullet, if the bullet is supersonic. The uncooled infrared warning system provides sniper detection and fine location information based upon the weapons's muzzle flash. Combining the two technologies improves detection probability and reduces false alarm rate. This paper describes the integrated sniper location system, focusing on the uncooled infrared sensor and its associated signal processing. In addition, preliminary results from Phase I testing of the system are presented. Finally, the paper addresses the plans for implementing Phases II and III, during which the system will be optimized in terms of detection and location performance, size, weight, power, and cost.

Design, demonstration and testing of low F-number LWIR panoramic imaging relay optics

NASA Astrophysics Data System (ADS)

Furxhi, Orges; Frascati, Joe; Driggers, Ronald

2018-04-01

Panoramic imaging is inherently wide field of view. High sensitivity uncooled Long Wave Infrared (LWIR) imaging requires low F-number optics. These two requirements result in short back working distance designs that, in addition to being costly, are challenging to integrate with commercially available uncooled LWIR cameras and cores. Common challenges include the relocation of the shutter flag, custom calibration of the camera dynamic range and NUC tables, focusing, and athermalization. Solutions to these challenges add to the system cost and make panoramic uncooled LWIR cameras commercially unattractive. In this paper, we present the design of Panoramic Imaging Relay Optics (PIRO) and show imagery and test results with one of the first prototypes. PIRO designs use several reflective surfaces (generally two) to relay a panoramic scene onto a real, donut-shaped image. The PIRO donut is imaged on the focal plane of the camera using a commercially-off-the-shelf (COTS) low F-number lens. This approach results in low component cost and effortless integration with pre-calibrated commercially available cameras and lenses.

Paul W. Kruse (1927-2012), In Memoriam

NASA Astrophysics Data System (ADS)

Reine, Marion B.; Norton, Paul R.; Stelzer, Ernie L.

2013-06-01

During his distinguished 37-year career as a research physicist at the Honeywell Research Center in Minneapolis, Minnesota, Dr. Paul W. Kruse (1927-2012) played leadership roles in two disruptive infrared detector technologies, the narrow-gap semiconductor alloy HgCdTe and the silicon CMOS-based microbolometer array, both of which revolutionized the worldwide infrared detector industry. He served on numerous government advisory boards and panels, including the Army Scientific Advisory Panel and the Army Science Board, for which he received the Outstanding Civilian Service Medal. After retiring for Honeywell in 1993, he remained active in the infrared detector field in several roles: as a successful small-business entrepreneur, as an author of two books, and as a SPIE lecturer. His books, papers and lectures have educated new generations of workers in the infrared detector industry. His career, a model for industrial research physicists, has had major and permanent impacts on the worldwide infrared detector industry. This paper is a summary of the career of Paul W. Kruse, as well as a tribute to that career and its lasting legacy.

Wavelength- or Polarization-Selective Thermal Infrared Detectors for Multi-Color or Polarimetric Imaging Using Plasmonics and Metamaterials

PubMed Central

Ogawa, Shinpei; Kimata, Masafumi

2017-01-01

Wavelength- or polarization-selective thermal infrared (IR) detectors are promising for various novel applications such as fire detection, gas analysis, multi-color imaging, multi-channel detectors, recognition of artificial objects in a natural environment, and facial recognition. However, these functions require additional filters or polarizers, which leads to high cost and technical difficulties related to integration of many different pixels in an array format. Plasmonic metamaterial absorbers (PMAs) can impart wavelength or polarization selectivity to conventional thermal IR detectors simply by controlling the surface geometry of the absorbers to produce surface plasmon resonances at designed wavelengths or polarizations. This enables integration of many different pixels in an array format without any filters or polarizers. We review our recent advances in wavelength- and polarization-selective thermal IR sensors using PMAs for multi-color or polarimetric imaging. The absorption mechanism defined by the surface structures is discussed for three types of PMAs—periodic crystals, metal-insulator-metal and mushroom-type PMAs—to demonstrate appropriate applications. Our wavelength- or polarization-selective uncooled IR sensors using various PMAs and multi-color image sensors are then described. Finally, high-performance mushroom-type PMAs are investigated. These advanced functional thermal IR detectors with wavelength or polarization selectivity will provide great benefits for a wide range of applications. PMID:28772855

Wavelength- or Polarization-Selective Thermal Infrared Detectors for Multi-Color or Polarimetric Imaging Using Plasmonics and Metamaterials.

PubMed

Ogawa, Shinpei; Kimata, Masafumi

2017-05-04

Wavelength- or polarization-selective thermal infrared (IR) detectors are promising for various novel applications such as fire detection, gas analysis, multi-color imaging, multi-channel detectors, recognition of artificial objects in a natural environment, and facial recognition. However, these functions require additional filters or polarizers, which leads to high cost and technical difficulties related to integration of many different pixels in an array format. Plasmonic metamaterial absorbers (PMAs) can impart wavelength or polarization selectivity to conventional thermal IR detectors simply by controlling the surface geometry of the absorbers to produce surface plasmon resonances at designed wavelengths or polarizations. This enables integration of many different pixels in an array format without any filters or polarizers. We review our recent advances in wavelength- and polarization-selective thermal IR sensors using PMAs for multi-color or polarimetric imaging. The absorption mechanism defined by the surface structures is discussed for three types of PMAs-periodic crystals, metal-insulator-metal and mushroom-type PMAs-to demonstrate appropriate applications. Our wavelength- or polarization-selective uncooled IR sensors using various PMAs and multi-color image sensors are then described. Finally, high-performance mushroom-type PMAs are investigated. These advanced functional thermal IR detectors with wavelength or polarization selectivity will provide great benefits for a wide range of applications.

Material of LAPAN's thermal IR camera equipped with two microbolometers in one aperture

NASA Astrophysics Data System (ADS)

Bustanul, A.; Irwan, P.; Andi M., T.

2017-11-01

Besides the wavelength used, there is another factor that we have to notice in designing an optical system. It is material used which is correct for the spectral bands determined. Basically, due the limitation of the available range and expensive, choosing and determining materials for Infra Red (IR) wavelength are more difficult and complex rather than visible spectrum. We also had the same problem while designing our thermal IR camera equipped with two microbolometers sharing aperture. Two spectral bands, 3 - 4 μm (MWIR) and 8 - 12 μm (LWIR), have been decided to be our thermal IR camera spectrum to address missions, i.e., peat land fire, volcanoes activities, and Sea Surface Temperature (SST). Referring those bands, we chose the appropriate material for LAPAN's IR camera optics. This paper describes material of LAPAN's IR camera equipped with two microbolometer in one aperture. First of all, we were learning and understanding of optical materials properties all matters of IR technology including its bandwidths. Considering some aspects, i.e., Transmission, Index of Refraction, Thermal properties covering the index gradient and coefficient of thermal expansion (CTE), the analysis then has been accomplished. Moreover, we were utilizing a commercial software, Thermal Desktop/Sinda Fluint, to strengthen the process. Some restrictions such as space environment, low cost, and performance mainly durability and transmission, were also cared throughout the trade off the works. The results of all those analysis, either in graphs or in measurement, indicate that the lens of LAPAN's IR camera with sharing aperture is based on Germanium/Zinc Selenide materials.

Superconducting Mixers for Far-Infrared Spectroscopy

NASA Technical Reports Server (NTRS)

Betz, A. L.; Boreiko, R. T.; Grossman, E. R.; Reintsema, C. D.; Ono, R. H.; Gerecht, E.

2002-01-01

The goal of this project was to fabricate and test planar arrays of superconducting mixers for the 2-6 THz band. The technology is intended for multi-beam receivers aboard Explorer-class missions and the SOFIA Airborne Observatory. The mixer technology is the superconducting transition-edge microbolometer, which is more commonly known as the Hot-Electron micro-Bolometer (HEB). As originally proposed, two superconducting technologies were to be developed: (1) low-Tc niobium HEBs which could approach quantum-noise-limited sensitivities but require cooling to 2- 4 K, and (2) high-Tc YBCO HEBs with sensitivities 10 times worse but with a relaxed cooling requirement of 30-60 K. The low-Tc devices would be best for astronomy applications on SOFIA, whereas the high-Tc devices would be more suitable for planetary missions using systems without stored cryogens. The work plan called for planar micro-fabrication and initial testing of HEB devices at the NIST Boulder clean-room facility. Subsequent assembly and RF testing of selected devices would be done at the CASA laboratory at U. Colorado. Approximately 1-year after work began on this project, Dr. Eyal Gerecht joined the NIST group, and assumed day-to-day responsibility for Nb-HEB development at NIST outside of micro-fabrication. The YBCO-HEB work was to be guided by Dr. Ron Ono, who was the NIST expert in YBCO technology. Unfortunately, recurrent health problems limited the time Ron could devote to the project in its first year. These problems became aggravated in early 2001, and sadly led to Ron's death in October, 2001. His loss was not only a blow to his friends and associates at NIST, but was mounted by the US superconductivity community at large. With his passing, work on high-Tc HEBs ceased at NIST. There was no one to replace him or his expertise. Our work subsequently shifted solely to Nb-HEB devices. In the sections which follow, our progress in the development of diffusion-cooled Nb-HEB mixers is detailed. To simplify the terminology, these devices will subsequently be called DHEB mixers to distinguish them from phonon-cooled devices (PHEBs).

Infrared to visible image up-conversion using optically addressed spatial light modulator utilizing liquid crystal and InGaAs photodiodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Solodar, A., E-mail: asisolodar@gmail.com; Arun Kumar, T.; Sarusi, G.

2016-01-11

Combination of InGaAs/InP heterojunction photodetector with nematic liquid crystal (LC) as the electro-optic modulating material for optically addressed spatial light modulator for short wavelength infra-red (SWIR) to visible light image conversion was designed, fabricated, and tested. The photodetector layer is composed of 640 × 512 photodiodes array based on heterojunction InP/InGaAs having 15 μm pitch on InP substrate and with backside illumination architecture. The photodiodes exhibit extremely low, dark current at room temperature, with optimum photo-response in the SWIR region. The photocurrent generated in the heterojunction, due to the SWIR photons absorption, is drifted to the surface of the InP,more » thus modulating the electric field distribution which modifies the orientation of the LC molecules. This device can be attractive for SWIR to visible image upconversion, such as for uncooled night vision goggles under low ambient light conditions.« less

A New Remote Sensing Filter Radiometer Employing a Fabry-Perot Etalon and a CCD Camera for Column Measurements of Methane in the Earth Atmosphere

NASA Technical Reports Server (NTRS)

Georgieva, E. M.; Huang, W.; Heaps, W. S.

2012-01-01

A portable remote sensing system for precision column measurements of methane has been developed, built and tested at NASA GSFC. The sensor covers the spectral range from 1.636 micrometers to 1.646 micrometers, employs an air-gapped Fabry-Perot filter and a CCD camera and has a potential to operate from a variety of platforms. The detector is an XS-1.7-320 camera unit from Xenics Infrared solutions which combines an uncooled InGaAs detector array working up to 1.7 micrometers. Custom software was developed in addition to the graphical user basic interface X-Control provided by the company to help save and process the data. The technique and setup can be used to measure other trace gases in the atmosphere with minimal changes of the etalon and the prefilter. In this paper we describe the calibration of the system using several different approaches.

Long-wave infrared profile feature extractor (PFx) sensor

NASA Astrophysics Data System (ADS)

Sartain, Ronald B.; Aliberti, Keith; Alexander, Troy; Chiu, David

2009-05-01

The Long Wave Infrared (LWIR) Profile Feature Extractor (PFx) sensor has evolved from the initial profiling sensor that was developed by the University of Memphis (Near IR) and the Army Research Laboratory (visible). This paper presents the initial signatures of the LWIR PFx for human with and without backpacks, human with animal (dog), and a number of other animals. The current version of the LWIR PFx sensor is a diverging optical tripwire sensor. The LWIR PFx signatures are compared to the signatures of the Profile Sensor in the visible and Near IR spectral regions. The LWIR PFx signatures were collected with two different un-cooled micro bolometer focal plane array cameras, where the individual pixels were used as stand alone detectors (a non imaging sensor). This approach results in a completely passive, much lower bandwidth, much longer battery life, low weight, small volume sensor that provides sufficient information to classify objects into human Vs non human categories with a 98.5% accuracy.

Resonant and resistive dual-mode uncooled infrared detectors toward expanded dynamic range and high linearity

NASA Astrophysics Data System (ADS)

Li, Xin; Liang, Ji; Zhang, Hongxiang; Yang, Xing; Zhang, Hao; Pang, Wei; Zhang, Menglun

2017-06-01

This paper reports an uncooled infrared (IR) detector based on a micromachined piezoelectric resonator operating in resonant and resistive dual-modes. The two sensing modes achieved IR responsivities of 2.5 Hz/nW and 900 μdB/nW, respectively. Compared with the single mode operation, the dual-mode measurement improves the limit of detection by two orders of magnitude and meanwhile maintains high linearity and responsivity in a higher IR intensity range. A combination of the two sensing modes compensates for its own shortcomings and provides a much larger dynamic range, and thus, a wider application field of the proposed detector is realized.

Low-cost directionally-solidified turbine blades, volume 2. [TFE731-3 turbofan engine

NASA Technical Reports Server (NTRS)

Dennis, R. E.; Hoppin, G. S., III; Hurst, L. G.

1979-01-01

An endothermically heated technology was used to manufacture low cost, directionally solidified, uncooled nickel-alloy blades for the TFE731-3 turbofan engine. The MAR-M 247 and MER-M 100+Hf blades were finish processed through heat treatment, machining, and coating operations prior to 150 hour engine tests consisting of the following sequences: (1) 50 hours of simulated cruise cycling (high fatigue evaluation); (2) 50 hours at the maximum continuous power rating (stress rupture endurance (low cycle fatigue). None of the blades visually showed any detrimental effects from the test. This was verified by post test metallurgical evaluation. The specific fuel consumption was reduced by 2.4% with the uncooled blades.

Nanostructured vanadium oxide thin film with high TCR at room temperature for microbolometer

NASA Astrophysics Data System (ADS)

Wang, Bin; Lai, Jianjun; Li, Hui; Hu, Haoming; Chen, Sihai

2013-03-01

In order to obtain high quality of thermal sensitive material, VOx thin film of high temperature coefficient of resistance (TCR) of 6.5%/K at room temperature has been deposited by reactive ion beam sputtering and post annealing method. AFM and XRD measurements indicate that the VOx thin film with nanostructured crystalline is composed of VO2 and V2O3. The nanostructured VOx microbolometer has been designed and fabricated. The measurement of the film system with TiN absorbing layer indicates that it has about 92% infrared absorption in the range of 8-14 μm. The performance of this bolometer, comparing with that of bolometer with common VOx, has a better result. At 20 Hz frequency and 10 μA bias current, the bolometer with high TCR has reached detectivity of 1.0 × 109 cm Hz1/2/W. It also indicates that this nanostructured VOx thin film has not only a higher TCR but also a lower noise than common VOx thin film without annealing.

Spectroscopic Terahertz Imaging at Room Temperature Employing Microbolometer Terahertz Sensors and Its Application to the Study of Carcinoma Tissues

PubMed Central

Kašalynas, Irmantas; Venckevičius, Rimvydas; Minkevičius, Linas; Sešek, Aleksander; Wahaia, Faustino; Tamošiūnas, Vincas; Voisiat, Bogdan; Seliuta, Dalius; Valušis, Gintaras; Švigelj, Andrej; Trontelj, Janez

2016-01-01

A terahertz (THz) imaging system based on narrow band microbolometer sensors (NBMS) and a novel diffractive lens was developed for spectroscopic microscopy applications. The frequency response characteristics of the THz antenna-coupled NBMS were determined employing Fourier transform spectroscopy. The NBMS was found to be a very sensitive frequency selective sensor which was used to develop a compact all-electronic system for multispectral THz measurements. This system was successfully applied for principal components analysis of optically opaque packed samples. A thin diffractive lens with a numerical aperture of 0.62 was proposed for the reduction of system dimensions. The THz imaging system enhanced with novel optics was used to image for the first time non-neoplastic and neoplastic human colon tissues with close to wavelength-limited spatial resolution at 584 GHz frequency. The results demonstrated the new potential of compact RT THz imaging systems in the fields of spectroscopic analysis of materials and medical diagnostics. PMID:27023551

Further applications for mosaic pixel FPA technology

NASA Astrophysics Data System (ADS)

Liddiard, Kevin C.

2011-06-01

In previous papers to this SPIE forum the development of novel technology for next generation PIR security sensors has been described. This technology combines the mosaic pixel FPA concept with low cost optics and purpose-designed readout electronics to provide a higher performance and affordable alternative to current PIR sensor technology, including an imaging capability. Progressive development has resulted in increased performance and transition from conventional microbolometer fabrication to manufacture on 8 or 12 inch CMOS/MEMS fabrication lines. A number of spin-off applications have been identified. In this paper two specific applications are highlighted: high performance imaging IRFPA design and forest fire detection. The former involves optional design for small pixel high performance imaging. The latter involves cheap expendable sensors which can detect approaching fire fronts and send alarms with positional data via mobile phone or satellite link. We also introduce to this SPIE forum the application of microbolometer IR sensor technology to IoT, the Internet of Things.

Third-generation imaging sensor system concepts

NASA Astrophysics Data System (ADS)

Reago, Donald A.; Horn, Stuart B.; Campbell, James, Jr.; Vollmerhausen, Richard H.

1999-07-01

Second generation forward looking infrared sensors, based on either parallel scanning, long wave (8 - 12 um) time delay and integration HgCdTe detectors or mid wave (3 - 5 um), medium format staring (640 X 480 pixels) InSb detectors, are being fielded. The science and technology community is now turning its attention toward the definition of a future third generation of FLIR sensors, based on emerging research and development efforts. Modeled third generation sensor performance demonstrates a significant improvement in performance over second generation, resulting in enhanced lethality and survivability on the future battlefield. In this paper we present the current thinking on what third generation sensors systems will be and the resulting requirements for third generation focal plane array detectors. Three classes of sensors have been identified. The high performance sensor will contain a megapixel or larger array with at least two colors. Higher operating temperatures will also be the goal here so that power and weight can be reduced. A high performance uncooled sensor is also envisioned that will perform somewhere between first and second generation cooled detectors, but at significantly lower cost, weight, and power. The final third generation sensor is a very low cost micro sensor. This sensor can open up a whole new IR market because of its small size, weight, and cost. Future unattended throwaway sensors, micro UAVs, and helmet mounted IR cameras will be the result of this new class.

Evaluation of fatigue-prone details using a low-cost thermoelastic stress analysis system.

DOT National Transportation Integrated Search

2016-11-01

This study was designed to develop a novel approach for in situ evaluation of stress fields in the vicinity of fatigue-prone details on highway bridges using a low-cost microbolometer thermal imager. : The method was adapted into a field-deployable i...

Cloud Optical Depth Measured with Ground-Based, Uncooled Infrared Imagers

NASA Technical Reports Server (NTRS)

Shaw, Joseph A.; Nugent, Paul W.; Pust, Nathan J.; Redman, Brian J.; Piazzolla, Sabino

2012-01-01

Recent advances in uncooled, low-cost, long-wave infrared imagers provide excellent opportunities for remotely deployed ground-based remote sensing systems. However, the use of these imagers in demanding atmospheric sensing applications requires that careful attention be paid to characterizing and calibrating the system. We have developed and are using several versions of the ground-based "Infrared Cloud Imager (ICI)" instrument to measure spatial and temporal statistics of clouds and cloud optical depth or attenuation for both climate research and Earth-space optical communications path characterization. In this paper we summarize the ICI instruments and calibration methodology, then show ICI-derived cloud optical depths that are validated using a dual-polarization cloud lidar system for thin clouds (optical depth of approximately 4 or less).

Development of detailed design concepts for the EarthCARE multi-spectral imager

NASA Astrophysics Data System (ADS)

Lobb, Dan; Escadero, Isabel; Chang, Mark; Gode, Sophie

2017-11-01

The EarthCARE mission is dedicated to the study of clouds by observations from a satellite in low Earth orbit. The payload will include major radar and LIDAR instruments, supported by a multi-spectral imager (MSI) and a broadband radiometer. The paper describes development of detailed design concepts for the MSI, and analysis of critical performance parameters. The MSI will form Earth images at 500m ground sample distance (GSD) over a swath width of 150km, from a nominal platform altitude of around 400km. The task of the MSI is to provide spatial context for the single-point measurements made by the radar and LIDAR systems; it will image Earth in 7 spectral bands: one visible, one near-IR, two short-wave IR and three thermal IR. The MSI instrument will be formed in two parts: a visible-NIR-SWIR (VNS) system, radiometrically calibrated using a sunilluminated diffuser, and a thermal IR (TIR) system calibrated using cold space and an internal black-body. The VNS system will perform push-broom imaging, using linear array detectors (silicon and InGaAs) and 4 separate lenses. The TIR system will use a microbolometer array detector in a time delay and integration (TDI) mode. Critical issues discussed for the VNS system include detector selection and detailed optical design trade-offs. The latter are related to the desirability of dichroics to achieve a common aperture, which influences the calibration hardware and lens design. The TIR system's most significant problems relate to control of random noise and bias errors, requiring optimisation of detector operation and calibration procedures.

Design and simulation of multi-color infrared CMOS metamaterial absorbers

NASA Astrophysics Data System (ADS)

Cheng, Zhengxi; Chen, Yongping; Ma, Bin

2016-05-01

Metamaterial electromagnetic wave absorbers, which usually can be fabricated in a low weight thin film structure, have a near unity absorptivity in a special waveband, and therefore have been widely applied from microwave to optical waveband. To increase absorptance of CMOS MEMS devices in 2-5 μmm waveband, multi-color infrared metamaterial absorbers are designed with CSMC 0.5 μmm 2P3M and 0.18 μmm 1P6M CMOS technology in this work. Metal-insulator-metal (MIM) three-layer MMAs and Insulator-metal-insulator-metal (MIMI) four-layer MMAs are formed by CMOS metal interconnect layers and inter metal dielectrics layer. To broaden absorption waveband in 2-5μmm range, MMAs with a combination of different sizes cross bars are designed. The top metal layer is a periodic aluminum square array or cross bar array with width ranging from submicron to several microns. The absorption peak position and intensity of MMAs can be tuned by adjusting the top aluminum micro structure array. Post-CMOS process is adopted to fabricate MMAs. The infrared absorption spectra of MMAs are verified with finite element method simulation, and the effects of top metal structure sizes, patterns, and films thickness are also simulated and intensively discussed. The simulation results show that CMOS MEMS MMAs enhance infrared absorption in 2-20 μmm. The MIM broad MMA has an average absorptance of 0.22 in 2-5 μmm waveband, and 0.76 in 8-14 μm waveband. The CMOS metamaterial absorbers can be inherently integrated in many kinds of MEMS devices fabricated with CMOS technology, such as uncooled bolometers, infrared thermal emitters.

Development of a 150-GHz MMIC Module Prototype for Large-Scale CMB Radiation

NASA Technical Reports Server (NTRS)

Kangaslahti, Pekka P.; Samoska, Lorene A.; Gaier, Todd C.; Soria, Mary M.; Lau, Judy M.; Sieth, Matthew M.; VanWinkle, Daniel; Tantawi, Sami

2011-01-01

HEMT-based receiver arrays with excellent noise and scalability are already starting to be manufactured at 100 GHz, but the advances in technology should make it possible to develop receiver modules with even greater operation frequency up to 200 GHz. A prototype heterodyne amplifier module has been developed for operation from 140 to 170 GHz using monolithic millimeter-wave integrated circuit (MMIC) low-noise InP high electron mobility transistor (HEMT) amplifiers. The compact, scalable module is centered on the 150-GHz atmospheric window using components known to operate well at these frequencies. Arrays equipped with hundreds of these modules can be optimized for many different astrophysical measurement techniques, including spectroscopy and interferometry. This module is a heterodyne receiver module that is extremely compact, and makes use of 35-nm InP HEMT technology, and which has been shown to have excellent noise temperatures when cooled cryogenically to 30 K. This reduction in system noise over prior art has been demonstrated in commercial mixers (uncooled) at frequencies of 160-180 GHz. The module is expected to achieve a system noise temperature of 60 K when cooled. An MMIC amplifier module has been designed to demonstrate the feasibility of expanding heterodyne amplifier technology to the 140 to 170-GHz frequency range for astronomical observations. The miniaturization of many standard components and the refinement of RF interconnect technology have cleared the way to mass-production of heterodyne amplifier receivers, making it a feasible technology for many large-population arrays. This work furthers the recent research efforts in compact coherent receiver modules, including the development of the Q/U Imaging ExperimenT (QUIET) modules centered at 40 and 90 GHz, and the production of heterodyne module prototypes at 90 GHz.

Array-based infra-red detection: an enabling technology for people counting, sensing, tracking, and intelligent detection

NASA Astrophysics Data System (ADS)

Stogdale, Nick; Hollock, Steve; Johnson, Neil; Sumpter, Neil

2003-09-01

A 16x16 element un-cooled pyroelectric detector array has been developed which, when allied with advanced tracking and detection algorithms, has created a universal detector with multiple applications. Low-cost manufacturing techniques are used to fabricate a hybrid detector, intended for economic use in commercial markets. The detector has found extensive application in accurate people counting, detection, tracking, secure area protection, directional sensing and area violation; topics which are all pertinent to the provision of Homeland Security. The detection and tracking algorithms have, when allied with interpolation techniques, allowed a performance much higher than might be expected from a 16x16 array. This paper reviews the technology, with particular attention to the array structure, algorithms and interpolation techniques and outlines its application in a number of challenging market areas. Viewed from above, moving people are seen as 'hot blobs' moving through the field of view of the detector; background clutter or stationary objects are not seen and the detector works irrespective of lighting or environmental conditions. Advanced algorithms detect the people and extract size, shape, direction and velocity vectors allowing the number of people to be detected and their trajectories of motion to be tracked. Provision of virtual lines in the scene allows bi-directional counting of people flowing in and out of an entrance or area. Definition of a virtual closed area in the scene allows counting of the presence of stationary people within a defined area. Definition of 'counting lines' allows the counting of people, the ability to augment access control devices by confirming a 'one swipe one entry' judgement and analysis of the flow and destination of moving people. For example, passing the 'wrong way' up a denied passageway can be detected. Counting stationary people within a 'defined area' allows the behaviour and size of groups of stationary people to be analysed and counted, an alarm condition can also be generated when people stray into such areas.

Access control violation prevention by low-cost infrared detection

NASA Astrophysics Data System (ADS)

Rimmer, Andrew N.

2004-09-01

A low cost 16x16 un-cooled pyroelectric detector array, allied with advanced tracking and detection algorithms, has enabled the development of a universal detector with a wide range of applications in people monitoring and homeland security. Violation of access control systems, whether controlled by proximity card, biometrics, swipe card or similar, may occur by 'tailgating' or 'piggybacking' where an 'approved' entrant with a valid entry card is accompanied by a closely spaced 'non-approved' entrant. The violation may be under duress, where the accompanying person is attempting to enter a secure facility by force or threat. Alternatively, the violation may be benign where staff members collude either through habit or lassitude, either with each other or with third parties, without considering the security consequences. Examples of the latter could include schools, hospitals or maternity homes. The 16x16 pyroelectric array is integrated into a detector or imaging system which incorporates data processing, target extraction and decision making algorithms. The algorithms apply interpolation to the array output, allowing a higher level of resolution than might otherwise be expected from such a low resolution array. The pyroelectric detection principle means that the detection will work in variable light conditions and even in complete darkness, if required. The algorithms can monitor the shape, form, temperature and number of persons in the scene and utilise this information to determine whether a violation has occurred or not. As people are seen as 'hot blobs' and are not individually recognisable, civil liberties are not infringed in the detection process. The output from the detector is a simple alarm signal which may act as input to the access control system as an alert or to trigger CCTV image display and storage. The applications for a tailgate detector can be demonstrated across many medium security applications where there are no physical means to prevent this type of security breach.

High-speed uncooled MWIR hostile fire indication sensor

NASA Astrophysics Data System (ADS)

Zhang, L.; Pantuso, F. P.; Jin, G.; Mazurenko, A.; Erdtmann, M.; Radhakrishnan, S.; Salerno, J.

2011-06-01

Hostile fire indication (HFI) systems require high-resolution sensor operation at extremely high speeds to capture hostile fire events, including rocket-propelled grenades, anti-aircraft artillery, heavy machine guns, anti-tank guided missiles and small arms. HFI must also be conducted in a waveband with large available signal and low background clutter, in particular the mid-wavelength infrared (MWIR). The shortcoming of current HFI sensors in the MWIR is the bandwidth of the sensor is not sufficient to achieve the required frame rate at the high sensor resolution. Furthermore, current HFI sensors require cryogenic cooling that contributes to size, weight, and power (SWAP) in aircraft-mounted applications where these factors are at a premium. Based on its uncooled photomechanical infrared imaging technology, Agiltron has developed a low-SWAP, high-speed MWIR HFI sensor that breaks the bandwidth bottleneck typical of current infrared sensors. This accomplishment is made possible by using a commercial-off-the-shelf, high-performance visible imager as the readout integrated circuit and physically separating this visible imager from the MWIR-optimized photomechanical sensor chip. With this approach, we have achieved high-resolution operation of our MWIR HFI sensor at 1000 fps, which is unprecedented for an uncooled infrared sensor. We have field tested our MWIR HFI sensor for detecting all hostile fire events mentioned above at several test ranges under a wide range of environmental conditions. The field testing results will be presented.

Electrical and Infrared Optical Properties of Vanadium Oxide Semiconducting Thin-Film Thermometers

NASA Astrophysics Data System (ADS)

Zia, Muhammad Fakhar; Abdel-Rahman, Mohamed; Alduraibi, Mohammad; Ilahi, Bouraoui; Awad, Ehab; Majzoub, Sohaib

2017-10-01

A synthesis method has been developed for preparation of vanadium oxide thermometer thin film for microbolometer application. The structure presented is a 95-nm thin film prepared by sputter-depositing nine alternating multilayer thin films of vanadium pentoxide (V2O5) with thickness of 15 nm and vanadium with thickness of 5 nm followed by postdeposition annealing at 300°C in nitrogen (N2) and oxygen (O2) atmospheres. The resulting vanadium oxide (V x O y ) thermometer thin films exhibited temperature coefficient of resistance (TCR) of -3.55%/°C with room-temperature resistivity of 2.68 Ω cm for structures annealed in N2 atmosphere, and TCR of -3.06%/°C with room-temperature resistivity of 0.84 Ω cm for structures annealed in O2 atmosphere. Furthermore, optical measurements of N2- and O2-annealed samples were performed by Fourier-transform infrared ellipsometry to determine their dispersion curves, refractive index ( n), and extinction coefficient ( k) at wavelength from 7000 nm to 14,000 nm. The results indicate the possibility of applying the developed materials in thermometers for microbolometers.

Thin film materials and devices for resistive temperature sensing applications

NASA Astrophysics Data System (ADS)

Basantani, Hitesh A.

Thin films of vanadium oxide (VOx) and hydrogenated amorphous silicon (a-Si:H) are the two dominant material systems used in resistive infrared radiation detectors (microbolometers) for sensing long wave infrared (LWIR) wavelengths in the 8--14 microm range. Typical thin films of VO x (x < 2) currently used in the bolometer industry have a magnitude of temperature coefficient of resistance (TCR) between 2%/K -- 3%/K. In contrast, thin films of hydrogenated germanium (SiGe:H) have |TCR| between 3%/K to 4%/K. Devices made from either of these materials have resulted in similar device performance with NETD ≈ 25 mK. The performance of the microbolometers is limited by the electronic noise, especially 1/f noise. Therefore, regardless of the choice of bolometer sensing material and read out circuitry, manufacturers are constantly striving to reduce 1/f noise while simultaneously increasing TCR to give better signal to noise ratios in their bolometers and ultimately, better image quality with more thermal information to the end user. In this work, thin films of VOx and hydrogenated germanium (Ge:H), having TCR values > 4 %/K are investigated as potential candidates for higher sensitivity next generation of microbolometers. Thin films of VO x were deposited by Biased Target Ion Beam Deposition (BTIBD) (˜85 nm thick). Electrical characterization of lateral resistor structures showed resistivity ranging from 104 O--cm to 2.1 x 104 O--cm, TCR varying from --4%/K to --5%/K, normalized Hooge parameter (alphaH/n) of 5 x 10 -21 to 5 x 10-18 cm3. Thin films of Ge:H were deposited by plasma enhanced chemical vapor deposition (PECVD) by incorporating an increasing amount of crystal fraction in the growing thin films. Thin films of Ge:H having a mixed phase, amorphous + nanocrystalline, having a |TCR| > 6 %/K were deposited with resistivity < 2,300 O--cm and a normalized Hooge's parameter 'alphaH/n' < 2 x 10-20 cm3. Higher TCR materials are desired, however, such materials have higher resistivity and therefore unacceptable large electrical resistance in a lateral resistor configuration. This work looks at an alternate bolometer device design which incorporates higher TCR materials in a vertically integrated configuration. Thin films of high TCR hydrogenated germanium (Ge:H, |TCR| > 6%/K) and vanadium oxide (VOx, TCR > 5%/K) were integrated in lateral and through film configuration. The electrical performance of the vertically integrated devices is compared with lateral resistance structures. It was confirmed experimentally that the device impedance was significantly lowered while maintaining the signal to noise ratio of the lateral resistor configuration. The vertically integrated devices allow higher device currents without any increase in self heating. These structures may help reduce integration time and may result in higher frame rate. Finally, one dimensional arrays were fabricated using both lateral and vertically integrated configurations and their performance was evaluated. It was found that the performance of the lateral devices was limited by noise floor of the measurement setup used. However, due to the lower impedance of the vertically integrated resistors, a higher signal and therefore higher signal to noise ratio could be obtained. These vertically integrated devices exhibited low RMS noise values of 12 mK.

Thales Angenieux recent progress in night vision technology

NASA Astrophysics Data System (ADS)

Rollin, Joel; Teszner, Jean Louis; Espie, Jean-Luc

2004-02-01

Uncooled LWIR technology yields now an attractive alternative within the thermal sights area: TAGX launched one year ago, a new product line ELVIR, promoting cost-efficient solutions whilst meeting performances that are likely to suit most hand-held military purposes. We backed on our earnest skills on previous in-house made equipment such as light intensifier goggles, to reach the best trends, both complying with operational demands and current market prices. The very first step which is aiming at settling the main device characteristics will be emphasized thought typical requirements upon current customer"s requests: quick and flexible range computations models should answer that purpose and we will rely on operational feed back. ELVIR is built around micro- bolometer arrays that are available in France: a very best effort was done on each cost budget contributor, involving mechanics, electronics and optics. As detailed hereafter, many improvements were steered up by the latest research outcomes, partly sponsored by the French DGA, as, for instance, low cost LWIR lenses already off-the-shelves in France thanks to the UMICORE IR Glass Company. All these compromises will be displayed

Passive Collision Avoidance System for UAS

DTIC Science & Technology

2008-09-01

feasibility of using SWAP efficient LWIR microbolometers as outlined in the Priest report circa 1998 as a solution to the collision avoidance problems for UASs...81 7.3 LWIR Multispectral Sensor ..........................................................................................84 7.4 LWIR ... LWIR image of the Ultralight. Muffler runs at approximately 1200 F. ......................32 Figure 36: 3D model of LVDS circuit board with L-3

Fabrication of a 20.5-inch-diameter segmented silicon annular optic prototype for the ROMA program

NASA Astrophysics Data System (ADS)

Hassell, Frank R.; Groark, Frank M.

1995-10-01

Recent advancements in single crystal silicon material science and fabrication capabilities and very low absorption (VLA) multi-layer dielectric coating technology have led to the development of uncooled, large aperture, high power mirrors for high energy laser (HEL) systems. Based on this success, a segmented single-crystal silicon substrate concept has been selected as the baseline fabrication approach for uncooled 1.2 meter diameter resonator annular optics for the Alpha space based high energy laser. The objective of this Resonator Optics Materials Assessment (ROMA) task was to demonstrate all of the key fabrication processes required to fabricate the full sized annular optics for the Alpha space based high energy laser. This paper documents the fabrication of a half-scale annular optic prototype (AOP) of the Alpha laser rear cone.

Solution-processed nanoparticle super-float-gated organic field-effect transistor as un-cooled ultraviolet and infrared photon counter.

PubMed

Yuan, Yongbo; Dong, Qingfeng; Yang, Bin; Guo, Fawen; Zhang, Qi; Han, Ming; Huang, Jinsong

2013-01-01

High sensitivity photodetectors in ultraviolet (UV) and infrared (IR) range have broad civilian and military applications. Here we report on an un-cooled solution-processed UV-IR photon counter based on modified organic field-effect transistors. This type of UV detectors have light absorbing zinc oxide nanoparticles (NPs) sandwiched between two gate dielectric layers as a floating gate. The photon-generated charges on the floating gate cause high resistance regions in the transistor channel and tune the source-drain output current. This "super-float-gating" mechanism enables very high sensitivity photodetectors with a minimum detectable ultraviolet light intensity of 2.6 photons/μm(2)s at room temperature as well as photon counting capability. Based on same mechansim, infrared photodetectors with lead sulfide NPs as light absorbing materials have also been demonstrated.

Uncooled pump combiners for fiber laser and amplifier systems

NASA Astrophysics Data System (ADS)

Bansal, L.; Sienkowski, R.; Neale, C.; Mann, J.; Headley, C.

2018-02-01

In this work we demonstrate a high transmission pump combiner that can operate uncooled at a maximum power of 400W for a continuous duration of 100hrs. The 7x1 pump combiner has seven 105/125 μm diameter 0.22 NA input pump fibers and a 247 μm diameter and 0.22 NA glass clad output fiber. The combiner has a high, 99%, pump transmission efficiency. These devices withstand without failure, a series of environmental stress tests, namely Thermal Cycling (-40 to 85ºC) and Damp Humidity (85ºC/85RH). These tests are conducted to uncover any latent defects in the device structure. The combiner's also survive an elevated temperature of 75ºC at a power of 365W for duration of 5hrs, without any noticeable change in pump transmission.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kagan, Daniel; Nakar, Ehud; Piran, Tsvi, E-mail: daniel.kagan@mail.huji.ac.il

The maximum synchrotron burnoff limit of 160 MeV represents a fundamental limit to radiation resulting from electromagnetic particle acceleration in one-zone ideal plasmas. In magnetic reconnection, however, particle acceleration and radiation are decoupled because the electric field is larger than the magnetic field in the diffusion region. We carry out two-dimensional particle-in-cell simulations to determine the extent to which magnetic reconnection can produce synchrotron radiation above the burnoff limit. We use the test particle comparison (TPC) method to isolate the effects of cooling by comparing the trajectories and acceleration efficiencies of test particles incident on such a reconnection region withmore » and without cooling them. We find that the cooled and uncooled particle trajectories are typically similar during acceleration in the reconnection region, and derive an effective limit on particle acceleration that is inversely proportional to the average magnetic field experienced by the particle during acceleration. Using the calculated distribution of this average magnetic field as a function of uncooled final particle energy, we find analytically that cooling does not affect power-law particle energy spectra except at energies far above the synchrotron burnoff limit. Finally, we compare fully cooled and uncooled simulations of reconnection, confirming that the synchrotron burnoff limit does not produce a cutoff in the particle energy spectrum. Our results indicate that the TPC method accurately predicts the effects of cooling on particle acceleration in relativistic reconnection, and that, even far above the burnoff limit, the synchrotron energy of radiation produced in reconnection is not limited by cooling.« less

Spiral Antenna-Coupled Microbridge Structures for THz Application.

PubMed

Gou, Jun; Zhang, Tian; Wang, Jun; Jiang, Yadong

2017-12-01

Bolometer sensor is a good candidate for THz imaging due to its compact system, low cost, and wideband operation. Based on infrared microbolometer structures, two kinds of antenna-coupled microbridge structures are proposed with different spiral antennas: spiral antenna on support layer and spiral antenna with extended legs. Aiming at applications in detection and imaging, simulations are carried out mainly for optimized absorption at 2.52 THz, which is the radiation frequency of far-infrared CO 2 lasers. The effects of rotation angle, line width, and spacing of the spiral antenna on THz wave absorption of microbridge structures are discussed. Spiral antenna, with extended legs, is a good solution for high absorption rate at low absorption frequency and can be used as electrode lead simultaneously for simplified manufacturing process. A spiral antenna-coupled microbridge structure with an absorption rate of more than 75% at 2.52 THz is achieved by optimizing the structure parameters. This research demonstrates the use of different spiral antennas for enhanced and tunable THz absorption of microbridge structures and provides an effective way to fabricate THz microbolometer detectors with great potential in the application of real-time THz imaging.

Modular uncooled video engines based on a DSP processor

NASA Astrophysics Data System (ADS)

Schapiro, F.; Milstain, Y.; Aharon, A.; Neboshchik, A.; Ben-Simon, Y.; Kogan, I.; Lerman, I.; Mizrahi, U.; Maayani, S.; Amsterdam, A.; Vaserman, I.; Duman, O.; Gazit, R.

2011-06-01

The market demand for low SWaP (Size, Weight and Power) uncooled engines keeps growing. Low SWaP is especially critical in battery-operated applications such as goggles and Thermal Weapon Sights. A new approach for the design of the engines was implemented by SCD to optimize size and power consumption at system level. The new approach described in the paper, consists of: 1. A modular hardware design that allows the user to define the exact level of integration needed for his system 2. An "open architecture" based on the OMAPTM530 DSP that allows the integrator to take advantage of unused hardware (FPGA) and software (DSP) resources, for implementation of additional algorithms or functionality. The approach was successfully implemented on the first generation of 25μm pitch BIRD detectors, and more recently on the new, 640 x480, 17 μm pitch detector.

Development of the infrared instrument for gas detection

NASA Astrophysics Data System (ADS)

Chen, Ching-Wei; Chen, Chia-Ray

2017-08-01

MWIR (Mid-Wave Infrared) spectroscopy shows a large potential in the current IR devices market, due to its multiple applications, such as gas detection, chemical analysis, industrial monitoring, combustion and flame characterization. It opens this technique to the fields of application, such as industrial monitoring and control, agriculture and environmental monitoring. However, a major barrier, which is the lack of affordable specific key elements such a MWIR light sources and low cost uncooled detectors, have held it back from its widespread use. In this paper an uncooled MWIR detector combined with image enhancement technique is reported. This investigation shows good results in gas leakage detection test. It also verify the functions of self-developed MWIR lens and optics. A good agreement in theoretical design and experiment give us the lessons learned for the potential application in infrared satellite technology. A brief discussions will also be presented in this paper.

Cooled variable nozzle radial turbine for rotor craft applications

NASA Technical Reports Server (NTRS)

Rogo, C.

1981-01-01

An advanced, small 2.27 kb/sec (5 lbs/sec), high temperature, variable area radial turbine was studied for a rotor craft application. Variable capacity cycles including single-shaft and free-turbine engine configurations were analyzed to define an optimum engine design configuration. Parametric optimizations were made on cooled and uncooled rotor configurations. A detailed structural and heat transfer analysis was conducted to provide a 4000-hour life HP turbine with material properties of the 1988 time frame. A pivoted vane and a moveable sidewall geometry were analyzed. Cooling and variable geometry penalties were included in the cycle analysis. A variable geometry free-turbine engine configuration with a design 1477K (2200 F) inlet temperature and a compressor pressure ratio of 16:1 was selected. An uncooled HP radial turbine rotor with a moveable sidewall nozzle showed the highest performance potential for a time weighted duty cycle.

Uncooled tunneling infrared sensor

NASA Technical Reports Server (NTRS)

Kenny, Thomas W. (Inventor); Kaiser, William J. (Inventor); Podosek, Judith A. (Inventor); Vote, Erika C. (Inventor); Muller, Richard E. (Inventor); Maker, Paul D. (Inventor)

1995-01-01

An uncooled infrared tunneling sensor in which the only moving part is a diaphragm which is deflected into contact with a micromachined silicon tip electrode prepared by a novel lithographic process. Similarly prepared deflection electrodes employ electrostatic force to control the deflection of a silicon nitride, flat diaphragm membrane. The diaphragm exhibits a high resonant frequency which reduces the sensor's sensitivity to vibration. A high bandwidth feedback circuit controls the tunneling current by adjusting the deflection voltage to maintain a constant deflection of the membrane. The resulting infrared sensor can be miniaturized to pixel dimensions smaller than 100 .mu.m. An alternative embodiment is implemented using a corrugated membrane to permit large deflection without complicated clamping and high deflection voltages. The alternative embodiment also employs a pinhole aperture in a membrane to accommodate environmental temperature variation and a sealed chamber to eliminate environmental contamination of the tunneling electrodes and undesireable accoustic coupling to the sensor.

Thermal Damage Done to Bone by Burring and Sawing With and Without Irrigation in Knee Arthroplasty.

PubMed

Tawy, Gwenllian F; Rowe, Philip J; Riches, Philip E

2016-05-01

Heat from bone resecting tools used in knee surgery can induce thermal osteonecrosis, potentially causing aseptic implant loosening. This study compared oscillating saws to burrs in terms of temperature generation and histologic damage. Use of irrigation to reduce bone temperature was also investigated. Temperatures were recorded during sawing and burring with or without irrigation (uncooled or cooled). Histologic analyses were then carried out. Differences between groups were tested statistically (α = 0.05). On average, burring produced higher temperatures than sawing (P < .001). When uncooled irrigation was used, bone temperatures were significantly lower in sawed bone than in burred bone (P < .001). Irrigation lowered temperatures and thermal damage depths and increased osteocyte viability (P < .001). These results suggest that irrigating bone during resection could prevent osteonecrosis onset. Copyright © 2016 Elsevier Inc. All rights reserved.

Uncooled infrared photodetectors in Poland

NASA Astrophysics Data System (ADS)

Piotrowski, Jozef; Piotrowski, Adam

2005-09-01

The history and present status of the middle and long wavelength Hg1xCdxTe infrared detectors in Poland are reviewed. Research and development efforts in Poland were concentrated mostly on uncooled market niche. Technology of the infrared photodetectors has been developed by several research groups. The devices are based on mercury-based variable band gap semiconductor alloys. Modified isothermal vapor phase epitaxy (ISOVPE) has been used for many years for research and commercial fabrication of photoconductive, photoelectromagnetic and other devices. Bulk growth and liquid phase epitaxy was also used. At present, the fabrication of IR devices relies on low temperature epitaxial technique, namely metalorganic vapor phase deposition (MOCVD), frequently in combination with the ISOVPE. Photoconductive and photoelectromagnetic detectors are still in production. The devices are gradually replaced with photovoltaic devices which offer inherent advantages of no electric or magnetic bias, no heat load and no flicker noise. Potentially, the PV devices could offer high performance and very fast response. Actually, the uncooled long wavelength devices of conventional design suffer from two issues; namely low quantum efficiency and very low junction resistance. It makes them useless for practical applications. The problems have been solved with advanced 3D band gap engineered architecture, multiple cell heterojunction devices connected in series, monolithic integration of the detectors with microoptics and other improvements. Present fabrication program includes devices which are optimized for operation at any wavelength within a wide spectral range 1-15 μm and 200-300 K temperature range. Special solutions have been applied to improve speed of response. Some devices show picoseconds range response time. The devices have found numerous civilian and military applications.

Novel fast catadioptric objective with wide field of view

NASA Astrophysics Data System (ADS)

Muñoz, Fernando; Infante Herrero, José M.; Benítez, Pablo; Miñano, Juan C.; Lin, Wang; Vilaplana, Juan; Biot, Guillermo; de la Fuente, Marta

2010-08-01

Using the Simultaneous Multiple Surface method in 2D (SMS2D), we present a fast catadioptric objective with a wide field of view (125°×96°) designed for a microbolometer detector with 640×480 pixels and 25 microns pixel pitch Keywords: Infrared lens design, thermal imaging, Schwarzschild configuration, SMS2D, wide field of view, driving cameras, panoramic systems

Strategic options towards an affordable high-performance infrared camera

NASA Astrophysics Data System (ADS)

Oduor, Patrick; Mizuno, Genki; Dutta, Achyut K.; Lewis, Jay; Dhar, Nibir K.

2016-05-01

The promise of infrared (IR) imaging attaining low-cost akin to CMOS sensors success has been hampered by the inability to achieve cost advantages that are necessary for crossover from military and industrial applications into the consumer and mass-scale commercial realm despite well documented advantages. Banpil Photonics is developing affordable IR cameras by adopting new strategies to speed-up the decline of the IR camera cost curve. We present a new short-wave IR (SWIR) camera; 640x512 pixel InGaAs uncooled system that is high sensitivity low noise (<50e-), high dynamic range (100 dB), high-frame rates (> 500 frames per second (FPS)) at full resolution, and low power consumption (< 1 W) in a compact system. This camera paves the way towards mass market adoption by not only demonstrating high-performance IR imaging capability value add demanded by military and industrial application, but also illuminates a path towards justifiable price points essential for consumer facing application industries such as automotive, medical, and security imaging adoption. Among the strategic options presented include new sensor manufacturing technologies that scale favorably towards automation, multi-focal plane array compatible readout electronics, and dense or ultra-small pixel pitch devices.

Surface plasmon-enhanced dual-band infrared absorber for {{VO}}_{{\\boldsymbol{x}}}-based microbolometer application

NASA Astrophysics Data System (ADS)

Li, Qi; Yu, Bing-qiang; Li, Zhao-feng; Wang, Xiao-feng; Zhang, Zi-chen; Pan, Ling-feng

2017-08-01

Not Available Project supported by the One Hundred Talents Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China (Grant Nos. 61376083 and 61307077), the China Postdoctoral Science Foundation (Grant Nos. 2013M530613 and 2015T80080), and the Guangxi Key Laboratory of Precision Navigation Technology and Application (Grant Nos. DH201505, DH201510, and DH201511).

Antenna-coupled high T.sub.c superconducting microbolometer

DOEpatents

Hu, Qing

1992-01-01

A device is provided for measuring radiant energy, the device comprising a substrate; a bolometer formed from a high T.sub.c superconducting material disposed on the substrate in an area that is about 1.times.5 .mu.m.sup.2 and about 0.02 .mu.m in depth; and a planar antenna disposed on the substrate and coupled to receive radiation and to impart the received radiation to the bolometer.

Frequency Modulation and Absorption Improvement of THz Micro-bolometer with Micro-bridge Structure by Spiral-Type Antennas

NASA Astrophysics Data System (ADS)

Gou, Jun; Niu, Qingchen; Liang, Kai; Wang, Jun; Jiang, Yadong

2018-03-01

Antenna-coupled micro-bridge structure is proven to be a good solution to extend infrared micro-bolometer technology for THz application. Spiral-type antennas are proposed in 25 μm × 25 μm micro-bridge structure with a single separate linear antenna, two separate linear antennas, or two connected linear antennas on the bridge legs, in addition to traditional spiral-type antenna on the support layer. The effects of structural parameters of each antenna on THz absorption of micro-bridge structure are discussed for optimized absorption of 2.52 THz wave radiated by far infrared CO2 lasers. The design of spiral-type antenna with two separate linear antennas for wide absorption peak and spiral-type antenna with two connected linear antennas for relatively stable absorption are good candidates for high absorption at low absorption frequency with a rotation angle of 360* n ( n = 1.6). Spiral-type antenna with extended legs also provides a highly integrated micro-bridge structure with fast response and a highly compatible, process-simplified way to realize the structure. This research demonstrates the design of several spiral-type antenna-coupled micro-bridge structures and provides preferred schemes for potential device applications in room temperature sensing and real-time imaging.

Frequency Modulation and Absorption Improvement of THz Micro-bolometer with Micro-bridge Structure by Spiral-Type Antennas.

PubMed

Gou, Jun; Niu, Qingchen; Liang, Kai; Wang, Jun; Jiang, Yadong

2018-03-05

Antenna-coupled micro-bridge structure is proven to be a good solution to extend infrared micro-bolometer technology for THz application. Spiral-type antennas are proposed in 25 μm × 25 μm micro-bridge structure with a single separate linear antenna, two separate linear antennas, or two connected linear antennas on the bridge legs, in addition to traditional spiral-type antenna on the support layer. The effects of structural parameters of each antenna on THz absorption of micro-bridge structure are discussed for optimized absorption of 2.52 THz wave radiated by far infrared CO 2 lasers. The design of spiral-type antenna with two separate linear antennas for wide absorption peak and spiral-type antenna with two connected linear antennas for relatively stable absorption are good candidates for high absorption at low absorption frequency with a rotation angle of 360*n (n = 1.6). Spiral-type antenna with extended legs also provides a highly integrated micro-bridge structure with fast response and a highly compatible, process-simplified way to realize the structure. This research demonstrates the design of several spiral-type antenna-coupled micro-bridge structures and provides preferred schemes for potential device applications in room temperature sensing and real-time imaging.

Integration of uncooled scraper elements and its diagnostics into Wendelstein 7-X

DOE PAGES

Fellinger, Joris; Loesser, Doug; Neilson, Hutch; ...

2017-08-08

The modular stellarator Wendelstein 7-X in Greifswald (Germany) successfully started operation in 2015 with short pulse limiter plasmas. In 2017, the next operation phase (OP) OP1.2 will start once 10 uncooled test divertor units (TDU) with graphite armor will be installed. The TDUs allow for plasma pulses of 10 s with 8 MW heating. OP2, allowing for steady state operation, is planned for 2020 after the TDUs will be replaced by 10 water cooled CFC armored divertors. Due to the development of plasma currents like bootstrap currents in long pulse plasmas in OP2, the plasma could hit the edge ofmore » the divertor targets which has a reduced cooling capacity compared to the central part of the target tiles. To prevent overloading of these edges, a so-called scraper element can be positioned in front of the divertor, intersecting those strike lines that would otherwise hit the divertor edges. As a result, these edges are protected but as a drawback the pumping efficiency of neutrals is also reduced. As a test an uncooled scraper element with graphite tiles will be placed in two out of ten half modules in OP1.2. A decision to install ten water cooled scraper elements for OP2 is pending on the results of this test in OP1.2. To monitor the impact of the scraper element on the plasma, Langmuir probes are integrated in the plasma facing surface, and a neutral gas manometer measures the neutral density directly behind the plasma facing surface. Moreover, IR and VIS cameras observe the plasma facing surface and thermocouples monitor the temperatures of the graphite tiles and underlying support structure. This paper describes the integration of the scraper element and its diagnostics in Wendelstein 7-X.« less

Next generation cooled long range thermal sights with minimum size, weight, and power

NASA Astrophysics Data System (ADS)

Breiter, R.; Ihle, T.; Wendler, J.; Rühlich, I.; Ziegler, J.

2013-06-01

Situational awareness and precise targeting at day, night and severe weather conditions are key elements for mission success in asymmetric warfare. To support these capabilities for the dismounted soldier, AIM has developed a family of stand-alone thermal weapon sights based on high performance cooled IR-modules which are used e.g. in the infantryman of the future program of the German army (IdZ). The design driver for these sights is a long ID range <1500m for the NATO standard target to cover the operational range of a platoon with the engagement range of .50 cal rifles, 40mm AGLs or for reconnaissance tasks. The most recent sight WBZG has just entered into serial production for the IdZ enhanced system of the German army with additional capabilities like a wireless data link to the soldier backbone computer. Minimum size, weight and power (SWaP) are most critical requirements for the dismounted soldiers' equipment and sometimes push a decision towards uncooled equipment with marginal performance referring to the outstanding challenges in current asymmetric warfare, e.g. the capability to distinguish between combatants and non-combatants in adequate ranges. To provide the uncompromised e/o performance with SWaP parameters close to uncooled, AIM has developed a new thermal weapon sight based on high operating temperature (HOT) MCT MWIR FPAs together with a new low power single piston stirling cooler. In basic operation the sight is used as a clip-on in front of the rifle scope. An additional eyepiece for stand-alone targeting with e.g. AGLs or a biocular version for relaxed surveillance will be available. The paper will present details of the technologies applied for such long range cooled sights with size, weight and power close to uncooled.

Uncooled infrared photodetectors in Poland

NASA Astrophysics Data System (ADS)

Piotrowski, J.; Piotrowski, A.

2006-03-01

The history and present status of the middle and long wavelength Hg1-xCdxTe infrared detectors in Poland are reviewed. Research and development efforts in Poland were concentrated mostly on uncooled market niche. Technology of the infrared photodetectors has been developed by several research groups. The devices are based on mercury-based variable band gap semiconductor alloys. Modified isothermal vapour phase epitaxy (ISOVPE) has been used for many years for research and commercial fabrication of photoconductive, photoelectromagnetic and other devices. Bulk growth and liquid phase epitaxy was also used. At present, the fabrication of IR devices relies on low temperature epitaxial technique, namely metalorganic vapour phase deposition (MOCVD), frequently in combination with the ISOVPE. Photoconductive and photoelectromagnetic detectors are still in production. The devices are gradually replaced with photovoltaic devices which offer inherent advantages of no electric or magnetic bias, no heat load and no flicker noise. Potentially, the PV devices could offer high performance and very fast response. At present, the uncooled long wavelength devices of conventional design suffer from two issues; namely low quantum efficiency and very low junction resistance. It makes them useless for practical applications. The problems have been solved with advanced 3D band gap engineered architecture, multiple cell heterojunction devices connected in series, monolithic integration of the detectors with microoptics and other improvements. Present fabrication program includes devices which are optimized for operation at any wavelength within a wide spectral range 1-15 μm and 200-300 K temperature range. Special solutions have been applied to improve speed of response. Some devices show picoseconds range response time. The devices have found numerous civilian and military applications.

Sealing apparatus for airfoils of gas turbine engines

DOEpatents

Jones, Russell B.

1998-01-01

An improved airfoil tip sealing apparatus is disclosed wherein brush seals are attached to airfoil tips with the distal ends of the brush seal fibers sealingly contacting opposing wall surfaces. Embodiments for variable vanes, stators and both cooled and uncooled turbine blade applications are disclosed.

Experimental evaluation of a translating nozzle sidewall radial turbine

NASA Technical Reports Server (NTRS)

Roelke, Richard J.; Rogo, Casimir

1987-01-01

An experimental performance evaluation was made of two movable sidewall variable area radial turbines. The turbine designs were representative of the gas generator turbine of a variable flow capacity rotorcraft engine. The first turbine was an uncooled design while the second turbine had a cooled nozzle but an uncooled rotor. The cooled nozzle turbine was evaluated both with and without coolant flow. The test results showed that the movable nozzle wall is a viable and efficient means to effectively control the flow capacity of a radial turbine. Peak efficiencies of the second turbine with and without nozzle coolant were 86.5 and 88 percent respectively. These values are comparable to pivoting vane variable geometry turbines; however, the decrease in efficiency as the flow was varied from the design value was much less for the movable wall turbine. Several design improvements which should increase the turbine efficiency one or two more points are identified. These design improvements include reduced leakage losses and relocation of the vane coolant ejection holes to reduce mainstream disturbance.

Implementation of real-time nonuniformity correction with multiple NUC tables using FPGA in an uncooled imaging system

NASA Astrophysics Data System (ADS)

Oh, Gyong Jin; Kim, Lyang-June; Sheen, Sue-Ho; Koo, Gyou-Phyo; Jin, Sang-Hun; Yeo, Bo-Yeon; Lee, Jong-Ho

2009-05-01

This paper presents a real time implementation of Non Uniformity Correction (NUC). Two point correction and one point correction with shutter were carried out in an uncooled imaging system which will be applied to a missile application. To design a small, light weight and high speed imaging system for a missile system, SoPC (System On a Programmable Chip) which comprises of FPGA and soft core (Micro-blaze) was used. Real time NUC and generation of control signals are implemented using FPGA. Also, three different NUC tables were made to make the operating time shorter and to reduce the power consumption in a large range of environment temperature. The imaging system consists of optics and four electronics boards which are detector interface board, Analog to Digital converter board, Detector signal generation board and Power supply board. To evaluate the imaging system, NETD was measured. The NETD was less than 160mK in three different environment temperatures.

Passive Euro-American terahertz camera (PEAT-CAM): passive indoor THz imaging at video rates for security applications

NASA Astrophysics Data System (ADS)

Luukanen, Arttu; Grönberg, Leif; Helistö, Panu; Penttilä, Jari S.; Seppä, Heikki; Sipola, Hannu; Dietlein, Charles R.; Grossman, Erich N.

2007-04-01

The objective of this program is to demonstrate a system capable of passive indoors detection and identification of concealed threat items hidden underneath the clothing of non-cooperative subjects from a stand-off distance of several meters. To meet this difficult task, we are constructing an imaging system utilising superconducting ultrawideband antenna-coupled microbolometers, coupled to innovative room temperature read-out electronics, and operated within a cryogen-free pulse tube refrigerator. Previously, we have demonstrated that these devices are capable of a Noise Equivalent Temperature Difference (NETD) of 125 mK over a pre-detection bandwidth from 0.2-1 THz using a post-detection integration time of 30 ms. Further improvements on our devices are reducing this number to a few tens of mK. Such an exquisite sensitivity is necessary in order to achieve the undoubtedly stringent requirements for low false positive alarm rate combined with high probability of detection dictated by the application. Our technological approach allows for excellent per frame NETD (objective 0.5 K or below at 30 Hz frame rate), and is also amenable to multispectral (colour) imagery that enhances the discrimination of innocuous objects against real threats. In the paper we present results obtained with an 8-pixel subarray from our linear array of 128 pixels constructed using a modular approach. Two-dimensional imaging will be achieved by the use of conical scanning.

NASA Tech Briefs, January 2014

NASA Technical Reports Server (NTRS)

2014-01-01

Topics include: Multi-Source Autonomous Response for Targeting and Monitoring of Volcanic Activity; Software Suite to Support In-Flight Characterization of Remote Sensing Systems; Visual Image Sensor Organ Replacement; Ultra-Wideband, Dual-Polarized, Beam-Steering P-Band Array Antenna; Centering a DDR Strobe in the Middle of a Data Packet; Using a Commercial Ethernet PHY Device in a Radiation Environment; Submerged AUV Charging Station; Habitat Demonstration Unit (HDU) Vertical Cylinder Habitat; Origami-Inspired Folding of Thick, Rigid Panels; A Novel Protocol for Decoating and Permeabilizing Bacterial Spores for Epifluorescent Microscopy; Method and Apparatus for Automated Isolation of Nucleic Acids from Small Cell Samples; Enabling Microliquid Chromatography by Microbead Packing of Microchannels; On-Command Force and Torque Impeding Devices (OC-FTID) Using ERF; Deployable Fresnel Rings; Transition-Edge Hot-Electron Microbolometers for Millimeter and Submillimeter Astrophysics; Spacecraft Trajectory Analysis and Mission Planning Simulation (STAMPS) Software; Cross Support Transfer Service (CSTS) Framework Library; Arbitrary Shape Deformation in CFD Design; Range Safety Flight Elevation Limit Calculation Software; Frequency-Modulated, Continuous-Wave Laser Ranging Using Photon-Counting Detectors; Calculation of Operations Efficiency Factors for Mars Surface Missions; GPU Lossless Hyperspectral Data Compression System; Robust, Optimal Subsonic Airfoil Shapes; Protograph-Based Raptor-Like Codes; Fuzzy Neuron: Method and Hardware Realization; Kalman Filter Input Processor for Boresight Calibration; Organizing Compression of Hyperspectral Imagery to Allow Efficient Parallel Decompression; and Temperature Dependences of Mechanisms Responsible for the Water-Vapor Continuum Absorption.

Simulated MERTIS observation of the Rudaki-Kuiper craters area on Mercury

NASA Astrophysics Data System (ADS)

D'Amore, M.; Helbert, J.; Maturilli, A.; Ferrari, S.; Bauch, K.; D'Incecco, P.; Hiesinger, H.; Head, J. W.; Holsclaw, G. M.; Lorin, D. D.; Denevi, B. W.; Stockstill-Cahill, K. R.

2013-12-01

The MErcury Radiometer and Thermal infrared Imaging Spectrometer (MERTIS) is part of the payload of the BepiColombo mission. The mission is scheduled for launch in 2015 with arrival at Mercury in 2021. To achieve MERTIS's scientific goals the instrument maps the surface of Mercury with a spatial resolution of 500m for the spectrometer channel and 2km for the radiometer channel. MERTIS spans wavelength ranges of 7-14 and 7-40 μm with its two channels. Among it scientific goals, MERTIS will infer rock-forming minerals, map surface composition, and study surface temperature variations on Mercury with an uncooled microbolometer detector. To exploit the full potential of the unique MERTIS dataset, an extensive calibration campaign has been performed. This includes radiometric, spectral, and geometric calibration. In addition we have performed measurement of analog materials at temperatures of up to 500°C - similar to the peak temperatures expected at Mercury - with the MERTIS qualification model in the Planetary Emissivity Laboratory. These measurements allow for the evaluation of the MERTIS performance in direct comparison with the laboratory spectrometer. They also enable the creation of synthetic MERTIS datasets. For this purpose we use data from the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft as baseline. MESSENGER can provide geological information as well as spectral information in the UV, visible and near-infrared wavelengths range. For a first test we have selected the Kuiper-Rudaki region. The region has been extensively covered by measurements from the MESSENGER spacecraft. Recent analysis of observations by the Mercury Atmospheric and Surface Composition Spectrometer (MASCS) instrument on the MESSENGER spacecraft with an unsupervised hierarchical clustering method shows at global scales two major units: a Polar region (PR) spectrally flat and redder than the equatorial region (ER). The study area is primarily classified as a homogeneous expanse of the equatorial region (ER) cluster. Further clustering shows that the study area belongs to the 'core' ER, in opposition to some smaller patches of a transitional sub-unit, that are transitional region between global ER and the polar region (PR) cluster. Assuming a set of several potential mineralogies for the study area and modeled surface temperature at different local times we can obtain at PEL the spectra in the mid-infrared spectral range. Combining these with our knowledge of the MERTIS performance we can produce simulated MERTIS datasets of the study region at different point of the mission.

Sealing apparatus for airfoils of gas turbine engines

DOEpatents

Jones, R.B.

1998-05-19

An improved airfoil tip sealing apparatus is disclosed wherein brush seals are attached to airfoil tips with the distal ends of the brush seal fibers sealingly contacting opposing wall surfaces. Embodiments for variable vanes, stators and both cooled and uncooled turbine blade applications are disclosed. 17 figs.

Prototype of microbolometer thermal infrared camera for forest fire detection from space

NASA Astrophysics Data System (ADS)

Guerin, Francois; Dantes, Didier; Bouzou, Nathalie; Chorier, Philippe; Bouchardy, Anne-Marie; Rollin, Joël.

2017-11-01

The contribution of the thermal infrared (TIR) camera to the Earth observation FUEGO mission is to participate; to discriminate the clouds and smoke; to detect the false alarms of forest fires; to monitor the forest fires. Consequently, the camera needs a large dynamic range of detectable radiances. A small volume, low mass and power are required by the small FUEGO payload. These specifications can be attractive for other similar missions.

Antenna-coupled high T[sub c] superconducting microbolometer

DOEpatents

Hu, Q.

1992-12-15

A device is provided for measuring radiant energy, the device comprising a substrate; a bolometer formed from a high T[sub c] superconducting material disposed on the substrate in an area that is about 1[times]5 [mu]m[sup 2] and about 0.02 [mu]m in depth; and a planar antenna disposed on the substrate and coupled to receive radiation and to impart the received radiation to the bolometer. 5 figs.

Optical microsensor for continuous glucose measurements in interstitial fluid

NASA Astrophysics Data System (ADS)

Olesberg, Jonathon T.; Cao, Chuanshun; Yager, Jeffrey R.; Prineas, John P.; Coretsopoulos, Chris; Arnold, Mark A.; Olafsen, Linda J.; Santilli, Michael

2006-02-01

Tight control of blood glucose levels has been shown to dramatically reduce the long-term complications of diabetes. Current invasive technology for monitoring glucose levels is effective but underutilized by people with diabetes because of the pain of repeated finger-sticks, the inconvenience of handling samples of blood, and the cost of reagent strips. A continuous glucose sensor coupled with an insulin delivery system could provide closed-loop glucose control without the need for discrete sampling or user intervention. We describe an optical glucose microsensor based on absorption spectroscopy in interstitial fluid that can potentially be implanted to provide continuous glucose readings. Light from a GaInAsSb LED in the 2.2-2.4 μm wavelength range is passed through a sample of interstitial fluid and a linear variable filter before being detected by an uncooled, 32-element GaInAsSb detector array. Spectral resolution is provided by the linear variable filter, which has a 10 nm band pass and a center wavelength that varies from 2.18-2.38 μm (4600-4200 cm -1) over the length of the detector array. The sensor assembly is a monolithic design requiring no coupling optics. In the present system, the LED running with 100 mA of drive current delivers 20 nW of power to each of the detector pixels, which have a noise-equivalent-power of 3 pW/Hz 1/2. This is sufficient to provide a signal-to-noise ratio of 4500 Hz 1/2 under detector-noise limited conditions. This signal-to-noise ratio corresponds to a spectral noise level less than 10 μAU for a five minute integration, which should be sufficient for sub-millimolar glucose detection.

Athermal laser design.

PubMed

Bovington, Jock; Srinivasan, Sudharsanan; Bowers, John E

2014-08-11

This paper discusses circuit based and waveguide based athermalization schemes and provides some design examples of athermalized lasers utilizing fully integrated athermal components as an alternative to power hungry thermo-electric controllers (TECs), off-chip wavelength lockers or monitors with lookup tables for tunable lasers. This class of solutions is important for uncooled transmitters on silicon.

Hot-Electron Gallium Nitride Two Dimensional Electron Gas Nano-bolometers For Advanced THz Spectroscopy

NASA Astrophysics Data System (ADS)

Ramaswamy, Rahul

Two-dimensional electron gas (2DEG) in semiconductor heterostructures was identified as a promising medium for hot-electron bolometers (HEB) in the early 90s. Up until now all research based on 2DEG HEBs is done using high mobility AlGaAs/GaAs heterostructures. These systems have demonstrated very good performance, but only in the sub terahertz (THz) range. However, above ˜0.5 THz the performance of AlGaAs/GaAs detectors drastically deteriorates. It is currently understood, that detectors fabricated from standard AlGaAs/GaAs heterostructures do not allow for reasonable coupling to THz radiation while maintaining high conversion efficiency. In this work we have developed 2DEG HEBs based on disordered Gallium Nitride (GaN) semiconductor, that operate at frequencies beyond 1THz at room temperature. We observe strong free carrier absorption at THz frequencies in our disordered 2DEG film due to Drude absorption. We show the design and fabrication procedures of novel micro-bolometers having ultra-low heat capacities. In this work the mechanism of 2DEG response to THz radiation is clearly identified as bolometric effect through our direct detection measurements. With optimal doping and detector geometry, impedances of 10--100 O have been achieved, which allow integration of these devices with standard THz antennas. We also demonstrate performance of the antennas used in this work in effectively coupling THz radiation to the micro-bolometers through polarization dependence and far field measurements. Finally heterodyne mixing due to hot electrons in the 2DEG micro-bolometer has been performed at sub terahertz frequencies and a mixing bandwidth greater than 3GHz has been achieved. This indicates that the characteristic cooling time in our detectors is fast, less than 50ps. Due to the ultra-low heat capacity; these detectors can be used in a heterodyne system with a quantum cascade laser (QCL) as a local oscillator (LO) which typically provides output powers in the micro watt range. Our studies suggest that such room temperature detectors from GaN semiconductor, with reasonable bandwidth, low LO power requirements and high sensitivity have numerous applications, ranging from precise identification of complex molecules, environmental monitoring of critical substances, remote detection of various pollutants in the atmosphere, and noninvasive medical imaging as well as a variety of applications for defense and homeland security.

Long-Wave Type-II Superlattice Detectors with Unipolar Electron and Hole Barriers

DTIC Science & Technology

2012-12-01

technologies are readily deployed for the visible, short- wave infrared (SWIR), mid-wave infrared (MWIR), and long-wave infrared ( LWIR ) spectral bands.1 These... LWIR band, sensor technologies include Hg1−xCdxTe (MCT), microbolometers, and Type-II superlattices (SLS).3 In addition to the aforementioned materials...well infrared photodetector (QWIP) was born,6 and has since become well-positioned as a mainstream technology for LWIR sen- sors. In recognition of the

Long-Wave Infrared (LWIR) Polarimetric and Radiometric Analysis for a Variety of Thermal and Electromagnetic Suppressing Materials

DTIC Science & Technology

2014-08-01

polarimetry for remote sensing applications. Appl Opt. 2006;45(22):5453–5469. 5. Kudenov M, Pezzaniti L, Gerhart G. Microbolometer-infrared imaging...infrared imaging polarimetry . In: Photonics for Port and Harbor Security, DeWeert MJ, Saito TT, editors. Proceedings of SPIE; 2005;5780. 13. Hecht E...metrology. In: Polarimetry : Radar, Infrared, Visible, Ultraviolet, and X-Ray, Chipman RA, Morris JW, editors. Proceedings of SPIE; 1990;1317:280

Design and instrumentation of an airborne far infrared radiometer for in-situ measurements of ice clouds

NASA Astrophysics Data System (ADS)

Proulx, Christian; Ngo Phong, Linh; Lamontagne, Frédéric; Wang, Min; Fisette, Bruno; Martin, Louis; Châteauneuf, François

2016-09-01

We report on the design and instrumentation of an aircraft-certified far infrared radiometer (FIRR) and the resulting instrument characteristics. FIRR was designed to perform unattended airborne measurements of ice clouds in the arctic in support of a microsatellite payload study. It provides radiometrically calibrated data in nine spectral channels in the range of 8-50 μm with the use of a rotating wheel of bandpass filters and reference blackbodies. Measurements in this spectral range are enabled with the use of a far infrared detector based on microbolometers of 104-μm pitch. The microbolometers have a new design because of the large structure and are coated with gold black to maintain uniform responsivity over the working spectral range. The vacuum sealed detector package is placed at the focal plane of a reflective telescope based on a Schwarschild configuration with two on-axis spherical mirrors. The telescope field-of-view is of 6° and illuminates an area of 2.1-mm diameter at the focal plane. In operation, FIRR was used as a nonimaging radiometer and exhibited a noise equivalent radiance in the range of 10-20 mW/m2-sr. The dynamic range and the detector vacuum integrity of FIRR were found to be suited for the conditions of the airborne experiments.

Design of a panoramic long-wave infrared athermal system

NASA Astrophysics Data System (ADS)

Yao, Yuan; Geng, Anbing; Bai, Jian; Wang, Haitao; Guo, Jie; Xiong, Tao; Luo, Yujie; Huang, Zhi; Hou, Xiyun

2016-12-01

A panoramic long-wave infrared athermal system is introduced in this paper. The proposed system includes a panoramic annular lens (PAL) block providing a stereo field of view of (30 deg - 100 deg) × 360 deg without the need to move its components. Moreover, to ensure the imaging quality at different temperatures, a refractive/diffractive hybrid lens is introduced to achieve optical passive athermalization. The system operates in a spectral band between 8 and 12 μm, with a total length of 175 mm and a focal length of 3.4 mm. To get a bright and clear image, the aperture of the system was set to f/1.15. The introduction of aspherical surface and even-order diffractive surface not only eliminates the differential thermal but also makes the structure simple and lightweight and improves the image quality. The results show that the modulation transfer function below 20 lp/mm of the system is above 0.2 at each temperature ranging from -20°C to +60°C, which is close to the diffraction limit. The system is suitable to be applied in an uncooled infrared focal plane array detector and will serve as a static alert system. It has a number of pixels of 640×480, and the pixel size is 25 μm.

Pyroelectric IR sensor arrays for fall detection in the older population

NASA Astrophysics Data System (ADS)

Sixsmith, A.; Johnson, N.; Whatmore, R.

2005-09-01

Uncooled pyroelectric sensor arrays have been studied over many years for their uses in thermal imaging applications. These arrays will only detect changes in IR flux and so systems based upon them are very good at detecting movements of people in the scene without sensing the background, if they are used in staring mode. Relatively-low element count arrays (16 x 16) can be used for a variety of people sensing applications, including people counting (for safety applications), queue monitoring etc. With appropriate signal processing such systems can be also be used for the detection of particular events such as a person falling over. There is a considerable need for automatic fall detection amongst older people, but there are important limitations to some of the current and emerging technologies available for this. Simple sensors, such as 1 or 2 element pyroelectric infra-red sensors provide crude data that is difficult to interpret; the use of devices worn on the person, such as wrist communicator and motion detectors have potential, but are reliant on the person being able and willing to wear the device; video cameras may be seen as intrusive and require considerable human resources to monitor activity while machine-interpretation of camera images is complex and may be difficult in this application area. The use of a pyroelectric thermal array sensor was seen to have a number of potential benefits. The sensor is wall-mounted and does not require the user to wear a device. It enables detailed analysis of a subject's motion to be achieved locally, within the detector, using only a modest processor. This is possible due to the relative ease with which data from the sensor can be interpreted relative to the data generated by alternative sensors such as video devices. In addition to the cost-effectiveness of this solution, it was felt that the lack of detail in the low-level data, together with the elimination of the need to transmit data outside the detector, would help to avert feelings intrusiveness on the part of the end-user.The main benefits of this type of technology would be for older people who spend time alone in unsupervised environments. This would include people living alone in ordinary housing or in sheltered accommodation (apartment complexes for older people with local warden) and non-communal areas in residential/nursing home environments (e.g. bedrooms and ensuite bathrooms and toilets). This paper will review the development of the array, the pyroelectric ceramic material upon which it is based and the system capabilities. It will present results from the Framework 5 SIMBAD project, which used the system to monitor the movements of elderly people over a considerable period of time.

Low temperature fabrication of VO x thin films for uncooled IR detectors by direct current reactive magnetron sputtering method

NASA Astrophysics Data System (ADS)

Dai, Jun; Wang, Xingzhi; He, Shaowei; Huang, Ying; Yi, Xinjian

2008-03-01

Vanadium oxide films have been fabricated on Si3N4-film-coated silicon substrates by direct current reactive magnetron sputtering method. Conditions of deposition are optimized making use of parameters such as sputtering time, dc power, oxygen partial pressure and substrate temperature. X-ray diffraction indicates that the film is a mixture of VO2, V2O3, and V3O5. Four-probe measurement shows that the VOx thin film owns high temperature coefficient of resistance (TCR ∼-2.05%/°C) and suitable square resistance 18.40 kΩ/□ (measured at 25 °C), indicating it is a well candidate material for uncooled IR detectors. In addition, IR absorption in the wavelength of 2-16 μm has been characterized. It is worth noting that the films are sputtered at a relatively low temperature of 210 °C in a controlled Ar/O2 atmosphere. Compared to traditional craft, this method needs no post-anneal at high temperature (400-500 °C).

Swap intensified WDR CMOS module for I2/LWIR fusion

NASA Astrophysics Data System (ADS)

Ni, Yang; Noguier, Vincent

2015-05-01

The combination of high resolution visible-near-infrared low light sensor and moderate resolution uncooled thermal sensor provides an efficient way for multi-task night vision. Tremendous progress has been made on uncooled thermal sensors (a-Si, VOx, etc.). It's possible to make a miniature uncooled thermal camera module in a tiny 1cm3 cube with <1W power consumption. For silicon based solid-state low light CCD/CMOS sensors have observed also a constant progress in terms of readout noise, dark current, resolution and frame rate. In contrast to thermal sensing which is intrinsic day&night operational, the silicon based solid-state sensors are not yet capable to do the night vision performance required by defense and critical surveillance applications. Readout noise, dark current are 2 major obstacles. The low dynamic range at high sensitivity mode of silicon sensors is also an important limiting factor, which leads to recognition failure due to local or global saturations & blooming. In this context, the image intensifier based solution is still attractive for the following reasons: 1) high gain and ultra-low dark current; 2) wide dynamic range and 3) ultra-low power consumption. With high electron gain and ultra low dark current of image intensifier, the only requirement on the silicon image pickup device are resolution, dynamic range and power consumption. In this paper, we present a SWAP intensified Wide Dynamic Range CMOS module for night vision applications, especially for I2/LWIR fusion. This module is based on a dedicated CMOS image sensor using solar-cell mode photodiode logarithmic pixel design which covers a huge dynamic range (> 140dB) without saturation and blooming. The ultra-wide dynamic range image from this new generation logarithmic sensor can be used directly without any image processing and provide an instant light accommodation. The complete module is slightly bigger than a simple ANVIS format I2 tube with <500mW power consumption.

YBCO Microbolometers for Infrared Detection: Enhancement of Performances with Regionally Thinned Microbridges

DTIC Science & Technology

2009-06-01

a specific regionally thinned microbridge design has 22 % higher stiffness than that of a standard pixel design with similar thermal properties. The...temps thermique τ plus petite (environ 1,6 ms) comparativement à la configuration standard (2,6 ms). D’un autre côté, la détectivité D* des...other hand, the increased speed is not accompanied by a loss of detection performance. The simulation results show that the thin pixel design

High-performance IR detectors at SCD present and future

NASA Astrophysics Data System (ADS)

Nesher, O.; Klipstein, P. C.

2005-09-01

For over 27 years, SCD has been manufacturing and developing a wide range of high performance infra-red detectors, designed to operate in either the mid-wave (MWIR) or the long-wave (LWIR) atmospheric windows. These detectors have been integrated successfully into many different types of system including missile seekers, Time Delay Integration scanning systems, Hand-Held cameras, Missile Warning Systems and many others. SCD's technology for the MWIR wavelength range is based on its well established 2-D arrays of InSb photodiodes. The arrays are flip-chip bonded to SCD's analogue or digital signal processors, all of which have been designed in-house. The 2-D Focal Plane Array (FPA) detectors have a format of 320×256 elements for a 30 μm pitch and 480×384 or 640×512 elements for a 20 μm pitch. Typical operating temperatures are around 77-85K. Five years ago SCD began to develop a new generation of MWIR detectors based on the epitaxial growth of Antimonide Based Compound Semiconductors (ABCS). This ABCS technology allows band-gap engineering of the detection material which enables higher operating temperatures and multi-spectral detection. This year SCD presented its first prototype FPA from this program, an InAlSb based detector operating at a temperature of 100 K. By the end of this year SCD will introduce the first prototype MWIR detector with a 640×512 element format and a pitch of 15 μm. For the LWIR wave-length range SCD manufactures both linear Hg1-xCdxTe (MCT) detectors with a line of 250 elements and Time Delay and Integration (TDI) detectors with formats of 288×4 and 480×6. Recently, SCD has demonstrated its first prototype un-cooled detector which is based on VOx technology and which has a format of 384×288 elements, a pitch of 25 μm and a typical NETD of 50mK at F/1. In this paper we describe the present technologies and products of SCD and the future evolution of our detectors for the MWIR and LWIR detection.

High-performance IR detectors at SCD present and future

NASA Astrophysics Data System (ADS)

Nesher, O.; Klipstein, P. C.

2006-03-01

For over 27 years, SCD has been manufacturing and developing a wide range of high performance infrared detectors, designed to operate in either the mid-wave (MWIR) or the long-wave (LWIR) atmospheric windows. These detectors have been integrated successfully into many different types of system including missile seekers, time delay integration scanning systems, hand-held cameras, missile warning systems and many others. SCD's technology for the MWIR wavelength range is based on its well established 2D arrays of InSb photodiodes. The arrays are flip-chip bonded to SCD's analogue or digital signal processors, all of which have been designed in-house. The 2D focal plane array (FPA) detectors have a format of 320×256 elements for a 30-μm pitch and 480×384 or 640×512 elements for a 20-μm pitch. Typical operating temperatures are around 77-85 K. Five years ago SCD began to develop a new generation of MWIR detectors based on the epitaxial growth of antimonide based compound semiconductors (ABCS). This ABCS technology allows band-gap engineering of the detection material which enables higher operating temperatures and multi-spectral detection. This year SCD presented its first prototype FPA from this program, an InAlSb based detector operating at a temperature of 100 K. By the end of this year SCD will introduce the first prototype MWIR detector with a 640×512 element format and a pitch of 15 μm. For the LWIR wavelength range SCD manufactures both linear Hg1-xCdxTe (MCT) detectors with a line of 250 elements and time delay and integration (TDI) detectors with formats of 288×4 and 480×6. Recently, SCD has demonstrated its first prototype uncooled detector which is based on VOx technology and which has a format of 384×288 elements, a pitch of 25 μm, and a typical NETD of 50 mK at F/1. In this paper, we describe the present technologies and products of SCD and the future evolution of our detectors for the MWIR and LWIR detection.

Pyxis handheld polarimetric imager

NASA Astrophysics Data System (ADS)

Chenault, David B.; Pezzaniti, J. Larry; Vaden, Justin P.

2016-05-01

The instrumentation for measuring infrared polarization signatures has seen significant advancement over the last decade. Previous work has shown the value of polarimetric imagery for a variety of target detection scenarios including detection of manmade targets in clutter and detection of ground and maritime targets while recent work has shown improvements in contrast for aircraft detection and biometric markers. These data collection activities have generally used laboratory or prototype systems with limitations on the allowable amount of target motion or the sensor platform and usually require an attached computer for data acquisition and processing. Still, performance and sensitivity have been steadily getting better while size, weight, and power requirements have been getting smaller enabling polarimetric imaging for a greater or real world applications. In this paper, we describe Pyxis®, a microbolometer based imaging polarimeter that produces live polarimetric video of conventional, polarimetric, and fused image products. A polarization microgrid array integrated in the optical system captures all polarization states simultaneously and makes the system immune to motion artifacts of either the sensor or the scene. The system is battery operated, rugged, and weighs about a quarter pound, and can be helmet mounted or handheld. On board processing of polarization and fused image products enable the operator to see polarimetric signatures in real time. Both analog and digital outputs are possible with sensor control available through a tablet interface. A top level description of Pyxis® is given followed by performance characteristics and representative data.

Fast Uncooled Low Density FPA of VPD PbSe for Applications in Hyperspectral Imagery

DTIC Science & Technology

2009-10-01

Marañosa (ITM-CIDA). Area de Optronica y Acustica Unidad de Sensores y Micro-Nano Tecnologia Arturo Soria, 289 E-28033 Madrid, Spain ABSTRACT...ADDRESS(ES) Instituto Tecnologico de la Marañosa (ITM-CIDA). Area de Optronica y Acustica Unidad de Sensores y Micro-Nano Tecnologia Arturo Soria, 289

Unmanned Aerial Vehicles Roadmap 2000-2025

DTIC Science & Technology

2001-04-01

Develop and mature enabling materials technologies such as gamma titanium aluminides , refractory intermetallic alloys, ceramic matrix composites, higher...percent (see Figure 4.1.2-1). For UAV use, these goals may partially be met by deleting turbine blade containment rings and redundant controls, as well...and Barium Strontium Titanium (BST) used in uncooled LWIR detectors, and fabrication techniques of thin pixels will enable improved thermal

Characterization of Perovskite Films Grown by a Novel Low-Temperature Process for Uncooled IR Detector Applications

DTIC Science & Technology

2008-12-01

hydrolysis and polycondensation of molecular precursors in vitro to form SiO2, anatase-TiO2, and - Ga2O3 under very mild conditions, whereas...forming high temperature crystalline polymorphs of TiO2 and Ga2O3 lies in kinetically controlled, slow catalytic hydrolysis and growth. In an

The development of a μ-biomimetic uncooled IR-Sensor inspired by the infrared receptors of Melanophila acuminata.

PubMed

Siebke, Georg; Holik, Peter; Schmitz, Sam; Tätzner, Simon; Thiesler, Jan; Steltenkamp, Siegfried

2015-03-30

The beetle Melanophila acuminata uses a specialized organ to detect infrared radiation. The organ consists of about 100 individual sensilla. The main component of the sensillum is a pressure chamber. Upon absorption of radiation, the pressure increases, and the tip of a dendrite is deformed. A unique feature of the organ is a compensation mechanism that prevents large pressures. The beetle uses this organ to detect forest fires and to navigate inside burning woods. However, the sensitivity is part of a long-lasting discussion, providing thresholds between [Formula: see text] and [Formula: see text]. To end the decade-long discussion and to provide a novel type of infrared sensor, we are developing an uncooled μ-biomimetic infrared (IR) sensor inspired by Melanophila acuminata using MEMS technology. Here, we present the development of a μ-capacitor that is used to detect pressure changes and the characterization of the compensation mechanism. We describe the microtechnological fabrication process for air-filled capacitors with a ratio of diameter-to-electrode distance of 1000 and a technique to fill the sensor bubble-free with water. Finally, we estimate the sensitivity of the beetle using a theoretical model of the sensillum.

Long wave infrared (8 to 14 microns) hyperspectral imager based on an uncooled thermal camera and the traditional CI block interferometer (SI-LWIR-UC)

NASA Astrophysics Data System (ADS)

Cabib, Dario; Lavi, Moshe; Gil, Amir; Milman, Uri

2011-06-01

Since the early '90's CI has been involved in the development of FTIR hyperspectral imagers based on a Sagnac or similar type of interferometer. CI also pioneered the commercialization of such hyperspectral imagers in those years. After having developed a visible version based on a CCD in the early '90's (taken on by a spin-off company for biomedical applications) and a 3 to 5 micron infrared version based on a cooled InSb camera in 2008, it is now developing an LWIR version based on an uncooled camera for the 8 to 14 microns range. In this paper we will present design features and expected performance of the system. The instrument is designed to be rugged for field use, yield a relatively high spectral resolution of 8 cm-1, an IFOV of 0.5 mrad., a 640x480 pixel spectral cube in less than a minute and a noise equivalent spectral radiance of 40 nW/cm2/sr/cm-1 at 10μ. The actually measured performance will be presented in a future paper.

A review on applications of magnetoelectric composites: from heterostructural uncooled magnetic sensors, energy harvesters to highly efficient power converters

NASA Astrophysics Data System (ADS)

Leung, Chung Ming; Li, Jiefang; Viehland, D.; Zhuang, X.

2018-07-01

Over the past two decades, magnetoelectric (ME) composites and their devices have been an important topic of research. Potential applications ranging from low-power sensing to high-power converters have been investigated. This review, first begins with a summary of multiferroic materials that work at room temperature. Such ME materials are usually in composites, and their ME effect generated as a product property of magnetostrictive and piezoelectric composite layers. After that, mechanisms, working principles, and applications of ME composites from heterostructural uncooled magnetic sensors, energy harvesters to highly efficient power converters will be discussed. First, the development of ME sensors in terms of materials and structures to enhance their sensitivities and to reduce noise level is reviewed and discussed. Second, the structure of ME-based energy harvesters is discussed and summarized. Third, the development of ME gyrators is summarized for power applications, including current/voltage conversion, power efficiency, power density and figures of merit. Results demonstrate that our ME gyrator has the ability to satisfy the needs of power conversion with superior efficiency (>90%), offering potential uses in power electronic applications.

Snapshot Imaging Spectrometry in the Visible and Long Wave Infrared

NASA Astrophysics Data System (ADS)

Maione, Bryan David

Imaging spectrometry is an optical technique in which the spectral content of an object is measured at each location in space. The main advantage of this modality is that it enables characterization beyond what is possible with a conventional camera, since spectral information is generally related to the chemical composition of the object. Due to this, imaging spectrometers are often capable of detecting targets that are either morphologically inconsistent, or even under resolved. A specific class of imaging spectrometer, known as a snapshot system, seeks to measure all spatial and spectral information simultaneously, thereby rectifying artifacts associated with scanning designs, and enabling the measurement of temporally dynamic scenes. Snapshot designs are the focus of this dissertation. Three designs for snapshot imaging spectrometers are developed, each providing novel contributions to the field of imaging spectrometry. In chapter 2, the first spatially heterodyned snapshot imaging spectrometer is modeled and experimentally validated. Spatial heterodyning is a technique commonly implemented in non-imaging Fourier transform spectrometry. For Fourier transform imaging spectrometers, spatial heterodyning improves the spectral resolution trade space. Additionally, in this chapter a unique neural network based spectral calibration is developed and determined to be an improvement beyond Fourier and linear operator based techniques. Leveraging spatial heterodyning as developed in chapter 2, in chapter 3, a high spectral resolution snapshot Fourier transform imaging spectrometer, based on a Savart plate interferometer, is developed and experimentally validated. The sensor presented in this chapter is the highest spectral resolution sensor in its class. High spectral resolution enables the sensor to discriminate narrowly spaced spectral lines. The capabilities of neural networks in imaging spectrometry are further explored in this chapter. Neural networks are used to perform single target detection on raw instrument data, thereby eliminating the need for an explicit spectral calibration step. As an extension of the results in chapter 2, neural networks are once again demonstrated to be an improvement when compared to linear operator based detection. In chapter 4 a non-interferometric design is developed for the long wave infrared (wavelengths spanning 8-12 microns). The imaging spectrometer developed in this chapter is a multi-aperture filtered microbolometer. Since the detector is uncooled, the presented design is ultra-compact and low power. Additionally, cost effective polymer absorption filters are used in lieu of interference filters. Since, each measurement of the system is spectrally multiplexed, an SNR advantage is realized. A theoretical model for the filtered design is developed, and the performance of the sensor for detecting liquid contaminants is investigated. Similar to past chapters, neural networks are used and achieve false detection rates of less than 1%. Lastly, this dissertation is concluded with a discussion on future work and potential impact of these devices.

Cryogenic photodetectors

NASA Astrophysics Data System (ADS)

Chardin, G.

2000-03-01

Some of the most significant developments in cryogenic photodetectors are presented. In particular, the main characteristics of microbolometers involving Transition Edge- and NTD-sensors and offering resolutions of a few eV in the keV range, superconducting tunnel junction detectors with resolutions of the order of 10 eV or offering position sensitivity, and infrared bolometers with recent developments towards matrix detectors are discussed. Some of the recent achievements using large mass bolometers for gamma and neutron discriminating detectors, and future prospects of single photon detection in the far infrared using Single Electron Transistor devices are also presented.

Fulfilling the pedestrian protection directive using a long-wavelength infrared camera designed to meet both performance and cost targets

NASA Astrophysics Data System (ADS)

Källhammer, Jan-Erik; Pettersson, Håkan; Eriksson, Dick; Junique, Stéphane; Savage, Susan; Vieider, Christian; Andersson, Jan Y.; Franks, John; Van Nylen, Jan; Vercammen, Hans; Kvisterøy, Terje; Niklaus, Frank; Stemme, Göran

2006-04-01

Pedestrian fatalities are around 15% of the traffic fatalities in Europe. A proposed EU regulation requires the automotive industry to develop technologies that will substantially decrease the risk for Vulnerable Road Users when hit by a vehicle. Automatic Brake Assist systems, activated by a suitable sensor, will reduce the speed of the vehicle before the impact, independent of any driver interaction. Long Wavelength Infrared technology is an ideal candidate for such sensors, but requires a significant cost reduction. The target necessary for automotive serial applications are well below the cost of systems available today. Uncooled bolometer arrays are the most mature technology for Long Wave Infrared with low-cost potential. Analyses show that sensor size and production yield along with vacuum packaging and the optical components are the main cost drivers. A project has been started to design a new Long Wave Infrared system with a ten times cost reduction potential, optimized for the pedestrian protection requirement. It will take advantage of the progress in Micro Electro-Mechanical Systems and Long Wave Infrared optics to keep the cost down. Deployable and pre-impact braking systems can become effective alternatives to passive impact protection systems solutions fulfilling the EU pedestrian protection regulation. Low-cost Long Wave Infrared sensors will be an important enabler to make such systems cost competitive, allowing high market penetration.

Development of an advanced uncooled 10-Gb DFB laser for volume manufacture

NASA Astrophysics Data System (ADS)

Burns, Gordon; Charles, Paul M.

2003-03-01

Optical communication systems operating at 10Gbit/s such as 10Gigabit Ethernet are becoming more and more important in Local Area Networks (LAN) and Metropolitan Area Networks (MAN). This market requires optical transceivers of low cost, size and power consumption. This drives a need for uncooled DFB lasers directly modulated at 10Gbit/s. This paper describes the development of a state of the art uncooled high speed DFB laser which is capable of being manufactured in high volume at the low cost demanded by the GbE market. A DFB laser was designed by developing technological building blocks within the 'conventional" InGaAsP materials system, using existing well proven manufacturing processes modules wherever possible, limiting the design risk to a few key areas where innovation was required. The temperature and speed performance of the InGaAsP SMQW active layer system was carefully optimized and then coupled with a low parasitic lateral confinement system. Using concurrent engineering, new processes were demonstrated to have acceptable process capability within a manufacturing fabrication environment, proving their ability to support high volume manufacturing requirements. The DFB laser fabricated was shown to operate at 100C chip temperature with an open eye at 10Gbit/s operation (with an extinction ratio >5dB). Up to 90C operation this DFB shows threshold current as low as 29mA, optical power as high as 13mW and it meets the 10Gb scaled Ethernet mask with extinction ratio >6dB. It was found that the high temperature dynamic behavior of these lasers could not be fully predicted from static test data. A production test strategy was therefore followed where equipment was designed to fully test devices/subassemblies at 100C and up to 20Gbit/s at key points in the product build. This facilitated the rapid optimisation of product yields upon manufacturing ramp up and minimization of product costs. This state of the art laser is now transferred into volume manufacture.

A Thermal Imaging Instrument with Uncooled Detectors

NASA Astrophysics Data System (ADS)

Joseph, A. T.; Barrentine, E. M.; Brown, A. D.

2017-12-01

In this work, we perform an instrument concept study for sustainable thermal imaging over land with uncooled detectors. The National Research Council's Committee on Implementation of a Sustained Land Imaging Program has identified the inclusion of a thermal imager as critical for both current and future land imaging missions. Such an imaging instrument operating in two bands located at approximately 11 and 12 microns (for example, in Landsat 8, and also Landsat 9 when launched) will provide essential information for furthering our hydrologic understanding at scales of human influence, and produce field-scale moisture information through accurate retrievals of evapotranspiration (ET). Landsat 9 is slated to recycle the TIRS-2 instrument launched with Landsat 8 that uses cooled quantum well infrared photodetectors (QWIPs), hence requiring expensive and massive cryocooler technology to achieve its required spectral and spatial accuracies. Our goal is to conceptualize and develop a thermal imaging instrument which leverages recent and imminent technology advances in uncooled detectors. Such detector technology will offer the benefit of greatly reduced instrument cost, mass, and power at the expense of some acceptable loss in detector sensitivity. It would also allow a thermal imaging instrument to be fielded on board a low-cost platform, e.g., a CubeSat. Sustained and enhanced land imaging is crucial for providing high-quality science data on change in land use, forest health, crop status, environment, and climate. Accurate satellite mapping of ET at the agricultural field scale (the finest spatial scale of the environmental processes of interest) requires high-quality thermal data to produce the corresponding accurate land surface temperature (LST) retrievals used to drive an ET model. Such an imaging instrument would provide important information on the following: 1) the relationship between land-use and land/water management practices and water use dynamics; 2) the interconnections between anthropogenic water management and changes in hydrologic budget at scales of human influence; and 3) complimentary field-scale moisture values for interpreting coarser resolution datasets. There is a clear need for continuing innovation in thermal remote sensing detector technology.

Middle infrared (wavelength range: 8 μm-14 μm) 2-dimensional spectroscopy (total weight with electrical controller: 1.7 kg, total cost: less than 10,000 USD) so-called hyperspectral camera for unmanned air vehicles like drones

NASA Astrophysics Data System (ADS)

Yamamoto, Naoyuki; Saito, Tsubasa; Ogawa, Satoru; Ishimaru, Ichiro

2016-05-01

We developed the palm size (optical unit: 73[mm]×102[mm]×66[mm]) and light weight (total weight with electrical controller: 1.7[kg]) middle infrared (wavelength range: 8[μm]-14[μm]) 2-dimensional spectroscopy for UAV (Unmanned Air Vehicle) like drone. And we successfully demonstrated the flights with the developed hyperspectral camera mounted on the multi-copter so-called drone in 15/Sep./2015 at Kagawa prefecture in Japan. We had proposed 2 dimensional imaging type Fourier spectroscopy that was the near-common path temporal phase-shift interferometer. We install the variable phase shifter onto optical Fourier transform plane of infinity corrected imaging optical systems. The variable phase shifter was configured with a movable mirror and a fixed mirror. The movable mirror was actuated by the impact drive piezo-electric device (stroke: 4.5[mm], resolution: 0.01[μm], maker: Technohands Co.,Ltd., type:XDT50-45, price: around 1,000USD). We realized the wavefront division type and near common path interferometry that has strong robustness against mechanical vibrations. Without anti-mechanical vibration systems, the palm-size Fourier spectroscopy was realized. And we were able to utilize the small and low-cost middle infrared camera that was the micro borometer array (un-cooled VOxMicroborometer, pixel array: 336×256, pixel pitch: 17[μm], frame rate 60[Hz], maker: FLIR, type: Quark 336, price: around 5,000USD). And this apparatus was able to be operated by single board computer (Raspberry Pi.). Thus, total cost was less than 10,000 USD. We joined with KAMOME-PJ (Kanagawa Advanced MOdule for Material Evaluation Project) with DRONE FACTORY Corp., KUUSATSU Corp., Fuji Imvac Inc. And we successfully obtained the middle infrared spectroscopic imaging with multi-copter drone.

Uncooled Split-off Quantum Infrared Sensors for 3-5 Micron Imaging Applications

DTIC Science & Technology

2012-12-20

nonuniformity and needs to be optimized. Figure 5 (a) shows plots of Figure 3: (a) The responsivity and (b) detectivity variation with emitter...devices with larger mesa sizes than that with smaller sizes. The current nonuniformity originally results from the electric potential gradient in the...respectively. x = 0 represents the device center. The nonuniformity becomes remarkable when the temperature is increased. 5 2.3 Design of resonant

Laser-heated rocket thruster

NASA Technical Reports Server (NTRS)

Shoji, J. M.

1977-01-01

A space vehicle application using 5,000-kw input laser power was conceptually evaluated. A detailed design evaluation of a 10-kw experimental thruster including plasma size, chamber size, cooling, and performance analyses, was performed for 50 psia chamber pressure and using hydrogen as a propellant. The 10-kw hardware fabricated included a water cooled chamber, an uncooled copper chamber, an injector, igniters, and a thrust stand. A 10-kw optical train was designed.

Extension of spectral range of Peltier cooled photodetectors to 16 μm

NASA Astrophysics Data System (ADS)

Piotrowski, A.; Piotrowski, J.; Gawron, W.; Pawluczyk, J.; Pedzinska, M.

2009-05-01

We have developed various types of photodetectors operating without cryocooling. Initially, the devices were mostly used for uncooled detection of CO2 laser radiation. Over the years the performance and speed of response has been steadily improved. At present the uncooled or Peltier cooled photodetectors can be used for sensitive and fast response detection in the MWIR and LWIR spectral range. The devices have found important applications in IR spectrometry, quantum cascade laser based gas analyzers, laser radiation alerters and many other IR systems. Recent efforts were concentrated on the extension of useful spectral range to >13 μm, as required for its application in FTIR spectrometers. This was achieved with improved design of the active elements, use of monolithic optical immersion technology, enhanced absorption of radiation, dedicated electronics, series connection of small cells in series, and last but not least, applying more efficient Peltier coolers. Practical devices are based on the complex HgCdTe heterostructures grown on GaAs substrates with MOCVD technique with immersion lens formed by micromachining in the GaAs substrates. The results are very encouraging. The devices cooled with miniature 4 stage Peltier coolers mounted in TO-8 style housings show significant response at wavelength exceeding 16 μm.

Optical response of laser-doped silicon carbide for an uncooled midwave infrared detector.

PubMed

Lim, Geunsik; Manzur, Tariq; Kar, Aravinda

2011-06-10

An uncooled mid-wave infrared (MWIR) detector is developed by doping an n-type 4H-SiC with Ga using a laser doping technique. 4H-SiC is one of the polytypes of crystalline silicon carbide and a wide bandgap semiconductor. The dopant creates an energy level of 0.30  eV, which was confirmed by optical spectroscopy of the doped sample. This energy level corresponds to the MWIR wavelength of 4.21  μm. The detection mechanism is based on the photoexcitation of electrons by the photons of this wavelength absorbed in the semiconductor. This process modifies the electron density, which changes the refractive index, and, therefore, the reflectance of the semiconductor is also changed. The change in the reflectance, which is the optical response of the detector, can be measured remotely with a laser beam, such as a He-Ne laser. This capability of measuring the detector response remotely makes it a wireless detector. The variation of refractive index was calculated as a function of absorbed irradiance based on the reflectance data for the as-received and doped samples. A distinct change was observed for the refractive index of the doped sample, indicating that the detector is suitable for applications at the 4.21  μm wavelength.

Wrapping cytochrome c around single-wall carbon nanotube: engineered nanohybrid building blocks for infrared detection at high quantum efficiency

PubMed Central

Gong, Youpin; Liu, Qingfeng; Wilt, Jamie Samantha; Gong, Maogang; Ren, Shenqiang; Wu, Judy

2015-01-01

Biomolecule cytochrome c (Cty c), a small molecule of a chain of amino acids with extraordinary electron transport, was helically wrapped around a semiconductive single-wall carbon nanotube (s-SWCNT) to form a molecular building block for uncooled infrared detection with two uniquely designed functionalities: exciton dissociation to free charge carriers at the heterojunction formed on the s-SWCNT/Cty c interface and charge transport along the electron conducting chain of Cty c (acceptor) and hole conducting channel through s-SWCNT (donor). Such a design aims at addressing the long-standing challenges in exciton dissociation and charge transport in an SWCNT network, which have bottlenecked development of photonic SWCNT-based infrared detectors. Using these building blocks, uncooled s-SWCNT/Cyt c thin film infrared detectors were synthesized and shown to have extraordinary photoresponsivity up to 0.77 A W−1 due to a high external quantum efficiency (EQE) in exceeding 90%, which represents a more than two orders of magnitude enhancement than the best previously reported on CNT-based infrared detectors with EQE of only 1.72%. From a broad perspective, this work on novel s-SWCNT/Cyt c nanohybrid infrared detectors has developed a successful platform of engineered carbon nanotube/biomolecule building blocks with superior properties for optoelectronic applications. PMID:26066737

Wrapping cytochrome c around single-wall carbon nanotube: engineered nanohybrid building blocks for infrared detection at high quantum efficiency.

PubMed

Gong, Youpin; Liu, Qingfeng; Wilt, Jamie Samantha; Gong, Maogang; Ren, Shenqiang; Wu, Judy

2015-06-11

Biomolecule cytochrome c (Cty c), a small molecule of a chain of amino acids with extraordinary electron transport, was helically wrapped around a semiconductive single-wall carbon nanotube (s-SWCNT) to form a molecular building block for uncooled infrared detection with two uniquely designed functionalities: exciton dissociation to free charge carriers at the heterojunction formed on the s-SWCNT/Cty c interface and charge transport along the electron conducting chain of Cty c (acceptor) and hole conducting channel through s-SWCNT (donor). Such a design aims at addressing the long-standing challenges in exciton dissociation and charge transport in an SWCNT network, which have bottlenecked development of photonic SWCNT-based infrared detectors. Using these building blocks, uncooled s-SWCNT/Cyt c thin film infrared detectors were synthesized and shown to have extraordinary photoresponsivity up to 0.77 A W(-1) due to a high external quantum efficiency (EQE) in exceeding 90%, which represents a more than two orders of magnitude enhancement than the best previously reported on CNT-based infrared detectors with EQE of only 1.72%. From a broad perspective, this work on novel s-SWCNT/Cyt c nanohybrid infrared detectors has developed a successful platform of engineered carbon nanotube/biomolecule building blocks with superior properties for optoelectronic applications.

Infrared Camera Diagnostic for Heat Flux Measurements on NSTX

DOE Office of Scientific and Technical Information (OSTI.GOV)

D. Mastrovito; R. Maingi; H.W. Kugel

2003-03-25

An infrared imaging system has been installed on NSTX (National Spherical Torus Experiment) at the Princeton Plasma Physics Laboratory to measure the surface temperatures on the lower divertor and center stack. The imaging system is based on an Indigo Alpha 160 x 128 microbolometer camera with 12 bits/pixel operating in the 7-13 {micro}m range with a 30 Hz frame rate and a dynamic temperature range of 0-700 degrees C. From these data and knowledge of graphite thermal properties, the heat flux is derived with a classic one-dimensional conduction model. Preliminary results of heat flux scaling are reported.

Uncooled Infrared Imaging Face Recognition Using Kernel-Based Feature Vector Selection

DTIC Science & Technology

2006-09-01

j ij i jCI j G G p s t id g id p P t p P P ≥ = = ∀ ∈ (4.10) A visualization of that trade-off relationship is depicted in Figure 4.2...X_train_proj a value a_f a_g end t_hat(:,step)=(pp1(:,1))/sqrt(.2*sum(s2)) end 131 clear A1 A2 Num_replic dim1

NACA Conference on Turbojet Engines for Supersonic Propulsion. A Compilation of Technical Material Presented

DTIC Science & Technology

1953-10-01

turbojet Pngine with a turbine cooled by compressor air involves several design pruilems that do not e~ist in an uncooled turbo - jet engine . Careful...facilitate testing the sheet-metal blades in the turbojet engine , bases were formed by removing the solid airfoil portion from the standard turbine blade ...OF TURBINE BLADES by J. C. Freche 6. APPLICATION AND OPERATION OF AIR-COOLED TURBINES IN TURBOJET ENGINES

Changing requirements and solutions for unattended ground sensors

NASA Astrophysics Data System (ADS)

Prado, Gervasio; Johnson, Robert

2007-10-01

Unattended Ground Sensors (UGS) were first used to monitor Viet Cong activity along the Ho Chi Minh Trail in the 1960's. In the 1980's, significant improvement in the capabilities of UGS became possible with the development of digital signal processors; this led to their use as fire control devices for smart munitions (for example: the Wide Area Mine) and later to monitor the movements of mobile missile launchers. In these applications, the targets of interest were large military vehicles with strong acoustic, seismic and magnetic signatures. Currently, the requirements imposed by new terrorist threats and illegal border crossings have changed the emphasis to the monitoring of light vehicles and foot traffic. These new requirements have changed the way UGS are used. To improve performance against targets with lower emissions, sensors are used in multi-modal arrangements. Non-imaging sensors (acoustic, seismic, magnetic and passive infrared) are now being used principally as activity sensors to cue imagers and remote cameras. The availability of better imaging technology has made imagers the preferred source of "actionable intelligence". Infrared cameras are now based on un-cooled detector-arrays that have made their application in UGS possible in terms of their cost and power consumption. Visible light imagers are also more sensitive extending their utility well beyond twilight. The imagers are equipped with sophisticated image processing capabilities (image enhancement, moving target detection and tracking, image compression). Various commercial satellite services now provide relatively inexpensive long-range communications and the Internet provides fast worldwide access to the data.

12 -μ m -Pitch Electromechanical Resonator for Thermal Sensing

NASA Astrophysics Data System (ADS)

Laurent, Ludovic; Yon, Jean-Jacques; Moulet, Jean-Sébastien; Roukes, Michael; Duraffourg, Laurent

2018-02-01

We provide here a demonstration of 12 -μ m -pitch nanoelectromechanical resonant infrared sensors with fully integrated capacitive transduction. A low-temperature fabrication process is used to manufacture torsional resonator arrays. An H -shaped pixel with 9 -μ m -long nanorods and (250 ×30 )-nm2 cross section is designed to provide high thermal response whose experimental measurements reach up to 1024 Hz /nW . A mechanical dynamic range of over 113 dB is obtained, which leads to an Allan deviation of σA=3 ×10-7 at room temperature and 50-Hz noise bandwidth (σA=1.5 ×10-7 over 10 Hz). These features allow us to reach a sensitivity of (8 - 12 )-μ m radiation of 27 pW / √{Hz } leading to a noise-equivalent temperature difference (NETD) of 2 K for a 50-Hz noise bandwidth (NETD =1.5 K at 10 Hz). We demonstrate that the resolution is no more set by the phonon noise but by the anomalous phase noise already encountered in flexural nanoresonators. By both improving the temperature coefficient of frequency of a factor 10 and using a readout electronics at the pixel level, these resonators will lead to a breakthrough for uncooled infrared detectors. We expect that the NETD will rapidly drop to 180 mK with electronics close to the pixel. As a result of the features of our torsional resonators, an alternative readout scheme of pixels is suggested.

InGaAs focal plane array developments at III-V Lab

NASA Astrophysics Data System (ADS)

Rouvié, Anne; Reverchon, Jean-Luc; Huet, Odile; Djedidi, Anis; Robo, Jean-Alexandre; Truffer, Jean-Patrick; Bria, Toufiq; Pires, Mauricio; Decobert, Jean; Costard, Eric

2012-06-01

SWIR detection band benefits from natural (sun, night glow, thermal radiation) or artificial (eye safe lasers) photons sources combined to low atmospheric absorption and specific contrast compared to visible wavelengths. It gives the opportunity to address a large spectrum of applications such as defense and security (night vision, active imaging), space (earth observation), transport (automotive safety) or industry (non destructive process control). InGaAs material appears as a good candidate to satisfy SWIR detection needs. The lattice matching with InP constitutes a double advantage to this material: attractive production capacity and uncooled operation thanks to low dark current level induced by high quality material. For few years, III-VLab has been studying InGaAs imagery, gathering expertise in InGaAs material growth and imaging technology respectively from Alcatel-Lucent and Thales, its two mother companies. This work has lead to put quickly on the market a 320x256 InGaAs module, exhibiting high performances in terms of dark current, uniformity and quantum efficiency. In this paper, we present the last developments achieved in our laboratory, mainly focused on increasing the pixels number to VGA format associated to pixel pitch decrease (15μm) and broadening detection spectrum toward visible wavelengths. Depending on targeted applications, different Read Out Integrated Circuits (ROIC) have been used. Low noise ROIC have been developed by CEA LETI to fit the requirements of low light level imaging whereas logarithmic ROIC designed by NIT allows high dynamic imaging adapted for automotive safety.

Image quality testing of assembled IR camera modules

NASA Astrophysics Data System (ADS)

Winters, Daniel; Erichsen, Patrik

2013-10-01

Infrared (IR) camera modules for the LWIR (8-12_m) that combine IR imaging optics with microbolometer focal plane array (FPA) sensors with readout electronics are becoming more and more a mass market product. At the same time, steady improvements in sensor resolution in the higher priced markets raise the requirement for imaging performance of objectives and the proper alignment between objective and FPA. This puts pressure on camera manufacturers and system integrators to assess the image quality of finished camera modules in a cost-efficient and automated way for quality control or during end-of-line testing. In this paper we present recent development work done in the field of image quality testing of IR camera modules. This technology provides a wealth of additional information in contrast to the more traditional test methods like minimum resolvable temperature difference (MRTD) which give only a subjective overall test result. Parameters that can be measured are image quality via the modulation transfer function (MTF) for broadband or with various bandpass filters on- and off-axis and optical parameters like e.g. effective focal length (EFL) and distortion. If the camera module allows for refocusing the optics, additional parameters like best focus plane, image plane tilt, auto-focus quality, chief ray angle etc. can be characterized. Additionally, the homogeneity and response of the sensor with the optics can be characterized in order to calculate the appropriate tables for non-uniformity correction (NUC). The technology can also be used to control active alignment methods during mechanical assembly of optics to high resolution sensors. Other important points that are discussed are the flexibility of the technology to test IR modules with different form factors, electrical interfaces and last but not least the suitability for fully automated measurements in mass production.

Methods for LWIR Radiometric Calibration and Characterization

NASA Technical Reports Server (NTRS)

Ryan, Robert; Pagnutti, Mary; Zanoni, Vicki; Harrington, Gary; Howell, Dane; Stewart, Randy

2002-01-01

The utility of a thermal remote sensing system increases with it's ability to retrieve surface temperature or radiance accurately. The radiometer measures the water surface radiant temperature. Combining these measurements with atmospheric pressure, temperature, and water vapor profiles, a top-of-the-atmosphere tradiance estimate can be caluclated with a radiativer transfer code to compare to trhe sensor's output. A novel approach has been developed using an uncooled infrared camera mounted on a boom, to quantify buoy effects.

Strategic Defense Initiative Program: Extent of Foreign Participation

DTIC Science & Technology

1990-02-07

the Air Force to a West German company, . Chemical Lasers project, for fabrication of a lightweight hig mirror . The firished product will be a 70...centimeter mirror lightweight, uncool"P glass ceramic material with no tus.rm. Two contracts, totaling $1.7 million, were au-arded under th Definition...Ground-Based Free The ground-based laser system concept is to fire a free electrru Electron Laser Project beam generated on the ground to a mirror relay

Micromachined Electron-Tunneling Infrared Detectors

NASA Technical Reports Server (NTRS)

Kenny, Thomas W.; Kaiser, William J.; Waltman, Stephen B.

1993-01-01

Pneumatic/thermal infrared detectors based partly on Golay-cell concept, but smaller and less fragile. Include containers filled with air or other gas trapped behind diaphragms. Infrared radiation heats sensors, causing gas to expand. Resulting deflections of diaphragms measured by displacement sensors based on principle of electron-tunneling transducers of scanning tunneling microscopes. Exceed sensitivity of all other miniature, uncooled infrared sensors presently available. Expected to include low consumption of power, broadband sensitivity, room-temperature operation, and invulnerability to ionizing radiation.

Infrared Stokes polarimetry and spectropolarimetry

NASA Astrophysics Data System (ADS)

Kudenov, Michael William

In this work, three methods of measuring the polarization state of light in the thermal infrared (3-12 mum) are modeled, simulated, calibrated and experimentally verified in the laboratory. The first utilizes the method of channeled spectropolarimetry (CP) to encode the Stokes polarization parameters onto the optical power spectrum. This channeled spectral technique is implemented with the use of two Yttrium Vanadate (YVO4) crystal retarders. A basic mathematical model for the system is presented, showing that all the Stokes parameters are directly present in the interferogram. Theoretical results are compared with real data from the system, an improved model is provided to simulate the effects of absorption within the crystal, and a modified calibration technique is introduced to account for this absorption. Lastly, effects due to interferometer instabilities on the reconstructions, including non-uniform sampling and interferogram translations, are investigated and techniques are employed to mitigate them. Second is the method of prismatic imaging polarimetry (PIP), which can be envisioned as the monochromatic application of channeled spectropolarimetry. Unlike CP, PIP encodes the 2-dimensional Stokes parameters in a scene onto spatial carrier frequencies. However, the calibration techniques derived in the infrared for CP are extremely similar to that of the PIP. Consequently, the PIP technique is implemented with a set of four YVO4 crystal prisms. A mathematical model for the polarimeter is presented in which diattenuation due to Fresnel effects and dichroism in the crystal are included. An improved polarimetric calibration technique is introduced to remove the diattenuation effects, along with the relative radiometric calibration required for the BPIP operating with a thermal background and large detector offsets. Data demonstrating emission polarization are presented from various blackbodies, which are compared to data from our Fourier transform infrared spectropolarimeter. Additionally, limitations in the PIP technique with regards to the spectral bandwidth and F/# of the imaging system are analyzed. A model able to predict the carrier frequency's fringe visibility is produced and experimentally verified, further reinforcing the PIP's limitations. The last technique is significantly different from CP or PIP and involves the simulation and calibration of a thermal infrared division of amplitude imaging Stokes polarimeter. For the first time, application of microbolometer focal plane array (FPA) technology to polarimetry is demonstrated. The sensor utilizes a wire-grid beamsplitter with imaging systems positioned at each output to analyze two orthogonal linear polarization states simultaneously. Combined with a form birefringent wave plate, the system is capable of snapshot imaging polarimetry in any one Stokes vector (S1, S2 or S3). Radiometric and polarimetric calibration procedures for the instrument are provided and the reduction matrices from the calibration are compared to rigorous coupled wave analysis (RCWA) and raytracing simulations. The design and optimization of the sensor's wire-grid beam splitter and wave plate are presented, along with their corresponding prescriptions. Polarimetric calibration error due to the spectrally broadband nature of the instrument is also overviewed. Image registration techniques for the sensor are discussed and data from the instrument are presented, demonstrating a microbolometer's ability to measure the small intensity variations corresponding to polarized emission in natural environments.

Uncooled infrared photon detector and multicolor infrared detection using microoptomechanical sensors

DOEpatents

Datskos, Panagiotis G.; Rajic, Solobodan; Datskou, Irene C.

1999-01-01

Systems and methods for infrared detection are described. An optomechanical photon detector includes a semiconductor material and is based on measurement of a photoinduced lattice strain. A multicolor infrared sensor includes a stack of frequency specific optomechanical detectors. The stack can include one, or more, of the optomechanical photon detectors that function based on the measurement of photoinduced lattice strain. The systems and methods provide advantages in that rapid, sensitive multicolor infrared imaging can be performed without the need for a cooling subsystem.

Efficacy of Liquid, Air, and Phase Change Material Torso Cooling During Light Exercise While Wearing NBC Clothing

DTIC Science & Technology

1998-03-01

and Thermal Comfort 6 Blood Sampling 6 Statistical Analyses 6 RESULTS 7 Indices of Hydration Status 7 Liquid-Cooling and PCM Cooling Vests...of Uncooled Sites 12 Vapour Pressure 12 Ratings of Thermal Comfort and Perceived Exertion 18 Indices of Heat Tolerance 18 DISCUSSION 20...ill Figures 8A and B Changes in ratings of thermal comfort of the torso and whole body during light exercise at 40°C and 30% relative humidity while

Users manual and modeling improvements for axial turbine design and performance computer code TD2-2

NASA Technical Reports Server (NTRS)

Glassman, Arthur J.

1992-01-01

Computer code TD2 computes design point velocity diagrams and performance for multistage, multishaft, cooled or uncooled, axial flow turbines. This streamline analysis code was recently modified to upgrade modeling related to turbine cooling and to the internal loss correlation. These modifications are presented in this report along with descriptions of the code's expanded input and output. This report serves as the users manual for the upgraded code, which is named TD2-2.

Construction of University of Missouri-Rolla’s Full Scale Cloud Simulation Chamber and Applied Research

DTIC Science & Technology

1985-03-01

aluminum outer walls by a matrix of studs screwed into blind holes in the inner wall plates and extending through the outer walls. Thermoelectric cooling...studied. The problem of the uncooled sample ports might have been dealt with, however the failure of several sections of thermoelectric cooling...encountered with the Proto I chamber. It should be kept in mind that the basic cooled wall design consists of thermoelectric cooling modules (TEM’s

Engine Cycle Analysis for a Particle Bed Reactor Nuclear Rocket

DTIC Science & Technology

1991-03-01

0 DTIC USERS UNCLASSIFIED 22a. NAME OF RESPONSIBLE INDIVIDUAL ZZb. TELEPHONE (Include Area Code) 22c. OFFICE SYMBOL Lt Timothy J . Lawrence 805-275...Cycle with 2000 MW PBR and Uncooled Nozzle J : Output for Bleed Cycle with 2000 MW PBR and Cooled Nozzle K: Output for Expander Cycle with 2000 MW PBR L...Mars with carbon dioxide, the primary component of the Martian atmosphere. Carbon dioxide would delivera smaller ! j , but its use would eliminate the

Biotechnology Opens New Routes to High-Performance Materials for Improved Photovoltaics, Batteries, Uncooled IR Detectors, Ferroelectrics and Optical Applications

DTIC Science & Technology

2006-11-01

for High Power-Density, Safe Batteries and Solar Energy applications Cloning reveals: Protein template is an enzyme catalyst: γ- Ga2O3 Enzyme that...catalyzes & templates synthesis of silica at low temperature also makes semiconductors from molecular precursors: TiO2 , Ga2O3 , ZnO...CoO, RuOx (311) γ- Ga2O3 Low-temperature catalysis & templating of semiconductor synthesis The catalyst IS the template! Catalytic & Structure

Wide-band gas leak imaging detection system using UFPA

NASA Astrophysics Data System (ADS)

Jin, Wei-qi; Li, Jia-kun; Dun, Xiong; Jin, Minglei; Wang, Xia

2014-11-01

The leakage of toxic or hazardous gases not only pollutes the environment, but also threatens people's lives and property safety. Many countries attach great importance to the rapid and effective gas leak detection technology and instrument development. However, the gas leak imaging detection systems currently existing are generally limited to a narrow-band in Medium Wavelength Infrared (MWIR) or Long Wavelength Infrared (LWIR) cooled focal plane imaging, which is difficult to detect the common kinds of the leaking gases. Besides the costly cooled focal plane array is utilized, the application promotion is severely limited. To address this issue, a wide-band gas leak IR imaging detection system using Uncooled Focal Plane Array (UFPA) detector is proposed, which is composed of wide-band IR optical lens, sub-band filters and switching device, wide-band UFPA detector, video processing and system control circuit. A wide-band (3µm~12µm) UFPA detector is obtained by replacing the protection window and optimizing the structural parameters of the detector. A large relative aperture (F#=0.75) wide-band (3μm~12μm) multispectral IR lens is developed by using the focus compensation method, which combining the thickness of the narrow-band filters. The gas leak IR image quality and the detection sensitivity are improved by using the IR image Non-Uniformity Correction (NUC) technology and Digital Detail Enhancement (DDE) technology. The wide-band gas leak IR imaging detection system using UFPA detector takes full advantage of the wide-band (MWIR&LWIR) response characteristic of the UFPA detector and the digital image processing technology to provide the resulting gas leak video easy to be observed for the human eyes. Many kinds of gases, which are not visible to the naked eyes, can be sensitively detected and visualized. The designed system has many commendable advantages, such as scanning a wide range simultaneously, locating the leaking source quickly, visualizing the gas plume intuitively and so on. The simulation experiment shows that the gas IR imaging detection has great advantages and widely promotion space compared with the traditional techniques, such as point-contact or line-contactless detection.

Improving land vehicle situational awareness using a distributed aperture system

NASA Astrophysics Data System (ADS)

Fortin, Jean; Bias, Jason; Wells, Ashley; Riddle, Larry; van der Wal, Gooitzen; Piacentino, Mike; Mandelbaum, Robert

2005-05-01

U.S. Army Research, Development, and Engineering Command (RDECOM) Communications Electronics Research, Development and Engineering Center (CERDEC) Night Vision and Electronic Sensors Directorate (NVESD) has performed early work to develop a Distributed Aperture System (DAS). The DAS aims at improving the situational awareness of armored fighting vehicle crews under closed-hatch conditions. The concept is based on a plurality of sensors configured to create a day and night dome of surveillance coupled with heads up displays slaved to the operator's head to give a "glass turret" feel. State-of-the-art image processing is used to produce multiple seamless hemispherical views simultaneously available to the vehicle commander, crew members and dismounting infantry. On-the-move automatic cueing of multiple moving/pop-up low silhouette threats is also done with the possibility to save/revisit/share past events. As a first step in this development program, a contract was awarded to United Defense to further develop the Eagle VisionTM system. The second-generation prototype features two camera heads, each comprising four high-resolution (2048x1536) color sensors, and each covering a field of view of 270°hx150°v. High-bandwidth digital links interface the camera heads with a field programmable gate array (FPGA) based custom processor developed by Sarnoff Corporation. The processor computes the hemispherical stitch and warp functions required for real-time, low latency, immersive viewing (360°hx120°v, 30° down) and generates up to six simultaneous extended graphics array (XGA) video outputs for independent display either on a helmet-mounted display (with associated head tracking device) or a flat panel display (and joystick). The prototype is currently in its last stage of development and will be integrated on a vehicle for user evaluation and testing. Near-term improvements include the replacement of the color camera heads with a pixel-level fused combination of uncooled long wave infrared (LWIR) and low light level intensified imagery. It is believed that the DAS will significantly increase situational awareness by providing the users with a day and night, wide area coverage, immersive visualization capability.

Applications of multi-spectral imaging: failsafe industrial flame detector

NASA Astrophysics Data System (ADS)

Wing Au, Kwong; Larsen, Christopher; Cole, Barry; Venkatesha, Sharath

2016-05-01

Industrial and petrochemical facilities present unique challenges for fire protection and safety. Typical scenarios include detection of an unintended fire in a scene, wherein the scene also includes a flare stack in the background. Maintaining a high level of process and plant safety is a critical concern. In this paper, we present a failsafe industrial flame detector which has significant performance benefits compared to current flame detectors. The design involves use of microbolometer in the MWIR and LWIR spectrum and a dual band filter. This novel flame detector can help industrial facilities to meet their plant safety and critical infrastructure protection requirements while ensuring operational and business readiness at project start-up.

High Spatial Resolution Thermal Satellite Technologies

NASA Technical Reports Server (NTRS)

Ryan, Robert

2003-01-01

This document in the form of viewslides, reviews various low-cost alternatives to high spatial resolution thermal satellite technologies. There exists no follow-on to Landsat 7 or ASTER high spatial resolution thermal systems. This document reviews the results of the investigation in to the use of new technologies to create a low-cost useful alternative. Three suggested technologies are examined. 1. Conventional microbolometer pushbroom modes offers potential for low cost Landsat Data Continuity Mission (LDCM) thermal or ASTER capability with at least 60-120 ground sampling distance (GSD). 2. Backscanning could produce MultiSpectral Thermal Imager performance without cooled detectors. 3. Cooled detector could produce hyperspectral thermal class system or extremely high spatial resolution class instrument.

YBCO microbolometer operating below Tc - A modelization based on critical current-temperature dependence

NASA Astrophysics Data System (ADS)

Robbes, D.; Langlois, P.; Dolabdjian, C.; Bloyet, D.; Hamet, J. F.; Murray, H.

1993-03-01

Using careful measurements of the I-V curve of a YBCO thin-film microbridge under light irradiation at 780 nm and temperature close to 77 K, it is shown that the critical current versus temperature dependence is a good thermometer for estimating bolometric effects in the film. A novel dynamic voltage bias is introduced which directly gives the device current responsitivity and greatly reduces risks of thermal runaway. Detectivity is very low but it is predicted that a noise equivalent temperature of less than 10 exp -7 K/sq rt Hz would be achievable in a wide temperature range (10-80 K), which is an improvement over thermometry at the resistive transition.

Miniature near-infrared spectrometer for point-of-use chemical analysis

NASA Astrophysics Data System (ADS)

Friedrich, Donald M.; Hulse, Charles A.; von Gunten, Marc; Williamson, Eric P.; Pederson, Christopher G.; O'Brien, Nada A.

2014-03-01

Point-of-use chemical analysis holds tremendous promise for a number of industries, including agriculture, recycling, pharmaceuticals and homeland security. Near infrared (NIR) spectroscopy is an excellent candidate for these applications, with minimal sample preparation for real-time decision-making. We will detail the development of a golf ball-sized NIR spectrometer developed specifically for this purpose. The instrument is based upon a thin-film dispersive element that is very stable over time and temperature, with less than 2 nm change expected over the operating temperature range and lifetime of the instrument. This filter is coupled with an uncooled InGaAs detector array in a small, rugged, environmentally stable optical bench ideally suited to unpredictable environments. The resulting instrument weighs less than 60 grams, includes onboard illumination and collection optics for diffuse reflectance applications in the 900-1700 nm wavelength range, and is USB-powered. It can be driven in the field by a laptop, tablet or even a smartphone. The software design includes the potential for both on-board and cloud-based storage, analysis and decision-making. The key attributes of the instrument and the underlying design tradeoffs will be discussed, focusing on miniaturization, ruggedization, power consumption and cost. The optical performance of the instrument, as well as its fit-for purpose will be detailed. Finally, we will show that our manufacturing process has enabled us to build instruments with excellent unit-to-unit reproducibility. We will show that this is a key enabler for instrumentindependent chemical analysis models, a requirement for mass point-of-use deployment.

Heat Transfer on a Film-Cooled Rotating Blade

NASA Technical Reports Server (NTRS)

Garg, Vijay K.

1999-01-01

A multi-block, three-dimensional Navier-Stokes code has been used to compute heat transfer coefficient on the blade, hub and shroud for a rotating high-pressure turbine blade with 172 film-cooling holes in eight rows. Film cooling effectiveness is also computed on the adiabatic blade. Wilcox's k-omega model is used for modeling the turbulence. Of the eight rows of holes, three are staggered on the shower-head with compound-angled holes. With so many holes on the blade it was somewhat of a challenge to get a good quality grid on and around the blade and in the tip clearance region. The final multi-block grid consists of 4784 elementary blocks which were merged into 276 super blocks. The viscous grid has over 2.2 million cells. Each hole exit, in its true oval shape, has 80 cells within it so that coolant velocity, temperature, k and omega distributions can be specified at these hole exits. It is found that for the given parameters, heat transfer coefficient on the cooled, isothermal blade is highest in the leading edge region and in the tip region. Also, the effectiveness over the cooled, adiabatic blade is the lowest in these regions. Results for an uncooled blade are also shown, providing a direct comparison with those for the cooled blade. Also, the heat transfer coefficient is much higher on the shroud as compared to that on the hub for both the cooled and the uncooled cases.

Environmental dew point and skin and lip weathering.

PubMed

Devillers, C; Piérard, G E; Quatresooz, P; Piérard, S

2010-05-01

Xerosis represents a physiological response of the stratum corneum (SC) to environmental threats. The influence of the environmental dew point (DP) is not fully understood. This parameter is the air temperature at which the relative humidity is maximum. This study aimed to assess the relationship between the environmental DP and the water-holding capacity of the skin and lower lip vermilion. For comparison, SC property was evaluated after occlusive application of cooled and uncooled hydrogel pads. Electrometric measurements using a dermal phase meter (DPM) device were performed on the back of the hands, the cheeks and the lower lip of 40 healthy menopausal women. Assessments were performed in the outdoor conditions during winter and spring. The same measurements were recorded after hydrogel pads, at room temperature or cooled to 4 degrees C, were placed for 15 min on the test sites. The environmental DP was recorded at each evaluation time. The SC water-holding capacity was discretely influenced by the DP. In the open-air environmental conditions, a positive linear relationship was found on the cheeks between the DP and DPM values. The relationship was weaker on the lips. Conversely, a consistent increase in DPM values was recorded immediately after removal of the cooled and uncooled hydrogel pads. The observations made in the open-air testing conditions are consistent with the predicted events following the Arrhenius law. By contrast, the combination of cooling and occlusion by the hydrogel pads is responsible for the reverse effect on the SC.

History of HgTe-based photodetectors in Poland

NASA Astrophysics Data System (ADS)

Rogalski, A.

2010-09-01

In Poland, the HgCdTe studies began in 1960 at the Institute of Physics, Warsaw University. The material processing laboratory was created by Giriat and later by Dziuba, Gałązka, and others. Bridgman technique with sealed thick wall quartz ampoules was used to grow material suitable for research and experimental devices. Among the first papers published in 1961 and 1963 there were the Polish works devoted to preparation, doping, and electrical properties of HgCdTe. Infrared detector's research and development efforts in Poland were concentrated mostly on uncooled market niche. At the beginning, a modified isothermal vapour phase epitaxy has been used for research and commercial fabrication of photoconductive, photoelectromagnetic and other HgCdTe devices. Bulk growth and liquid phase epitaxy were also used. Recently, the fabrication of infrared devices relies on low temperature epitaxial technique, namely metalorganic vapour phase deposition. At present stage of development, the photoconductive and photoelectromagnetic (PEM) detectors are gradually replaced with photovoltaic devices which offer inherent advantages of no electric or magnetic bias, no heat load and no flicker noise. Potentially, photodiodes offer high performance and very fast response. However, conventional photovoltaic uncooled detectors suffer from low quantum efficiency and very low junction resistance. The problems have been solved with advanced band gap engineered architecture, multiple cell heterojunction devices connected in series, and monolithic integration of the detectors with microoptics. In final part of the paper, the Polish achievements in technology and performance of HgMnTe and HgZnTe photodetectors are presented.

An Enhanced Personal Cooling Garment for Aircrew

DTIC Science & Technology

2002-04-01

Thermal Comfort Thermal comfort was rated by the subject on a scale of 1 (so cold I am helpless) to 13 (so hot I am...0- N-EC ~25 0 -25 -50 - 0 30 60 90 120 150 180 Time (min) Figure 6 - Mean Heat Flow (uncooled sites) Rating of Thermal Comfort Ratings of thermal ... comfort for group C and N are shown in Figure 7. 12 SC-AC 11 9• C-EC 6--- 5 4 3- 0 30 60 90 120 150 180 Time (min) Figure 7 - Rating of Thermal Comfort

Development of an Uncooled Photomechanic Infrared Sensor Based on the IR Organ of the Pyrophilous Jewel Beetle Melanophila Acuminata

DTIC Science & Technology

2007-01-04

been found to be a suitable means for depositing thin films of chitosan onto the surface of a silicon wafer. A small amount of liquid solution is...response of the system to changes of the meniscus position in the capillary. This was done by gradually filling the working volume with an ionic liquid ...from the wetting of the electrodes by the ionic liquid . From this data we have calculated a signal to noise ratio of 100 for the read out mechanism

A Versatile Rocket Engine Hot Gas Facility

NASA Technical Reports Server (NTRS)

Green, James M.

1993-01-01

The capabilities of a versatile rocket engine facility, located in the Rocket Laboratory at the NASA Lewis Research Center, are presented. The gaseous hydrogen/oxygen facility can be used for thermal shock and hot gas testing of materials and structures as well as rocket propulsion testing. Testing over a wide range of operating conditions in both fuel and oxygen rich regimes can be conducted, with cooled or uncooled test specimens. The size and location of the test cell provide the ability to conduct large amounts of testing in short time periods with rapid turnaround between programs.

Air cooling of disk of a solid integrally cast turbine rotor for an automotive gas turbine

NASA Technical Reports Server (NTRS)

Gladden, H. J.

1977-01-01

A thermal analysis is made of surface cooling of a solid, integrally cast turbine rotor disk for an automotive gas turbine engine. Air purge and impingement cooling schemes are considered and compared with an uncooled reference case. Substantial reductions in blade temperature are predicted with each of the cooling schemes studied. It is shown that air cooling can result in a substantial gain in the stress-rupture life of the blade. Alternatively, increases in the turbine inlet temperature are possible.

Gas Dynamic Modernization of Axial Uncooled Turbine by Means of CFD and Optimization Software

NASA Astrophysics Data System (ADS)

Marchukov, E. Yu; Egorov, I. N.

2018-01-01

The results of multicriteria optimization of three-stage low-pressure turbine are described in the paper. The aim of the optimization is to improve turbine operation process by three criteria: turbine outlet flow angle, value of residual swirl at the turbine outlet, and turbine efficiency. Full reprofiling of all blade rows is carried out while solving optimization problem. Reprofiling includes a change in both shape of flat blade sections (profiles) and three-dimensional shape of the blades. The study is carried out with 3D numerical models of turbines.

Photonics and bioinspiration

NASA Astrophysics Data System (ADS)

Lewis, Keith

2014-10-01

Biological systems exploiting light have benefitted from thousands of years of genetic evolution and can provide insight to support the development of new approaches for imaging, image processing and communication. For example, biological vision systems can provide significant diversity, yet are able to function with only a minimal degree of neural processing. Examples will be described underlying the processes used to support the development of new concepts for photonic systems, ranging from uncooled bolometers and tunable filters, to asymmetric free-space optical communication systems and new forms of camera capable of simultaneously providing spectral and polarimetric diversity.

An analytical study of the effect of coolant flow variables on the kinetic energy output of a cooled turbine blade row.

NASA Technical Reports Server (NTRS)

Prust, H. W., Jr.

1972-01-01

Demonstration that the change in output of a cooled turbine blade row relative to the specific output of the uncooled blade row can be positive, negative, or zero, depending on the velocity, injection location, injection angle, and temperature of the coolant. Comparisons between the analytical results and experimental results for four different cases of coolant discharge, all at a coolant temperature ratio of unity, show good agreement for three cases, and rather poor agreement for the other.

Far-Infrared Heterodyne Spectrometer for Sofia

NASA Technical Reports Server (NTRS)

Betz, A. L.

1998-01-01

The project goal was to evaluate the scientific capabilities and technical requirements for a far-infrared heterodyne spectrometer suitable for the SOFIA Airborne Observatory, which is now being developed by NASA under contract to the Universities Space Research Association (USRA). The conclusions detailed below include our specific recommendations for astronomical observations, as well as our intended technical approach for reaching these scientific goals. These conclusions were presented to USRA in the form of a proposal to build this instrument. USRA subsequently awarded the University of Colorado a 3-year grant to develop the proposed Hot-Electron micro-Bolometer (HEB) mixer concept for high frequencies above 3 THz, as well as other semiconductor mixer technologies suitable for high sensitivity receivers in the 2-6 THz frequency band.

A multi-spectral optical system (1.55μm and 8 - 12μm) of GASIR ®1 design and coating aspects

NASA Astrophysics Data System (ADS)

Zadravec, Dusan; Franks, John W.; Rogers, Kenneth A.; Hendry, Alec F.; Drach, Patrick

2009-05-01

Small size and low weight are among the main drivers in modern military hand-held applications. Consequently, design-ers of such systems strive for combining multiple optical and electronic functions into the same piece of hardware. Present paper deals with the partial integration of an eye safe laser rangefinder into an optical channel for uncooled thermal imager using UMICORE's GASIR® optics. GASIR® is a chalcogenide glass with a transmission window from 0.8-15 µm, making it an effective material for use in near infrared, mid-wave infrared and far infrared applications. Due to the fact that uncooled sensors in the LWIR spectral band require optics with low f/numbers and that laser range-finders typically need a larger receiver aperture - in order to comply with the maximum range requirement - this ap-proach at first sight promises favorable synergies. However, it soon turns out that such a dual band approach makes life for the rangefinder part of the job difficult - by imposing special surface types required for achieving optical specifica-tions of the thermal channel, which may deteriorate the beam quality of the laser light as well as by introducing special coatings with potentially insufficient transmission at the specific laser wavelength. Several design versions have been developed and evaluated with the purpose of finding optimal balance between image quality of the thermal channel and the laser rangefinder performance. In this paper various optical and coating design aspects will be addressed together with the limitations of such a multi-spectral approach.

High-performance mushroom plasmonic metamaterial absorbers for infrared polarimetric imaging

NASA Astrophysics Data System (ADS)

Ogawa, Shinpei; Fujisawa, Daisuke; Hata, Hisatoshi; Uetsuki, Mitsuharu; Kuboyama, Takafumi; Kimata, Masafumi

2017-02-01

Infrared (IR) polarimetric imaging is a promising approach to enhance object recognition with conventional IR imaging for applications such as artificial object recognition from the natural environment and facial recognition. However, typical infrared polarimetric imaging requires the attachment of polarizers to an IR camera or sensor, which leads to high cost and lower performance caused by their own IR radiation. We have developed asymmetric mushroom plasmonic metamaterial absorbers (A-MPMAs) to address this challenge. The A-MPMAs have an all-Al construction that consists of micropatches and a reflector layer connected with hollow rectangular posts. The asymmetric-shaped micropatches lead to strong polarization-selective IR absorption due to localized surface plasmon resonance at the micropatches. The operating wavelength region can be controlled mainly by the micropatch and the hollow rectangular post size. AMPMAs are complicated three-dimensional structures, the fabrication of which is challenging. Hollow rectangular post structures are introduced to enable simple fabrication using conventional surface micromachining techniques, such as sacrificial layer etching, with no degradation of the optical properties. The A-MPMAs have a smaller thermal mass than metal-insulator-metal based metamaterials and no influence of the strong non-linear dispersion relation of the insulator materials constant, which produces a gap in the wavelength region and additional absorption insensitive to polarization. A-MPMAs are therefore promising candidates for uncooled IR polarimetric image sensors in terms of both their optical properties and ease of fabrication. The results presented here are expected to contribute to the development of highperformance polarimetric uncooled IR image sensors that do not require polarizers.

Modeling syngas-fired gas turbine engines with two dilutants

NASA Astrophysics Data System (ADS)

Hawk, Mitchell E.

2011-12-01

Prior gas turbine engine modeling work at the University of Wyoming studied cycle performance and turbine design with air and CO2-diluted GTE cycles fired with methane and syngas fuels. Two of the cycles examined were unconventional and innovative. The work presented herein reexamines prior results and expands the modeling by including the impacts of turbine cooling and CO2 sequestration on GTE cycle performance. The simple, conventional regeneration and two alternative regeneration cycle configurations were examined. In contrast to air dilution, CO2 -diluted cycle efficiencies increased by approximately 1.0 percentage point for the three regeneration configurations examined, while the efficiency of the CO2-diluted simple cycle decreased by approximately 5.0 percentage points. For CO2-diluted cycles with a closed-exhaust recycling path, an optimum CO2-recycle pressure was determined for each configuration that was significantly lower than atmospheric pressure. Un-cooled alternative regeneration configurations with CO2 recycling achieved efficiencies near 50%, which was approximately 3.0 percentage points higher than the conventional regeneration cycle and simple cycle configurations that utilized CO2 recycling. Accounting for cooling of the first two turbine stages resulted in a 2--3 percentage point reduction in un-cooled efficiency, with air dilution corresponding to the upper extreme. Additionally, when the work required to sequester CO2 was accounted for, cooled cycle efficiency decreased by 4--6 percentage points, and was more negatively impacted when syngas fuels were used. Finally, turbine design models showed that turbine blades are shorter with CO2 dilution, resulting in fewer design restrictions.

Passive cavity surface-emitting lasers: option of temperature-insensitive lasing wavelength for uncooled dense wavelength division multiplexing systems

NASA Astrophysics Data System (ADS)

Shchukin, V. A.; Ledentsov, N. N.; Slight, T.; Meredith, W.; Gordeev, N. Y.; Nadtochy, A. M.; Payusov, A. S.; Maximov, M. V.; Blokhin, S. A.; Blokhin, A. A.; Zadiranov, Yu. M.; Maleev, N. A.; Ustinov, V. M.; Choquette, K. D.

2016-03-01

A concept of passive cavity surface-emitting laser is proposed aimed to control the temperature shift of the lasing wavelength. The device contains an all-semiconductor bottom distributed Bragg reflector (DBR), in which the active medium is placed, a dielectric resonant cavity and a dielectric top DBR, wherein at least one of the dielectric materials has a negative temperature coefficient of the refractive index, dn/dT < 0. This is shown to be the case for commonly used dielectric systems SiO2/TiO2 and SiO2/Ta2O5. Two SiO2/TiO2 resonant structures having a cavity either of SiO2 or TiO2 were deposited on a substrate, their optical power reflectance spectra were measured at various temperatures, and refractive index temperature coefficients were extracted, dn/dT = 0.0021 K-1 for SiO2 and dn/dT = -0.0092 K-1 for TiO2. Using such dielectric materials allows designing passive cavity surface-emitting lasers having on purpose either positive, or zero, or negative temperature shift of the lasing wavelength dλ/dT. A design for temperature-insensitive lasing wavelength (dλ/dT = 0) is proposed. Employing devices with temperature-insensitive lasing wavelength in wavelength division multiplexing systems may allow significant reducing of the spectral separation between transmission channels and an increase in number of channels for a defined spectral interval enabling low cost energy efficient uncooled devices.

D Surface Generation from Aerial Thermal Imagery

NASA Astrophysics Data System (ADS)

Khodaei, B.; Samadzadegan, F.; Dadras Javan, F.; Hasani, H.

2015-12-01

Aerial thermal imagery has been recently applied to quantitative analysis of several scenes. For the mapping purpose based on aerial thermal imagery, high accuracy photogrammetric process is necessary. However, due to low geometric resolution and low contrast of thermal imaging sensors, there are some challenges in precise 3D measurement of objects. In this paper the potential of thermal video in 3D surface generation is evaluated. In the pre-processing step, thermal camera is geometrically calibrated using a calibration grid based on emissivity differences between the background and the targets. Then, Digital Surface Model (DSM) generation from thermal video imagery is performed in four steps. Initially, frames are extracted from video, then tie points are generated by Scale-Invariant Feature Transform (SIFT) algorithm. Bundle adjustment is then applied and the camera position and orientation parameters are determined. Finally, multi-resolution dense image matching algorithm is used to create 3D point cloud of the scene. Potential of the proposed method is evaluated based on thermal imaging cover an industrial area. The thermal camera has 640×480 Uncooled Focal Plane Array (UFPA) sensor, equipped with a 25 mm lens which mounted in the Unmanned Aerial Vehicle (UAV). The obtained results show the comparable accuracy of 3D model generated based on thermal images with respect to DSM generated from visible images, however thermal based DSM is somehow smoother with lower level of texture. Comparing the generated DSM with the 9 measured GCPs in the area shows the Root Mean Square Error (RMSE) value is smaller than 5 decimetres in both X and Y directions and 1.6 meters for the Z direction.

Infrared negative luminescent devices and higher operating temperature detectors

NASA Astrophysics Data System (ADS)

Nash, G. R.; Gordon, N. T.; Hall, D. J.; Ashby, M. K.; Little, J. C.; Masterton, G.; Hails, J. E.; Giess, J.; Haworth, L.; Emeny, M. T.; Ashley, T.

2004-01-01

Infrared LEDs and negative luminescent devices, where less light is emitted than in equilibrium, have been attracting an increasing amount of interest recently. They have a variety of applications, including as a ‘source’ of IR radiation for gas sensing; radiation shielding for, and non-uniformity correction of, high sensitivity staring infrared detectors; and dynamic infrared scene projection. Similarly, infrared (IR) detectors are used in arrays for thermal imaging and, discretely, in applications such as gas sensing. Multi-layer heterostructure epitaxy enables the growth of both types of device using designs in which the electronic processes can be precisely controlled and techniques such as carrier exclusion and extraction can be implemented. This enables detectors to be made which offer good performance at higher than normal operating temperatures, and efficient negative luminescent devices to be made which simulate a range of effective temperatures whilst operating uncooled. In both cases, however, additional performance benefits can be achieved by integrating optical concentrators around the diodes to reduce the volume of semiconductor material, and so minimise the thermally activated generation-recombination processes which compete with radiative mechanisms. The integrated concentrators are in the form of Winston cones, which can be formed using an iterative dry etch process involving methane/hydrogen and oxygen. We present results on negative luminescence in the mid- and long-IR wavebands, from devices made from indium antimonide and mercury cadmium telluride, where the aim is sizes greater than 1 cm×1 cm. We also discuss progress on, and the potential for, operating temperature and/or sensitivity improvement of detectors, where very high-performance imaging is anticipated from systems which require no mechanical cooling.

Infrared negative luminescent devices and higher operating temperature detectors

NASA Astrophysics Data System (ADS)

Nash, Geoff R.; Gordon, Neil T.; Hall, David J.; Little, J. Chris; Masterton, G.; Hails, J. E.; Giess, J.; Haworth, L.; Emeny, Martin T.; Ashley, Tim

2004-02-01

Infrared LEDs and negative luminescent devices, where less light is emitted than in equilibrium, have been attracting an increasing amount of interest recently. They have a variety of applications, including as a ‘source" of IR radiation for gas sensing; radiation shielding for and non-uniformity correction of high sensitivity starring infrared detectors; and dynamic infrared scene projection. Similarly, IR detectors are used in arrays for thermal imaging and, discretely, in applications such as gas sensing. Multi-layer heterostructure epitaxy enables the growth of both types of device using designs in which the electronic processes can be precisely controlled and techniques such as carrier exclusion and extraction can be implemented. This enables detectors to be made which offer good performance at higher than normal operating temperatures, and efficient negative luminescent devices to be made which simulate a range of effective temperatures whilst operating uncooled. In both cases, however, additional performance benefits can be achieved by integrating optical concentrators around the diodes to reduce the volume of semiconductor material, and so minimise the thermally activated generation-recombination processes which compete with radiative mechanisms. The integrated concentrators are in the form of Winston cones, which can be formed using an iterative dry etch process involving methane/hydrogen and oxygen. We will present results on negative luminescence in the mid and long IR wavebands, from devices made from indium antimonide and mercury cadmium telluride, where the aim is sizes greater than 1cm x 1cm. We will also discuss progress on, and the potential for, operating temperature and/or sensitivity improvement of detectors, where very higher performance imaging is anticipated from systems which require no mechanical cooling.

Infrared Negative Luminescent Devices and Higher Operating Temperature Detectors

NASA Astrophysics Data System (ADS)

Ashley, Tim

2003-03-01

Infrared LEDs and negative luminescent devices, where less light is emitted than in equilibrium, have been attracting an increasing amount of interest recently. They have a variety of applications, including as a source' of IR radiation for gas sensing; radiation shielding for and non-uniformity correction of high sensitivity starring infrared detectors; and dynamic infrared scene projection. Similarly, IR detectors are used in arrays for thermal imaging and, discretely, in applications such as gas sensing. Multi-layer heterostructure epitaxy enables the growth of both types of device using designs in which the electronic processes can be precisely controlled and techniques such as carrier exclusion and extraction can be implemented. This enables detectors to be made which offer good performance at higher than normal operating temperatures, and efficient negative luminescent devices to be made which simulate a range of effective temperatures whilst operating uncooled. In both cases, however, additional performance benefits can be achieved by integrating optical concentrators around the diodes to reduce the volume of semiconductor material, and so minimise the thermally activated generation-recombination processes which compete with radiative mechanisms. The integrated concentrators are in the form of Winston cones, which can be formed using an iterative dry etch process involving methane/hydrogen and oxygen. We will present results on negative luminescence in the mid and long IR wavebands, from devices made from indium antimonide and mercury cadmium telluride, where the aim is sizes greater than 1cm x 1cm. We will also discuss progress on, and the potential for, operating temperature and/or sensitivity improvement of detectors, where very high performance imaging is anticipated from systems which require no mechanical cooling.

Science applications of a multispectral microscopic imager for the astrobiological exploration of Mars

USGS Publications Warehouse

Nunez, Jorge; Farmer, Jack; Sellar, R. Glenn; Swayze, Gregg A.; Blaney, Diana L.

2014-01-01

Future astrobiological missions to Mars are likely to emphasize the use of rovers with in situ petrologic capabilities for selecting the best samples at a site for in situ analysis with onboard lab instruments or for caching for potential return to Earth. Such observations are central to an understanding of the potential for past habitable conditions at a site and for identifying samples most likely to harbor fossil biosignatures. The Multispectral Microscopic Imager (MMI) provides multispectral reflectance images of geological samples at the microscale, where each image pixel is composed of a visible/shortwave infrared spectrum ranging from 0.46 to 1.73 μm. This spectral range enables the discrimination of a wide variety of rock-forming minerals, especially Fe-bearing phases, and the detection of hydrated minerals. The MMI advances beyond the capabilities of current microimagers on Mars by extending the spectral range into the infrared and increasing the number of spectral bands. The design employs multispectral light-emitting diodes and an uncooled indium gallium arsenide focal plane array to achieve a very low mass and high reliability. To better understand and demonstrate the capabilities of the MMI for future surface missions to Mars, we analyzed samples from Mars-relevant analog environments with the MMI. Results indicate that the MMI images faithfully resolve the fine-scale microtextural features of samples and provide important information to help constrain mineral composition. The use of spectral endmember mapping reveals the distribution of Fe-bearing minerals (including silicates and oxides) with high fidelity, along with the presence of hydrated minerals. MMI-based petrogenetic interpretations compare favorably with laboratory-based analyses, revealing the value of the MMI for future in situ rover-mediated astrobiological exploration of Mars.

Science applications of a multispectral microscopic imager for the astrobiological exploration of Mars.

PubMed

Núñez, Jorge I; Farmer, Jack D; Sellar, R Glenn; Swayze, Gregg A; Blaney, Diana L

2014-02-01

Future astrobiological missions to Mars are likely to emphasize the use of rovers with in situ petrologic capabilities for selecting the best samples at a site for in situ analysis with onboard lab instruments or for caching for potential return to Earth. Such observations are central to an understanding of the potential for past habitable conditions at a site and for identifying samples most likely to harbor fossil biosignatures. The Multispectral Microscopic Imager (MMI) provides multispectral reflectance images of geological samples at the microscale, where each image pixel is composed of a visible/shortwave infrared spectrum ranging from 0.46 to 1.73 μm. This spectral range enables the discrimination of a wide variety of rock-forming minerals, especially Fe-bearing phases, and the detection of hydrated minerals. The MMI advances beyond the capabilities of current microimagers on Mars by extending the spectral range into the infrared and increasing the number of spectral bands. The design employs multispectral light-emitting diodes and an uncooled indium gallium arsenide focal plane array to achieve a very low mass and high reliability. To better understand and demonstrate the capabilities of the MMI for future surface missions to Mars, we analyzed samples from Mars-relevant analog environments with the MMI. Results indicate that the MMI images faithfully resolve the fine-scale microtextural features of samples and provide important information to help constrain mineral composition. The use of spectral endmember mapping reveals the distribution of Fe-bearing minerals (including silicates and oxides) with high fidelity, along with the presence of hydrated minerals. MMI-based petrogenetic interpretations compare favorably with laboratory-based analyses, revealing the value of the MMI for future in situ rover-mediated astrobiological exploration of Mars. Mars-Microscopic imager-Multispectral imaging-Spectroscopy-Habitability-Arm instrument.

ManPortable and UGV LIVAR: advances in sensor suite integration bring improvements to target observation and identification for the electronic battlefield

NASA Astrophysics Data System (ADS)

Lynam, Jeff R.

2001-09-01

A more highly integrated, electro-optical sensor suite using Laser Illuminated Viewing and Ranging (LIVAR) techniques is being developed under the Army Advanced Concept Technology- II (ACT-II) program for enhanced manportable target surveillance and identification. The ManPortable LIVAR system currently in development employs a wide-array of sensor technologies that provides the foot-bound soldier and UGV significant advantages and capabilities in lightweight, fieldable, target location, ranging and imaging systems. The unit incorporates a wide field-of-view, 5DEG x 3DEG, uncooled LWIR passive sensor for primary target location. Laser range finding and active illumination is done with a triggered, flash-lamp pumped, eyesafe micro-laser operating in the 1.5 micron region, and is used in conjunction with a range-gated, electron-bombarded CCD digital camera to then image the target objective in a more- narrow, 0.3$DEG, field-of-view. Target range determination is acquired using the integrated LRF and a target position is calculated using data from other onboard devices providing GPS coordinates, tilt, bank and corrected magnetic azimuth. Range gate timing and coordinated receiver optics focus control allow for target imaging operations to be optimized. The onboard control electronics provide power efficient, system operations for extended field use periods from the internal, rechargeable battery packs. Image data storage, transmission, and processing performance capabilities are also being incorporated to provide the best all-around support, for the electronic battlefield, in this type of system. The paper will describe flash laser illumination technology, EBCCD camera technology with flash laser detection system, and image resolution improvement through frame averaging.

Low dark current MCT-based focal plane detector arrays for the LWIR and VLWIR developed at AIM

NASA Astrophysics Data System (ADS)

Gassmann, Kai Uwe; Eich, Detlef; Fick, Wolfgang; Figgemeier, Heinrich; Hanna, Stefan; Thöt, Richard

2015-10-01

For nearly 40 years AIM develops, manufactures and delivers photo-voltaic and photo-conductive infrared sensors and associated cryogenic coolers which are mainly used for military applications like pilotage, weapon sights, UAVs or vehicle platforms. In 2005 AIM started to provide the competences also for space applications like IR detector units for the SLSTR instrument on board of the Sentinel 3 satellite, the hyperspectral SWIR Imager for EnMAP or pushbroom detectors for high resolution Earth observation satellites. Meanwhile AIM delivered more than 25 Flight Models for several customers. The first European pulse-tube cooler ever operating on-board of a satellite is made by AIM. AIM homes the required infrared core capabilities such as design and manufacturing of focal plane assemblies, detector housing technologies, development and manufacturing of cryocoolers and also data processing for thermal IR cameras under one roof which enables high flexibility to react to customer needs and assures economical solutions. Cryogenically cooled Hg(1-x)CdxTe (MCT) quantum detectors are unequalled for applications requiring high imaging as well as high radiometric performance in the infrared spectral range. Compared with other technologies, they provide several advantages, such as the highest quantum efficiency, lower power dissipation compared to photoconductive devices and fast response times, hence outperforming micro-bolometer arrays. However, achieving an excellent MCT detector performance at long (LWIR) and very long (VLWIR) infrared wavelengths is challenging due to the exponential increase in the thermally generated photodiode dark current with increasing cut-off wavelength and / or operating temperature. Dark current is a critical design driver, especially for LWIR / VLWIR multi-spectral imagers with moderate signal levels or hyper-spectral Fourier spectrometers operating deep into the VLWIR spectral region. Consequently, low dark current (LDC) technologies are the prerequisite for future scientific space and earth observation missions. Aiming, for example at exoplanet or earth atmospheric spectral analysis, significant improvement in LWIR / VLWIR detector material performance is mandatory. LDC material optimization can target different directions of impact: (i) reduction of dark current for a given operational temperature to increase SNR and reduce thermally induced signal offset variations. (ii) operation at elevated temperatures at a given dark current level to reduce mass and power budget of the required cryocooler and to reduce cryostat complexity. (iii) increase the accessible cut-off wavelength at constant detector temperature and dark current level. This paper presents AIM's latest results on n-on-p as well as p-on-n low dark current planar MCT photodiode focal plane detector arrays at cut-off wavelengths >11 μm at 80 K. Dark current densities below Tennant's `Rule07'1 have been demonstrated for n-on-p and p-on-n devices. This work has been carried out under ESA contract ESTEC 4000107414/13/NL/SFe².

Internal-Film Cooling of Rocket Nozzles

NASA Technical Reports Server (NTRS)

Sloop, J L; Kinney, George R

1948-01-01

Experiments were conducted with 1000-pound-thrust rocket engine to determine feasibility of cooling convergent-divergent nozzle by internal film of water introduced at nozzle entrance. Water flow of 3 percent of propellant flow reduced heat flow into nozzle to 55 percent of uncooled heat flow. Introduction of water by porous ring before nozzle resulted in more uniform coverage of nozzle than water introduced by single arrangement of 36 jets directed along nozzle wall. Water flow through porous ring of 3.5 percent of propellant flow stabilized wall temperature in convergent section but did not adequately cool throat or divergent sections.

Carbon-doped single-crystalline SiGe/Si thermistor with high temperature coefficient of resistance and low noise level

DOE Office of Scientific and Technical Information (OSTI.GOV)

Radamson, H. H.; Kolahdouz, M.; Shayestehaminzadeh, S.

2010-11-29

SiGe (C)/Si(C) multiquantum wells have been studied as a thermistor material for future bolometers. A thermistor material for uncooled Si-based thermal detectors with thermal coefficient of resistance of 4.5%/K for 100x100 {mu}m{sup 2} pixel sizes and low noise constant (K{sub 1/f}) value of 4.4x10{sup -15} is presented. The outstanding performance of the devices is due to Ni-silicide contacts, smooth interfaces, and high quality multiquantum wells containing high Ge content.

Design and cold-air test of single-stage uncooled turbine with high work output

NASA Technical Reports Server (NTRS)

Moffitt, T. P.; Szanca, E. M.; Whitney, W. J.; Behning, F. P.

1980-01-01

A solid version of a 50.8 cm single stage core turbine designed for high temperature was tested in cold air over a range of speed and pressure ratio. Design equivalent specific work was 76.84 J/g at an engine turbine tip speed of 579.1 m/sec. At design speed and pressure ratio, the total efficiency of the turbine was 88.6 percent, which is 0.6 point lower than the design value of 89.2 percent. The corresponding mass flow was 4.0 percent greater than design.

Cold-air annular-cascade investigation of aerodynamic performance of cooled turbine vanes. 2: Trailing-edge ejection, film cooling, and transpiration cooling

NASA Technical Reports Server (NTRS)

Goldman, L. J.; Mclallin, K. L.

1975-01-01

The aerodynamic performance of four different cooled vane configurations was experimentally determined in a full-annular cascade at a primary- to coolant-total-temperature ratio of 1.0. The vanes were tested over a range of coolant flow rates and pressure ratios. Overall vane efficiencies were obtained and compared, where possible, with the results obtained in a four-vane, annular-sector cascade. The vane efficiency and exit flow conditions as functions of radial position were also determined and compared with solid (uncooled) vane results.

Uncooled infrared photon detection concepts and devices

NASA Astrophysics Data System (ADS)

Piyankarage, Viraj Vishwakantha Jayaweera

This work describes infrared (IR) photon detector techniques based on novel semiconductor device concepts and detector designs. The aim of the investigation was to examine alternative IR detection concepts with a view to resolve some of the issues of existing IR detectors such as operating temperature and response range. Systems were fabricated to demonstrate the following IR detection concepts and determine detector parameters: (i) Near-infrared (NIR) detection based on dye-sensitization of nanostructured semiconductors, (ii) Displacement currents in semiconductor quantum dots (QDs) embedded dielectric media, (iii) Split-off band transitions in GaAs/AlGaAs heterojunction interfacial workfunction internal photoemission (HEIWIP) detectors. A far-infrared detector based on GaSb homojunction interfacial workfunction internal photoemission (HIWIP) structure is also discussed. Device concepts, detector structures, and experimental results discussed in the text are summarized below. Dye-sensitized (DS) detector structures consisting of n-TiO 2/Dye/p-CuSCN heterostructures with several IR-sensitive dyes showed response peaks at 808, 812, 858, 866, 876, and 1056 nm at room temperature. The peak specific-detectivity (D*) was 9.5x1010 cm Hz-1/2 W-1 at 812 nm at room temperature. Radiation induced carrier generation alters the electronic polarizability of QDs provided the quenching of excitation is suppressed by separation of the QDs. A device constructed to illustrate this concept by embedding PbS QDs in paraffin wax showed a peak D* of 3x108 cm Hz 1/2 W-1 at ˜540 nm at ambient temperature. A typical HEIWIP/HIWIP detector structures consist of single (or multiple) period(s) of doped emitter(s) and undoped barrier(s) which are sandwiched between two highly doped contact layers. A p-GaAs/AlGaAs HEIWIP structure showed enhanced absorption in NIR range due to heavy/light-hole band to split-off band transitions and leading to the development of GaAs based uncooled sensors for IR detection in the 2--5 microm wavelength range with a peak D* of 6.8x105 cm Hz1/2 W-1. A HIWIP detector based on p-GaSb/GaSb showed a free carrier response threshold wavelength at 97 microm (˜3 THz) with a peak D* of 5.7x1011 cm Hz1/2 W-1 at 36 microm and 4.9 K. In this detector, a bolometric type response in the 97--200 microm (3--1.5 THz) range was also observed. INDEX WORDS: Infrared detectors, Photon detection, NIR detectors, THz detectors, Uncooled detectors, Dye-sensitized, IR dye, Quantum dot, Split-off band, GaSb, GaAs, AlGaAs, TiO2, CuSCN, PbS, Homojunction, Heterojunction, Workfunction, Photoemission, Displacement currents, 1/f noise.

Thermal Infrared Imager on Hayabusa2: Science and Development

NASA Astrophysics Data System (ADS)

Okada, Tatsuaki

2015-04-01

Thermal Infrared Imager TIR was developed and calibrated for Haya-busa2 asteroid explorer, aiming at the investigation of thermo-physical properties of C-class near-Earth sub-km sized asteroid (162173) 1999JU3. TIR is based on the 2D micro-bolometer array with germani-um lens to image the surface of asteroid in 8 to 12 μm wavelength (1), measuring the thermal emission off the asteroid surface. Its field of view is 16° x 12° with 328 x 248 pixels. At least 40 (up to 100) images will be taken during asteroid rotation once a week, mainly from the Home Position which is about 20km sunward from asteroid surface. Therefore TIR will image the whole asteroid with spatial resolution of < 20m per pixel, and the temperature profile of each site on the asteroid will be traced from dawn to dusk regions by asteroid rotation. The scien-tific objectives of TIR include the mapping of asteroid surface condi-tions (regional distribution of thermal inertia), since the surface physical conditions are strongly correlated with thermal inertia. It is so informa-tive on understanding the re-accretion or surface sedimentation process-es of the asteroid to be the current form. TIR data will be used for searching for those sites having the typical particle size of 1mm for best sample collection, and within the proper thermal condition for space-craft safe operation. After launch of Hayabusa2, TIR has been tested successfully, covering from -100 to 150 °C using a single parameter settings (2). This implies that TIR is actually able to map the surface other than the sunlit areas. Performance of TIR was found basically the same as those in the pre-launch test, when the temperature of TIR is well controlled. References: (1) Fukuhara T. et al., (2011) Earth Planet. Space 63, 1009-1018; (2) Okada T. et al., (2015) Lunar Planet. Sci. Conf. 46, #1331.

BIB mixers

NASA Technical Reports Server (NTRS)

1995-01-01

We have determined that the multi-pin 'microprocessor style' packages in which current Blocked Impurity Band (BIB) devices are mounted will not meet our IF bandwidth spec of greater than 2 GHz for a practical mixer. Hence we have started to repackage the Ga:Ge BIB devices in new microwave compatible packages. The smaller size of the microwave package mount necessitates cutting the BIB array down to include only the 3 smallest detectors: 0.2, 0.4, and 0.6 mm sq. A FIR beam incident at f/1.5 can be focussed on the smallest element for wavelengths shorter than 100 microns. A more typical (easier) beam convergence of f/3 will require 0.4 mm elements at 100 microns and 0.6 mm elements at 170 microns wavelength. Since the device capacitance (parasitic loss) scales with detector size, there is a tradeoff of speed of response and optical convenience. Our existing optics produce only the slower convergence beam, so we need to redesign the optical layout and are looking at long focal length all-reflective microscope objectives. BIB detectors and the edge-coupled microbolometers have restricted IF bandwidths, an order of magnitude less than what is possible with the Schottky-diode mixers we currently use for astronomical observations. Consequently the frequencies of the FIR laser lines must be close to the astronomical line of interest to be an effective Local Oscillator (LO). We have therefore begun a coordinated effort to discover and measure new FIR laser transition lines in close frequency coincidence with important astrophysical lines. Most of this effort involves pumping isotopic variants of known good laser molecules with laser lines from isotopic variants of CO2. We have been most successful in detecting new FIR lines in deuterated ammonia. One line in particular is very close to the frequency of HD rotational line at 2675 GHz.

A fabrication and characterictics of microbolometer detectors using VOx/ZnO/VOx multilayer thin film processing

NASA Astrophysics Data System (ADS)

Han, Myung-Soo; Kim, Dae Hyeon; Ko, Hang Ju; Shin, Jae Chul; Kim, Hyo Jin; Kim, Do Gun

2014-06-01

In this work, a novel fabrication method for VOx-ZnO multilayers with mixed phase of the VO2 and V2O3 through the diffusion of oxygen by annealing at low temperature is presented. A stable sandwich structure of a VOx/ZnO/VOx multilayer was deposited at room temperature, through the oxygen gas flow rate, by RF sputtering system, and the mixed phase was formed through oxygen diffusion by annealing at O2 atmosphere. The results show that the single phase like multilayer formed by this process has a high TCR of more than -2.5%/K and low resistance of about 100 kohm at room temperature. XRD results for the as-deposited VOx/ZnO/VOx multilayer.

Parylene supported 20um*20um uncooled thermoelectric infrared detector with high fill factor

NASA Astrophysics Data System (ADS)

Modarres-Zadeh, Mohammad J.; Carpenter, Zachary S.; Rockley, Mark G.; Abdolvand, Reza

2012-06-01

Presented is a novel design for an uncooled surface-micromachined thermoelectric (TE) infrared (IR) detector. The detector features a P-doped polysilicon/Nichrome (Cr20-Ni80) thermocouple, which is embedded into a thin layer of Parylene-N to provide structural support. The low thermal conductivity (~0.1W/m.K), chemical resistance, and ease of deposition/patterning of Parylene-N make it an excellent choice of material for use in MEMS thermal detectors. This detector also features an umbrella-like IR absorber composed of a three layer stack of NiCr/SiN/NiCr to optimize IR absorption. The total device area is 20 um * 20 um per pixel with an absorber area of ~19 um * 19 um resulting in a fill factor of 90%. At room temperature, a DC responsivity of ~170V/W with a rise time of less than 8 ms is measured from the fabricated devices in vacuum when viewing a 500K blackbody without any concentrating optics. The dominant source of noise in thermoelectric IR detectors is typically Johnson noise when the detectors are operating in an open circuit condition. The fabricated detectors have resistances about 85KOhm which results in Johnson noise of about 38nV/Hz^0.5. The D* is calculated to be 9 * 106 cm*Hz0.5/ W. Preliminary finite element analysis indicates that the thermal conduction from the hot junction to the substrate through the TE wires is dominant ( GTE >> Gparylene) considering the fabricated dimensions of the parylene film and the TE wires. Thus, by further reducing the size of the TE wires, GTE can be decreased and hence, responsivity can be improved while the parylene film sustains the structural integrity of the cell.

High-density fuel combustion and cooling investigation. [kengine design

NASA Technical Reports Server (NTRS)

Labotz, R. J.; Rousar, D. C.; Valler, H. W.

1980-01-01

The analysis, design, fabrication and testing of several engine configurations are discussed with respect to the combustion and heat transfer characteristics of LOX/RP-1 at chamber pressures between 6895 and 13790 kPa (1000 and 2000 psia). The different engine configurations discussed include: 8274 kPa and 13790 kPa (1200 psia and 2000 psia) chamber pressure injectors with like doublet and preatomized triplet elements; cooled and uncooled acoustic resonators; and graphite, regeneratively cooled and calorimetric chambers ranging in length from 27.9 to 37.5 cm (11 to 15 in.). A high pressure LOX/RP-1 spark igniter is also evaluated.

A Combustion Research Facility for Testing Advanced Materials for Space Applications

NASA Technical Reports Server (NTRS)

Bur, Michael J.

2003-01-01

The test facility presented herein uses a groundbased rocket combustor to test the durability of new ceramic composite and metallic materials in a rocket engine thermal environment. A gaseous H2/02 rocket combustor (essentially a ground-based rocket engine) is used to generate a high temperature/high heat flux environment to which advanced ceramic and/or metallic materials are exposed. These materials can either be an integral part of the combustor (nozzle, thrust chamber etc) or can be mounted downstream of the combustor in the combustor exhaust plume. The test materials can be uncooled, water cooled or cooled with gaseous hydrogen.

Design and evaluation of active cooling systems for Mach 6 cruise vehicle wings

NASA Technical Reports Server (NTRS)

Mcconarty, W. A.; Anthony, F. M.

1971-01-01

Active cooling systems, which included transpiration, film, and convective cooling concepts, are examined. Coolants included hydrogen, helium, air, and water. Heat shields, radiation barriers, and thermal insulation are considered to reduce heat flow to the cooling systems. Wing sweep angles are varied from 0 deg to 75 deg and wing leading edge radii of 0.05 inch and 2.0 inches are examined. Structural temperatures are varied to allow comparison of aluminum alloy, titanium alloy, and superalloy structural materials. Cooled wing concepts are compared among themselves, and with the uncooled concept on the basis of structural weight, cooling system weight, and coolant weight.

Development of mercuric iodide uncooled x ray detectors and spectrometers

NASA Technical Reports Server (NTRS)

Iwanczyk, Jan S.

1990-01-01

The results obtained in the development of miniature, lowpower, light weight mercuric iodide, HgI2, x ray spectrometers for future space missions are summarized. It was demonstrated that HgI2 detectors can be employed in a high resolution x ray spectrometer, operating in a scanning electron microscope. Also, the development of HgI2 x ray detectors to augment alpha backscattering spectrometers is discussed. These combination instruments allow for the identification of all chemical elements, with the possible exception of hydrogen, and their respective concentrations. Additionally, further investigations of questions regarding radiation damage effects in the HgI2 x ray detectors are reported.

Flight velocity effects on jet noise of several variations of a 48-tube suppressor installed on a plug nozzle

NASA Technical Reports Server (NTRS)

Burley, R. R.; Head, V. L.

1974-01-01

Because of the relatively high takeoff speeds of supersonic transport aircraft, it is important to know if the flight velocity affects the noise level of suppressor nozzles. To investigate this, a modified F-106B aircraft was used to conduct a series of flyover and static tests on a 48-tube suppressor installed on an uncooled plug nozzle. Comparison of flyover and static spectra indicated that flight velocity had little effect on the noise suppression of the 48-tube suppressor configuration. However, flight velocity adversely affected noise suppression of the 48-tube suppressor with an acoustic shroud and plug installed.

A sub-μs thermal time constant electrically driven Pt nanoheater: thermo-dynamic design and frequency characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ottonello Briano, Floria, E-mail: floria@kth.se; Sohlström, Hans; Forsberg, Fredrik

2016-05-09

Metal nanowires can emit coherent polarized thermal radiation, work as uncooled bolometers, and provide localized heating. In this paper, we engineer the temperature dynamics of electrically driven Pt nanoheaters on a silicon-on-insulator substrate. We present three designs and we electrically characterize and model their thermal impedance in the frequency range from 3 Hz to 3 MHz. Finally, we show a temperature modulation of 300 K while consuming less than 5 mW of power, up to a frequency of 1.3 MHz. This result can lead to significant advancements in thermography and absorption spectroscopy.

Uncooled spectrometer for x-ray astrophysics

NASA Astrophysics Data System (ADS)

Urban, Martin; Nentvich, Ondrej; Stehlikova, Veronika; Sieger, Ladislav

2017-05-01

In the field of X-ray detection for Astrophysics there are mainly two objectives; first is to create 2D images as a result of sensing radiation by detectors consisting of a pixels matrix and the second is a spectral analysis of the incident radiation. For spectral analysis, the basis is usually the principle of diffraction. This paper describes the new design of X-ray spectrometer based on Timepix detector with optics positioned in front of it. The advantage of this setup is the ability to get the image and spectrum from the same devices. With other modifications is possible to shift detection threshold into areas of soft X-ray radiation.

Solar loading thermography: Time-lapsed thermographic survey and advanced thermographic signal processing for the inspection of civil engineering and cultural heritage structures

NASA Astrophysics Data System (ADS)

Ibarra-Castanedo, Clemente; Sfarra, Stefano; Klein, Matthieu; Maldague, Xavier

2017-05-01

The experimental results from infrared thermography surveys over two buildings externally exposed walls are presented. Data acquisition was performed on a static configuration by recording direct and indirect solar loading during several days and was processed using advanced signal processing techniques in order to increase signal-to-noise ratio and signature contrast of the elements of interest. It is demonstrated that it is possible to detect the thermal signature of large internal structures as well as surface features under such thermographic scenarios. Results from a long-wave microbolometer compared favorably to those from a mid-wave cooled infrared camera for the detection of large subsurface features from unprocessed images. In both cases, however, advanced signal processing greatly improved contrast of the internal features.

SCC500: next-generation infrared imaging camera core products with highly flexible architecture for unique camera designs

NASA Astrophysics Data System (ADS)

Rumbaugh, Roy N.; Grealish, Kevin; Kacir, Tom; Arsenault, Barry; Murphy, Robert H.; Miller, Scott

2003-09-01

A new 4th generation MicroIR architecture is introduced as the latest in the highly successful Standard Camera Core (SCC) series by BAE SYSTEMS to offer an infrared imaging engine with greatly reduced size, weight, power, and cost. The advanced SCC500 architecture provides great flexibility in configuration to include multiple resolutions, an industry standard Real Time Operating System (RTOS) for customer specific software application plug-ins, and a highly modular construction for unique physical and interface options. These microbolometer based camera cores offer outstanding and reliable performance over an extended operating temperature range to meet the demanding requirements of real-world environments. A highly integrated lens and shutter is included in the new SCC500 product enabling easy, drop-in camera designs for quick time-to-market product introductions.

Micro and Nano Electromechanical Systems for Near-Zero Power Infrared Detection

NASA Astrophysics Data System (ADS)

Qian, Zhenyun

Light is one of the most important tools for human beings to probe and sense the physical world. Infrared (IR) radiation located in longer wavelengths than those of visible light carries rich information of an environment as it reveals the temperature distribution and chemical composition of objects. In addition, it has been utilized for communication and distance measurement owing to the atmospheric window and insensitiveness of human eyes to the IR radiation. As a result, IR detectors nowadays can be found in a wide variety of applications, including thermal imaging, automotive night vision, standoff chemical detection, remote control and laser ranging, just to mention a few. On the other hand, due to the recent fast development of the Internet of Things (IoT), there is a growing demand for miniaturized and power efficient unattended sensors that can be widely distributed in large volumes to form a wireless sensor networks capable of monitoring the environment with high accuracy and long lifetime. In this context, micro and nano electromechanical systems (MEMS/NEMS) may provide a huge impact, since they can be used for the implementation of miniaturized, low power, high-performance sensors and wireless communication devices fully compatible with standard integrated circuitry. This dissertation presents the design and the experimental verification of high performance uncooled IR detectors based on Aluminum Nitride (AlN) nano electromechanical resonators, and a first-of-its-kind near-zero power IR digitizer based on plasmonically-enhanced micromechanical photoswitches. The unique advantages of the piezoelectric AlN thin film in terms of scaling in thickness and transduction efficiency are exploited by the first experimental demonstration of ultra-fast (thermal time constant, tau ˜ 80 mus) and high resolution (noise equivalent power, NEP ˜ 656 pW/Hz1/2) AlN NEMS resonant IR detectors with reduced pixel size comparable to the state-of-the-art microbolometers. Furthermore, the spectral selectivity of the proposed IR detector technology is investigated and demonstrated by the seamless integration of ultra-thin plasmonic absorbers. The first prototypes show strong absorption (> 92%) in mid-wavelength infrared range with a narrow bandwidth (full width at half maximum, FWHM < 17%), resulting in the demonstration of high resolution (NEP ˜ 130 pW/Hz1/2) narrowband infrared detectors suitable for IR spectroscopy and multispectral imaging system. The second part of the dissertation is focused on the discussion and development of a new class of IR wake-up sensors that can remain dormant, with near-zero power consumption, until awoken by an external signal of interest. The proposed near-zero power IR digitizer combines sensing, signal processing and comparator functionalities into a single passive microelectromechanical system capable of producing a digitized output bit in the presence of the unique infrared spectral signature associated to an event of interest. The prototypes reported in this dissertation are capable of producing a digitized output bit (i.e. a large and sharp OFF-to-ON state transition with ON/OFF conductance ratio > 1012 and subthreshold slope > 9 dec/nW) when exposed to IR radiation in a specific narrow spectral band (˜ 900 nm bandwidth in the mid-IR) with intensity above a power threshold of only ˜ 500 nW, which is not achievable with any existing photoswitch technologies. The two IR sensing elements presented here set a stepping stone towards the development of highly sensitive and persistent IR sensor nodes that required for the future event-driven wireless sensor networks.

The Small Bodies Thermal Mapper: An Instrument for Future Missions to Study the Compositional and Thermal Properties of Phobos

NASA Astrophysics Data System (ADS)

Donaldson Hanna, Kerri; Bowles, Neil; Calcutt, Simon; Greenhagen, Benjamin; Glotch, Timothy; Edwards, Christopher

2015-04-01

The surface of Phobos holds many keys for understanding its formation and evolution as well as the history and dynamics of the Mars-Phobos system. Phobos has been the target for numerous flyby and sample return missions in the past (e.g. Rosetta [Pajola et al., 2012] and Phobos Grunt [Kuzmin et al., 2003]). Previous telescopic and spacecraft observations have revealed a surface that is compositionally heterogeneous [e.g. Pang et al., 1978; Pollack et al., 1978, Lunine et al., 1982; Murchie and Erard, 1996; Roush and Hogan, 2001; Rivkin et al., 2002; Giuranna et al., 2011; Fraeman et al., 2014] and with large variations in surface topography [e.g. Shi et al., 2011; 2012; Willner et al., 2014]. For any future sample return mission, remote sensing observations, in particular thermal infrared observations, will be key in characterising possible landing/sampling sites and placing returned samples into their geological context. The European Space Agency has identified Phootprint, a European sample return mission to Phobos, as a candidate mission of the Mars Robotic Exploration Preparation Programme 2 (MREP-2). Using this mission concept as a baseline, we have studied the options for a simple multichannel radiometer to provide thermal mapping and compositional remote sensing data. By mapping Phobos' diurnal thermal response, a thermal imaging instrument will provide key information on the nature of the surface and near sub-surface (the thermal inertia) and composition. These measurements will support visible imaging observations to determine landing sites that are compatible with the spacecraft's sampling mechanisms. Remotely sensed thermal maps of the surface will also prevent otherwise unpredictable thermal loads on the spacecraft due to variations in local topography and albedo. The instrument design resulting from this study, the Small Bodies Thermal Mapper (SBTM), is a compact multichannel radiometer and thermal imager. The SBTM is based on the Compact Modular Sounder (CMS) instrument currently flying on the UK's TechDemoSat-1 spacecraft in low Earth orbit. This gives a significant level of flight heritage with optimisations for the expected Phobos environment. The SBTM instrument uses a two-dimensional uncooled thermal detector array to provide imaging of Phobos. In addition, ten narrow-band infrared filters located around diagnostic mineral spectral features provide additional compositional discrimination. For the SBTM, the optimisations studied include options for the detector and filters required to cover the wide range of diurnal temperatures expected at Phobos (e.g. 130 to > 300 K) [e.g. Kuzmin et al., 2003]. Options studied include the use of a broadband micro bolometer array (e.g. http://www.ulis-ir.com/uploads/Products/PICO640E-041-BroadBand.pdf) or a thermopile detector [Foote et al., 1998] array. Optimisation of filter band passes for remote measurement of composition is also considered, based on mineral spectra measured under simulated Phobos environment [e.g. Glotch et al., 2014].

Design of a Wideband Radio Telescope

NASA Technical Reports Server (NTRS)

Imbriale, William A.; Weinreb, Sander; Mani, Handi

2007-01-01

A wideband Radio Telescope is being designed for use in the Goldstone Apple Valley Radio Telescope program. It uses an existing 34-meter antenna retrofitted with a tertiary offset mirror placed at the apex of the main reflector. It can be rotated to use two feeds that cover the 1.2 to 14 GHz band. The feed for 4.0 to 14.0 GHz is a cryogenically cooled commercially available open boundary quadridge horn from ETS-Lindgren. Coverage from 1.2 to 4.0 GHz is provided by an un-cooled scaled version of the same feed. The performance is greater than 40% over most of the band and greater than 55%from 6 to 13.5 GHz.

Color mixing from monolithically integrated InGaN-based light-emitting diodes by local strain engineering

NASA Astrophysics Data System (ADS)

Chung, Kunook; Sui, Jingyang; Demory, Brandon; Ku, Pei-Cheng

2017-07-01

Additive color mixing across the visible spectrum was demonstrated from an InGaN based light-emitting diode (LED) pixel comprising red, green, and blue subpixels monolithically integrated and enabled by local strain engineering. The device was fabricated using a top-down approach on a metal-organic chemical vapor deposition-grown sample consisting of a typical LED epitaxial stack. The three color subpixels were defined in a single lithographic step. The device was characterized for its electrical properties and emission spectra under an uncooled condition, which is desirable in practical applications. The color mixing was controlled by pulse-width modulation, and the degree of color control was also characterized.

Design and experimental evaluation of a high temperature radial turbine with a moveable sidewall nozzle

NASA Technical Reports Server (NTRS)

Rogo, Casimir; Roelke, Richard J.

1987-01-01

The uncooled, 2.27 kg/sec mass flow radial turbine designed to operate at 1477 K in the gas generator of an advanced, variable-capacity 683 kW turboshaft engine was configured with a cooled, movable sidewall nozzle capable of changing the stage flow capacity from 50 to 100 percent of maximum. Overall performance test data were obtained in a turbine test rig that duplicated engine Reynolds numbers; attention is given to the changing of flow capacity by moving the hub or shroud sidewall, vane sidewall leakage, vaneless space sidewall geometry, and nozzle-cooling injection. Data are presented in the form of turbine flow, efficiency, work parameter, and performance mappings.

Description of a Pressure Measurement Technique for Obtaining Surface Static Pressures of a Radial Turbine

NASA Technical Reports Server (NTRS)

Dicicco, L. Danielle; Nowlin, Brent C.; Tirres, Lizet

1992-01-01

The aerodynamic performance of a solid uncooled version of a cooled radial turbine was evaluated in the Small Engine Components Test Facility Turbine rig at the NASA Lewis Research Center. Specifically, an experiment was conducted to rotor surface static pressures. This was the first time surface static pressures had been measured on a radial turbine at NASA Lewis. These pressures were measured by a modified Rotating Data Package (RDP), a standard product manufactured by Scanivalve, Inc. Described here are the RDP, and the modifications that were made, as well as the checkout, installation, and testing procedures. The data presented are compared to analytical results obtained from NASA's MERIDL TSONIC BLAYER (MTSB) code.

Description of a pressure measurement technique for obtaining surface static pressures of a radial turbine

NASA Technical Reports Server (NTRS)

Dicicco, L. D.; Nowlin, Brent C.; Tirres, Lizet

1992-01-01

The aerodynamic performance of a solid uncooled version of a cooled radial turbine was evaluated in the Small Engine Components Test Facility Turbine rig at the NASA Lewis Research Center. Specifically, an experiment was conducted to rotor surface static pressures. This was the first time surface static pressures had been measured on a radial turbine at NASA Lewis. These pressures were measured by a modified Rotating Data Package (RDP), a standard product manufactured by Scanivalve, Inc. Described here are the RDP, and the modifications that were made, as well as the checkout, installation, and testing procedures. The data presented are compared to analytical results obtained from NASA's MERIDL TSONIC BLAYER (MTSB) code.

Materials Problems in Chemical Liquid-Propellant Rocket Systems

NASA Technical Reports Server (NTRS)

Gilbert, L. L.

1959-01-01

With the advent of the space age, new adjustments in technical thinking and engineering experience are necessary. There is an increasing and extensive interest in the utilization of materials for components to be used at temperatures ranging from -423 to over 3500 deg F. This paper presents a description of the materials problems associated with the various components of chemical liquid rocket systems. These components include cooled and uncooled thrust chambers, injectors, turbine drive systems, propellant tanks, and cryogenic propellant containers. In addition to materials limitations associated with these components, suggested research approaches for improving materials properties are made. Materials such as high-temperature alloys, cermets, carbides, nonferrous alloys, plastics, refractory metals, and porous materials are considered.

High Temperature Composite Heat Exchangers

NASA Technical Reports Server (NTRS)

Eckel, Andrew J.; Jaskowiak, Martha H.

2002-01-01

High temperature composite heat exchangers are an enabling technology for a number of aeropropulsion applications. They offer the potential for mass reductions of greater than fifty percent over traditional metallics designs and enable vehicle and engine designs. Since they offer the ability to operate at significantly higher operating temperatures, they facilitate operation at reduced coolant flows and make possible temporary uncooled operation in temperature regimes, such as experienced during vehicle reentry, where traditional heat exchangers require coolant flow. This reduction in coolant requirements can translate into enhanced range or system payload. A brief review of the approaches and challengers to exploiting this important technology are presented, along with a status of recent government-funded projects.

The Effect of a Pre-Lens Aperture on the Temperature Range and Image Uniformity of Microbolometer Infrared Cameras

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dinwiddie, Ralph Barton; Parris, Larkin S.; Lindal, John M.

This paper explores the temperature range extension of long-wavelength infrared (LWIR) cameras by placing an aperture in front of the lens. An aperture smaller than the lens will reduce the radiance to the sensor, allowing the camera to image targets much hotter than typically allowable. These higher temperatures were accurately determined after developing a correction factor which was applied to the built-in temperature calibration. The relationship between aperture diameter and temperature range is linear. The effect of pre-lens apertures on the image uniformity is a form of anti-vignetting, meaning the corners appear brighter (hotter) than the rest of the image.more » An example of using this technique to measure temperatures of high melting point polymers during 3D printing provide valuable information of the time required for the weld-line temperature to fall below the glass transition temperature.« less

Far-Infrared Heterodyne Spectrometer for SOFIA

NASA Technical Reports Server (NTRS)

Betz, A. L.; Boreiko, R. T.

1998-01-01

This report summarizes work done under NASA Grant NAG2-1062 awarded to the University of Colorado. The project goal was to evaluate the scientific capabilities and technical requirements for a far-infrared heterodyne spectrometer suitable for the SOFIA Airborne Observatory, which is now being developed by NASA under contract to the Universities Space Research Association (USRA). The conclusions detailed below include our specific recommendations for astronomical observations, as well as our intended technical approach for reaching these scientific goals. These conclusions were presented to USRA in the form of a proposal to build this instrument. USRA subsequently awarded the University of Colorado a 3-year grant (USRA 8500-98-010) to develop the proposed Hot-Electron micro-Bolometer (HEB) mixer concept for high frequencies above 3 THz, as well as other semiconductor mixer technologies suitable for high sensitivity receivers in the 2-6 THz frequency band.

TOPICAL REVIEW: GaN-based diodes and transistors for chemical, gas, biological and pressure sensing

NASA Astrophysics Data System (ADS)

Pearton, S. J.; Kang, B. S.; Kim, Suku; Ren, F.; Gila, B. P.; Abernathy, C. R.; Lin, Jenshan; Chu, S. N. G.

2004-07-01

There is renewed emphasis on development of robust solid-state sensors capable of uncooled operation in harsh environments. The sensors should be capable of detecting chemical, gas, biological or radiation releases as well as sending signals to central monitoring locations. We discuss the advances in use of GaN-based solid-state sensors for these applications. AlGaN/GaN high electron mobility transistors (HEMTs) show a strong dependence of source/drain current on the piezoelectric polarization-induced two-dimensional electron gas (2DEG). Furthermore, spontaneous and piezoelectric polarization-induced surface and interface charges can be used to develop very sensitive but robust sensors to detect gases, polar liquids and mechanical pressure. AlGaN/GaN HEMT structures have been demonstrated to exhibit large changes in source-drain current upon exposing the gate region to various block co-polymer solutions. Pt-gated GaN Schottky diodes and Sc2O3/AlGaN/GaN metal-oxide semiconductor diodes also show large change in forward currents upon exposure to H2. Of particular interest is detection of ethylene (C2H4), which has strong double bonds and hence is difficult to dissociate at modest temperatures. Apart from combustion gas sensing, the AlGaN/GaN heterostructure devices can be used as sensitive detectors of pressure changes. In addition, large changes in source-drain current of the AlGaN/GaN HEMT sensors can be detected upon adsorption of biological species on the semiconductor surface. Finally, the nitrides provide an ideal platform for fabrication of surface acoustic wave (SAW) devices. The GaN-based devices thus appear promising for a wide range of chemical, biological, combustion gas, polar liquid, strain and high temperature pressure-sensing applications. In addition, the sensors are compatible with high bit-rate wireless communication systems that facilitate their use in remote arrays.

High performance digital read out integrated circuit (DROIC) for infrared imaging

NASA Astrophysics Data System (ADS)

Mizuno, Genki; Olah, Robert; Oduor, Patrick; Dutta, Achyut K.; Dhar, Nibir K.

2016-05-01

Banpil Photonics has developed a high-performance Digital Read-Out Integrated Circuit (DROIC) for image sensors and camera systems targeting various military, industrial and commercial Infrared (IR) imaging applications. The on-chip digitization of the pixel output eliminates the necessity for an external analog-to-digital converter (ADC), which not only cuts costs, but also enables miniaturization of packaging to achieve SWaP-C camera systems. In addition, the DROIC offers new opportunities for greater on-chip processing intelligence that are not possible in conventional analog ROICs prevalent today. Conventional ROICs, which typically can enhance only one high performance attribute such as frame rate, power consumption or noise level, fail when simultaneously targeting the most aggressive performance requirements demanded in imaging applications today. Additionally, scaling analog readout circuits to meet such requirements leads to expensive, high-power consumption with large and complex systems that are untenable in the trend towards SWaP-C. We present the implementation of a VGA format (640x512 pixels 15μm pitch) capacitivetransimpedance amplifier (CTIA) DROIC architecture that incorporates a 12-bit ADC at the pixel level. The CTIA pixel input circuitry has two gain modes with programmable full-well capacity values of 100K e- and 500K e-. The DROIC has been developed with a system-on-chip architecture in mind, where all the timing and biasing are generated internally without requiring any critical external inputs. The chip is configurable with many parameters programmable through a serial programmable interface (SPI). It features a global shutter, low power, and high frame rates programmable from 30 up 500 frames per second in full VGA format supported through 24 LVDS outputs. This DROIC, suitable for hybridization with focal plane arrays (FPA) is ideal for high-performance uncooled camera applications ranging from near IR (NIR) and shortwave IR (SWIR) to mid-wave IR (MWIR) and long-wave IR (LWIR) spectral bands.

Low-cost thermo-electric infrared FPAs and their automotive applications

NASA Astrophysics Data System (ADS)

Hirota, Masaki; Ohta, Yoshimi; Fukuyama, Yasuhiro

2008-04-01

This paper describes three low-cost infrared focal plane arrays (FPAs) having a 1,536, 2,304, and 10,800 elements and experimental vehicle systems. They have a low-cost potential because each element consists of p-n polysilicon thermocouples, which allows the use of low-cost ultra-fine microfabrication technology commonly employed in the conventional semiconductor manufacturing processes. To increase the responsivity of FPA, we have developed a precisely patterned Au-black absorber that has high infrared absorptivity of more than 90%. The FPA having a 2,304 elements achieved high resposivity of 4,300 V/W. In order to reduce package cost, we developed a vacuum-sealed package integrated with a molded ZnS lens. The camera aiming the temperature measurement of a passenger cabin is compact and light weight devices that measures 45 x 45 x 30 mm and weighs 190 g. The camera achieves a noise equivalent temperature deviation (NETD) of less than 0.7°C from 0 to 40°C. In this paper, we also present a several experimental systems that use infrared cameras. One experimental system is a blind spot pedestrian warning system that employs four infrared cameras. It can detect the infrared radiation emitted from a human body and alerts the driver when a pedestrian is in a blind spot. The system can also prevent the vehicle from moving in the direction of the pedestrian. Another system uses a visible-light camera and infrared sensors to detect the presence of a pedestrian in a rear blind spot and alerts the driver. The third system is a new type of human-machine interface system that enables the driver to control the car's audio system without letting go of the steering wheel. Uncooled infrared cameras are still costly, which limits their automotive use to high-end luxury cars at present. To promote widespread use of IR imaging sensors on vehicles, we need to reduce their cost further.

Science Applications of a Multispectral Microscopic Imager for the Astrobiological Exploration of Mars

PubMed Central

Farmer, Jack D.; Sellar, R. Glenn; Swayze, Gregg A.; Blaney, Diana L.

2014-01-01

Abstract Future astrobiological missions to Mars are likely to emphasize the use of rovers with in situ petrologic capabilities for selecting the best samples at a site for in situ analysis with onboard lab instruments or for caching for potential return to Earth. Such observations are central to an understanding of the potential for past habitable conditions at a site and for identifying samples most likely to harbor fossil biosignatures. The Multispectral Microscopic Imager (MMI) provides multispectral reflectance images of geological samples at the microscale, where each image pixel is composed of a visible/shortwave infrared spectrum ranging from 0.46 to 1.73 μm. This spectral range enables the discrimination of a wide variety of rock-forming minerals, especially Fe-bearing phases, and the detection of hydrated minerals. The MMI advances beyond the capabilities of current microimagers on Mars by extending the spectral range into the infrared and increasing the number of spectral bands. The design employs multispectral light-emitting diodes and an uncooled indium gallium arsenide focal plane array to achieve a very low mass and high reliability. To better understand and demonstrate the capabilities of the MMI for future surface missions to Mars, we analyzed samples from Mars-relevant analog environments with the MMI. Results indicate that the MMI images faithfully resolve the fine-scale microtextural features of samples and provide important information to help constrain mineral composition. The use of spectral endmember mapping reveals the distribution of Fe-bearing minerals (including silicates and oxides) with high fidelity, along with the presence of hydrated minerals. MMI-based petrogenetic interpretations compare favorably with laboratory-based analyses, revealing the value of the MMI for future in situ rover-mediated astrobiological exploration of Mars. Key Words: Mars—Microscopic imager—Multispectral imaging—Spectroscopy—Habitability—Arm instrument. Astrobiology 14, 132–169. PMID:24552233

Transition-Edge Hot-Electron Microbolometers for Millimeter and Submillimeter Astrophysics

NASA Technical Reports Server (NTRS)

Hsieh, Wen-Ting; Stevenson, Thomas; U-yen, Kongpop; Wollack, Edward; Barrentine, Emily

2014-01-01

The millimeter and the submillimeter wavelengths of the electromagnetic spectrum hold a wealth of information about the evolution of the universe. In particular, cosmic microwave background (CMB) radiation and its polarization carry the oldest information in the universe, and provide the best test of the inflationary paradigm available to astronomy today. Detecting gravity waves through their imprint on the CMB polarization would have extraordinary repercussions for cosmology and physics. A transition-edge hot-electron micro - bolometer (THM) consists of a superconducting bilayer transition-edge sensor (TES) with a thin-film absorber. Unlike traditional monolithic bolometers that make use of micromachined structures, the THM em ploys the decoupling between electrons and phonons at millikelvin temperatures to provide thermal isolation. The devices are fabricated photolithographically and are easily integrated with antennas via microstrip transmission lines, and with SQUID (superconducting quantum interference device) readouts. The small volume of the absorber and TES produces a short thermal time constant that facilitates rapid sky scanning. The THM consists of a thin-film metal absorber overlapping a superconducting TES. The absorber forms the termination of a superconducting microstripline that carries RF power from an antenna. The purpose of forming a separate absorber and TES is to allow flexibility in the optimization of the two components. In particular, the absorbing film's impedance can be chosen to match the antenna, while the TES impedance can be chosen to match to the readout SQUID amplifier. This scheme combines the advantages of the TES with the advantages of planar millimeter-wave transmission line circuits. Antenna-coupling to the detectors via planar transmission lines allows the detector dimensions to be much smaller than a wavelength, so the technique can be extended across the entire microwave, millimeter, and submillimeter wavelength ranges. The circuits are fabricated using standard microlithographic techniques and are compatible with uniform, large array formats. Unlike traditional monolithic bolometers that make use of micromachined structures, the THM employs the decoupling between electrons and phonons at millikelvin temperatures to provide thermal isolation. There is no fragile membrane in the structure for thermal isolation, which improves the fabrication yield.

Near-surface Thermal Infrared Imaging of a Mixed Forest

NASA Astrophysics Data System (ADS)

Aubrecht, D. M.; Helliker, B. R.; Richardson, A. D.

2014-12-01

Measurement of an organism's temperature is of basic physiological importance and therefore necessary for ecosystem modeling, yet most models derive leaf temperature from energy balance arguments or assume it is equal to air temperature. This is because continuous, direct measurement of leaf temperature outside of a controlled environment is difficult and rarely done. Of even greater challenge is measuring leaf temperature with the resolution required to understand the underlying energy balance and regulation of plant processes. To measure leaf temperature through the year, we have mounted a high-resolution, thermal infrared camera overlooking the canopy of a temperate deciduous forest. The camera is co-located with an eddy covariance system and a suite of radiometric sensors. Our camera measures longwave thermal infrared (λ = 7.5-14 microns) using a microbolometer array. Suspended in the canopy within the camera FOV is a matte black copper plate instrumented with fine wire thermocouples that acts as a thermal reference for each image. In this presentation, I will discuss the challenges of continuous, long-term field operation of the camera, as well as measurement sensitivity to physical and environmental parameters. Based on this analysis, I will show that the uncertainties in converting radiometric signal to leaf temperature are well constrained. The key parameter for minimizing uncertainty is the emissivity of the objects being imaged: measuring the emissivity to within 0.01 enables leaf temperature to be calculated to within 0.5°C. Finally, I will present differences in leaf temperature observed amongst species. From our two-year record, we characterize high frequency, daily, and seasonal thermal signatures of leaves and crowns, in relation to environmental conditions. Our images are taken with sufficient spatial and temporal resolution to quantify the preferential heating of sunlit portions of the canopy and the cooling effect of wind gusts. Future work will be focused on correlations between hyperspectral vegetation indices, fluxes, and thermal signatures to characterize vegetation stress. As water stress increases, causing photosynthesis and transpiration to shutdown, heat fluxes, leaf temperature, and narrow band vegetation indices should report signatures of the affected processes.

Evaluate depth of field limits of fixed focus lens arrangements in thermal infrared

NASA Astrophysics Data System (ADS)

Schuster, Norbert

2016-05-01

More and more modern thermal imaging systems use uncooled detectors. High volume applications work with detectors that have a reduced pixel count (typically between 200x150 and 640x480). This reduces the usefulness of modern image treatment procedures such as wave front coding. On the other hand, uncooled detectors demand lenses with fast fnumbers, near f/1.0, which reduces the expected Depth of Field (DoF). What are the limits on resolution if the target changes distance to the camera system? The desire to implement lens arrangements without a focusing mechanism demands a deeper quantification of the DoF problem. A new approach avoids the classic "accepted image blur circle" and quantifies the expected DoF by the Through Focus MTF of the lens. This function is defined for a certain spatial frequency that provides a straightforward relation to the pixel pitch of imaging device. A certain minimum MTF-level is necessary so that the complete thermal imaging system can realize its basic functions, such as recognition or detection of specified targets. Very often, this technical tradeoff is approved with a certain lens. But what is the impact of changing the lens for one with a different focal length? Narrow field lenses, which give more details of targets in longer distances, tighten the DoF problem. A first orientation is given by the hyperfocal distance. It depends in a square relation on the focal length and in a linear relation on the through focus MTF of the lens. The analysis of these relations shows the contradicting requirements between higher thermal and spatial resolution, faster f-number and desired DoF. Furthermore, the hyperfocal distance defines the DoF-borders. Their relation between is such as the first order imaging formulas. A calculation methodology will be presented to transfer DoF-results from an approved combination lens and camera to another lens in combination with the initial camera. Necessary input for this prediction is the accepted DoF of the initial combination and the through focus MTFs of both lenses. The accepted DoF of the initial combination defines an application and camera related MTF-level, which must be provided also by the new lens. Examples are provided. The formula of the Diffraction-Limited-Through-Focus-MTF (DLTF) quantifies the physical limit and works without any ray trace. This relation respects the pixel pitch, the waveband and the aperture based f-number, but is independent of detector size. The DLTF has a steeper slope than the ray traced Through-Focus-MTF; its maximum is the diffraction limit. The DLTF predicts the DoF-relations quite precisely. Differences to ray trace results are discussed. Last calculations with modern detectors show that a static chosen MTF-level doesn't reflect the reality for the DoFproblem. The MTF-level to respect depends on application, pixel pitch, IR-camera and image treatment. A value of 0.250 at the detector Nyquist frequency seems to be a reasonable starting point for uncooled FPAs with 17μm pixel pitch.

Evaluation of concepts for controlling exhaust emissions from minimally processed petroleum and synthetic fuels

NASA Technical Reports Server (NTRS)

Russell, P. L.; Beal, G. W.; Sederquist, R. A.; Shultz, D.

1981-01-01

Rich-lean combustor concepts designed to enhance rich combustion chemistry and increase combustor flexibility for NO(x) reduction with minimally processed fuels are examined. Processes such as rich product recirculation in the rich chamber, rich-lean annihilation, and graduated air addition or staged rich combustion to release bound nitrogen in steps of reduced equivalence ratio are discussed. Variations to the baseline rapid quench section are considered, and the effect of residence time in the rich zone is investigated. The feasibility of using uncooled non-metallic materials for the rich zone combustion construction is also addressed. The preliminary results indicate that rich primary zone staged combustion provides environmentally acceptable operation with residual and/or synthetic coal-derived liquid fuels

Study of active cooling for supersonic transports

NASA Technical Reports Server (NTRS)

Brewer, G. D.; Morris, R. E.

1975-01-01

The potential benefits of using the fuel heat sink of hydrogen fueled supersonic transports for cooling large portions of the aircraft wing and fuselage are examined. The heat transfer would be accomplished by using an intermediate fluid such as an ethylene glycol-water solution. Some of the advantages of the system are: (1) reduced costs by using aluminum in place of titanium, (2) reduced cabin heat loads, and (3) more favorable environmental conditions for the aircraft systems. A liquid hydrogen fueled, Mach 2.7 supersonic transport aircraft design was used for the reference uncooled vehicle. The cooled aircraft designs were analyzed to determine their heat sink capability, the extent and location of feasible cooled surfaces, and the coolant passage size and spacing.

Deposition stress effects on thermal barrier coating burner rig life

NASA Technical Reports Server (NTRS)

Watson, J. W.; Levine, S. R.

1984-01-01

A study of the effect of plasma spray processing parameters on the life of a two layer thermal barrier coating was conducted. The ceramic layer was plasma sprayed at plasma arc currents of 900 and 600 amps onto uncooled tubes, cooled tubes, and solid bars of Waspalloy in a lathe with 1 or 8 passes of the plasma gun. These processing changes affected the residual stress state of the coating. When the specimens were tested in a Mach 0.3 cyclic burner rig at 1130 deg C, a wide range of coating lives resulted. Processing factors which reduced the residual stress state in the coating, such as reduced plasma temperature and increased heat dissipation, significantly increased coating life.

Deposition stress effects on the life of thermal barrier coatings on burner rigs

NASA Technical Reports Server (NTRS)

Watson, J. W.; Levine, S. R.

1984-01-01

A study of the effect of plasma spray processing parameters on the life of a two layer thermal barrier coating was conducted. The ceramic layer was plasma sprayed at plasma arc currents of 900 and 600 amps onto uncooled tubes, cooled tubes, and solid bars of Waspalloy in a lathe with 1 or 8 passes of the plasma gun. These processing changes affected the residual stress state of the coating. When the specimens were tested in a Mach 0.3 cyclic burner rig at 1130 deg C, a wide range of coating lives resulted. Processing factors which reduced the residual stress state in the coating, such as reduced plasma temperature and increased heat dissipation, significantly increased coating life.

Autonomous microsystems for ground observation (AMIGO)

NASA Astrophysics Data System (ADS)

Laou, Philips

2005-05-01

This paper reports the development of a prototype autonomous surveillance microsystem AMIGO that can be used for remote surveillance. Each AMIGO unit is equipped with various sensors and electronics. These include passive infrared motion sensor, acoustic sensor, uncooled IR camera, electronic compass, global positioning system (GPS), and spread spectrum wireless transceiver. The AMIGO unit was configured to multipoint (AMIGO units) to point (base station) communication mode. In addition, field trials were conducted with AMIGO in various scenarios. These scenarios include personnel and vehicle intrusion detection (motion or sound) and target imaging; determination of target GPS position by triangulation; GPS position real time tracking; entrance event counting; indoor surveillance; and aerial surveillance on a radio controlled model plane. The architecture and test results of AMIGO will be presented.

Superconducting terahertz mixer using a transition-edge microbolometer

NASA Technical Reports Server (NTRS)

Prober, D. E.

1993-01-01

We present a new device concept for a mixer element for THz frequencies. This uses a superconducting transition-edge microbridge biased at the center of its superconducting transition near 4.2 K. It is fed from an antenna or waveguide structure. Power from a local oscillator and an RF signal produce a temperature and resulting resistance variation at the difference frequency. The new aspect is the use of a very short bridge in which rapid (less than 0.1 ns) outdiffusion of hot electrons occurs. This gives large intermediate frequency (IF) response. The mixer offers about 4 GHz IF bandwidth, about 80 ohm RF resistive impedance, good match to the IF amplifier, and requires only 1-20 nW of local oscillator power. The upper RF frequency is determined by antenna or waveguide properties. Predicted mixer conversion efficiency is 1/8, and predicted double-sideband receiver noise temperatures are 260 and 90 K for transition widths of 0.1 and 0.5 Tc, respectively.

Reflective all-sky thermal infrared cloud imager.

PubMed

Redman, Brian J; Shaw, Joseph A; Nugent, Paul W; Clark, R Trevor; Piazzolla, Sabino

2018-04-30

A reflective all-sky imaging system has been built using a long-wave infrared microbolometer camera and a reflective metal sphere. This compact system was developed for measuring spatial and temporal patterns of clouds and their optical depth in support of applications including Earth-space optical communications. The camera is mounted to the side of the reflective sphere to leave the zenith sky unobstructed. The resulting geometric distortion is removed through an angular map derived from a combination of checkerboard-target imaging, geometric ray tracing, and sun-location-based alignment. A tape of high-emissivity material on the side of the reflector acts as a reference that is used to estimate and remove thermal emission from the metal sphere. Once a bias that is under continuing study was removed, sky radiance measurements from the all-sky imager in the 8-14 μm wavelength range agreed to within 0.91 W/(m 2 sr) of measurements from a previously calibrated, lens-based infrared cloud imager over its 110° field of view.

Infrared Technology Trends and Implications to Home and Building Energy Use Efficiency

NASA Astrophysics Data System (ADS)

Woolaway, James T.

2008-09-01

It has long been realized that infrared technology would have applicability in improving the energy efficiency of homes and buildings. Walls that are missing or are poorly insulated can be quickly evaluated by looking at the thermal images of these surfaces. Similarly, air infiltration leaks under doors and around windows leave a telltale thermal signature easily seen in the infrared. The ability to view, evaluate and quickly respond to these images has immediate benefits in addressing and correcting situations where these types of losses are occurring. The principle issue that has been limiting the use of infrared technology in these applications has been the lack of availability and accessibility of infrared technology at a cost point suited to this market. The emergence of low cost microbolometer based infrared cameras, not needing sensor cooling, will greatly increase the accessibility and use of infrared technology for House Doctor inspections. The technology cost for this use is projected to be less than 1 per inspection.

Pt silicide/poly-Si Schottky diodes as temperature sensors for bolometers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuryev, V. A., E-mail: vyuryev@kapella.gpi.ru; Chizh, K. V.; Chapnin, V. A.

Platinum silicide Schottky diodes formed on films of polycrystalline Si doped by phosphorus are demonstrated to be efficient and manufacturable CMOS-compatible temperature sensors for microbolometer detectors of radiation. Thin-film platinum silicide/poly-Si diodes have been produced by a CMOS-compatible process on artificial Si{sub 3}N{sub 4}/SiO{sub 2}/Si(001) substrates simulating the bolometer cells. Layer structure and phase composition of the original Pt/poly-Si films and the Pt silicide/poly-Si films synthesized by a low-temperature process have been studied by means of the scanning transmission electron microscopy; they have also been explored by means of the two-wavelength X-ray structural phase analysis and the X-ray photoelectron spectroscopy.more » Temperature coefficient of voltage for the forward current of a single diode is shown to reach the value of about −2%/ °C in the temperature interval from 25 to 50 °C.« less

BAE Systems' 17μm LWIR camera core for civil, commercial, and military applications

NASA Astrophysics Data System (ADS)

Lee, Jeffrey; Rodriguez, Christian; Blackwell, Richard

2013-06-01

Seventeen (17) µm pixel Long Wave Infrared (LWIR) Sensors based on vanadium oxide (VOx) micro-bolometers have been in full rate production at BAE Systems' Night Vision Sensors facility in Lexington, MA for the past five years.[1] We introduce here a commercial camera core product, the Airia-MTM imaging module, in a VGA format that reads out in 30 and 60Hz progressive modes. The camera core is architected to conserve power with all digital interfaces from the readout integrated circuit through video output. The architecture enables a variety of input/output interfaces including Camera Link, USB 2.0, micro-display drivers and optional RS-170 analog output supporting legacy systems. The modular board architecture of the electronics facilitates hardware upgrades allow us to capitalize on the latest high performance low power electronics developed for the mobile phones. Software and firmware is field upgradeable through a USB 2.0 port. The USB port also gives users access to up to 100 digitally stored (lossless) images.

Wafer-scale metasurface for total power absorption, local field enhancement and single molecule Raman spectroscopy

PubMed Central

Wang, Dongxing; Zhu, Wenqi; Best, Michael D.; Camden, Jon P.; Crozier, Kenneth B.

2013-01-01

The ability to detect molecules at low concentrations is highly desired for applications that range from basic science to healthcare. Considerable interest also exists for ultrathin materials with high optical absorption, e.g. for microbolometers and thermal emitters. Metal nanostructures present opportunities to achieve both purposes. Metal nanoparticles can generate gigantic field enhancements, sufficient for the Raman spectroscopy of single molecules. Thin layers containing metal nanostructures (“metasurfaces”) can achieve near-total power absorption at visible and near-infrared wavelengths. Thus far, however, both aims (i.e. single molecule Raman and total power absorption) have only been achieved using metal nanostructures produced by techniques (high resolution lithography or colloidal synthesis) that are complex and/or difficult to implement over large areas. Here, we demonstrate a metasurface that achieves the near-perfect absorption of visible-wavelength light and enables the Raman spectroscopy of single molecules. Our metasurface is fabricated using thin film depositions, and is of unprecedented (wafer-scale) extent. PMID:24091825

Demonstration of Raman-based, dispersion-managed VCSEL technology for fibre-to-the-hut application

NASA Astrophysics Data System (ADS)

Rotich Kipnoo, E. K.; Kiboi Boiyo, D.; Isoe, G. M.; Chabata, T. V.; Gamatham, R. R. G.; Leitch, A. W. R.; Gibbon, T. B.

2017-03-01

For the first time, we experimentally investigate the use of vertical cavity surface emitting lasers (VCSELs) in the fibre-to-the-home (FTTH) flavour for Africa, known as fibre-to-the-hut. Fibre-to-the-hut is a VCSEL based passive optical network technology designed and optimized for African continent. VCSELs have attracted attention in optical communication due to its vast advantages; low power consumption, relatively cheap costs among others. A 4.25 Gb/s uncooled VCSEL is used in a dispersion managed, Raman assisted network achieving beyond 100 km of error free transmission suited for FTTHut scenario. Energy-efficient high performance VCSEL is modulated using a 27-1 PRBS pattern and the signal transmitted on a G.655 fibre utilizing the minimum attenuation window.

Low-cost CWDM transmitter package

NASA Astrophysics Data System (ADS)

Bhandarkar, Navin; Castillega, Jaime

2005-03-01

A low-cost coarse-wavelength-division multiplexer (CWDM) transmitter that combines four channels (wavelengths) in the infrared spectrum (~1310 nm) in a small form-factor un-cooled package is demonstrated. The package utilizes precision molded optics to multiplex beams from four grating-outcoupled surface-emitting (GSE) lasers into a single beam suitable for coupling into multimode fiber. This paper summarizes the optical and opto-mechanical design, fabrication and assembly of prototypes, and optical, thermal and electrical measurement results of the prototypes. This unique design enables multiplexing of wavelengths without the use of filters, waveguides, couplers and fiber splicing. Commercial fabrication and alignment technology is used to manufacture the package, resulting in a more robust, reliable and low-cost transmitter. The transmitter package is enabled by the unique characteristics of the long-wavelength GSE laser.

Incidence loss for a core turbine rotor blade in a two-dimensional cascade

NASA Technical Reports Server (NTRS)

Stabe, R. G.; Kline, J. F.

1974-01-01

The effect of incidence angle on the aerodynamic performance of an uncooled core turbine rotor blade was investigated experimentally in a two-dimensional cascade. The cascade test covered a range of incidence angles from minus 15 deg to 15 deg in 5-degree increments and a range of pressure ratios corresponding to ideal exit critical velocity ratios of 0.6 to 0.95. The principal measurements were blade-surface static pressures and cross-channel surveys of exit total pressure, static pressure, and flow angle. The results of the investigation include blade-surface velocity distribution and overall performance in terms of weight flow and loss for the range of incidence angles and exit velocity ratios investigated. The measured losses are also compared with two common methods of predicting incidence loss.

A Compact, Multi-view Net Flux Radiometer for Future Uranus and Neptune Probes

NASA Technical Reports Server (NTRS)

Aslam, S.; Amato, M.; Atkinson, D. H.; Hewagama, T.; Jennings, D. E.; Nixon, C. A.; Mousis, O.

2017-01-01

A Net Flux Radiometer (NFR) is presented that can be included in an atmospheric structure instrument suite for future probe missions to the icy giants Uranus and Neptune. The baseline design has two spectral channels i.e., a solar channel (0.4-to-3.5 m) and a thermal channel (4-to-300 m). The NFR is capable of viewing five distinct viewing angles during the descent. Non-imaging Winston cones with band-pass filters are used for each spectral channel and to define a 5 angular acceptance. Uncooled thermopile detectors are used in each spectral channel and are read out using a custom radiation hard application specific integrated circuit (ASIC). The baseline design can easily be changed to increase the number of detector channels from two to seven.

Mid-infrared two-photon absorption in an extended-wavelength InGaAs photodetector

NASA Astrophysics Data System (ADS)

Piccardo, Marco; Rubin, Noah A.; Meadowcroft, Lauren; Chevalier, Paul; Yuan, Henry; Kimchi, Joseph; Capasso, Federico

2018-01-01

We investigate the nonlinear optical response of a commercial extended-wavelength In0.81Ga0.19As uncooled photodetector. Degenerate two-photon absorption in the mid-infrared range is observed using a quantum cascade laser emitting at λ = 4.5 μm as the excitation source. From the measured two-photon photocurrent signal, we extract a two-photon absorption coefficient β(2) = 0.6 ± 0.2 cm/MW, in agreement with the theoretical value obtained from the Eg-3 scaling law. Considering the wide spectral range covered by extended-wavelength InxGa1-xAs alloys, this result holds promise for applications based on two-photon absorption for this family of materials at wavelengths between 1.8 and 5.6 μm.

Design of a handheld infrared imaging device based on uncooled infrared detector

NASA Astrophysics Data System (ADS)

Sun, Xianzhong; Li, Junwei; Zhang, Yazhou

2017-02-01

This paper, we introduced the system structure and operation principle of the device, and discussed our solutions for image data acquisition and storage, operating states and modes control and power management in detail. Besides, we proposed a algorithm of pseudo color for thermal image and applied it to the image processing module of the device. The thermal images can be real time displayed in a 1.8 inches TFT-LCD. The device has a compacted structure and can be held easily by one hand. It also has a good imaging performance with low power consumption, thermal sensitivity is less than 150mK. At last, we introduced one of its applications for fault diagnosis in electronic circuits, the test shows that: it's a good solution for fast fault detection.

Modular liquid-cooled helmet liner for thermal comfort

NASA Technical Reports Server (NTRS)

Williams, B. A.; Shitzer, A.

1974-01-01

A modular liquid-cooled helmet liner made of eight form-fitting neoprene patches was constructed. The liner was integrated into the sweatband of an Army SPH-4 helicopter aircrew helmet. This assembly was tested on four subjects seated in a hot (47 C), humid (40%) environment. Results indicate a marked reduction in the rate of increase of physiological body functions. Rectal temperature, weight loss, heart rate, and strain indices are all reduced to approximately 50% of uncooled levels. The cooling liner removed from 10% to 30% of total metabolic heat produced. This study also demonstrated the technical feasilibity of using a cooling liner in conjunction with a standard hard helmet. Potential applications of the cooling liner in thermally stressful environments are numerous, notably for helicopter and other aircrews.

An analytical study of the effect of coolant flow variables on the kinetic energy output of a cooled turbine blade flow

NASA Technical Reports Server (NTRS)

Prust, H. W., Jr.

1971-01-01

The results of an analytical study to determine the effect of changes in the amount, velocity, injection location, injection angle, and temperature of coolant flow on blade row performance are presented. The results show that the change in output of a cooled turbine blade row relative to the specific output of the uncooled blade row can be positive, negative, or zero. Comparisons between the analytical results and experimental results for four different cases of coolant discharge, all at a coolant temperature ratio of unity, show good agreement for three cases and rather poor agreement for the other. To further test the validity of the method, more experimental data is needed, particularly at different coolant temperature ratios.

Design of a Far-Infrared Spectrometer for Atmospheric Thermal Emission Measurements

NASA Technical Reports Server (NTRS)

Johnson, David G.

2004-01-01

Global measurements of far infrared emission from the upper troposphere are required to test models of cloud radiative forcing, water vapor continuum emission, and cooling rates. Spectra with adequate resolution can also be used for retrieving atmospheric temperature and humidity profiles, and yet there are few spectrally resolved measurements of outgoing longwave flux at wavelengths longer than 16 m. It has been difficult to make measurements in the far infrared due to the need for liquid-helium cooled detectors and large optics to achieve adequate sensitivity and bandwidth. We review design considerations for infrared Fourier transform spectrometers, including the dependence of system performance on basic system parameters, and discuss the prospects for achieving useful sensitivity from a satellite platform with a lightweight spectrometer using uncooled detectors.

Physics-Based Design Tools for Lightweight Ceramic Composite Turbine Components with Durable Microstructures

NASA Technical Reports Server (NTRS)

DiCarlo, James A.

2011-01-01

Under the Supersonics Project of the NASA Fundamental Aeronautics Program, modeling and experimental efforts are underway to develop generic physics-based tools to better implement lightweight ceramic matrix composites into supersonic engine components and to assure sufficient durability for these components in the engine environment. These activities, which have a crosscutting aspect for other areas of the Fundamental Aero program, are focusing primarily on improving the multi-directional design strength and rupture strength of high-performance SiC/SiC composites by advanced fiber architecture design. This presentation discusses progress in tool development with particular focus on the use of 2.5D-woven architectures and state-of-the-art constituents for a generic un-cooled SiC/SiC low-pressure turbine blade.

Comparison of Theoretically and Experimentally Determined Effects of Oxide Coatings Supplied by Fuel Additives on Uncooled Turbine-blade Temperature During Transient Turbojet-engine Operation

NASA Technical Reports Server (NTRS)

Schafer, Louis J; Stepka, Francis S; Brown, W Byron

1953-01-01

An analysis was made to permit the calculation of the effectiveness of oxide coatings in retarding the transient heat flow into turbine blades when the combustion gas temperature of a turbojet engine is suddenly changed. The analysis is checked with experimental data obtained from a turbojet engine whose blades were coated with two different coating materials (silicon dioxide and boric oxide) by adding silicone oil and tributyl borate to the engine fuel. The very thin coatings (approximately 0.001 in.) that formed on the blades produced a negligible effect on the turbine-blade transient temperature response. With the analysis discussed here, it was possible to predict the turbine rotor-blade temperature response with a maximum error of 40 F.

Properties of reactively sputtered AlxNy thin films for pyroelectric detectors

NASA Astrophysics Data System (ADS)

Calvano, Nicholas; Chrostoski, Philip; Voshell, Andrew; Braithwaite, Keesean; Rana, Mukti

2017-08-01

Uncooled infrared detectors are utilized in various radiometric devices and cameras because of their low cost, light weight and performance. A pyroelectric detector is a class of uncooled infrared detector whose polarization changes with change in temperature. Infrared radiation from objects falls on top of the sensing layer of the pyroelectric detector and the absorbed radiation causes the temperature of the sensing layer to change. This work describes the deposition and characterization of AlxNy thin films for using them as pyroelectric detector's sensing material. To test the sensitivity of infrared detection or pyroelectric effect of AlxNy thin films, capacitors of various sizes were fabricated. The diameter of the electrodes for capacitor used during testing of the device was 1100 μm while the distances between these two electrodes was 1100 μm. On a 3-inch diameter cleaned silicon wafer, 100 nm thick AlxNy thin films were deposited by radio frequency (RF) sputtering from an Al target in Ar: N2 environment. On top of this, a 100-nm thick Au layer was deposited and lifted off by using conventional photo lithography to form the electrodes of capacitors. All the layers were deposited by RF sputtering at room temperature. The thin film samples were annealed at 700 °C in N2 environment for 10 minutes. X-ray diffraction showed the films are poly-crystalline with peaks in (100), (002) and (101) directions. When the temperature varied between 303 K to 353 K, the pyroelectric coefficient was increased from 8.60 × 10-9 C/m2K to 3.76 × 10-8C/m2K with a room temperature pyroelectric coefficient value of 8.60×10-9C/m2K. The non-annealed films were found to be transparent between the wavelengths of 600 nm to 3000 nm. The refraction coefficient was found to be varied between 2.0 and 2.2 while the extinction coefficient was found to be zero. The optical bandgap determined using Tauc's equation was 1.65 eV.

Detection of Special Operations Forces Using Night Vision Devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, C.M.

2001-10-22

Night vision devices, such image intensifiers and infrared imagers, are readily available to a host of nations, organizations, and individuals through international commerce. Once the trademark of special operations units, these devices are widely advertised to ''turn night into day''. In truth, they cannot accomplish this formidable task, but they do offer impressive enhancement of vision in limited light scenarios through electronically generated images. Image intensifiers and infrared imagers are both electronic devices for enhancing vision in the dark. However, each is based upon a totally different physical phenomenon. Image intensifiers amplify the available light energy whereas infrared imagers detectmore » the thermal energy radiated from all objects. Because of this, each device operates from energy which is present in a different portion of the electromagnetic spectrum. This leads to differences in the ability of each device to detect and/or identify objects. This report is a compilation of the available information on both state-of-the-art image intensifiers and infrared imagers. Image intensifiers developed in the United States, as well as some foreign made image intensifiers, are discussed. Image intensifiers are categorized according to their spectral response and sensitivity using the nomenclature of GEN I, GEN II, and GEN III. As the first generation of image intensifiers, GEN I, were large and of limited performance, this report will deal with only GEN II and GEN III equipment. Infrared imagers are generally categorized according to their spectral response, sensor materials, and related sensor operating temperature using the nomenclature Medium Wavelength Infrared (MWIR) Cooled and Long Wavelength Infrared (LWIR) Uncooled. MWIR Cooled refers to infrared imagers which operate in the 3 to 5 {micro}m wavelength electromagnetic spectral region and require either mechanical or thermoelectric coolers to keep the sensors operating at 77 K. LWIR Uncooled refers to infrared imagers which operate in the 8 to 12 {micro}m wavelength electromagnetic spectral region and do not require cooling below room temperature. Both commercial and military infrared sensors of these two types are discussed.« less

Laser beam welding quality monitoring system based in high-speed (10 kHz) uncooled MWIR imaging sensors

NASA Astrophysics Data System (ADS)

Linares, Rodrigo; Vergara, German; Gutiérrez, Raúl; Fernández, Carlos; Villamayor, Víctor; Gómez, Luis; González-Camino, Maria; Baldasano, Arturo; Castro, G.; Arias, R.; Lapido, Y.; Rodríguez, J.; Romero, Pablo

2015-05-01

The combination of flexibility, productivity, precision and zero-defect manufacturing in future laser-based equipment are a major challenge that faces this enabling technology. New sensors for online monitoring and real-time control of laserbased processes are necessary for improving products quality and increasing manufacture yields. New approaches to fully automate processes towards zero-defect manufacturing demand smarter heads where lasers, optics, actuators, sensors and electronics will be integrated in a unique compact and affordable device. Many defects arising in laser-based manufacturing processes come from instabilities in the dynamics of the laser process. Temperature and heat dynamics are key parameters to be monitored. Low cost infrared imagers with high-speed of response will constitute the next generation of sensors to be implemented in future monitoring and control systems for laser-based processes, capable to provide simultaneous information about heat dynamics and spatial distribution. This work describes the result of using an innovative low-cost high-speed infrared imager based on the first quantum infrared imager monolithically integrated with Si-CMOS ROIC of the market. The sensor is able to provide low resolution images at frame rates up to 10 KHz in uncooled operation at the same cost as traditional infrared spot detectors. In order to demonstrate the capabilities of the new sensor technology, a low-cost camera was assembled on a standard production laser welding head, allowing to register melting pool images at frame rates of 10 kHz. In addition, a specific software was developed for defect detection and classification. Multiple laser welding processes were recorded with the aim to study the performance of the system and its application to the real-time monitoring of laser welding processes. During the experiments, different types of defects were produced and monitored. The classifier was fed with the experimental images obtained. Self-learning strategies were implemented with very promising results, demonstrating the feasibility of using low-cost high-speed infrared imagers in advancing towards a real-time / in-line zero-defect production systems.

Uncooled pulsed zinc oxide semiconductor laser

NASA Astrophysics Data System (ADS)

Bogdankevich, O. V.; Darznek, S. A.; Zverev, M. M.; Kostin, N. N.; Krasavina, E. M.

1985-02-01

An optimized ZnO laser which operates at ambient temperature without cooling is reported, along with extension of the design to form a multielement high-power laser. ZnO single crystal plane-parallel wafers 0.22 mm thick, covered with total and semi-transparent coatings, were exposed to a 200 keV electron beam with a 10 nsec pulse and a current density up to 1 kA/sq cm. No damage was observed in the crystals at saturation. A 7 percent maximum efficiency at a reflection coefficient (RC) of 0.4 was associated with a maximum output of 25 kW and a light power density of 3 MW/sq cm. Cementing a ZnO wafer to a sapphire substrate, applying the same type of coatings and working with a RC of 0.6 yielded a maximum power of 300 kW/sq cm.

Performance-Enhanced Bolometric Terahertz Detectors Based on V2O5 for 15 to 30 THz

NASA Astrophysics Data System (ADS)

Sumesh, M. A.; Karanth, S. P.; Thomas, Beno; Rao, G. M.; Viswanathan, M.; Chakraborty, P.; Rao, G. N.

2017-02-01

Terahertz (THz) radiation perception using uncooled detectors are gaining importance due to the increasing demands in the areas of military, space, and industrial, medical, and surveillance applications. In spite of the efforts of researchers to fill the THz gap, there exists a need for detectors in the range between 15 THz and 30 THz. In this paper, we discuss the development of bolometric detectors whose performance is enhanced by an optical immersion technique and their characterization in the aforesaid range of frequencies. These detectors are characterized by high specific detectivity ( D*) of 1.28 × 109 cmHz1/2 W-1 and high radiometric resolution (noise-equivalent temperature difference = 26 mK) and are fast enough for bolometric detectors (time constant = 1.7 ms), which make them suitable for spectroscopic and imaging applications.

Aerodynamic performance of high turning core turbine vanes in a two dimensional cascade

NASA Technical Reports Server (NTRS)

Schwab, J. R.

1982-01-01

Experimental and theoretical aerodynamic performance data are presented for four uncooled high turning core turbine vanes with exit angles of 74.9, 75.0, 77.5, and 79.6 degrees in a two dimensional cascade. Data for a more conservative 67.0 degree vane are included for comparison. Correction of the experimental aftermix kinetic energy losses to a common 0.100 centimeter trailing edge thickness yields a linear trend of increased loss from 0.020 to 0.025 as the vane exit angle increases from 67.0 to 79.6 degrees. The theoretical losses show a similar trend. The experimental and theoretical vane surface velocity distributions generally agree within approximately five percent, although the suction surface theoretical velocities are generally higher than the experimental velocities as the vane exit angle increases.

1.25-3.125 Gb/s per user PON with RSOA as phase modulator for statistical wavelength ONU

NASA Astrophysics Data System (ADS)

Chu, Guang Yong; Polo, Victor; Lerín, Adolfo; Tabares, Jeison; Cano, Iván N.; Prat, Josep

2015-12-01

We report a new scheme to support, cost efficiently, ultra-dense wavelength division multiplexing (UDWDM) for optical access networks. As validating experiment, we apply phase modulation of a reflective semiconductor optical amplifier (RSOA) at the ONU with a single DFB, and simplified coherent receiver at OLT for upstream. We extend the limited 3-dB modulation bandwidth of available uncooled To-can packaged RSOA (~400 MHz) and operate it at 3.125 Gb/s with the optimal performance for phase modulation using small and large signal measurement characteristics. The optimal condition is selected at input power of 0 dBm, with 70 mA bias condition. The sensitivities at 3.125 Gb/s (at BER=10-3) for heterodyne and intradyne detection reach -34.3 dBm and -38.8 dBm, respectively.

Centroid Position as a Function of Total Counts in a Windowed CMOS Image of a Point Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wurtz, R E; Olivier, S; Riot, V

2010-05-27

We obtained 960,200 22-by-22-pixel windowed images of a pinhole spot using the Teledyne H2RG CMOS detector with un-cooled SIDECAR readout. We performed an analysis to determine the precision we might expect in the position error signals to a telescope's guider system. We find that, under non-optimized operating conditions, the error in the computed centroid is strongly dependent on the total counts in the point image only below a certain threshold, approximately 50,000 photo-electrons. The LSST guider camera specification currently requires a 0.04 arcsecond error at 10 Hertz. Given the performance measured here, this specification can be delivered with a singlemore » star at 14th to 18th magnitude, depending on the passband.« less

Evaluation of active cooling systems for a Mach 6 hypersonic transport airframe, part 2

NASA Technical Reports Server (NTRS)

Helenbrook, R. G.; Mcconarty, W. A.; Anthony, F. M.

1971-01-01

Transpiration and convective cooling concepts are examined for the fuselage and tail surface of a Mach 6 hypersonic transport aircraft. Hydrogen, helium, and water are considered as coolants. Heat shields and radiation barriers are examined to reduce heat flow to the cooled structures. The weight and insulation requirements for the cryogenic fuel tanks are examined so that realistic totals can be estimated for the complete fuselage and tail. Structural temperatures are varied to allow comparison of aluminum alloy, titanium alloy, and superalloy contruction materials. The results of the study are combined with results obtained on the wing structure, obtained in a previous study, to estimate weights for the complete airframe. The concepts are compared among themselves, and with the uncooled concept on the basis of structural weight, cooling system weight, and coolant weight.

Sniper detection using infrared camera: technical possibilities and limitations

NASA Astrophysics Data System (ADS)

Kastek, M.; Dulski, R.; Trzaskawka, P.; Bieszczad, G.

2010-04-01

The paper discusses technical possibilities to build an effective system for sniper detection using infrared cameras. Descriptions of phenomena which make it possible to detect sniper activities in infrared spectra as well as analysis of physical limitations were performed. Cooled and uncooled detectors were considered. Three phases of sniper activities were taken into consideration: before, during and after the shot. On the basis of experimental data the parameters defining the target were determined which are essential in assessing the capability of infrared camera to detect sniper activity. A sniper body and muzzle flash were analyzed as targets. The simulation of detection ranges was done for the assumed scenario of sniper detection task. The infrared sniper detection system was discussed, capable of fulfilling the requirements. The discussion of the results of analysis and simulations was finally presented.

Radial turbine cooling

NASA Technical Reports Server (NTRS)

Roelke, Richard J.

1992-01-01

Radial turbines have been used extensively in many applications including small ground based electrical power generators, automotive engine turbochargers and aircraft auxiliary power units. In all of these applications the turbine inlet temperature is limited to a value commensurate with the material strength limitations and life requirements of uncooled metal rotors. To take advantage of all the benefits that higher temperatures offer, such as increased turbine specific power output or higher cycle thermal efficiency, requires improved high temperature materials and/or blade cooling. Extensive research is on-going to advance the material properties of high temperature superalloys as well as composite materials including ceramics. The use of ceramics with their high temperature potential and low cost is particularly appealing for radial turbines. However until these programs reach fruition the only way to make significant step increases beyond the present material temperature barriers is to cool the radial blading.

The EarthCARE mission BBR instrument: ground testing of radiometric performance

NASA Astrophysics Data System (ADS)

Caldwell, Martin E.; Spilling, David; Grainger, William; Theocharous, E.; Whalley, Martin; Wright, Nigel; Ward, Anthony K.; Jones, Edward; Hampton, Joseph; Parker, David; Delderfield, John; Pearce, Alan; Richards, Anthony G.; Munro, Grant J.; Poynz Wright, Oliver; Hampson, Matthew; Forster, David

2017-09-01

In the EarthCARE mission the BBR (Broad Band Radiometer) has the role of measuring the net earth radiance (i.e. total reflected-solar and thermally-emitted radiances), from the same earth scene as viewed by the other instruments (aerosol lidar, cloud radar and spectral imager). It does this measurement at 10km scene size and in 3 view angles. It is an imaging radiometer in that it uses micro-bolometer linear-array detector (pushbroom orientation), to over-sample these required scenes, with the samples being binned on-ground to produce the 10km radiance data. For the measurements of total earth radiance, the BBR is based on the heritage of Earth Radiation Budget (ERB) instruments. The ground calibration methods of this type of sensor is technically very similar to other EO instruments that measure in the thermalIR, but with added challenges: (1) The thermal-IR measurement has to have a much wider spectral range than normal thermal-IR channels to cover the whole earth-emission spectrum i.e. 4 to >50microns (2) The 2nd channel (reflected solar radiance) must also have a broad response to cover almost the whole solar spectrum, i.e. 0.3 to 4microns. And this solar channel must be measured on the same radiometric calibration as the thermal channel, which in practice is best done by using the same radiometer for both channels. The radiometer is designed to be very broad-band i.e. 0.3 to 50microns (i.e. more than two decades), to cover both ranges, and a switchable spectral filter (short-pass cutoff at 4μm) is used to separate the channels. The on-ground measurements which are required to link the calibration of these channels will be described. A calibration of absolute responsivity in each of the two bands is needed; in the thermal-IR channel this is by the normal method of using a calibrated blackbody test source, and in the solar channel it is by means of a narrow-band (laser) and a reference radiometer (from NPL). A calibration of relative spectral response is also needed, across this wide range, for the purpose of linking the two channels, and for converting the narrow-band solar channel measurement to broad-band.

Fire testing and infrared thermography of oak barrels filled with distilled spirits (Conference Presentation)

NASA Astrophysics Data System (ADS)

de Vries, Jaap

2017-05-01

Adequate fire protection of distilled spirits stored in oak barrels requires understanding the failure mode of these barrels, including quantifying the leak rate. In this study, the use of a custom-calibrated, long-wave microbolometer camera is demonstrated to seek new protection methods for rack-stored distilled spirits. Individual oak barrels ranging between 200 L and 500 L filled with 75%/25% ethanol/water were exposed to both propane gas fires and pure ethanol pool fires. The IR camera was used to see through the smoke and flames showing the location of the leaks. The increase in HRR due to the leaked content was measured using gas calorimetry of the combustion products. This study showed that barrels leaked at a rate of approximately 4-8 lpm, resulting in heat release rates ranging between 1.2 and 2.4 MW. These numbers are confirmed by the quantitative measurements of gaseous H2O and CO¬2 in the exhaust. Surface temperature of the exposed oak could reach temperatures up to 750ºC.

Reflective all-sky thermal infrared cloud imager

DOE Office of Scientific and Technical Information (OSTI.GOV)

Redman, Brian J.; Shaw, Joseph A.; Nugent, Paul W.

A reflective all-sky imaging system has been built using a long-wave infrared microbolometer camera and a reflective metal sphere. This compact system was developed for measuring spatial and temporal patterns of clouds and their optical depth in support of applications including Earth-space optical communications. The camera is mounted to the side of the reflective sphere to leave the zenith sky unobstructed. The resulting geometric distortion is removed through an angular map derived from a combination of checkerboard-target imaging, geometric ray tracing, and sun-location-based alignment. A tape of high-emissivity material on the side of the reflector acts as a reference thatmore » is used to estimate and remove thermal emission from the metal sphere. In conclusion, once a bias that is under continuing study was removed, sky radiance measurements from the all-sky imager in the 8-14 μm wavelength range agreed to within 0.91 W/(m 2 sr) of measurements from a previously calibrated, lens-based infrared cloud imager over its 110° field of view.« less

Reflective all-sky thermal infrared cloud imager

DOE PAGES

Redman, Brian J.; Shaw, Joseph A.; Nugent, Paul W.; ...

2018-04-17

A reflective all-sky imaging system has been built using a long-wave infrared microbolometer camera and a reflective metal sphere. This compact system was developed for measuring spatial and temporal patterns of clouds and their optical depth in support of applications including Earth-space optical communications. The camera is mounted to the side of the reflective sphere to leave the zenith sky unobstructed. The resulting geometric distortion is removed through an angular map derived from a combination of checkerboard-target imaging, geometric ray tracing, and sun-location-based alignment. A tape of high-emissivity material on the side of the reflector acts as a reference thatmore » is used to estimate and remove thermal emission from the metal sphere. In conclusion, once a bias that is under continuing study was removed, sky radiance measurements from the all-sky imager in the 8-14 μm wavelength range agreed to within 0.91 W/(m 2 sr) of measurements from a previously calibrated, lens-based infrared cloud imager over its 110° field of view.« less

High-Tc superconducting microbolometer for terahertz applications

NASA Astrophysics Data System (ADS)

Ulysse, C.; Gaugue, A.; Adam, A.; Kreisler, A. J.; Villégier, J.-C.; Thomassin, J.-L.

2002-05-01

Superconducting hot electron bolometer mixers are now a competitive alternative to Schottky diode mixers in the terahertz frequency range because of their ultra wideband (from millimeter waves to visible light), high conversion gain, and low intrinsic noise level. High Tc superconductor materials can be used to make hot electron bolometers and present some advantage in term of operating temperature and cooling. In this paper, we present first a model for the study of superconducting hot electron bolometers responsivity in direct detection mode, in order to establish a firm basis for the design of future THz mixers. Secondly, an original process to realize YBaCuO hot electron bolometer mixers will be described. Submicron YBaCuO superconducting structures are expitaxially sputter deposited on MgO substrates and patterned by using electron beam lithography in combination with optical lithography. Metal masks achieved by electron beam lithography are insuring a good bridge definition and protection during ion etching. Finally, detection experiments are being performed with a laser at 850 nm wavelength, in homodyne mode in order to prove the feasibility and potential performances of these devices.

The 32-GHz performance of the DSS-14 70-meter antenna: 1989 configuration

NASA Technical Reports Server (NTRS)

Gatti, M. S.; Klein, M. J.; Kuiper, T. B. H.

1989-01-01

The results of preliminary 32 GHz calibrations of the 70 meter antenna at Goldstone are presented. Measurements were done between March and July 1989 using Virgo A and Venus as the primary efficiency calibrators. The flux densites of theses radio sources at 32 GHz are not known with high accuracy, but were extrapolated from calibrated data at lower frequencies. The measured value of efficiency (0.35) agreed closely with the predicted value (0.32), and the results are very repeatable. Flux densities of secondary sources used in the observations were subsequently derived. These measurements were performed using a beamswitching radiometer that employed an uncooled high-electron mobility transistor (HEMT) low-noise amplifier. This system was installed primarily to determine the performance of the antenna in its 1989 configuration, but the experience will also aid in successful future calibration of the Deep Space Network (DSN) at this frequency.

IR radiation characteristics and operating range research for a quad-rotor unmanned aircraft vehicle.

PubMed

Gong, Mali; Guo, Rui; He, Sifeng; Wang, Wei

2016-11-01

The security threats caused by multi-rotor unmanned aircraft vehicles (UAVs) are serious, especially in public places. To detect and control multi-rotor UAVs, knowledge of IR characteristics is necessary. The IR characteristics of a typical commercial quad-rotor UAV are investigated in this paper through thermal imaging with an IR camera. Combining the 3D geometry and IR images of the UAV, a 3D IR characteristics model is established so that the radiant power from different views can be obtained. An estimation of operating range to detect the UAV is calculated theoretically using signal-to-noise ratio as the criterion. Field experiments are implemented with an uncooled IR camera in an environment temperature of 12°C and a uniform background. For the front view, the operating range is about 150 m, which is close to the simulation result of 170 m.

Thermal Texture Selection and Correction for Building Facade Inspection Based on Thermal Radiant Characteristics

NASA Astrophysics Data System (ADS)

Lin, D.; Jarzabek-Rychard, M.; Schneider, D.; Maas, H.-G.

2018-05-01

An automatic building façade thermal texture mapping approach, using uncooled thermal camera data, is proposed in this paper. First, a shutter-less radiometric thermal camera calibration method is implemented to remove the large offset deviations caused by changing ambient environment. Then, a 3D façade model is generated from a RGB image sequence using structure-from-motion (SfM) techniques. Subsequently, for each triangle in the 3D model, the optimal texture is selected by taking into consideration local image scale, object incident angle, image viewing angle as well as occlusions. Afterwards, the selected textures can be further corrected using thermal radiant characteristics. Finally, the Gauss filter outperforms the voted texture strategy at the seams smoothing and thus for instance helping to reduce the false alarm rate in façade thermal leakages detection. Our approach is evaluated on a building row façade located at Dresden, Germany.

Cost/benefit analysis of advanced material technologies for small aircraft turbine engines

NASA Technical Reports Server (NTRS)

Comey, D. H.

1977-01-01

Cost/benefit studies were conducted on ten advanced material technologies applicable to small aircraft gas turbine engines to be produced in the 1985 time frame. The cost/benefit studies were applied to a two engine, business-type jet aircraft in the 6800- to 9100-Kg (15,000- to 20,000-lb) gross weight class. The new material technologies are intended to provide improvements in the areas of high-pressure turbine rotor components, high-pressure turbine rotor components, high-pressure turbine stator airfoils, and static structural components. The cost/benefit of each technology is presented in terms of relative value, which is defined as a change in life cycle cost times probability of success divided by development cost. Technologies showing the most promising cost/benefits based on relative value are uncooled single crystal MAR-M 247 turbine blades, cooled DS MAR-M 247 turbine blades, and cooled ODS 'M'CrAl laminate turbine stator vanes.

Preburner of Staged Combustion Rocket Engine

NASA Technical Reports Server (NTRS)

Yost, M. C.

1978-01-01

A regeneratively cooled LOX/hydrogen staged combustion assembly system with a 400:1 expansion area ratio nozzle utilizing an 89,000 Newton (20,000 pound) thrust regeneratively cooled thrust chamber and 175:1 tubular nozzle was analyzed, assembled, and tested. The components for this assembly include two spark/torch oxygen-hydrogen igniters, two servo-controlled LOX valves, a preburner injector, a preburner combustor, a main propellant injector, a regeneratively cooled combustion chamber, a regeneratively cooled tubular nozzle with an expansion area ratio of 175:1, an uncooled heavy-wall steel nozzle with an expansion area ratio of 400:1, and interconnecting ducting. The analytical effort was performed to optimize the thermal and structural characteristics of each of the new components and the ducting, and to reverify the capabilities of the previously fabricated components. The testing effort provided a demonstration of the preburner/combustor chamber operation, chamber combustion efficiency and stability, and chamber and nozzle heat transfer.

Operating characteristics of a hydrogen-argon plasma torch for supersonic combustion applications

NASA Technical Reports Server (NTRS)

Barbi, E.; Mahan, J. R.; O'Brien, W. F.; Wagner, T. C.

1989-01-01

The residence time of the combustible mixture in the combustion chamber of a scramjet engine is much less than the time normally required for complete combustion. Hydrogen and hydrocarbon fuels require an ignition source under conditions typically found in a scramjet combustor. Analytical studies indicate that the presence of hydrogen atoms should greatly reduce the ignition delay in this environment. Because hydrogen plasmas are prolific sources of hydrogen atoms, a low-power, uncooled hydrogen plasma torch has been built and tested to evaluate its potential as a possible flame holder for supersonic combustion. The torch was found to be unstable when operated on pure hydrogen; however, stable operation could be obtained by using argon as a body gas and mixing in the desired amount of hydrogen. The stability limits of the torch are delineated and its electrical and thermal behavior documented. An average torch thermal efficiency of around 88 percent is demonstrated.

Plasmonic piezoelectric nanomechanical resonator for spectrally selective infrared sensing

PubMed Central

Hui, Yu; Gomez-Diaz, Juan Sebastian; Qian, Zhenyun; Alù, Andrea; Rinaldi, Matteo

2016-01-01

Ultrathin plasmonic metasurfaces have proven their ability to control and manipulate light at unprecedented levels, leading to exciting optical functionalities and applications. Although to date metasurfaces have mainly been investigated from an electromagnetic perspective, their ultrathin nature may also provide novel and useful mechanical properties. Here we propose a thin piezoelectric plasmonic metasurface forming the resonant body of a nanomechanical resonator with simultaneously tailored optical and electromechanical properties. We experimentally demonstrate that it is possible to achieve high thermomechanical coupling between electromagnetic and mechanical resonances in a single ultrathin piezoelectric nanoplate. The combination of nanoplasmonic and piezoelectric resonances allows the proposed device to selectively detect long-wavelength infrared radiation with unprecedented electromechanical performance and thermal capabilities. These attributes lead to the demonstration of a fast, high-resolution, uncooled infrared detector with ∼80% absorption for an optimized spectral bandwidth centered around 8.8 μm. PMID:27080018

Integrated multispectral high-power laser platform for the defeat of heat-seeking missiles

NASA Astrophysics Data System (ADS)

Tadjikov, Boris; Tsekoun, Alexei; Lyakh, Arkadiy; Maulini, Richard; Barron, Rodolfo; Patel, C. Kumar N.

2011-06-01

Quantum cascade lasers are finding rapid acceptance in many defense and security applications. Our new multispectral laser platform providing watt-level outputs near 2.0 μm, 4.0 μm and 4.6 μm in continuous wave regime at room temperature. Individual lasers are spectrally beam combined into a single output beam with excellent quality. Our rugged, compact (11 × 10 × 6.5 inches), and highly reliable, air-cooled multispectral laser platform is already finding acceptance at system level. Our uncooled devices produce > 2W at 4.6 μm and >1.5W at 4.0 μm at room temperature, and maintain watt-level output at 67°C with real wallplug efficiencies >10%. Finally, all of our QCLs undergo 100-hour pre-delivery burn-in and pass shock, vibration, and temperature testing according to MIL-STD-810G.

High Temperature Dynamic Pressure Measurements Using Silicon Carbide Pressure Sensors

NASA Technical Reports Server (NTRS)

Okojie, Robert S.; Meredith, Roger D.; Chang, Clarence T.; Savrun, Ender

2014-01-01

Un-cooled, MEMS-based silicon carbide (SiC) static pressure sensors were used for the first time to measure pressure perturbations at temperatures as high as 600 C during laboratory characterization, and subsequently evaluated in a combustor rig operated under various engine conditions to extract the frequencies that are associated with thermoacoustic instabilities. One SiC sensor was placed directly in the flow stream of the combustor rig while a benchmark commercial water-cooled piezoceramic dynamic pressure transducer was co-located axially but kept some distance away from the hot flow stream. In the combustor rig test, the SiC sensor detected thermoacoustic instabilities across a range of engine operating conditions, amplitude magnitude as low as 0.5 psi at 585 C, in good agreement with the benchmark piezoceramic sensor. The SiC sensor experienced low signal to noise ratio at higher temperature, primarily due to the fact that it was a static sensor with low sensitivity.

Uncooled middle wavelength infrared photoconductors based on (111) and (100) oriented HgCdTe

NASA Astrophysics Data System (ADS)

Madejczyk, Paweł; Kębłowski, Artur; Gawron, Waldemar; Martyniuk, Piotr; Kopytko, Małgorzata; Stępień, Dawid; Rutkowski, Jarosław; Piotrowski, Józef; Piotrowski, Adam; Rogalski, Antoni

2017-09-01

We present progress in metal organic chemical vapor deposition (MOCVD) growth of (100) HgCdTe epilayers achieved recently at the Institute of Applied Physics, Military University of Technology and Vigo System S.A. It is shown that MOCVD technology is an excellent tool for the fabrication of different HgCdTe detector structures with a wide range of composition, donor/acceptor doping, and without post grown ex-situ annealing. Surface morphology, residual background concentration, and acceptor doping efficiency are compared in (111) and (100) oriented HgCdTe epilayers. At elevated temperatures, the carrier lifetime in measured p-type photoresistors is determined by Auger 7 process with about one order of magnitude difference between theoretical and experimental values. Particular progress has been achieved in the growth of (100) HgCdTe epilayers for medium wavelength infrared photoconductors operated in high-operating temperature conditions.

Development and testing of the EVS 2000 enhanced vision system

NASA Astrophysics Data System (ADS)

Way, Scott P.; Kerr, Richard; Imamura, Joe J.; Arnoldy, Dan; Zeylmaker, Richard; Zuro, Greg

2003-09-01

An effective enhanced vision system must operate over a broad spectral range in order to offer a pilot an optimized scene that includes runway background as well as airport lighting and aircraft operations. The large dynamic range of intensities of these images is best handled with separate imaging sensors. The EVS 2000 is a patented dual-band Infrared Enhanced Vision System (EVS) utilizing image fusion concepts to provide a single image from uncooled infrared imagers in both the LWIR and SWIR. The system is designed to provide commercial and corporate airline pilots with improved situational awareness at night and in degraded weather conditions. A prototype of this system was recently fabricated and flown on the Boeing Advanced Technology Demonstrator 737-900 aircraft. This paper will discuss the current EVS 2000 concept, show results taken from the Boeing Advanced Technology Demonstrator program, and discuss future plans for EVS systems.

Evaluation of water cooled supersonic temperature and pressure probes for application to 1366 K flows

NASA Technical Reports Server (NTRS)

Lagen, Nicholas; Seiner, John M.

1990-01-01

Water cooled supersonic probes are developed to investigate total pressure, static pressure, and total temperature in high-temperature jet plumes and thereby determine the mean flow properties. Two probe concepts, designed for operation at up to 1366 K in a Mach 2 flow, are tested on a water cooled nozzle. The two probe designs - the unsymmetric four-tube cooling configuration and the symmetric annular cooling design - take measurements at 755, 1089, and 1366 K of the three parameters. The cooled total and static pressure readings are found to agree with previous test results with uncooled configurations. The total-temperature probe, however, is affected by the introduction of water coolant, and effect which is explained by the increased heat transfer across the thermocouple-bead surface. Further investigation of the effect of coolant on the temperature probe is proposed to mitigate the effect and calculate more accurate temperatures in jet plumes.

Heat-sink free CW operation of injection microdisk lasers grown on Si substrate with emission wavelength beyond 1.3  μm.

PubMed

Kryzhanovskaya, Natalia; Moiseev, Eduard; Polubavkina, Yulia; Maximov, Mikhail; Kulagina, Marina; Troshkov, Sergey; Zadiranov, Yury; Guseva, Yulia; Lipovskii, Andrey; Tang, Mingchu; Liao, Mengya; Wu, Jiang; Chen, Siming; Liu, Huiyun; Zhukov, Alexey

2017-09-01

High-performance injection microdisk (MD) lasers grown on Si substrate are demonstrated for the first time, to the best of our knowledge. Continuous-wave (CW) lasing in microlasers with diameters from 14 to 30 μm is achieved at room temperature. The minimal threshold current density of 600  A/cm 2 (room temperature, CW regime, heatsink-free uncooled operation) is comparable to that of high-quality MD lasers on GaAs substrates. Microlasers on silicon emit in the wavelength range of 1320-1350 nm via the ground state transition of InAs/InGaAs/GaAs quantum dots. The high stability of the lasing wavelength (dλ/dI=0.1  nm/mA) and the low specific thermal resistance of 4×10 -3 °C×cm 2 /W are demonstrated.

Exoskeletal Engine Concept: Feasibility Studies for Medium and Small Thrust Engines

NASA Technical Reports Server (NTRS)

Halliwell, Ian

2001-01-01

The exoskeletal engine concept is one in which the shafts and disks are eliminated and are replaced by rotating casings that support the blades in spanwise compression. Omission of the shafts and disks leads to an open channel at the engine centerline. This has immense potential for reduced jet noise and for the accomodation of an alternative form of thruster for use in a combined cycle. The use of ceramic composite materials has the potential for significantly reduced weight as well as higher working temperatures without cooling air. The exoskeletal configuration is also a natural stepping-stone to complete counter-rotating turbomachinery. Ultimately this will lead to reductions in weight, length, parts count and improved efficiency. The feasibility studies are in three parts. Part I-Systems and Component Requirements addressed the mechanical aspects of components from a functionality perspective. This effort laid the groundwork for preliminary design studies. Although important, it is not felt to be particularly original, and has therefore not been included in the current overview. Part 2-Preliminary Design Studies turned to some of the cycle and performance issues inherent in an exoskeletal configuration and some initial attempts at preliminary design of turbomachinery were described. Twin-spoon and single-spool 25.800-lbf-thrust turbofans were used as reference vehicles in a mid-size commercial subsonic category in addition to a single-spool 5,000-lbf-thrust turbofan that represented a general aviation application. The exoskeletal engine, with its open centerline, has tremendous potential for noise suppression and some preliminary analysis was done which began to quantify the benefits. Part 3-Additional Preliminary Design Studies revisited the design of single-spool 25,800-lbf-thrust turbofan configurations, but in addition to the original FPR = 1.6 and BPR = 5.1 reference engine, two additional configurations used FPR = 2.4 and BPR = 3.0 and FPR = 3.2 and BPR = 2.0 were investigated. The single-spool 5,000-lbf-thrust turbofan was refined and the small engine study was extended to include a 2,000-lbf-thrust turbojet. More attention was paid to optimizing the turbomachinery. Turbine cooling flows were eliminated, in keeping with the use of uncooled CMC material in exoskeletal engines. The turbine performance parameters moved much closer to the nominal target values, demonstrating the great benefits to the cycle of uncooled turbines.

Exoskeletal Engine Concept: Feasibility Studies for Medium and Small Thrust Engines

NASA Technical Reports Server (NTRS)

Halliwell, Ian

2001-01-01

The exoskeletal engine concept is one in which the shafts and disks are eliminated and are replaced by rotating casings that support the blades in spanwise compression. Omission of the shafts and disks leads to an open channel at the engine centerline. This has immense potential for reduced jet noise and for the accommodation of an alternative form of thruster for use in a combined cycle. The use of ceramic composite materials has the potential for significantly reduced weight as well as higher working temperatures without cooling air. The exoskeletal configuration is also a natural stepping-stone to complete counter-rotating turbomachinery. Ultimately this will lead to reductions in weight, length, parts count and improved efficiency. The feasibility studies are in three parts. Part 1: Systems and Component Requirements addressed the mechanical aspects of components from a functionality perspective. This effort laid the groundwork for preliminary design studies. Although important, it is not felt to be particularly original, and has therefore not been included in the current overview. Part 2: Preliminary Design Studies turned to some of the cycle and performance issues inherent in an exoskeletal configuration and some initial attempts at preliminary design of turbomachinery were described. Twin-spoon and single-spool 25,800-lbf-thrust turbofans were used as reference vehicles in a mid-size commercial subsonic category in addition to a single-spool 5,000-lbf-thrust turbofan that represented a general aviation application. The exoskeletal engine, with its open centerline, has tremendous potential for noise suppression and some preliminary analysis was done which began to quantify the benefits. Part 3: Additional Preliminary Design Studies revisited the design of single-spool 25,800-lbf-thrust turbofan configurations, but in addition to the original FPR = 1.6 and BPR = 5.1 reference engine. two additional configurations used FPR = 2.4 and BPR = 3.0 and FPR = 3.2 and BPR = 2.0 were investigated. The single-spool 5.000-lbf-thrust turbofan was refined and the small engine study was extended to include a 2,000-lbf-thrust turbojet. More attention was paid to optimizing the turbomachinery. Turbine cooling flows were eliminated, in keeping with the use of uncooled CMC materials in exoskeletal engines. The turbine performance parameters moved much closer to the nominal target values, demonstrating the great benefits to the cycle of uncooled turbines.

Low-Noise Wide Bandwith, Hot Electron Bolometer Mixers for Submillimeter Wavelengths

NASA Technical Reports Server (NTRS)

McGrath, W. R.

1995-01-01

Recently a novel superconductive hot-electron micro-bolometer has been proposed which is both fast and sensitive (D. E. Prober, Appl. Phys. Lett. 62, 2119, 1993). This device has several important properties which make it useful as a heterodyne sensor for radioastronomy applications at frequencies above 1 THz. The thermal response time of the device is fast enough, several 10's of picoseconds, to allow for IF's of several GHz. This bolometer mixer should operate well up to at least 10 THz. There is no energy gap limitation as in an SIS mixer, since the mixing process relies on heating of the electron gas. In fact, rf power is absorbed more uniformly above the gap frequency. The mixer noise should be near quantum-limited, and the local oscillator (LO) power requirement is very low: / 10 nW for a Nb device. One of the unique features of this device is that it employs rapid electron diffusion into a normal metal, rather than phonon emission, as the thermal conductance that cools the heated electrons. In order for diffusion to dominate over phonon emission, the device must be short, less than 0.5.

The elimination of zero-order diffraction of 10.6 μm infrared digital holography

NASA Astrophysics Data System (ADS)

Liu, Ning; Yang, Chao

2017-05-01

A new method of eliminating the zero-order diffraction in infrared digital holography has been raised in this paper. Usually in the reconstruction of digital holography, the spatial frequency of the infrared thermal imager, such as microbolometer, cannot be compared to the common visible CCD or CMOS devices. The infrared imager suffers the problems of large pixel size and low spatial resolution, which cause the zero-order diffraction a severe influence of the reconstruction process of digital holograms. The zero-order diffraction has very large energy and occupies the central region in the spectrum domain. In this paper, we design a new filtering strategy to overcome this problem. This filtering strategy contains two kinds of filtering process which are the Gaussian low-frequency filter and the high-pass phase averaging filter. With the correct set of the calculating parameters, these filtering strategies can work effectively on the holograms and fully eliminate the zero-order diffraction, as well as the two crossover bars shown in the spectrum domain. Detailed explanation and discussion about the new method have been proposed in this paper, and the experiment results are also demonstrated to prove the performance of this method.

Applications of superconducting bolometers in security imaging

NASA Astrophysics Data System (ADS)

Luukanen, A.; Leivo, M. M.; Rautiainen, A.; Grönholm, M.; Toivanen, H.; Grönberg, L.; Helistö, P.; Mäyrä, A.; Aikio, M.; Grossman, E. N.

2012-12-01

Millimeter-wave (MMW) imaging systems are currently undergoing deployment World-wide for airport security screening applications. Security screening through MMW imaging is facilitated by the relatively good transmission of these wavelengths through common clothing materials. Given the long wavelength of operation (frequencies between 20 GHz to ~ 100 GHz, corresponding to wavelengths between 1.5 cm and 3 mm), existing systems are suited for close-range imaging only due to substantial diffraction effects associated with practical aperture diameters. The present and arising security challenges call for systems that are capable of imaging concealed threat items at stand-off ranges beyond 5 meters at near video frame rates, requiring substantial increase in operating frequency in order to achieve useful spatial resolution. The construction of such imaging systems operating at several hundred GHz has been hindered by the lack of submm-wave low-noise amplifiers. In this paper we summarize our efforts in developing a submm-wave video camera which utilizes cryogenic antenna-coupled microbolometers as detectors. Whilst superconducting detectors impose the use of a cryogenic system, we argue that the resulting back-end complexity increase is a favorable trade-off compared to complex and expensive room temperature submm-wave LNAs both in performance and system cost.

Automatic Spatio-Temporal Flow Velocity Measurement in Small Rivers Using Thermal Image Sequences

NASA Astrophysics Data System (ADS)

Lin, D.; Eltner, A.; Sardemann, H.; Maas, H.-G.

2018-05-01

An automatic spatio-temporal flow velocity measurement approach, using an uncooled thermal camera, is proposed in this paper. The basic principle of the method is to track visible thermal features at the water surface in thermal camera image sequences. Radiometric and geometric calibrations are firstly implemented to remove vignetting effects in thermal imagery and to get the interior orientation parameters of the camera. An object-based unsupervised classification approach is then applied to detect the interest regions for data referencing and thermal feature tracking. Subsequently, GCPs are extracted to orient the river image sequences and local hot points are identified as tracking features. Afterwards, accurate dense tracking outputs are obtained using pyramidal Lucas-Kanade method. To validate the accuracy potential of the method, measurements obtained from thermal feature tracking are compared with reference measurements taken by a propeller gauge. Results show a great potential of automatic flow velocity measurement in small rivers using imagery from a thermal camera.

Hot ion plasma production in HIP-1 using water-cooled hollow cathodes

NASA Technical Reports Server (NTRS)

Reinmann, J. J.; Lauver, M. R.; Patch, R. W.; Layman, R. W.; Snyder, A.

1975-01-01

The paper reports on hot-ion plasma experiments conducted in a magnetic mirror facility. A steady-state E x B plasma was formed by applying a strong radially inward dc electric field near the mirror throats. Most of the results were for hydrogen, but deuterium and helium plasmas were also studied. Three water-cooled hollow cathodes were operated in the hot-ion plasma mode with the following results: (1) thermally emitting cathodes were not required to achieve the hot-ion mode; (2) steady-state operation (several minutes) was attained; (3) input powers greater than 40 kW were achieved; (4) cathode outside diameters were increased from 1.2 cm (uncooled) to 4.4 cm (water-cooled); (5) steady-state hydrogen plasmas with ion temperatures from 185 to 770 eV and electron temperatures from 5 to 21 eV were produced. Scaling relations were empirically obtained for discharge current, ion temperature, electron temperature, and relative ion density as a function of hydrogen gas feed rate, magnetic field, and cathode voltage.

Development of intense terahertz coherent synchrotron radiation at KU-FEL

NASA Astrophysics Data System (ADS)

Sei, Norihiro; Zen, Heishun; Ohgaki, Hideaki

2016-10-01

We produced intense coherent synchrotron radiation (CSR) in the terahertz (THz) region using an S-band linac at the Kyoto University Free Electron Laser (KU-FEL), which is a mid-infrared free-electron laser facility. The CSR beam was emitted from short-pulse electron bunches compressed by a 180° arc, and was transferred to air at a large solid angle of 0.10 rad. The measured CSR energy was 55 μJ per 7 μs macropulse, and KU-FEL was one of the most powerful CSR sources in normal conducting linear accelerator facilities. The CSR spectra were measured using an uncooled pyroelectric detector and a Michelson-type interferometer designed specifically for the KU-FEL electron beam, and had a maximum at a frequency of 0.11 THz. We found that adjusting the energy slit enhanced the CSR energy and shortened the electron beam bunch length in the CSR spectra measurements. Our results demonstrated that the efficient use of the energy slit can help improve the characteristics of CSR.

Two-color detector: Mercury-cadmium-telluride as a terahertz and infrared detector

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sizov, F.; Zabudsky, V.; Petryakov, V.

2015-02-23

In this paper, issues associated with the development of infrared (IR) and terahertz (THz) radiation detectors based on HgCdTe are discussed. Two-color un-cooled and cooled to 78 K narrow-gap mercury-cadmium-telluride semiconductor thin layers with antennas were considered both as sub-THz (sub-THz) direct detection bolometers and 3–10 μm IR photoconductors. The noise equivalent power (NEP) for one of the detectors studied at ν ≈ 140 GHz reaches NEP{sub 300 K} ≈ 4.5 × 10{sup −10} W/Hz{sup 1/2} and NEP{sub 78 K} ≈ 5 × 10{sup −9} W/Hz{sup 1/2}. The same detector used as an IR photoconductor showed the responsivity at temperatures T = 78 K and 300 K with signal-to-noisemore » ratio S/N ≈ 750 and 50, respectively, under illumination by using IR monochromator and globar as a thermal source.« less

Micromachined electron tunneling infrared sensors

NASA Technical Reports Server (NTRS)

Kenny, T. W.; Kaiser, W. J.; Podosek, J. A.; Rockstad, H. K.; Reynolds, J. K.

1993-01-01

The development of an improved Golay cell is reported. This new sensor is constructed entirely from micromachined silicon components. A silicon oxynitride (SiO(x)N(y)) membrane is deflected by the thermal expansion of a small volume of trapped gas. To detect the motion of the membrane, an electron tunneling transducer is used. This sensor detects electrons which tunnel through the classically forbidden barrier between a tip and a surface; the electron current is exponentially dependent on the separation between the tip and the surface. The sensitivity of tunneling transducers constructed was typically better than 10(exp -3) A/square root of Hz. Through use of the electron tunneling transducer, the scaling laws which have prevented the miniaturization of the Golay cell are avoided. This detector potentially offers low cost fabrication, compatibility with silicon readout electronics, and operation without cooling. Most importantly, this detector may offer better sensitivity than any other uncooled infrared sensor, with the exception of the original Golay cell.

Modified lead titanate thin films for pyroelectric infrared detectors on gold electrodes

NASA Astrophysics Data System (ADS)

Ahmed, Moinuddin; Butler, Donald P.

2015-07-01

Pyroelectric infrared detectors provide the advantage of both a wide spectral response and dynamic range, which also has enabled systems to be developed with reduced size, weight and power consumption. This paper demonstrates the deposition of lead zirconium titanate (PZT) and lead calcium titanate (PCT) thin films for uncooled pyroelectric detectors with the utilization of gold electrodes. The modified lead titanate thin films were deposited by pulsed laser deposition on gold electrodes. The PZT and PCT thins films deposited and annealed at temperatures of 650 °C and 550 °C respectively demonstrated the best pyroelectric performance in this work. The thin films displayed a pyroelectric effect that increased with temperature. Poling of the thin films was carried out for a fixed time periods and fixed dc bias voltages at elevated temperature in order to increase the pyroelectric coefficient by establishing a spontaneous polarization of the thin films. Poling caused the pyroelectric current to increase one order of magnitude.

Slow positron beam production by a 14 MeV C.W. electron accelerator

NASA Astrophysics Data System (ADS)

Begemann, M.; Gräff, G.; Herminghaus, H.; Kalinowsky, H.; Ley, R.

1982-10-01

A 14 MeV c.w. electron accelerator is used for pair production in a tungsten target of 0.7 radiation lengths thickness. A small fraction of the positrons is thermalized and diffuses out of the surface ofsurface of a well annealed tungsten foil coated with MgO which is positioned immediately behind the target. The slow positrons are extracted from the target region and magnetically guided over a distance of 10 m onto a channelplate multiplier at the end of an S-shaped solenoid. The positrons are identified by their annihilation radiation using two NaI-detectors. The intensity of the slow positrons is proportional to the accelerator electron beam current. The maximum intensity of 2.2 × 10 5 slow positrons per second reaching thedetector at an accelerator current of 15 μA was limited by the power deposited in the uncooled target. The energy of the positrons is concentrated in a small region at about 1 eV and clearly demonstrates the emission of thermal positrons.

Compact GaSb/silicon-on-insulator 2.0x μm widely tunable external cavity lasers.

PubMed

Wang, Ruijun; Malik, Aditya; Šimonytė, Ieva; Vizbaras, Augustinas; Vizbaras, Kristijonas; Roelkens, Gunther

2016-12-12

2.0x µm widely tunable external cavity lasers realized by combining a GaSb gain chip with a silicon photonics waveguide circuit for wavelength selection are demonstrated. Wavelength tuning over 58 nm from 2.01 to 2.07 µm is demonstrated. In the silicon photonic integrated circuit, laser feedback is realized by using a silicon Bragg grating and continuous tuning is realized by using two thermally tuned silicon microring resonators (MRRs) and a phase section. The uncooled laser has maximum output power of 7.5 mW and threshold current density of 0.8 kA/cm². The effect of the coupling gap of the MRRs on tunable laser performance is experimentally assessed. A side mode suppression ratio better than 52 dB over the full tuning range and in the optimum operation point of more than 60 dB is achieved for the laser with weakly coupled MRRs.

Layerwise Monitoring of the Selective Laser Melting Process by Thermography

NASA Astrophysics Data System (ADS)

Krauss, Harald; Zeugner, Thomas; Zaeh, Michael F.

Selective Laser Melting is utilized to build parts directly from CAD data. In this study layerwise monitoring of the temperature distribution is used to gather information about the process stability and the resulting part quality. The heat distribution varies with different kinds of parameters including scan vector length, laser power, layer thickness and inter-part distance in the job layout. By integration of an off-axis mounted uncooled thermal detector, the solidification as well as the layer deposition are monitored and evaluated. This enables the identification of hot spots in an early stage during the solidification process and helps to avoid process interrupts. Potential quality indicators are derived from spatially resolved measurement data and are correlated to the resulting part properties. A model of heat dissipation is presented based on the measurement of the material response for varying heat input. Current results show the feasibility of process surveillance by thermography for a limited section of the building platform in a commercial system.

Climate change impact on microclimate of work environment related to occupational health and productivity.

PubMed

Marchetti, Enrico; Capone, Pasquale; Freda, Daniela

2016-01-01

Climate change is a global emergency that influences human health and occupational safety. Global warming characterized by an increase in temperature of the ambience and humidity affects human health directly impairing body thermoregulation with serious consequences: dehydration, fatigue, heat stroke and even death. Several studies have demonstrated negative effects of climate change on working populations in a wide variety of workplaces with particular regard to outdoor and uncooled indoor workplaces. Most vulnerable workers are outdoor workers in tropical and subtropical countries usually involved in heavy labor during hot seasons. Many of the consequences therefore, regarding working people are possible, even without health symptoms by reducing work productivity. The scope of this review is to investigate effects of climate change on workers both in relation to health and work productivity. This study has been realized by analyzing recent international literature. In order to reduce negative effects of climate change on working populations it is essential to implement preventive measures with a multidisciplinary strategy limiting health risks and improving work productivity.

Design of a tokamak fusion reactor first wall armor against neutral beam impingement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myers, R.A.

1977-12-01

The maximum temperatures and thermal stresses are calculated for various first wall design proposals, using both analytical solutions and the TRUMP and SAP IV Computer Codes. Beam parameters, such as pulse time, cycle time, and beam power, are varied. It is found that uncooled plates should be adequate for near-term devices, while cooled protection will be necessary for fusion power reactors. Graphite and tungsten are selected for analysis because of their desirable characteristics. Graphite allows for higher heat fluxes compared to tungsten for similar pulse times. Anticipated erosion (due to surface effects) and plasma impurity fraction are estimated. Neutron irradiationmore » damage is also discussed. Neutron irradiation damage (rather than erosion, fatigue, or creep) is estimated to be the lifetime-limiting factor on the lifetime of the component in fusion power reactors. It is found that the use of tungsten in fusion power reactors, when directly exposed to the plasma, will cause serious plasma impurity problems; graphite should not present such an impurity problem.« less

LWIR hyperspectral micro-imager for detection of trace explosive particles

NASA Astrophysics Data System (ADS)

Bingham, Adam L.; Lucey, Paul G.; Akagi, Jason T.; Hinrichs, John L.; Knobbe, Edward T.

2014-05-01

Chemical micro-imaging is a powerful tool for the detection and identification of analytes of interest against a cluttered background (i.e. trace explosive particles left behind in a fingerprint). While a variety of groups have demonstrated the efficacy of Raman instruments for these applications, point by point or line by line acquisition of a targeted field of view (FOV) is a time consuming process if it is to be accomplished with useful spatial resolutions. Spectrum Photonics has developed and demonstrated a prototype system utilizing long wave infrared hyperspectral microscopy, which enables the simultaneous collection of LWIR reflectance spectra from 8-14 μm in a 30 x 7 mm FOV with 30 μm spatial resolution in 30 s. An overview of the uncooled Sagnac-based LWIR HSM system will be given, emphasizing the benefits of this approach. Laboratory Hyperspectral data collected from custom mixtures and fingerprint residues is shown, focusing on the ability of the LWIR chemical micro-imager to detect chemicals of interest out of a cluttered background.

Advances in 133Cs Fountains: Control of the Cold Collision Shift and Observation of Feshbach Resonances

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bize, S.; Marion, H.; Cacciapuoti, L.

2005-05-05

This paper describes the work performed at BNM-SYRTE (Observatoire de Paris) over the past few years toward the improvement and the use of microwave frequency standards using laser-cooled atoms. First, recent improvements of the 133Cs and 87Rb atomic fountains are described. An important advance is the achievement of a fractional frequency instability of 1.6 x 10-14{tau}-1/2 where {tau} is the measurement time in seconds, thanks to the routine use of a cryogenic sapphire oscillator as an ultra-stable local frequency reference. The second advance is a powerful method to control the frequency shift due to cold collisions. These two advances leadmore » to a frequency stability of 2 x 10-16 at 50,000 s for the first time for primary standards. In addition, these clocks realize the SI second with an accuracy of 7 x 10-16, one order of magnitude below that of uncooled devices.« less

Multispectral Microscopic Imager (MMI): Multispectral Imaging of Geological Materials at a Handlens Scale

NASA Astrophysics Data System (ADS)

Farmer, J. D.; Nunez, J. I.; Sellar, R. G.; Gardner, P. B.; Manatt, K. S.; Dingizian, A.; Dudik, M. J.; McDonnell, G.; Le, T.; Thomas, J. A.; Chu, K.

2011-12-01

The Multispectral Microscopic Imager (MMI) is a prototype instrument presently under development for future astrobiological missions to Mars. The MMI is designed to be a arm-mounted rover instrument for use in characterizing the microtexture and mineralogy of materials along geological traverses [1,2,3]. Such geological information is regarded as essential for interpreting petrogenesis and geological history, and when acquired in near real-time, can support hypothesis-driven exploration and optimize science return. Correlated microtexure and mineralogy also provides essential data for selecting samples for analysis with onboard lab instruments, and for prioritizing samples for potential Earth return. The MMI design employs multispectral light-emitting diodes (LEDs) and an uncooled focal plane array to achieve the low-mass (<1kg), low-cost, and high reliability (no moving parts) required for an arm-mounted instrument on a planetary rover [2,3]. The MMI acquires multispectral, reflectance images at 62 μm/pixel, in which each image pixel is comprised of a 21-band VNIR spectrum (0.46 to 1.73 μm). This capability enables the MMI to discriminate and resolve the spatial distribution of minerals and textures at the microscale [2, 3]. By extending the spectral range into the infrared, and increasing the number of spectral bands, the MMI exceeds the capabilities of current microimagers, including the MER Microscopic Imager (MI); 4, the Phoenix mission Robotic Arm Camera (RAC; 5) and the Mars Science Laboratory's Mars Hand Lens Imager (MAHLI; 6). In this report we will review the capabilities of the MMI by highlighting recent lab and field applications, including: 1) glove box deployments in the Astromaterials lab at Johnson Space Center to analyze Apollo lunar samples; 2) GeoLab glove box deployments during the 2011 Desert RATS field trials in northern AZ to characterize analog materials collected by astronauts during simulated EVAs; 3) field deployments on Mauna Kea Volcano, Hawaii, during NASA's 2010 ISRU field trials, to analyze materials at the primary feedstock mining site; 4) lab characterization of geological samples from a complex, volcanic-hydrothermal terrain in the Cady Mts., SE Mojave Desert, California. We will show how field and laboratory applications have helped drive the development and refinement of MMI capabilities, while identifying synergies with other potential payload instruments (e.g. X-ray Diffraction) for solving real geological problems.

Long range thermal weapon sights for the German future infantryman program IdZ

NASA Astrophysics Data System (ADS)

Breiter, Rainer; Ihle, Tobias; Mauk, Karl-Heinz; Münzberg, Mario; Rode, Werner

2007-04-01

In December 2004 AIM started the series production of the HuntIR long range thermal weapon sight. The sight is fielded in the Germany Future Infantryman (IdZ) basic system and since that time in continuous service in various out of area missions with German participation. For very long identification ranges >1500m cooled technology still outperforms uncooled sights, even with respect to smaller size and lower weight because the typical F/1 design of uncooled systems overcompensates cooler weight for focal length >175mm. The HuntIR sight is therefore based on a cooled MWIR detection module for long range battlefield surveillance and target engagement. The device specifically is a perfect match to state of the art small arms like 0.50 cal sniper rifles or crew served weapons like the 40mm high velocity grenade machine gun (GMG) which provide engagement ranges >1500m and need an adequate sight performance beyond that. A recent modification of HuntIR was done to provide a wider field of view for improved situation awareness in urban operations and specifically to allow the engagement of the 40mm GMG in ranges between 250-1200m. The qualification tests of the sight by the German infantry were successfully completed mid 2006. To match the demand of the follow-up program IdZ-ES additional components have to be integrated. Most important are a laser range finder (LRF), 3 axis digital magnetic compass (DMC) and a wireless data link. LRF and DMC together with a highly sophisticated fire control computer provide improved first round hit probability, the DMC additionally improves the fire control in any case of steep trajectories or for pronounced ballistic trajectories to avoid any need to precisely level the GMG. This new sight is done under the brand name RangIR. An important additional feature is the interface for air burst ammunition (ABM). The optical distance is measured by the LRF, the fire control computer accurately evaluates the trajectory under the given angle, muzzle velocity, temperature and range conditions to define the time-of-flight. This fully integrated IR fire control system is available mid 2007. The development phase of the IdZES program is under contract, series deliveries expected in 2009. The RangIR will see some specific modifications for the link and a man machine interface to control the whole IdZ-ES system components ergonomically from the weapon with optimized power supply concepts to minimize the number of batteries, chargers etc.

Automated recognition and tracking of aerosol threat plumes with an IR camera pod

NASA Astrophysics Data System (ADS)

Fauth, Ryan; Powell, Christopher; Gruber, Thomas; Clapp, Dan

2012-06-01

Protection of fixed sites from chemical, biological, or radiological aerosol plume attacks depends on early warning so that there is time to take mitigating actions. Early warning requires continuous, autonomous, and rapid coverage of large surrounding areas; however, this must be done at an affordable cost. Once a potential threat plume is detected though, a different type of sensor (e.g., a more expensive, slower sensor) may be cued for identification purposes, but the problem is to quickly identify all of the potential threats around the fixed site of interest. To address this problem of low cost, persistent, wide area surveillance, an IR camera pod and multi-image stitching and processing algorithms have been developed for automatic recognition and tracking of aerosol plumes. A rugged, modular, static pod design, which accommodates as many as four micro-bolometer IR cameras for 45deg to 180deg of azimuth coverage, is presented. Various OpenCV1 based image-processing algorithms, including stitching of multiple adjacent FOVs, recognition of aerosol plume objects, and the tracking of aerosol plumes, are presented using process block diagrams and sample field test results, including chemical and biological simulant plumes. Methods for dealing with the background removal, brightness equalization between images, and focus quality for optimal plume tracking are also discussed.

Wide-band 'black silicon' with atomic layer deposited NbN.

PubMed

Isakov, Kirill; Perros, Alexander Pyymaki; Shah, Ali; Lipsanen, Harri

2018-08-17

Antireflection surfaces are often utilized in optical components to reduce undesired reflection and increase absorption. We report on black silicon (b-Si) with dramatically enhanced absorption over a broad wavelength range (250-2500 nm) achieved by applying a 10-15 nm conformal coating of NbN with atomic layer deposition (ALD). The improvement is especially pronounced in the near infrared (NIR) range of 1100-2500 nm where absorption is increased by >90%. A significant increase of absorption is also observed over the ultraviolet range of 200-400 nm. Preceding NbN deposition with a nanostructured ALD Al 2 O 3 (n-Al 2 O 3 ) coating to enhance the NbN texture was also examined. Such texturing further improves absorption in the NIR, especially at longer wavelengths, strong absorption up to 4-5 μm wavelengths has been attested. For comparison, double side polished silicon and sapphire coated with 10 nm thick NbN exhibited absorption of only ∼55% in the NIR range of 1100-2500 nm. The results suggest a positive correlation between the surface area of NbN coating and optical absorption. Based on the wide-band absorption, the presented NbN-coated b-Si may be an attractive candidate for use in e.g. spectroscopic systems, infrared microbolometers.

Athermalization of infrared dual field optical system based on wavefront coding

NASA Astrophysics Data System (ADS)

Jiang, Kai; Jiang, Bo; Liu, Kai; Yan, Peipei; Duan, Jing; Shan, Qiu-sha

2017-02-01

Wavefront coding is a technology which combination of the optical design and digital image processing. By inserting a phase mask closed to the pupil plane of the optical system the wavefront of the system is re-modulated. And the depth of focus is extended consequently. In reality the idea is same as the athermalization theory of infrared optical system. In this paper, an uncooled infrared dual field optical system with effective focal as 38mm/19mm, F number as 1.2 of both focal length, operating wavelength varying from 8μm to 12μm was designed. A cubic phase mask was used at the pupil plane to re-modulate the wavefront. Then the performance of the infrared system was simulated with CODEV as the environment temperature varying from -40° to 60°. MTF curve of the optical system with phase mask are compared with the outcome before using phase mask. The result show that wavefront coding technology can make the system not sensitive to thermal defocus, and then realize the athermal design of the infrared optical system.

Conception of a cheap infrared camera using a Fresnel lens

NASA Astrophysics Data System (ADS)

Grulois, Tatiana; Druart, Guillaume; Guérineau, Nicolas; Crastes, Arnaud; Sauer, Hervé; Chavel, Pierre

2014-09-01

Today huge efforts are made in the research and industrial areas to design compact and cheap uncooled infrared optical systems for low-cost imagery applications. Indeed, infrared cameras are currently too expensive to be widespread. If we manage to cut their cost, we expect to open new types of markets. In this paper, we will present the cheap broadband microimager we have designed. It operates in the long-wavelength infrared range and uses only one silicon lens at a minimal cost for the manufacturing process. Our concept is based on the use of a thin optics. Therefore inexpensive unconventional materials can be used because some absorption can be tolerated. Our imager uses a thin Fresnel lens. Up to now, Fresnel lenses have not been used for broadband imagery applications because of their disastrous chromatic properties. However, we show that working in a high diffraction order can significantly reduce chromatism. A prototype has been made and the performance of our camera will be discussed. Its characterization has been carried out in terms of modulation transfer function (MTF) and noise equivalent temperature difference (NETD). Finally, experimental images will be presented.

Hot ion plasma production in HIP-1 using water-cooled hollow cathodes

NASA Technical Reports Server (NTRS)

Reinmann, J. J.; Lauver, M. R.; Patch, R. W.; Layman, R. W.; Snyder, A.

1975-01-01

A steady-state ExB plasma was formed by applying a strong radially inward dc electric field near the mirror throats. Most of the results were for hydrogen, but deuterium and helium plasmas were also studied. Three water-cooled hollow cathodes were operated in the hot-ion plasma mode with the following results: (1) thermally emitting cathodes were not required to achieve the hot-ion mode; (2) steady-state operation (several minutes) was attained; (3) input powers greater than 40 kW were achieved; (4) cathode outside diameters were increased from 1.2 cm (uncooled) to 4.4 cm (water-cooled); (5) steady-state hydrogen plasma with ion temperatures from 185 to 770 eV and electron temperatures from 5 to 21 eV were produced. Scaling relations were empirically obtained for discharge current, ion temperature, electron temperature, and relative ion density as a function of hydrogen gas feed rate, magnetic field, and cathode voltage. Neutrons were produced from deuterium plasma, but it was not established whether thay came from the plasma volume or from the electrode surfaces.