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Sample records for electro-optic imaging fourier

  1. Electro-optic imaging Fourier transform spectrometer

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin (Inventor); Znod, Hanying (Inventor)

    2009-01-01

    An Electro-Optic Imaging Fourier Transform Spectrometer (EOIFTS) for Hyperspectral Imaging is described. The EOIFTS includes an input polarizer, an output polarizer, and a plurality of birefringent phase elements. The relative orientations of the polarizers and birefringent phase elements can be changed mechanically or via a controller, using ferroelectric liquid crystals, to substantially measure the spectral Fourier components of light propagating through the EIOFTS. When achromatic switches are used as an integral part of the birefringent phase elements, the EIOFTS becomes suitable for broadband applications, with over 1 micron infrared bandwidth.

  2. Electro-optic Imaging Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    2005-01-01

    JPL is developing an innovative compact, low mass, Electro-Optic Imaging Fourier Transform Spectrometer (E-O IFTS) for hyperspectral imaging applications. The spectral region of this spectrometer will be 1 - 2.5 micron (1000-4000/cm) to allow high-resolution, high-speed hyperspectral imaging applications. One application will be the remote sensing of the measurement of a large number of different atmospheric gases simultaneously in the same airmass. Due to the use of a combination of birefringent phase retarders and multiple achromatic phase switches to achieve phase delay, this spectrometer is capable of hyperspectral measurements similar to that of the conventional Fourier transform spectrometer but without any moving parts. In this paper, the principle of operations, system architecture and recent experimental progress will be presented.

  3. Electro-optic Imaging Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    2005-01-01

    JPL is developing an innovative compact, low mass, Electro-Optic Imaging Fourier Transform Spectrometer (E-0IFTS) for hyperspectral imaging applications. The spectral region of this spectrometer will be 1 - 2.5 pm (1000 -4000 cm-') to allow high-resolution, high-speed hyperspectral imaging applications [l-51. One application will be theremote sensing of the measurement of a large number of different atmospheric gases simultaneously in the sameairmass. Due to the use of a combination of birefiingent phase retarders and multiple achromatic phase switches toachieve phase delay, this spectrometer is capable of hyperspectral measurements similar to that of the conventionalFourier transform spectrometer but without any moving parts. In this paper, the principle of operations, systemarchitecture and recent experimental progress will be presen.

  4. Electro-optic Imaging Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    2005-01-01

    JPL is developing an innovative compact, low mass, Electro-Optic Imaging Fourier Transform Spectrometer (E-0IFTS) for hyperspectral imaging applications. The spectral region of this spectrometer will be 1 - 2.5 pm (1000 -4000 cm-') to allow high-resolution, high-speed hyperspectral imaging applications [l-51. One application will be theremote sensing of the measurement of a large number of different atmospheric gases simultaneously in the sameairmass. Due to the use of a combination of birefiingent phase retarders and multiple achromatic phase switches toachieve phase delay, this spectrometer is capable of hyperspectral measurements similar to that of the conventionalFourier transform spectrometer but without any moving parts. In this paper, the principle of operations, systemarchitecture and recent experimental progress will be presen.

  5. Electro-optic Imaging Fourier Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin

    2005-01-01

    JPL is developing an innovative compact, low mass, Electro-Optic Imaging Fourier Transform Spectrometer (E-O IFTS) for hyperspectral imaging applications. The spectral region of this spectrometer will be 1 - 2.5 micron (1000-4000/cm) to allow high-resolution, high-speed hyperspectral imaging applications. One application will be the remote sensing of the measurement of a large number of different atmospheric gases simultaneously in the same airmass. Due to the use of a combination of birefringent phase retarders and multiple achromatic phase switches to achieve phase delay, this spectrometer is capable of hyperspectral measurements similar to that of the conventional Fourier transform spectrometer but without any moving parts. In this paper, the principle of operations, system architecture and recent experimental progress will be presented.

  6. Electro-Optical Imaging Fourier-Transform Spectrometer

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Zhou, Hanying

    2006-01-01

    An electro-optical (E-O) imaging Fourier-transform spectrometer (IFTS), now under development, is a prototype of improved imaging spectrometers to be used for hyperspectral imaging, especially in the infrared spectral region. Unlike both imaging and non-imaging traditional Fourier-transform spectrometers, the E-O IFTS does not contain any moving parts. Elimination of the moving parts and the associated actuator mechanisms and supporting structures would increase reliability while enabling reductions in size and mass, relative to traditional Fourier-transform spectrometers that offer equivalent capabilities. Elimination of moving parts would also eliminate the vibrations caused by the motions of those parts. Figure 1 schematically depicts a traditional Fourier-transform spectrometer, wherein a critical time delay is varied by translating one the mirrors of a Michelson interferometer. The time-dependent optical output is a periodic representation of the input spectrum. Data characterizing the input spectrum are generated through fast-Fourier-transform (FFT) post-processing of the output in conjunction with the varying time delay.

  7. Electro-Optic Surface Field Imaging System

    DTIC Science & Technology

    1989-06-01

    ELECTRO - OPTIC SURFACE FIELD IMAGING SYSTEM L. E. Kingsley and W. R. Donaldson LABORATORY FOR LASER ENERGETICS University of Rochester 250 East...surface electric fields present during switch operation. The electro - optic , or Pockel’s effect, provides an extremely useful probe of surface electric...fields. Using the electro - optic effect, surface fields can be measured with an optical probe. This paper describes an electro - optic probe which is

  8. Investigation on probing quadratic electro-optic coefficient of tantalum potassium niobate crystal based on Fourier transform

    NASA Astrophysics Data System (ADS)

    Gao, Ch. Y.; Yu, H. T.; Wen, J.; Zhao, M.; Shang, J. J.; Li, X. L.

    2016-02-01

    A method for probing quadratic electro-optic(QEO) coefficient of tantalum potassium niobate crystal based on Fourier transform was proposed. We acquired all the independent component of QEO coefficient tensor of crystal, they are h11 = 1.56 ×10-14m2 /V2 , h12 = 1.24 ×10-14m2 /V2 and h44 = 0.160 ×10-14m2 /V2 respectively. With the help of the computer digital image processing technology, this method should have further application prospect in the areas of optical properties parameters measuring to the optical functional materials.

  9. Spaceborne astronomy with electro-optical image sensors

    NASA Technical Reports Server (NTRS)

    Bradley, W. C.

    1977-01-01

    The Space Telescope, planned for orbiting in the early 1980s, is described, with emphasis on its electro-optical image sensing capability. Relative advantages of image tubes and solid state arrays as image detectors are summarized; image tube technology is well characterized, but preference may be given to a more versatile tandem solid state array consisting of one module with high silicon response covering most of the spectrum, and a second intensified array with ultraviolet sensitivity and low noise readout. The classical 'photoelectron noise limit' calculation is reviewed, and a detailed calculation of sensitivity limits adaptable to analysis of image tube or solid state array detectors is also given. In particular, characteristics of a filter to optimize the signal to noise ratio is determined. Typical sensitivity calculations for an image tube detector show that with an exposure of one orbital night (approximately 2000 seconds), 10% photometry may be done to a low limit of visual magnitude.

  10. Simulation of electro-optical imaging system based on OpenGL

    NASA Astrophysics Data System (ADS)

    Zhu, Yong; Fu, Qiang; Duan, Jin; Jing, Wen-bo

    2013-08-01

    With the development of electro-optical imaging system technology and simulation technology, and the demand of optimizing the new type electro-optical imaging system theoretical model, more and more scientific research institutes, colleges and universities research on the simulation of electro-optical imaging system, and the better results were obtained. Simulation technology saved the cost of system design development, meanwhile, some complex and hard to re-implement experiments can be carried repeatedly. According to the demand of complex environment construction technology and the requirement of imaging simulation system fidelity, considering the performance of electro-optical imaging system, an electro-optical imaging system is modeled. The modeling has two aspects which is scene characteristic modeling and electro-optical system modeling. Scene characteristic modeling can construct dynamic scenes in different kinds of complex environments by using powerful OpenGL three-dimension model visualization technology. Electro-optical system modeling is consist of optical system and imaging detector. Electro-optical imaging system simulation model is established with the analysis of electro-optical imaging system theory. The use of modular design concept and general interface technology is combined. Different imaging effect is received under different parameters by modifying the model's related parameters. The experimental results show that, the image produced from simulation basically reflects the performance of imaging system, so this kind of image can be used as a information source for imaging system performance analysis. It provides a simple and feasible method for the analysis of imaging system performance, which has a very important practical significance.

  11. Remote sensing of stress using electro-optics imaging technique

    NASA Astrophysics Data System (ADS)

    Chen, Tong; Yuen, Peter; Hong, Kan; Tsitiridis, Aristeidis; Kam, Firmin; Jackman, James; James, David; Richardson, Mark; Oxford, William; Piper, Jonathan; Thomas, Francis; Lightman, Stafford

    2009-09-01

    Emotional or physical stresses induce a surge of adrenaline in the blood stream under the command of the sympathetic nerve system, which, cannot be suppressed by training. The onset of this alleviated level of adrenaline triggers a number of physiological chain reactions in the body, such as dilation of pupil and an increased feed of blood to muscles etc. This paper reports for the first time how Electro-Optics (EO) technologies such as hyperspectral [1,2] and thermal imaging[3] methods can be used for the detection of stress remotely. Preliminary result using hyperspectral imaging technique has shown a positive identification of stress through an elevation of haemoglobin oxygenation saturation level in the facial region, and the effect is seen more prominently for the physical stressor than the emotional one. However, all results presented so far in this work have been interpreted together with the base line information as the reference point, and that really has limited the overall usefulness of the developing technology. The present result has highlighted this drawback and it prompts for the need of a quantitative assessment of the oxygenation saturation and to correlate it directly with the stress level as the top priority of the next stage of research.

  12. Electro-Optical Imaging Microscopy of Dye-Doped Artificial Lipidic Membranes

    PubMed Central

    Hajj, Bassam; De Reguardati, Sophie; Hugonin, Loïc; Le Pioufle, Bruno; Osaki, Toshihisa; Suzuki, Hiroaki; Takeuchi, Shoji; Mojzisova, Halina; Chauvat, Dominique; Zyss, Joseph

    2009-01-01

    Artificial lipidic bilayers are widely used as a model for the lipid matrix in biological cell membranes. We use the Pockels electro-optical effect to investigate the properties of an artificial lipidic membrane doped with nonlinear molecules in the outer layer. We report here what is believed to be the first electro-optical Pockels signal and image from such a membrane. The electro-optical dephasing distribution within the membrane is imaged and the signal is shown to be linear as a function of the applied voltage. A theoretical analysis taking into account the statistical orientation distribution of the inserted dye molecules allows us to estimate the doped membrane nonlinearity. Ongoing extensions of this work to living cell membranes are discussed. PMID:19948120

  13. Real-time digital signal processing for live electro-optic imaging.

    PubMed

    Sasagawa, Kiyotaka; Kanno, Atsushi; Tsuchiya, Masahiro

    2009-08-31

    We present an imaging system that enables real-time magnitude and phase detection of modulated signals and its application to a Live Electro-optic Imaging (LEI) system, which realizes instantaneous visualization of RF electric fields. The real-time acquisition of magnitude and phase images of a modulated optical signal at 5 kHz is demonstrated by imaging with a Si-based high-speed CMOS image sensor and real-time signal processing with a digital signal processor. In the LEI system, RF electric fields are probed with light via an electro-optic crystal plate and downconverted to an intermediate frequency by parallel optical heterodyning, which can be detected with the image sensor. The artifacts caused by the optics and the image sensor characteristics are corrected by image processing. As examples, we demonstrate real-time visualization of electric fields from RF circuits.

  14. High-speed digital processing of electro-optic holography images for a quantitative analysisElaboration digitale à grande vitesse des images d'holographie électro-optique pour une analyse quantitative

    NASA Astrophysics Data System (ADS)

    Schirripa Spagnolo, G.; Ambrosini, D.; Paoletti, D.; Borghi, R.

    1997-06-01

    A quasi-automatic quantitative analysis of electro-optic holography images is proposed. The phase information is extracted by means of the Fourier transform method. The phase map is unwrapped by an algorithm based on no-path-following scheme and fast cosine transform.

  15. Q selection for an electro-optical earth imaging system: theoretical and experimental results.

    PubMed

    Cochrane, Andy; Schulz, Kevin; Kendrick, Rick; Bell, Ray

    2013-09-23

    This paper explores practical design considerations for selecting Q for an electro-optical earth imaging system, where Q is defined as (λ FN) / pixel pitch. Analytical methods are used to show that, under imaging conditions with high SNR, increasing Q with fixed aperture cannot lead to degradation of image quality regardless of the angular smear rate of the system. The potential for degradation of image quality under low SNR is bounded by an increase of the detector noise scaling as Q. An imaging test bed is used to collect representative imagery for various Q configurations. The test bed includes real world errors such as image smear and haze. The value of Q is varied by changing the focal length of the imaging system. Imagery is presented over a broad range of parameters.

  16. Electro-optic modulation methods in range-gated active imaging.

    PubMed

    Chen, Zhen; Liu, Bo; Liu, Enhai; Peng, Zhangxian

    2016-01-20

    A time-resolved imaging method based on electro-optic modulation is proposed in this paper. To implement range resolution, two kinds of polarization-modulated methods are designed, and high spatial and range resolution can be achieved by the active imaging system. In the system, with polarization beam splitting the incident light is split into two parts, one of which is modulated with cos(2) function and the other is modulated with sin(2) function. Afterward, a depth map can be obtained from two simultaneously received images by dual electron multiplying charge-coupled devices. Furthermore, an intensity image can also be obtained from the two images. Comparisons of the two polarization-modulated methods indicate that range accuracy will be promoted when the polarized light is modulated before beam splitting.

  17. Multi-Sensor Fusion of Infrared and Electro-Optic Signals for High Resolution Night Images

    PubMed Central

    Huang, Xiaopeng; Netravali, Ravi; Man, Hong; Lawrence, Victor

    2012-01-01

    Electro-optic (EO) image sensors exhibit the properties of high resolution and low noise level at daytime, but they do not work in dark environments. Infrared (IR) image sensors exhibit poor resolution and cannot separate objects with similar temperature. Therefore, we propose a novel framework of IR image enhancement based on the information (e.g., edge) from EO images, which improves the resolution of IR images and helps us distinguish objects at night. Our framework superimposing/blending the edges of the EO image onto the corresponding transformed IR image improves their resolution. In this framework, we adopt the theoretical point spread function (PSF) proposed by Hardie et al. for the IR image, which has the modulation transfer function (MTF) of a uniform detector array and the incoherent optical transfer function (OTF) of diffraction-limited optics. In addition, we design an inverse filter for the proposed PSF and use it for the IR image transformation. The framework requires four main steps: (1) inverse filter-based IR image transformation; (2) EO image edge detection; (3) registration; and (4) blending/superimposing of the obtained image pair. Simulation results show both blended and superimposed IR images, and demonstrate that blended IR images have better quality over the superimposed images. Additionally, based on the same steps, simulation result shows a blended IR image of better quality when only the original IR image is available. PMID:23112602

  18. Multi-sensor fusion of infrared and electro-optic signals for high resolution night images.

    PubMed

    Huang, Xiaopeng; Netravali, Ravi; Man, Hong; Lawrence, Victor

    2012-01-01

    Electro-optic (EO) image sensors exhibit the properties of high resolution and low noise level at daytime, but they do not work in dark environments. Infrared (IR) image sensors exhibit poor resolution and cannot separate objects with similar temperature. Therefore, we propose a novel framework of IR image enhancement based on the information (e.g., edge) from EO images, which improves the resolution of IR images and helps us distinguish objects at night. Our framework superimposing/blending the edges of the EO image onto the corresponding transformed IR image improves their resolution. In this framework, we adopt the theoretical point spread function (PSF) proposed by Hardie et al. for the IR image, which has the modulation transfer function (MTF) of a uniform detector array and the incoherent optical transfer function (OTF) of diffraction-limited optics. In addition, we design an inverse filter for the proposed PSF and use it for the IR image transformation. The framework requires four main steps: (1) inverse filter-based IR image transformation; (2) EO image edge detection; (3) registration; and (4) blending/superimposing of the obtained image pair. Simulation results show both blended and superimposed IR images, and demonstrate that blended IR images have better quality over the superimposed images. Additionally, based on the same steps, simulation result shows a blended IR image of better quality when only the original IR image is available.

  19. Performance evaluation of panoramic electro-optic imagers using the TOD method

    NASA Astrophysics Data System (ADS)

    Désaulniers, Pierre; Thibault, Simon

    2011-05-01

    The triangle orientation discrimination (TOD) method is an emerging technique for the evaluation of electro-optical (EO) systems. In this method, the test pattern is a non-periodic equilateral triangle in one of four different orientations (apex up, down, left, or right), and the measurement procedure is a robust four-alternative forced-choice psychophysical process. This leads to a time-consuming task. Consequently, software models have been developed to replace the required human observers. These models base their decision on the orientation of the target using correlation between observed data and the set of four differently oriented targets. This study investigates for the first time how this method can be applied to highly distorted OE systems like hemispheric imagers. These types of systems have inherent large distortion, but the distortion should not be considered as an aberration but rather the result of the projection of a hemispheric field (3D) on a 2D sensor. The distortion deforms the image of the targets and image processing is usually performed to remove distortion and straighten the field of view. We present a comparison in accuracy and computational burden for the evaluation of EO system performance between cases where tested images are pre-processed and correlated to unchanged triangle targets and where untouched (distorted) images are correlated with position-wise distorted targets. This is a first evaluation of the application of the TOD with the goal of obtaining an image quality criterion for panoramic imagers.

  20. Single-shot time-resolved THz spectroscopy using non-collinear electro-optic imaging

    NASA Astrophysics Data System (ADS)

    Wang, Zhenyou; Su, Fuhai; Hegmann, Frank A.

    2010-03-01

    We demonstrate a technique for rapid substance identification via single-shot, coherent THz imaging using non-collinear electro-optic sampling. A THz probe pulse generated in ZnTe is transmitted through the sample then focused on a (110) ZnTe detection crystal. An 800nm, 100fs optical pulse employed as a sampling beam passes through the ZnTe detection crystal at an angle of 7^o relative to the THz beam.footnotetextT. Yasuda et al., Opt. Commun. 267, 128 (2006) The THz field induced birefringence is resolved as a variation of the intensity of the sampling pulse transmitted through a crossed polarizer. The modified sampling beam spot is imaged using a CCD camera. Because of the non-collinear geometry, the spatial overlap between the THz field and the optical pulse depends on the temporal position within the THz waveform. Consequently, we obtain high-resolution 2D images of the THz waveform without scanning the relative path length. The resolution of the absorption spectra extracted from wet paper and lactose using the single-shot imaging approach is comparable to the resolution obtained through conventional scanning lock-in measurements. Possible applications for substance detection are discussed.

  1. Electro-optical system for the high speed reconstruction of computed tomography images

    SciTech Connect

    Tresp, V.

    1989-01-01

    An electro-optical system for the high-speed reconstruction of computed tomography (CT) images has been built and studied. The system is capable of reconstructing high-contrast and high-resolution images at video rate (30 images per second), which is more than two orders of magnitude faster than the reconstruction rate achieved by special purpose digital computers used in commercial CT systems. The filtered back-projection algorithm which was implemented in the reconstruction system requires the filtering of all projections with a prescribed filter function. A space-integrating acousto-optical convolver, a surface acoustic wave filter and a digital finite-impulse response filter were used for this purpose and their performances were compared. The second part of the reconstruction, the back projection of the filtered projections, is computationally very expensive. An optical back projector has been built which maps the filtered projections onto the two-dimensional image space using an anamorphic lens system and a prism image rotator. The reconstructed image is viewed by a video camera, routed through a real-time image-enhancement system, and displayed on a TV monitor. The system reconstructs parallel-beam projection data, and in a modified version, is also capable of reconstructing fan-beam projection data. This extension is important since the latter are the kind of projection data actually acquired in high-speed X-ray CT scanners. The reconstruction system was tested by reconstructing precomputed projection data of phantom images. These were stored in a special purpose projection memory and transmitted to the reconstruction system as an electronic signal. In this way, a projection measurement system that acquires projections sequentially was simulated.

  2. Phase detection experiment for the down-looking synthetic aperture imaging ladar with electro-optic modulation

    NASA Astrophysics Data System (ADS)

    Lu, Zhiyong; Sun, Jianfeng; Zhi, Ya'nan; Zhang, Ning; Liu, Liren

    2014-09-01

    The down-looking synthetic aperture imaging ladar (SAIL) with electro-optic modulation was proposed. The measurement uses electrically controlled scanner to produce beams with spatial parabolic phase difference, which consists of electro-optic crystal and cylindrical lens. Due to the high modulation rate without mechanical scanning, this technique has a great potential for applications in extensive synthetic aperture imaging ladar fields. The phase mapping of electrically controlled scanner under the different applied voltage is achieved and measured by the polarized digital holographic interferometry. The phase mappings of the scanner in the down-looking SAIL with the o-polarized light and e-polarized light are obtained. The linear phase distribution and the parabolic phase distribution are observed after applying the external electric field. The corresponding analyses and discussions are proposed to explain the phenomena.

  3. TRM4: Range performance model for electro-optical imaging systems

    NASA Astrophysics Data System (ADS)

    Keßler, Stefan; Gal, Raanan; Wittenstein, Wolfgang

    2017-05-01

    TRM4 is a commonly used model for assessing device and range performance of electro-optical imagers. The latest version, TRM4.v2, has been released by Fraunhofer IOSB of Germany in June 2016. While its predecessor, TRM3, was developed for thermal imagers, assuming blackbody targets and backgrounds, TRM4 extends the TRM approach to assess three imager categories: imagers that exploit emitted radiation (TRM4 category Thermal), reflected radiation (TRM4 category Visible/NIR/SWIR), and both emitted and reflected radiation (TRM4 category General). Performance assessment in TRM3 and TRM4 is based on the perception of standard four-bar test patterns, whether distorted by under-sampling or not. Spatial and sampling characteristics are taken into account by the Average Modulation at Optimum Phase (AMOP), which replaces the system MTF used in previous models. The Minimum Temperature Difference Perceived (MTDP) figure of merit was introduced in TRM3 for assessing the range performance of thermal imagers. In TRM4, this concept is generalized to the MDSP (Minimum Difference Signal Perceived), which can be applied to all imager categories. In this paper, we outline and discuss the TRM approach and pinpoint differences between TRM4 and TRM3. In addition, an overview of the TRM4 software and its functionality is given. Features newly introduced in TRM4, such as atmospheric turbulence, irradiation sources, and libraries are addressed. We conclude with an outlook on future work and the new module for intensified CCD cameras that is currently under development

  4. Electro-Optic Identification Research Program

    DTIC Science & Technology

    2002-04-01

    Electro - optic identification (EOID) sensors provide photographic quality images that can be used to identify mine-like contacts provided by long...tasks such as validating existing electro - optic models, development of performance metrics, and development of computer aided identification and

  5. Electro-Optic Propagation

    DTIC Science & Technology

    2002-09-30

    Electro - Optic Propagation Stephen Doss-Hammel SPAWARSYSCEN San Diego code 2858 49170 Propagation Path San Diego, CA 92152-7385 phone: (619...OBJECTIVES The electro - optical propagation objectives are: 1) The acquisition and analysis of mid-wave and long-wave infrared transmission and...elements to the electro - optical propagation model development. The first element is the design and execution of field experiments to generate useful

  6. Electro-Optic Propagation

    DTIC Science & Technology

    2003-09-30

    Electro - Optic Propagation Stephen Doss-Hammel SPAWARSYSCEN San Diego code 2858 49170 Propagation Path San Diego, CA 92152-7385 phone: (619...scenarios to extend the capabilities of TAWS to surface and low altitude situations. OBJECTIVES The electro - optical propagation objectives are: 1...development of a new propagation assessment tool called EOSTAR ( Electro - Optical Signal Transmission and Ranging). The goal of the EOSTAR project is to

  7. Electro-Optic Modulator.

    DTIC Science & Technology

    An electro - optic modulator is used to modulate coherent light beams by the application of an electric potential. It combines a Fabry-Perot etalon and...a diffraction grating in a single unit. An etalon is constructed with an electro - optic material between reflecting surfaces. A voltage applied...between alternate, spaced-apart electrodes of a metal grid attached to one reflecting surface induces a diffraction grating in the electro optic material. Light entering the etalon is diffracted, reflected and efficiently coupled out.

  8. Imaging quality evaluation method of pixel coupled electro-optical imaging system

    NASA Astrophysics Data System (ADS)

    He, Xu; Yuan, Li; Jin, Chunqi; Zhang, Xiaohui

    2017-09-01

    With advancements in high-resolution imaging optical fiber bundle fabrication technology, traditional photoelectric imaging system have become ;flexible; with greatly reduced volume and weight. However, traditional image quality evaluation models are limited by the coupling discrete sampling effect of fiber-optic image bundles and charge-coupled device (CCD) pixels. This limitation substantially complicates the design, optimization, assembly, and evaluation image quality of the coupled discrete sampling imaging system. Based on the transfer process of grayscale cosine distribution optical signal in the fiber-optic image bundle and CCD, a mathematical model of coupled modulation transfer function (coupled-MTF) is established. This model can be used as a basis for following studies on the convergence and periodically oscillating characteristics of the function. We also propose the concept of the average coupled-MTF, which is consistent with the definition of traditional MTF. Based on this concept, the relationships among core distance, core layer radius, and average coupled-MTF are investigated.

  9. Electro-optic transient imaging instrumentation development at Lawrence Livermore National Laboratory: Implications for SSC instrumentation development

    SciTech Connect

    Lowry, M.; Jacoby, B.; Schulte, H.

    1990-12-01

    Over the last decade, the underground weapons physics laboratories fielded by LLNL's Nuclear Test and Experimental Sciences (NTES) program have experienced marked change. This change is characterized by a phenomenal growth in the amount of data returned per event. These techniques have been developed as a result of the severe demands placed upon transient instrumentation by the physics requirements of our underground nuclear laboratories. The detector front-ends must quickly detect, process and transmit a large volume of data to recording stations located approximately 1 km from the event. In a recent event, the detector front-ends successfully handled data at a prompt rate of approximately 13 Terabits/sec. Largely, this advance can be attributed directly to the increased use of electro-optic techniques. These highly-parallel high-bandwidth imaging instrumentation systems developed for the test program may have a lot to offer the high-energy physics community tackling the challenge of the unprecedented luminosity and fidelity demands at the SSC. In what follows, we discuss details of a few of our prompt instrumentation techniques and compare these capabilities to the detector requirements for the challenging physics at the SSC. 5 refs., 3 figs.

  10. Theoretical foundations for joint digital-optical analysis of electro-optical imaging systems.

    PubMed

    Stork, David G; Robinson, M Dirk

    2008-04-01

    We describe the mathematical and conceptual foundations for a novel methodology for jointly optimizing the design and analysis of the optics, detector, and digital image processing for imaging systems. Our methodology is based on the end-to-end merit function of predicted average pixel sum-squared error to find the optical and image processing parameters that minimize this merit function. Our approach offers several advantages over the traditional principles of optical design, such as improved imaging performance, expanded operating capabilities, and improved as-built performance.

  11. Electro-Optical BLM Chips Enabling Dynamic Imaging of Ordered Lipid Domains

    PubMed Central

    Shao, Chenren; Kendall, Eric; DeVoe, Don L.

    2012-01-01

    Studies of lipid rafts, ordered microdomains of sphingolipids and cholesterol within cell membranes, are essential in probing the relationships between membrane organization and cellular function. While in vitro studies of lipid phase separation are commonly performed using spherical vesicles as model membranes, the utility of these models is limited by a number of factors. Here we present a microfluidic device that supports simultaneous electrical measurements and confocal imaging of on-chip bilayer lipid membranes (BLMs), enabling real-time multi-domain imaging of membrane organization. The chips further support closed microfluidic access to both sides of the membrane, allowing the membrane boundary conditions to be rapidly changed and providing a mechanism for dynamically adjusting membrane curvature through application of a transmembrane pressure gradient. Here we demonstrate the platform through the study of dynamic generation and dissolution of ordered lipid domains as membrane components are transported to and from the supporting annulus containing solvated lipids and cholesterol. PMID:22728885

  12. Solid State Imaging Device Parameter Study for Use in Electro-Optic Tracking Systems.

    DTIC Science & Technology

    1977-10-01

    BALL PH.D. ELECTRICAL ENGINEERING W. H. EUBANKS, M.ED. ENGINEERING GRAPHICS FRANK 9. COTTON, JR., PH.D. INDUSTRIAL ENGINEERING For additional ,oples or...Inlormalion C. T. CARLEY, PH.D. address correspondence to: M4ECHANICAL ENGINEERING ENGINEERING AND INDUSTRIAL RESEARCH STATION JOHN I. PAULK, PH.D...1974. Altman, Laurence, "The New Concept for Memory and Imaging: Charge- Coupling," Electronica , pp. 50-59, June 21, 1971. Amelio, G. F., "Computer

  13. Electro-Optical Characterization

    SciTech Connect

    Not Available

    2006-06-01

    In the Electro-Optical Characterization group, within the National Center for Photovoltaic's Measurements and Characterization Division, we use various electrical and optical experimental techniques to relate photovoltaic device performance to the methods and materials used to produce them. The types of information obtained by these techniques range from small-scale atomic-bonding information to large-scale macroscopic quantities such as optical constants and electron-transport properties. Accurate and timely measurement of the electro-optical properties as a function of device processing provides researchers and manufacturers with the knowledge needed to troubleshoot problems and develop the knowledge base necessary for reducing cost, maximizing efficiency, improving reliability, and enhancing manufacturability. We work collaboratively with you to solve materials- and device-related R&D problems. This sheet summarizes our primary techniques and capabilities.

  14. Multidimensional System Analysis of Electro-Optic Sensors with Sampled Deterministic Output.

    DTIC Science & Technology

    1987-12-18

    System descriptions of scanning and staring electro - optic sensors with sampled output are developed as follows. Functions representing image...to complete the system descriptions. The results should be useful for designing electro - optic sensor systems and correcting data for instrumental...effects and other experimental conditions. Keywords include: Electro - optic system analysis, Scanning sensors, Staring sensors, Spatial sampling, and Temporal sampling.

  15. Fourier plane imaging microscopy

    SciTech Connect

    Dominguez, Daniel Peralta, Luis Grave de; Alharbi, Nouf; Alhusain, Mdhaoui; Bernussi, Ayrton A.

    2014-09-14

    We show how the image of an unresolved photonic crystal can be reconstructed using a single Fourier plane (FP) image obtained with a second camera that was added to a traditional compound microscope. We discuss how Fourier plane imaging microscopy is an application of a remarkable property of the obtained FP images: they contain more information about the photonic crystals than the images recorded by the camera commonly placed at the real plane of the microscope. We argue that the experimental results support the hypothesis that surface waves, contributing to enhanced resolution abilities, were optically excited in the studied photonic crystals.

  16. Fourier Modulus Image Construction.

    DTIC Science & Technology

    1981-05-01

    Fourier Optics: the Encoding of Infor- mation by Complex Zeroes," Optica Acta 26, 1139-46 (1979). 13. Y.M. Bruck and L.(. Sodin, "On the Ambiguity of the...0002 UNCLASSIFIED RADC-TR-81-63 NL -- END LEVEL# " DC-TR-61143 Finul Technical Relort 0 FOURIER MODULUS IMAGE "N CONSTRUCTION C Environmental Research... FOURIER MODULUS IMAGE CONSTRUCTION 7Sep 9--3 Sep 8 _ N/A 7. AUTHOR(s) N . James E Fienup. 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT

  17. An electro-optical imaging approach to the prompt signal processing problem of mega-channel SSC detector arrays

    SciTech Connect

    Lowry, M.; Ables, E.; Bionta, R.; Haigh, R.; Hugenberg, K.; Kalibjian, R.; McConaghy, C.; Milton, D.; Rotter, M.; Schulte, H.

    1990-12-01

    The physics demands of high luminosity at the SSC and the sometimes subtle measurements required to elucidate new physics will undoubtedly tax existing instrumentation. As is the case with most experimental fields, new physics follows from better measurement concepts and technologies. We expect this to be the case with the SSC as well. In what follows, we offer a glimpse of what may be possible using some of the recent results from the emerging technologies in the field of electro-optics. 12 refs., 4 figs.

  18. ELECTRO-OPTIC PROJECTION STUDY.

    DTIC Science & Technology

    light modulation. The light valve tubes used in the study employ an electron beam to develop discrete electric fields through an electro - optic material...Characteristics of two electro - optic materials, potassium dihydrogen phosphate and potassium dideuterium phosphate, were measured in order to optimize the

  19. ELECTRO-OPTIC PROJECTOR STUDY.

    DTIC Science & Technology

    The report describes research and development tasks undertaken in the development of a Pockels Effect electro - optic light valve. Two reflex...lens electron optics are used in different configurations. The electro - optic crystal utilized was KD2PO4 and when operated in a reflex mode provides

  20. Fourier multispectral imaging.

    PubMed

    Jia, Jie; Ni, Chuan; Sarangan, Andrew; Hirakawa, Keigo

    2015-08-24

    Current multispectral imaging systems use narrowband filters to capture the spectral content of a scene, which necessitates different filters to be designed for each application. In this paper, we demonstrate the concept of Fourier multispectral imaging which uses filters with sinusoidally varying transmittance. We designed and built these filters employing a single-cavity resonance, and made spectral measurements with a multispectral LED array. The measurements show that spectral features such as transmission and absorption peaks are preserved with this technique, which makes it a versatile technique than narrowband filters for a wide range of multispectral imaging applications.

  1. Hybrid Electro-Optic Processor

    DTIC Science & Technology

    1991-07-01

    This report describes the design of a hybrid electro - optic processor to perform adaptive interference cancellation in radar systems. The processor is...modulator is reported. Included is this report is a discussion of the design, partial fabrication in the laboratory, and partial testing of the hybrid electro ... optic processor. A follow on effort is planned to complete the construction and testing of the processor. The work described in this report is the

  2. Electro-optical Synergy Technique

    PubMed Central

    El-Domyati, Moetaz; El-Ammawi, Tarek S.; Medhat, Walid; Moawad, Osama; Mahoney, My G.

    2010-01-01

    Objectives: Electro-optical synergy technology is one of the most recently described methods for nonablative skin rejuvenation. The aim of this study is to evaluate the effects of electro-optical synergy on connective tissue composition by histological and immunohistochemical techniques coupled with computerized morphometric analysis. Design: A prospective clinical study. Participants: Six volunteers with Fitzpatrick skin types 3 to 4 and Glogau class I to II wrinkles were subjected to three months (6 sessions at 2-week intervals) of electro-optical synergy treatment. Measurements: Standard photographs and skin biopsies were obtained at baseline as well as three and six months after the start of treatment. The authors performed quantitative evaluation of total elastin, tropoelastin, collagen types I, III, and VII, and newly synthesized collagen. Results: Noticeable clinical and histological improvement was observed after electro-optical synergy treatment. A statistically significant increase in the means of collagen types I, III, and VII, as well as newly synthesized collagen, together with increased levels of tropoelastin, were detected, while the mean level of total elastin was significantly decreased at the end of treatment and three months post-treatment. Conclusion: Electro-optical synergy is an effective treatment for contouring facial skin laxity. This modality stimulates the repair processes and reverses the clinical, as well as the histopathological, signs of aging with the advantage of being a relatively risk-free procedure with minimal patient recovery time. PMID:21203352

  3. An electro-optical system for the measurement of strains

    NASA Astrophysics Data System (ADS)

    Bhat, Gopalakrishna K.

    Optical techniques for whole field displacement measurement, such as moire, holography, and speckle interferometry are attractive within the engineering industry in a variety of areas ranging from nondestructive testing and quality control to research and development. However, these techniques were restricted to research laboratories because of the specialized equipment and the laborious photographic process needed to record the images, and the skillful personnel needed to interpret the images. The major objective was to develop the basic principles of operation of an electro-optical system which can be used for the stress analysis of structures in the field. This objective was accomplished by means of three stages. The first stage was interfacing optical systems with the digital imaging system for the real time observation of whole field displacement patterns. Images of test objects are recorded using a TV camera (instead of a photographic film) and processed using a digital image processing system. The second stage was development of digital techniques for the analysis of interferometric fringes. Two dimensional Fourier transform techniques (spatial heterodyning and local heterodyning are developed to obtain the displacement and strain fields from the interferometric fringes. Techniques to minimize the errors introduced by the sharp object boundaries and to compute the strain field without obtaining the displacement field are also introduced. The third stage was application to study the feasibility of the system. The electro-optical system is employed to measure displacements and strains: under static and dynamic conditions, at normal and elevated temperatures and at the macro and micro levels. The applications include: measurement of strains in a disk subjected diametral compression, strain measurement at high temperatures, modal analysis of turbine blades, contact stress analysis; and measurement of the displacement field in the vicinity of a crack tip.

  4. Fourier plane image amplifier

    DOEpatents

    Hackel, L.A.; Hermann, M.R.; Dane, C.B.; Tiszauer, D.H.

    1995-12-12

    A solid state laser is frequency tripled to 0.3 {micro}m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only about 1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power. 1 fig.

  5. Fourier plane image amplifier

    DOEpatents

    Hackel, Lloyd A.; Hermann, Mark R.; Dane, C. Brent; Tiszauer, Detlev H.

    1995-01-01

    A solid state laser is frequency tripled to 0.3 .mu.m. A small portion of the laser is split off and generates a Stokes seed in a low power oscillator. The low power output passes through a mask with the appropriate hole pattern. Meanwhile, the bulk of the laser output is focused into a larger stimulated Brillouin scattering (SBS) amplifier. The low power beam is directed through the same cell in the opposite direction. The majority of the amplification takes place at the focus which is the fourier transform plane of the mask image. The small holes occupy large area at the focus and thus are preferentially amplified. The amplified output is now imaged onto the multichip module where the holes are drilled. Because of the fourier plane amplifier, only .about.1/10th the power of a competitive system is needed. This concept allows less expensive masks to be used in the process and requires much less laser power.

  6. Imaging Fourier Transform Spectrometer

    SciTech Connect

    Bennett, C.L.; Carter, M.R.; Fields, D.J.; Hernandez, J.

    1993-04-14

    The operating principles of an Imaging Fourier Transform Spectrometer (IFTS) are discussed. The advantages and disadvantages of such instruments with respect to alternative imaging spectrometers are discussed. The primary advantages of the IFTS are the capacity to acquire more than an order of magnitude more spectral channels than alternative systems with more than an order of magnitude greater etendue than for alternative systems. The primary disadvantage of IFTS, or FTS in general, is the sensitivity to temporal fluctuations, either random or periodic. Data from the IRIFTS (ir IFTS) prototype instrument, sensitive in the infrared, are presented having a spectral sensitivity of 0.01 absorbance units, a spectral resolution of 6 cm{sup {minus}1} over the range 0 to 7899 cm{sup {minus}1}, and a spatial resolution of 2.5 mr.

  7. Empirical electro-optical and x-ray performance evaluation of CMOS active pixels sensor for low dose, high resolution x-ray medical imaging.

    PubMed

    Arvanitis, C D; Bohndiek, S E; Royle, G; Blue, A; Liang, H X; Clark, A; Prydderch, M; Turchetta, R; Speller, R

    2007-12-01

    Monolithic complementary metal oxide semiconductor (CMOS) active pixel sensors with high performance have gained attention in the last few years in many scientific and space applications. In order to evaluate the increasing capabilities of this technology, in particular where low dose high resolution x-ray medical imaging is required, critical electro-optical and physical x-ray performance evaluation was determined. The electro-optical performance includes read noise, full well capacity, interacting quantum efficiency, and pixels cross talk. The x-ray performance, including x-ray sensitivity, modulation transfer function, noise power spectrum, and detection quantum efficiency, has been evaluated in the mammographic energy range. The sensor is a 525 x 525 standard three transistor CMOS active pixel sensor array with more than 75% fill factor and 25 x 25 microm pixel pitch. Reading at 10 f/s, it is found that the sensor has 114 electrons total additive noise, 10(5) electrons full well capacity with shot noise limited operation, and 34% interacting quantum efficiency at 530 nm. Two different structured CsI:Tl phosphors with thickness 95 and 115 microm, respectively, have been optically coupled via a fiber optic plate to the array resulting in two different system configurations. The sensitivity of the two different system configurations was 43 and 47 electrons per x-ray incident on the sensor. The MTF at 10% of the two different system configurations was 9.5 and 9 cycles/mm with detective quantum efficiency of 0.45 and 0.48, respectively, close to zero frequency at approximately 0.44 microC/kg (1.72 mR) detector entrance exposure. The detector was quantum limited at low spatial frequencies and its performance was comparable with high resolution a: Si and charge coupled device based x-ray imagers. The detector also demonstrates almost an order of magnitude lower noise than active matrix flat panel imagers. The results suggest that CMOS active pixel sensors when coupled

  8. Electro-Optic Computing Architectures. Volume I

    DTIC Science & Technology

    1998-02-01

    The objective of the Electro - Optic Computing Architecture (EOCA) program was to develop multi-function electro - optic interfaces and optical...interconnect units to enhance the performance of parallel processor systems and form the building blocks for future electro - optic computing architectures...Specifically, three multi-function interface modules were targeted for development - an Electro - Optic Interface (EOI), an Optical Interconnection Unit (OW

  9. Polymeric Materials for Electro-Optic Testing.

    DTIC Science & Technology

    1987-07-01

    what Langmuir Blodgett films are, how they are grown and deposited on a material, and the electro - optic effects in Langmuir/Blodgett films. Stephen...Kowel has experimented with several different types of organic dyes mixed in the films to increase the electro - optic effect in the films. The bulk of his...test integrated circuits. Keywords: Langmuir Blodgett films, Electro - optic testing, Integrated circuits, Linear electro - optic effect.

  10. Electro-Optic Diffraction Grating Tuned Laser.

    DTIC Science & Technology

    The patent concerns an electro - optic diffraction grating tuned laser comprising a laser medium, output mirror, retro-reflective grating and an electro - optic diffraction grating beam deflector positioned between the laser medium and the reflective diffraction grating. An optional angle multiplier may be used between the electro - optic diffraction grating and the reflective grating.

  11. Electro-optic KTN Devices

    NASA Astrophysics Data System (ADS)

    Yagi, Shogo; Fujiura, Kazuo

    We have grown KTN crystals with optical quality, and developed high-speed beam deflectors and variable focal length lenses based on KTN's large electro-optic effect. Furthermore, by using the KTN beam deflectors, we have developed a swept light source for OCT operable at 200 kHz.

  12. A methodology for estimating lateral range curves for electro-optical visible and infrared imaging systems for maritime search and detection applications

    NASA Astrophysics Data System (ADS)

    DeWeert, Michael J.; Leonard, Carrie L.; Stalder, Carrie L.; Iokepa, Judy; Gradie, Jonathan

    2005-05-01

    Electro-optical (EO) systems with digital image processing and computer-aided detection are increasingly coming into use for maritime surveillance, reconnaissance and search and rescue. EO systems have the potential to improve the consistency of detection, reduce operator workload and fatigue, and improve search efficiency. However, quantifying their performance versus more traditional approaches is problematic, because of the differences in how performance is specified for traditional systems versus modern computer-aided designs. In maritime search applications, system performance is commonly specified in terms of the lateral range curve (LRC). The LRC is a plot of the probability of detection versus horizontal range from the search platform. This metric has a long history, rooted in visual searches by trained human observers. However, it is specified without reference to any false-alarm rate or probability of false alarm. Computer-aided EO performance, on the other hand, is usually specified in terms of Signal-to-Noise Ratio (SNR), Receiver Operating Characteristic (ROC) curve, or some equivalent metric. In this paper, we demonstrate a methodology for estimating LRCs from SNRs or ROC curves. This methodology provides a consistent, quantifiable means for comparing the performance of new and legacy systems.

  13. Shuttle sortie electro-optical instruments study

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A study to determine the feasibility of adapting existing electro-optical instruments (designed and sucessfully used for ground operations) for use on a shuttle sortie flight and to perform satisfactorily in the space environment is considered. The suitability of these two instruments (a custom made image intensifier camera system and an off-the-shelf secondary electron conduction television camera) to support a barium ion cloud experiment was studied for two different modes of spacelab operation - within the pressurized module and on the pallet.

  14. Hybrid electro-optic processor

    NASA Astrophysics Data System (ADS)

    Welstead, Stephen T.; Ward, Michel J.

    1991-07-01

    This report describes the design of a hybrid electro-optic processor to perform adaptive interference cancellation in radar systems. The processor is designed to process wideband interference signals as well as multipath copies of these signals. The optical components in the processor include acousto-optic cells used as delay lines, a charge coupled device linear detector array, and a transmissive liquid crystal display spatial light modulator. The spatial light modulator is driven by an electronic microprocessor. A new way of achieving improved dynamic range for such a spatial light modulator is reported. Included in this report is a discussion of the design, partial fabrication in the laboratory, and partial testing of the hybrid electro-optic processor. A follow on effort is planned to complete the construction and testing of the processor. The work described in this report is the combined effort of RADC in-house project 4600P103 and Contract F30602-88-D-0027.

  15. Electro-optic network analyzer

    NASA Technical Reports Server (NTRS)

    Jackson, Todd A.

    1990-01-01

    The bandwidth of frequency domain measurement methods of electrical signals has usually been far greater than the bandwidth of time domain methods. The primary limits of the time domain approach have been the 20 to 30 GHz bandwidth limit for electronic waveform acquisition instrumentation, and the lack of usable electrical pulse generators for excitation of a test device. The bandwidth of frequency domain network analysis appears to have reached a plateau of between 100 to 200 GHz, while time domain measurement have improved markedly in both bandwidth and sensitivity with the introduction of the pulsed laser based electro-optic sampling approach. Network analysis or the measurement of device scattering parameters provides information necessary to the design of electronic network such as high frequency amplifiers, mixers, and phase shifter. The bandwidth of frequency domain network analysis is currently being exceeded by the next generations of high frequency transistors and devices. Thus the electro-optic approach is a natural means of extending network analysis into the range above 100 GHz by employing time domain methods. In this approach, a suitable electrical excitation pulse is generated and propagated along a transmission line toward a test device. In the picosecond domain, laser driven photoconductive switches provide a unique method of generating electrical transients. Several materials were studied for generating short electrical pulses using photoconductive switches. The various semiconductive materials tested for photoconductive switching, and the electro-optic measurement technique used to characterize the material performance are described.

  16. Advanced electro-optical imaging techniques. [conference papers on sensor technology applicable to Large Space Telescope program

    NASA Technical Reports Server (NTRS)

    Sobieski, S. (Editor); Wampler, E. J. (Editor)

    1973-01-01

    The papers presented at the symposium are given which deal with the present state of sensors, as may be applicable to the Large Space Telescope (LST) program. Several aspects of sensors are covered including a discussion of the properties of photocathodes and the operational imaging camera tubes.

  17. Advanced Electro-Optic Surety Devices

    SciTech Connect

    Watterson, C.E.

    1997-05-01

    The Advanced Electro-Optic Surety Devices project was initiated in march 1991 to support design laboratory guidance on electro-optic device packaging and evaluation. Sandia National Laboratory requested AlliedSignal Inc., Kansas City Division (KCD), to prepare for future packaging efforts in electro-optic integrated circuits. Los Alamos National Laboratory requested the evaluation of electro-optic waveguide devices for nuclear surety applications. New packaging techniques involving multiple fiber optic alignment and attachment, binary lens array development, silicon V-groove etching, and flip chip bonding were requested. Hermetic sealing of the electro-optic hybrid and submicron alignment of optical components present new challenges to be resolved. A 10-channel electro-optic modulator and laser amplifier were evaluated for potential surety applications.

  18. TRANSVERSE MODE ELECTRO-OPTIC MATERIALS.

    DTIC Science & Technology

    electro - optic modulators presently used are crystals such as KDP which exhibit a longitudinal electro - optic effect. It has been demonstrated that a more efficient modulator can be produced when a crystal having a transverse electro - optic effect is employed. Generally these crystals are produced either from the melt or from fluxes. Since melt grown crystals must be cooled through several hundred degrees and often must undergo phase transitions, these crystals are generally highly strained. Flux grown crystals are also

  19. Studies of the Electro-Optic Effect.

    DTIC Science & Technology

    1983-01-01

    electro - optic effect in crystalline solids has been pursued by employing a tight-binding theory for dielectric susceptibilities. The electronic and lattice contributions to the second-order electro - optic susceptibility have been treated separately and the lattice response of a crystal to an external dc electric field has been investigated in a general formalism. The theory has been specifically applied to the compound, tellurium dioxide. In addition, an experimental determination of the electro - optic coefficient, re, in thallium

  20. Electro-optic control of photographic imaging quality through ‘Smart Glass’ windows in optics demonstrations

    NASA Astrophysics Data System (ADS)

    Ozolinsh, Maris; Paulins, Paulis

    2017-09-01

    An experimental setup allowing the modeling of conditions in optical devices and in the eye at various degrees of scattering such as cataract pathology in human eyes is presented. The scattering in cells of polymer-dispersed liquid crystals (PDLCs) and ‘Smart Glass’ windows is used in the modeling experiments. Both applications are used as optical obstacles placed in different positions of the optical information flow pathway either directly on the stimuli demonstration computer screen or mounted directly after the image-formation lens of a digital camera. The degree of scattering is changed continuously by applying an AC voltage of up to 30-80 V to the PDLC cell. The setup uses a camera with 14 bit depth and a 24 mm focal length lens. Light-emitting diodes and diode-pumped solid-state lasers emitting radiation of different wavelengths are used as portable small-divergence light sources in the experiments. Image formation, optical system point spread function, modulation transfer functions, and system resolution limits are determined for such sample optical systems in student optics and optometry experimental exercises.

  1. Electro-Optic Modulator and Method

    DTIC Science & Technology

    An optical intensity modulator which uses a Sagnac interferometer having an electro - optic phase modulator therein. An electric modulation signal is...modulating the optical signals by the electrical signal, the electro - optic effect in the modulator phase shifts the optical signals with respect to one another

  2. Electro-Optic Identification (EOID) Research Program

    DTIC Science & Technology

    2001-09-30

    1 Electro - Optic Identification (EOID) Research Program Gene M. Cumm Northrop Grumman Oceanic and Naval Systems P.O. Box 1488 Annapolis...control number. 1. REPORT DATE 30 SEP 2001 2. REPORT TYPE 3. DATES COVERED 00-00-2001 to 00-00-2001 4. TITLE AND SUBTITLE Electro - Optic Identification

  3. Passive electro-optical projectiles tracker

    NASA Astrophysics Data System (ADS)

    Agurok, Ilya; Falicoff, Waqidi; Alvarez, Roberto; Shatford, Will

    2012-06-01

    Surveillance, detection, and tracking of multiple high-speed projectiles, particularly bullets, RPGs, and artillery shells, can help military forces immediately locate sources of enemy fire and trigger countermeasures. The traditional techniques for detection and tracing of fast moving objects typically employ various types of radar, which has inherently low resolution for such small objects. Fast moving projectiles are aerodynamically heated up to several hundred degree Kelvin temperatures depending on the speed of a projectile. Thereby, such projectiles radiate in the Mid- Infrared (MWIR) region, where electro-optical resolution is far superior, even to microwave radars. A new passive electro-optical tracker (or PET) uses a two-band IR intensity ratio to obtain a time-varying speed estimate from their time-varying temperatures. Based on an array of time-varying speed data and an array of azimuth/ elevation angles, PET can determines the 3D projectile trajectory and back track it to the source of fire. Various methods are given to determine the vector and range of a projectile, both for clear and for non-homogeneous atmospheric conditions. One approach uses the relative intensity of the image of the projectile on the pixels of a CCD camera to determine the azimuthal angle of trajectory with respect to the ground, and its range. Then by using directions to the tracked projectile (azimuth and elevation angles of the trajectory) and the array of instant projectile speeds, PET determines the distance to the projectile at any point on its tracked trajectory or its predicted trajectory backwards or forwards in time. A second approach uses a least-squares optimization technique over multiple frames based on a triangular representation of the smeared image to yield a real-time trajectory estimate. PET's estimated range accuracy is 0.2 m and the azimuth of the trajectory can be estimated within 0.2°.

  4. Electro-Optic Lighting Detector

    NASA Technical Reports Server (NTRS)

    Koshak, William J.; Solakiewicz, Richard J.

    1999-01-01

    The design, alignment, calibration, and field deployment of a solid-state lightning detector is described. The primary sensing component of the detector is a potassium dihydrogen phosphate electro-optic crystal that is attached in series to a flat-plate aluminum antenna; the antenna is exposed to the ambient thundercloud electric field. A semiconductor laser diode (lambda = 685 nm), polarizing optics, and the crystal are arranged in a Pockels cell configuration. Lightning-caused electric field changes are related to small changes in the transmission of laser light through the optical cell. Several hundred lightning electric field change excursions were recorded during five thunderstorms that occurred in the summer of 1998 at the NASA Marshall Space Flight Center in northern Alabama.

  5. Electro-optic modulator material

    DOEpatents

    Adams, John J.; Ebbers, Chris A.

    2005-02-22

    An electro-optic device for use with a laser beam. A crystal has a first face and a second face. Means are provided for applying a voltage across the crystal to obtain a net phase retardation on the polarization of the laser beam when the laser beam is passed through the crystal. In one embodiment the crystal is composed of a compound having the chemical formula ReAe40(BO3)3 where: RE consists of one or more of the following elements La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and two other elements Y and Sc; and where Ae is from the list of Ca, Sr, or Ba.

  6. Electro-Optic Lighting Detector

    NASA Technical Reports Server (NTRS)

    Koshak, William J.; Solakiewicz, Richard J.

    1999-01-01

    The design, alignment, calibration, and field deployment of a solid-state lightning detector is described. The primary sensing component of the detector is a potassium dihydrogen phosphate electro-optic crystal that is attached in series to a flat-plate aluminum antenna; the antenna is exposed to the ambient thundercloud electric field. A semiconductor laser diode (lambda = 685 nm), polarizing optics, and the crystal are arranged in a Pockels cell configuration. Lightning-caused electric field changes are related to small changes in the transmission of laser light through the optical cell. Several hundred lightning electric field change excursions were recorded during five thunderstorms that occurred in the summer of 1998 at the NASA Marshall Space Flight Center in northern Alabama.

  7. Electro-optic Lightning Detector

    NASA Technical Reports Server (NTRS)

    Koshak, William J.; Solakiewicz, Richard J.

    1996-01-01

    The design, alignment, calibration, and field deployment of a solid-state lightning detector is described. The primary sensing component of the detector is a potassium dihydrogen phosphate (KDP) electro-optic crystal that is attached in series to a flat plate aluminum antenna; the antenna is exposed to the ambient thundercloud electric field. A semiconductor laser diode (lambda = 685 nm), polarizing optics, and the crystal are arranged in a Pockels cell configuration. Lightning-caused electric field changes are related to small changes in the transmission of laser light through the optical cell. Several hundred lightning electric field change excursions were recorded during five thunderstorms that occurred in the summer of 1998 at the NASA Marshall Space Flight Center (MSFC) in northern Alabama.

  8. Fourier dimension of random images

    NASA Astrophysics Data System (ADS)

    Ekström, Fredrik

    2016-10-01

    Given a compact set of real numbers, a random C^{m + α}-diffeomorphism is constructed such that the image of any measure concentrated on the set and satisfying a certain condition involving a real number s, almost surely has Fourier dimension greater than or equal to s / (m + α). This is used to show that every Borel subset of the real numbers of Hausdorff dimension s is C^{m + α}-equivalent to a set of Fourier dimension greater than or equal to s / (m + α ). In particular every Borel set is diffeomorphic to a Salem set, and the Fourier dimension is not invariant under Cm-diffeomorphisms for any m.

  9. Bulk Electro-Optical Polymer Component

    NASA Technical Reports Server (NTRS)

    Gottsche, Allan; Perry, Joseph W.; Perry, Kelly J.

    1992-01-01

    Polymer serves in high-voltage sensors and laser-beam modulators. Electro-optical polymer of relatively low cost formed as bulk specimen from azo dye 4-(4-nitrophenylazo)-N-ethyl, N-2-hydroxyethylaniline, also known as Disperse Red 1 or DR1, and transparent epoxy. More stable than prior electro-optical polymers based on DR1 and poly(methylmethacrylate). If polymer were sandwiched between electrodes, it provides direct measurement of high voltage via electro-optical effect. Has significant nonlinear optical properties. Material useful in microelectronics, micro-optics, integrated optics, and testing of materials. Polymer withstands electric fields up to 120 kV/cm.

  10. Bulk Electro-Optical Polymer Component

    NASA Technical Reports Server (NTRS)

    Gottsche, Allan; Perry, Joseph W.; Perry, Kelly J.

    1992-01-01

    Polymer serves in high-voltage sensors and laser-beam modulators. Electro-optical polymer of relatively low cost formed as bulk specimen from azo dye 4-(4-nitrophenylazo)-N-ethyl, N-2-hydroxyethylaniline, also known as Disperse Red 1 or DR1, and transparent epoxy. More stable than prior electro-optical polymers based on DR1 and poly(methylmethacrylate). If polymer were sandwiched between electrodes, it provides direct measurement of high voltage via electro-optical effect. Has significant nonlinear optical properties. Material useful in microelectronics, micro-optics, integrated optics, and testing of materials. Polymer withstands electric fields up to 120 kV/cm.

  11. Electro-Optic Lightning Detector

    NASA Technical Reports Server (NTRS)

    Koshak, William J.; Solakiewica, R. J.

    1998-01-01

    Electric field measurements are fundamental to the study of thunderstorm electrification, thundercloud charge structure, and the determination of the locations and magnitudes of charges deposited by lightning. Continuous field observations can also be used to warn of impending electrical hazards. For example, the USAF Eastern Range (ER) and NASA Kennedy Space Center (KSC) in Florida currently operate a ground-based network of electric field mill sensors to warn against lightning hazards to space vehicle operations/launches. The sensors provide continuous recordings of the ambient field. Others investigators have employed flat-plate electric field antennas to detect changes In the ambient field due to lightning. In each approach, electronic circuitry is used to directly detect and amplify the effects of the ambient field on an exposed metal conductor (antenna plate); in the case of continuous field recordings, the antenna plate is alternately shielded and unshielded by a grounded conductor. In this work effort, an alternate optical method for detecting lightning-caused electric field changes is Introduced. The primary component in the detector is an anisotropic electro-optic crystal of potassium di-hydrogen phosphate (chemically written as KH2PO4 (KDP)). When a voltage Is placed across the electro-optic crystal, the refractive Indices of the crystal change. This change alters the polarization state of a laser light beam that is passed down the crystal optic axis. With suitable application of vertical and horizontal polarizers, a light transmission measurement is related to the applied crystal voltage (which in turn Is related to the lightning caused electric field change). During the past two years, all critical optical components were procured, assembled, and aligned. An optical housing, calibration set-up, and data acquisition system was integrated for breadboard testing. The sensor was deployed at NASA Marshall Space Flight Center (MSFC) in the summer of 1998 to

  12. Electro-Optic Lightning Detector

    NASA Technical Reports Server (NTRS)

    Koshak, William J.; Solakiewica, R. J.

    1998-01-01

    Electric field measurements are fundamental to the study of thunderstorm electrification, thundercloud charge structure, and the determination of the locations and magnitudes of charges deposited by lightning. Continuous field observations can also be used to warn of impending electrical hazards. For example, the USAF Eastern Range (ER) and NASA Kennedy Space Center (KSC) in Florida currently operate a ground-based network of electric field mill sensors to warn against lightning hazards to space vehicle operations/launches. The sensors provide continuous recordings of the ambient field. Others investigators have employed flat-plate electric field antennas to detect changes In the ambient field due to lightning. In each approach, electronic circuitry is used to directly detect and amplify the effects of the ambient field on an exposed metal conductor (antenna plate); in the case of continuous field recordings, the antenna plate is alternately shielded and unshielded by a grounded conductor. In this work effort, an alternate optical method for detecting lightning-caused electric field changes is Introduced. The primary component in the detector is an anisotropic electro-optic crystal of potassium di-hydrogen phosphate (chemically written as KH2PO4 (KDP)). When a voltage Is placed across the electro-optic crystal, the refractive Indices of the crystal change. This change alters the polarization state of a laser light beam that is passed down the crystal optic axis. With suitable application of vertical and horizontal polarizers, a light transmission measurement is related to the applied crystal voltage (which in turn Is related to the lightning caused electric field change). During the past two years, all critical optical components were procured, assembled, and aligned. An optical housing, calibration set-up, and data acquisition system was integrated for breadboard testing. The sensor was deployed at NASA Marshall Space Flight Center (MSFC) in the summer of 1998 to

  13. Electro-optic Waveguide Beam Deflector.

    DTIC Science & Technology

    beam deflection by variation in the electro - optic effect produced within the waveguide region in response to known or determinable magnitude variations in the electrical potential of an applied signal source.

  14. Electro-optic Q-switch

    NASA Technical Reports Server (NTRS)

    Zou, Yingyin (Inventor); Chen, Qiushui (Inventor); Zhang, Run (Inventor); Jiang, Hua (Inventor)

    2006-01-01

    An electro-optic Q-switch for generating sequence of laser pulses was disclosed. The Q-switch comprises a quadratic electro-optic material and is connected with an electronic unit generating a radio frequency wave with positive and negative pulses alternatively. The Q-switch is controlled by the radio frequency wave in such a way that laser pulse is generated when the radio frequency wave changes its polarity.

  15. Electro-Optic Identification (EOID) Research Program

    DTIC Science & Technology

    2002-09-30

    The goal of this research is to provide computer-assisted identification of underwater mines in electro - optic imagery. Identification algorithms will...greatly reduce the time and risk to reacquire mine-like-objects for positive classification and identification. The objectives are to collect electro ... optic data under a wide range of operating and environmental conditions and develop precise algorithms that can provide accurate target recognition on this data for all possible conditions.

  16. Electro-Optical Resonant Phase Modulator

    NASA Technical Reports Server (NTRS)

    Chen, Chien-Chung; Robinson, Deborah L.; Hemmati, Hamid

    1993-01-01

    Electro-optical phase modulator includes electro-optical crystal in resonant cavity suitable for use in transmitting digital data on laser beam at data rate of 10 MHz. Switching voltages applied to crystal, thereby switching cavity onto and off resonance, and large phase dispersion occurring near resonance provides output phase modulation. Driving voltages smaller than those of nonresonant modulators. Laser-damage thresholds of apparatus, incorporating bulk optics, inherently greater than modulators based on integrated optics.

  17. Electro-optic component mounting device

    DOEpatents

    Gruchalla, Michael E.

    1994-01-01

    A technique is provided for integrally mounting a device such as an electro-optic device (50) in a transmission line to avoid series resonant effects. A center conductor (52) of the transmission line has an aperture (58) formed therein for receiving the device (50). The aperture (58) splits the center conductor into two parallel sections on opposite sides of the device. For a waveguide application, the center conductor is surrounded by a conductive ground surface (54), which is spaced apart from the center conductor with a dielectric material (56). One set of electrodes formed on the surface of the electro-optic device (50) is directly connected to the center conductor 52 and an electrode formed on the surface of the electro-optic device is directly connected to the conductive ground surface (54). The electrodes formed on the surface of the electro-optic device are formed on curved sections of the surface of the device to mate with correspondingly shaped electrodes on the conductor and ground surface to provide a uniform electric field across the electro-optic device. The center conductor includes a passage ( 60) formed therein for passage of optical signals to an electro-optic device.

  18. Electro-optic component mounting device

    DOEpatents

    Gruchalla, M.E.

    1994-09-13

    A technique is provided for integrally mounting a device such as an electro-optic device in a transmission line to avoid series resonant effects. A center conductor of the transmission line has an aperture formed therein for receiving the device. The aperture splits the center conductor into two parallel sections on opposite sides of the device. For a waveguide application, the center conductor is surrounded by a conductive ground surface which is spaced apart from the center conductor with a dielectric material. One set of electrodes formed on the surface of the electro-optic device is directly connected to the center conductor and an electrode formed on the surface of the electro-optic device is directly connected to the conductive ground surface. The electrodes formed on the surface of the electro-optic device are formed on curved sections of the surface of the device to mate with correspondingly shaped electrodes on the conductor and ground surface to provide a uniform electric field across the electro-optic device. The center conductor includes a passage formed therein for passage of optical signals to an electro-optic device. 10 figs.

  19. Integrated Electro-optical Laser-Beam Scanners

    NASA Technical Reports Server (NTRS)

    Boord, Warren T.

    1990-01-01

    Scanners using solid-state devices compact, consume little power, and have no moving parts. Integrated electro-optical laser scanner, in conjunction with external lens, points outgoing beam of light in any number of different directions, depending on number of upper electrodes. Offers beam-deflection angles larger than those of acousto-optic scanners. Proposed for such diverse applications as nonimpact laser printing, color imaging, ranging, barcode reading, and robotic vision.

  20. Integrated Electro-optical Laser-Beam Scanners

    NASA Technical Reports Server (NTRS)

    Boord, Warren T.

    1990-01-01

    Scanners using solid-state devices compact, consume little power, and have no moving parts. Integrated electro-optical laser scanner, in conjunction with external lens, points outgoing beam of light in any number of different directions, depending on number of upper electrodes. Offers beam-deflection angles larger than those of acousto-optic scanners. Proposed for such diverse applications as nonimpact laser printing, color imaging, ranging, barcode reading, and robotic vision.

  1. Advanced electro-optical tracker/ranger

    NASA Astrophysics Data System (ADS)

    Bennett, R. A.; Defoe, D. N.

    1980-06-01

    The preliminary engineering design study of an Advanced Electro-Optical Tracker/Ranger (AEOTR) to provide passive target tracking and rangefinding for air to air gun fire control is described. Area correlation processing is used in the comparison of stereo image pairs for stereometric ranging and in the comparison of successive images for tracking. The application of these techniques to the AEOTR, the limitations imposed by packaging, environmental and state-of-the-art sensor and processing hardware constraints, and the projected performance are evaluated. Principal emphasis is given to the use of AEOTR in the gun director engagement mode in which target track and range data is provided to a gun fire control computer. The feasibility of use of the AEOTR to provide target video as an aid to visual target identification, and to provide automatic airborne target detection, is also evaluated. The necessary functions and subsystems are defined and integrated into a preliminary design, whose performance is estimated and compared with the program goals. In addition, a preliminary mounting location study for the F-15, F-16 and F-18 advanced fighters is included. CAI-built hardware was used to successfully demonstrate the feasibility of the ranging and tracking concepts employed in the AEOTR.

  2. Crosslinked polyimide electro-optic materials

    NASA Astrophysics Data System (ADS)

    Kowalczyk, T. C.; Kosc, T. Z.; Singer, K. D.; Beuhler, A. J.; Wargowski, D. A.; Cahill, P. A.; Seager, C. H.; Meinhardt, M. B.; Ermer, S.

    1995-11-01

    We report studies of the optical and electro-optic properties of guest-host polymeric nonlinear optical materials based on aromatic, fluorinated, fully imidized, organic soluble, thermally, and photochemically crosslinkable, guest-host polyimides. We have introduced temperature stable nonlinear optical chromophores into these polyimides and studied optical losses, electric field poling, electro-optic properties, and orientational stability. We measured electro-optic coefficients of 5.5 and 12.0 pm/V for ((2,6-Bis(2-(3-(9-(ethyl)carbazolyl))ethenyl)4H-pyran-4-ylidene)propanedinitrile (4-(Dicyanomethylene)-2-methyl-6-(p -dimethylaminostyryl)-4H-pyran) DCM-doped guest-host systems at 800 nm using a poling field of 1.3 MV/cm. Poling induced nonlinearities in single-layer films were in agreement with the oriented gas model, but were lower in three-layer films due to voltage division across the layers.

  3. Polarization Independent Electro-Optic Modulator

    NASA Technical Reports Server (NTRS)

    Yao, Xiao-Tian Steve (Inventor)

    1997-01-01

    A polarization insensitive electro-optic modulator is constructed by providing a polarization beamsplitter to separate an incoming light beam into two orthogonally plane polarized beams. Each of the polarized beams passes through a separate electro-optic modulator where each beam is modulated by the same data signal. After modulation the beams are combined to yield a modulated beam having modulated components that are orthogonally polarized. Not only is this device insensitive to changes in polarization of the input beam, the final modulated beam can be detected by optical receivers without regard to polarization alignment of the modulated beam and the receiver.

  4. Electro-Optic Generation and Detection of Femtosecond Electromagnetic Pulses

    DTIC Science & Technology

    1991-11-20

    electromagnetic pulses from an electro - optic crystal following their generation by electro - optic Cherenkov radiation, and their subsequent propagation and detection...in free space; (4) The measurement of subpicosecond electrical response of a new organic electrooptic material (polymer); (5) The observation of terahertz transition radiation from the surfaces of electro - optic crystals.

  5. Electro-Optic Data Acquisition and Processing.

    DTIC Science & Technology

    Methods for the analysis of electro - optic relaxation data are discussed. Emphasis is on numerical methods using high speed computers. A data acquisition system using a minicomputer for data manipulation is described. Relationship of the results obtained here to other possible uses is given. (Author)

  6. Electro-optic voltage sensor head

    DOEpatents

    Crawford, T.M.; Davidson, J.R.; Woods, G.K.

    1999-08-17

    The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers. 6 figs.

  7. Electro-optic voltage sensor head

    DOEpatents

    Crawford, Thomas M.; Davidson, James R.; Woods, Gregory K.

    1999-01-01

    The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers.

  8. Electro-Optic Beam Steering Using Domain Engineered Lithium Tantalate

    DTIC Science & Technology

    2005-03-01

    becomes (ne + ∆ne) d = ned + ∆ned. (6.1) where ∆ne is the electro- optically induced change in the index. Combining with Equation 2.32 ∆ned = ± 1 2 ...utilizing numerous electro-mechanical, acousto - optic and electro- optic steering mechanisms [3, 7, 14,15,17,18]. As a special motivation for this...angle electro- optic beam scanner,(b) Gradient type electro- optic beam scanner, (c)Prism type electro- optic beam scanner. 2 Additional attempts to

  9. Expected Energy Method for Electro-Optical SNR Calculations.

    DTIC Science & Technology

    1984-02-02

    r’AD-Ri39 984 EXPECTED ENERGY METHOD FOR ELECTPO-OPTICRL SNR i/i CALCULRTIONS(U) MASSRCHUSETTS INST OF TECH LEXINGTON LINCOLN LAB G J MAYER 82 FEB 84...ENERGY METHOD FOR ELECTRO-OPTICAL SNR CALCULATIONS * Ci. MA YER Group 9 TECHNICAL REPORT 634 2 FEBRUARY 1984 Approved for public release; distribution...analysis of image and sensor element configuration. This method allows the optimal pixel size to be selected to maximize the expected SNR for any point

  10. Differential operator approach for Fourier image processing.

    PubMed

    Núñez, Ismael; Ferrari, José A

    2007-08-01

    We present a differential operator approach for Fourier image processing. We demonstrate that when the mask in the processor Fourier plane is an analytical function, it can be described by means of a differential operator that acts directly on the input field to give the processed output image. In many cases (e.g., Schlieren imaging) this approach simplifies the calculations, which usually involve the evaluation of convolution integrals, and gives a new insight into the image-processing procedure.

  11. Rotational-translational fourier imaging system

    NASA Technical Reports Server (NTRS)

    Campbell, Jonathan W. (Inventor)

    2004-01-01

    This invention has the ability to create Fourier-based images with only two grid pairs. The two grid pairs are manipulated in a manner that allows (1) a first grid pair to provide multiple real components of the Fourier-based image and (2) a second grid pair to provide multiple imaginary components of the Fourier-based image. The novelty of this invention resides in the use of only two grid pairs to provide the same imaging information that has been traditionally collected with multiple grid pairs.

  12. Adaptive wiener image restoration kernel

    DOEpatents

    Yuan, Ding

    2007-06-05

    A method and device for restoration of electro-optical image data using an adaptive Wiener filter begins with constructing imaging system Optical Transfer Function, and the Fourier Transformations of the noise and the image. A spatial representation of the imaged object is restored by spatial convolution of the image using a Wiener restoration kernel.

  13. CoBOP: Electro-Optic Identification Laser Line Sean Sensors

    DTIC Science & Technology

    1998-01-01

    Electro - Optic Identification Sensors Project[1] is to develop and demonstrate high resolution underwater electro - optic (EO) imaging sensors, and associated image processing/analysis methods, for rapid visual identification of mines and mine-like contacts (MLCs). Identification of MLCs is a pressing Fleet need. During MCM operations, sonar contacts are classified as mine-like if they are sufficiently similar to signatures of mines. Each contact classified as mine-like must be identified as a mine or not a mine. During MCM operations in littoral areas,

  14. Strong Electro-Optic Effect and Spontaneous Domain Formation in Self-Assembled Peptide Structures.

    PubMed

    Gilboa, Barak; Lafargue, Clément; Handelman, Amir; Shimon, Linda J W; Rosenman, Gil; Zyss, Joseph; Ellenbogen, Tal

    2017-09-01

    Short peptides made from repeating units of phenylalanine self-assemble into a remarkable variety of micro- and nanostructures including tubes, tapes, spheres, and fibrils. These bio-organic structures are found to possess striking mechanical, electrical, and optical properties, which are rarely seen in organic materials, and are therefore shown useful for diverse applications including regenerative medicine, targeted drug delivery, and biocompatible fluorescent probes. Consequently, finding new optical properties in these materials can significantly advance their practical use, for example, by allowing new ways to visualize, manipulate, and utilize them in new, in vivo, sensing applications. Here, by leveraging a unique electro-optic phase microscopy technique, combined with traditional structural analysis, it is measured in di- and triphenylalanine peptide structures a surprisingly large electro-optic response of the same order as the best performing inorganic crystals. In addition, spontaneous domain formation is observed in triphenylalanine tapes, and the origin of their electro-optic activity is unveiled to be related to a porous triclinic structure, with extensive antiparallel beta-sheet arrangement. The strong electro-optic response of these porous peptide structures with the capability of hosting guest molecules opens the door to create new biocompatible, environmental friendly functional materials for electro-optic applications, including biomedical imaging, sensing, and optical manipulation.

  15. Long Range Electro-Optical Reconnaissance System

    DTIC Science & Technology

    1982-05-01

    of $100 000 under 22 usc9W Include this nistfce with any reproduced portion of this document. ~ MAR 20 0653 AVIONICS LABORATORY AIR FORCE WRLIGHT...Group Mission Avionics Division Mission Avionics Division Avionics Laboratory Avionics Laboratory FOR THE CO./A _DER GALE D. URSAN, Chief Electro-Optics...Branch Mission Avionics Division Avionics Laboratory If your address has changed, if you wish to be removed from our mailing list, or if the

  16. Nonintrusive electro-optic field sensor

    NASA Astrophysics Data System (ADS)

    Hales, Walter L.

    1990-08-01

    This invention utilizes the property of an electro-optic crystal which changes its index of refraction in the presence of electric field. Such a crystal is placed inside the resonant cavity of a Fabry-Perot type interferometer. Laser light travelling through the cavity and the crystal experiences modified optical path length in the presence of electric field. The fringe pattern at the focal plan is observed and used to detect and measures the ambient electric field.

  17. Crosslinked polyimide electro-optic materials

    SciTech Connect

    Kowalczyk, T.C.; Kosc, T.Z.; Singer, K.D.; Beuhler, A.J.; Wargowski, D.A.; Cahill, P.A.; Seager, C.H.; Meinhardt, M.B.; Ermer, S.

    1995-11-15

    We report studies of the optical and electro-optic properties of guest--host polymeric nonlinear optical materials based on aromatic, fluorinated, fully imidized, organic soluble, thermally, and photochemically crosslinkable, guest--host polyimides. We have introduced temperature stable nonlinear optical chromophores into these polyimides and studied optical losses, electric field poling, electro-optic properties, and orientational stability. We measured electro-optic coefficients of 5.5 and 12.0 pm/V for ((2,6-Bis(2-(3-(9-(ethyl)carbazolyl))ethenyl)4H-pyran-4-ylidene)propanedinitrile) (4-(Dicyanomethylene)-2-methyl-6-(p -dimethylaminostyryl)-4H-pyran) DCM-doped guest--host systems at 800 nm using a poling field of 1.3 MV/cm. Poling induced nonlinearities in single-layer films were in agreement with the oriented gas model, but were lower in three-layer films due to voltage division across the layers. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  18. Electro-optical voltage sensor head

    DOEpatents

    Woods, Gregory K.

    1998-01-01

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  19. Electro-optical voltage sensor head

    DOEpatents

    Woods, G.K.

    1998-03-24

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages is disclosed. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam`s polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured. 6 figs.

  20. Single-shot electro-optic sampling of coherent transition radiation at the A0 Photoinjector

    SciTech Connect

    Maxwell, T.J.; Ruan, J.; Piot, P.; Thurman-Keup, R.; /Fermilab

    2011-08-01

    Future collider applications and present high-gradient laser plasma wakefield accelerators operating with picosecond bunch durations place a higher demand on the time resolution of bunch distribution diagnostics. This demand has led to significant advancements in the field of electro-optic sampling over the past ten years. These methods allow the probing of diagnostic light such as coherent transition radiation or the bunch wakefields with sub-picosecond time resolution. Potential applications in shot-to-shot, non-interceptive diagnostics continue to be pursued for live beam monitoring of collider and pump-probe experiments. Related to our developing work with electro-optic imaging, we present results on single-shot electro-optic sampling of the coherent transition radiation from bunches generated at the A0 photoinjector.

  1. Nonlinear optical polymers for electro-optic signal processing

    NASA Technical Reports Server (NTRS)

    Lindsay, Geoffrey A.

    1991-01-01

    Photonics is an emerging technology, slated for rapid growth in communications systems, sensors, imagers, and computers. Its growth is driven by the need for speed, reliability, and low cost. New nonlinear polymeric materials will be a key technology in the new wave of photonics devices. Electron-conjubated polymeric materials offer large electro-optic figures of merit, ease of processing into films and fibers, ruggedness, low cost, and a plethora of design options. Several new broad classes of second-order nonlinear optical polymers were developed at the Navy's Michelson Laboratory at China Lake, California. Polar alignment in thin film waveguides was achieved by electric-field poling and Langmuir-Blodgett processing. Our polymers have high softening temperatures and good aging properties. While most of the films can be photobleached with ultraviolet (UV) light, some have excellent stability in the 500-1600 nm range, and UV stability in the 290-310 nm range. The optical nonlinear response of these polymers is subpicosecond. Electro-optic switches, frequency doublers, light modulators, and optical data storage media are some of the device applications anticipated for these polymers.

  2. Advances in automatic electro-optical tracking systems

    NASA Astrophysics Data System (ADS)

    Moy, Anthony J. E.; Hughes, Andrew D.

    1992-11-01

    British Aerospace (Systems & Equipment) Ltd (BASE) has been working in the field of automatic electro-optical tracking (Autotrack) systems for more than 12 years. BASE Autotrack systems carry out the automatic detection, tracking and classification of missiles and targets using image processing techniques operating on data received from electro-optical sensors. Typical systems also produce control data to move the sensor platform, enabling moving targets to be tracked accurately over a wide range of conditions. BASE Autotrack systems have been well proven in land, sea and air applications. This paper discusses the relevance of Autotrack systems to modern high-technology warfare and charts the progress of their development within BASE, both with respect to current products and active research programs. Two third generation BASE Autotrack systems are described, one of which provided a sophisticated air-to-ground tracking capability in the recent Gulf War. The latest Autotrack product is also described; this uses ASIC and Transputer technology to provide a high-performance, compact, missile and target tracker. Reference is also made to BASE's research work. Topics include an ASIC correlator, point target detection and, in particular, the use of neural networks for real-time target classification.

  3. Advances in automatic electro-optical tracking systems

    NASA Astrophysics Data System (ADS)

    Hughes, Andrew D.; Moy, Anthony J. E.

    1992-11-01

    British Aerospace (Systems & Equipment) Ltd (BASE) has been working in the field of automatic electro-optical tracking (Autotrack) systems for more than 12 years. BASE Autotrack systems carry out the automatic detection, tracking and classification of missiles and targets using image processing techniques operating on data received from electro-optical sensors. Typical systems also produce control data to move the sensor platform, enabling moving targets to be tracked accurately over a wide range of conditions. BASE Autotrack systems have been well proven in land, sea and air applications. This paper discusses the relevance of Autotrack systems to modern high-technology warfare and charts the progress of their development with BASE, both with respect to current products and active research programs. Two third generation BASE Autotrack systems are described, one of which provided a sophisticated air-to-ground tracking capability in the recent Gulf War. The latest Autotrack product is also described; this uses ASIC and Transputer technology to provide a high-performance, compact, missile and target tracker. Reference is also made to BASE's research work. Topics include an ASIC correlator, point target detection and, in particular, the use of neural networks for real-time target classification.

  4. Advanced Organic Electro-Optic Materials for Integrated Device Applications

    DTIC Science & Technology

    2001-06-01

    Electro - optic chromophores (FTC and CLD) were synthesized in bulk (kilogram) quantities and were distributed to the participants of this program...to stabilize electro - optic activity for operation at elevated temperatures and photon flux levels. Over 100 variants of these chromophores were...1.5-2.0 improvement over FTC and CLD chromophores in terms of electro - optic activity at telecommunication wavelengths. They also have proven more

  5. Processing and Fusion of Electro-Optic Information

    DTIC Science & Technology

    2001-04-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP010886 TITLE: Processing and Fusion of Electro - Optic Information...component part numbers comprise the compilation report: ADP010865 thru ADP010894 UNCLASSIFIED 21-1 Processing and Fusion of Electro - Optic Information I...additional electro - optic (EO) sensor model within OOPSDG. It describes TM IT TT T T T performance estimates found prior to producing the New Ne- New

  6. Wave-Coupled Millimeter-Wave Electro-Optic Techniques

    DTIC Science & Technology

    2001-03-01

    This report details results on two antenna-coupled millimeter-wave electro - optic modulators, the slot-vee antenna-coupled modulator and a 94 GHz...study of the effects of velocity mismatch on linearized electro - optic modulators was made and the results published. A key result was that directional...drift in electro - optic modulators was made and protons were determined to be the cause. Several inventions were made to reduce or eliminate proton-caused bias drift.

  7. Electro-optical properties of Rydberg excitons

    NASA Astrophysics Data System (ADS)

    Zielińska-Raczyńska, Sylwia; Ziemkiewicz, David; Czajkowski, Gerard

    2016-07-01

    We show how to compute the electro-optical functions (absorption, reflection, and transmission) when Rydberg exciton-polaritons appear, including the effect of the coherence between the electron-hole pair and the electromagnetic field. With the use of the real density matrix approach, numerical calculations applied for the Cu2O crystal are performed. We also examine in detail and explain the dependence of the resonance displacement on the state number and applied electric field strength. We report a fairly good agreement with recently published experimental data.

  8. A Spherical Electro Optic High Voltage Sensor

    DTIC Science & Technology

    1989-06-01

    electro - optic (EO) crystal is introduced for photonic measurement of pulsed high-voltage fields. A spherical shape is used in order to reduce electric field gradients in the vicinity of the sensor. The sensor is pure dielectric and is interrogated remotely using a laser. The sensor does not require the connection of any conducting components, which results in the highest electrical isolation. The spherical nature of the crystal coupled with the incident laser beam, and crossed polarizers (intensity modulation scheme). automatically produces interference figures. The

  9. Electro-Optic Analog/Digital Converter.

    DTIC Science & Technology

    electro - optic material and a source of linearly polarized light is arranged to transmit its light energy along each of the optical waveguides. Electrodes are disposed contiguous to the optical waveguides for impressing electric fields thereacross. An input signal potential is applied to the electrodes to produce electric fields of intensity relative to each of the waveguides such that causes phase shift and resultant change of polarization which can be detected as representative of a binary ’one’ or binary ’zero’ for each of the channel optical

  10. Optimization of electro-optic phase shifters for integrated optical phased arrays

    NASA Astrophysics Data System (ADS)

    Macik, Dwayne D.; Bravo, Tyler E.; Pentecost, Seeley M.; Espinal, Francisco A.; Madsen, Christi K.

    2017-05-01

    A low-loss, high-speed optical phased array (OPA) has been designed and fabricated. Two different platforms have been utilized in combination to leverage electro-optic (EO) tuning. A lithium niobate (LiNbO3) optical phased array was fabricated and used in conjunction with a silicon nitride (Si3N4) 8x8 waveguide array that condenses the output pitch and utilizes the TriplexTM waveguide technology. This OPA allows for the non-mechanical beam steering (NMBS) of 1550 nm light on an edge coupled optic platform and takes advantage of the high electro-optic coefficient and high speed capability of LiNbO3 for electro-optic phase tuning. This coupled OPA has an overall insertion loss of 3.5 dB which is advantageous to silicon-on-insulator OPAs that have shown overall insertion losses of 14 dB. To characterize and tune this device, a 3 lens imaging system was employed to produce both near- and far- field intensity patterns of the output of the OPA on a static image plane. At the image plane, a high resolution infrared camera was used to observe the resulting intensity pattern. The control software for tuning the OPA reads the intensity incident at a specified position on the detector array, and has a PWM interface to drive the electro-optic phase controls. Beam steering was accomplished using an iterative tuning algorithm.

  11. Electro-Optic Beam Steering Using Non-Linear Organic Materials

    DTIC Science & Technology

    1993-08-01

    York (SUNY), Buffalo, for potential application to the Hughes electro - optic beam deflector device. Evaluations include electro - optic coefficient...response time, transmission, and resistivity. Electro - optic coefficient measurements were made at 633 nm using a simple reflection technique. The

  12. Electro-optics and lasers in Israel

    NASA Astrophysics Data System (ADS)

    Van Zwaren, Joesph

    1992-05-01

    With over 3,000 scientists, engineers, and technicians spread out in some 86 companies, and in 10 universities and research institutes, all within less than a 2 hour drive from one another, Israel has no doubt one of the largest concentrations of researchers and skilled manpower in electro-optics and lasers in the world. This report presents an up-to-date picture of the field in Israel, covering the industry, academia and education. The recent wave of Russian immigration is bringing thousands of scientists and tens of thousands of engineers and is expected to make an impact on the field of electro-optics and lasers. A million immigrants from Russia are expected to come between 1990 and 1995. There were 3,700 scientists and 2,800 engineers among the first 200,000 Soviet immigrants. As most of this qualified manpower can not be expected to be absorbed by the existing industry, the Israeli government is actively encouraging local and foreign investors and local and multinational companies to help develop new and expanded high-tech enterprises in Israel. The Ministry of Industry and Trade has embarked upon a broad ranged program for industrial growth and immigrant absorption with the goal of doubling technology-based exports in the next four years. The Ministry of Science and Technology has started a program supporting R&D projects at the different universities for immigrant scientists with the goal of capitalizing on the talents of the newcomers to strengthen academia.

  13. Poling of Microwave Electro-Optic Devices

    NASA Technical Reports Server (NTRS)

    Singer, Kenneth D.

    1997-01-01

    The desire to transmit high frequency, microwave RF signals over fiber optic cables has necessitated the need for electro-optic modulation devices. However, in order to reap these potential benefits, it is necessary to develop the devices and their associated fabrication processes, particularly those processes associated with the poling of the devices. To this end, we entered into a cooperative research agreement with Richard Kunath of NASA LeRC. A graduate student in my group, Tony Kowalczyk, worked closely with the group at NASA to develop processes for construction of a microwave frequency electro-optic modulator. Materials were commercially obtained from Amoco Chemical and in collaboration with Lockheed-Martin. The photolithography processes were developed at NASA LeRC and the electric-field poling process was carried out in our laboratory at CWRU. During the grant period, the poling process conditions were investigated for these multilayer devices. Samples were poled and the resulting nonlinear optical properties were evaluated in our laboratory. Following the grant period, Kowalczyk went to NASA under a NRC fellowship, and I continued to collaborate as a consultant. Publications listed at the end of this report came out of this work. Another manuscript is in preparation and will be submitted shortly.

  14. Electro-optic resonant phase modulator

    NASA Technical Reports Server (NTRS)

    Chen, Chien-Chung (Inventor); Hemmati, Hamid (Inventor); Robinson, Deborah L. (Inventor)

    1992-01-01

    An electro-optic resonant cavity is used to achieve phase modulation with lower driving voltages. Laser damage thresholds are inherently higher than with previously used integrated optics due to the utilization of bulk optics. Phase modulation is achieved at higher speeds with lower driving voltages than previously obtained with non-resonant electro-optic phase modulators. The instant scheme uses a data locking dither approach as opposed to the conventional sinusoidal locking schemes. In accordance with a disclosed embodiment, a resonant cavity modulator has been designed to operate at a data rate in excess of 100 megabits per sec. By carefully choosing the cavity finesse and its dimension, it is possible to control the pulse switching time to within 4 nano-sec. and to limit the required switching voltage to within 10 V. This cavity locking scheme can be applied by using only the random data sequence, and without the need of dithering of the cavity. Compared to waveguide modulators, the resonant cavity has a comparable modulating voltage requirement. Because of its bulk geometry, the resonant cavity modulator has the potential of accommodating higher throughput power. Mode matching into the bulk device is easier and typically can be achieved with higher efficiency. An additional control loop is incorporated into the modulator to maintain the cavity on resonance.

  15. Electro-optic Phase Grating Streak Spectrometer

    SciTech Connect

    Goldin, F. J.

    2012-08-02

    The electro-optic phase grating streak spectrometer (EOPGSS) generates a time-resolved spectra equivalent to that obtained with a conventional spectrometer/streak camera combination, but without using a streak camera (by far the more expensive and problematic component of the conventional system). The EOPGSS is based on a phase, rather than an amplitude grating. Further, this grating is fabricated of electro-optic material such as, for example, KD*P, by either etching grooves into an E-O slab, or by depositing lines of the E-O material onto an optical flat. An electric field normal to the grating alters the material’s index of refraction and thus affects a shift (in angle) of the output spectrum. Ramping the voltage streaks the spectrum correspondingly. The streak and dispersion directions are the same, so a second (static, conventional) grating disperses the spectrum in the orthogonal direction to prevent different wavelengths from “overwriting” each other. Because the streaking is done by the grating, the streaked output spectrum is recorded with a time-integrating device, such as a CCD. System model, typical design, and performance expectations will be presented.

  16. Electro-optic Charon polymeric microring modulators.

    PubMed

    Rezzonico, Daniele; Jazbinsek, Mojca; Guarino, Andrea; Kwon, O-Pil; Günter, Peter

    2008-01-21

    We propose and demonstrate a new type of electro-optic polymeric microring resonators, where the shape of the transmission spectrum is controlled by losses and phase shifts induced at the asymmetric directional coupler between the cavity and the bus waveguide. The theoretical analysis of such Charon microresonators shows, depending on the coupler design, three different transmission characteristics: normal Lorentzian dips, asymmetric Fano resonances, and Lorentzian peaks. The combination of the active azo-stilbene based polyimide SANDM2 surrounded by the hybrid polymer Ormocomp allowed the first experimental demonstration of electro-optic modulation in Charon microresonators. The low-loss modulators (down to 0.6 dB per round trip), with a radius of 50 microm, were produced by micro-embossing and exhibit either highly asymmetric and steep Fano resonances with large 43-GHz modulation bandwidth or strong resonances with 11-dB extinction ratio. We show that Charon microresonators can lead to 1-V half wave voltage all-polymer micrometer-scale devices with larger tolerances to coupler fabrication limitations and wider modulation bandwidths than classical ring resonators.

  17. Electro-Optical System Simulation and Performance Prediction Extensions to EODES

    DTIC Science & Technology

    2010-01-01

    performed a preliminary validation of the Streak Tube Imaging Lidar (STIL) model using data from an August 2001 field test of electro-optical imaging...situations. It was also determined that the long fall time (see Fig. 2) of the proposed photodetector did adversely impact image quality. These... Lidar (STIL) sensor showed good agreement between EODES simulations and actual sensor imagery. In addition, the image quality predicted by EODES

  18. Electro-optical Probing Of Terahertz Integrated Circuits

    NASA Technical Reports Server (NTRS)

    Bhasin, K. B.; Romanofsky, R.; Whitaker, J. F.; Valdmanis, J. A.; Mourou, G.; Jackson, T. A.

    1990-01-01

    Electro-optical probe developed to perform noncontact, nondestructive, and relatively noninvasive measurements of electric fields over broad spectrum at millimeter and shorter wavelengths in integrated circuits. Manipulated with conventional intregrated-circuit-wafer-probing equipment and operated without any special preparation of integrated circuits. Tip of probe small electro-optical crystal serving as proximity electric-field sensor.

  19. Electro-Optical Laser Technology. Curriculum Utilization. Final Report.

    ERIC Educational Resources Information Center

    Nawn, John H.

    This report describes a program to prepare students for employment as laser technicians and laser operators and to ensure that they have the necessary skills required by the industry. The objectives are to prepare a curriculum and syllabus for an associate degree program in Electro-Optical Laser Technology. The 2-year Electro-Optical Laser program…

  20. Maximum Likelihood Detection of Electro-Optic Moving Targets

    DTIC Science & Technology

    1992-01-16

    The description of a maximum likelihood algorithm to detect moving targets in electro - optic data is presented. The algorithm is based on processing...optimum algorithm to determine the performance loss. A processing architecture concept is also described. Electro - optic sensor, detection, infrared sensor, moving target, binary integration, velocity filter.

  1. New Light Sources and Concepts for Electro-Optic Sampling

    DTIC Science & Technology

    1994-03-01

    Research to improve electro - optic sampling led to the development of several high performance optical phase modulators. These phase modulators serve...method of optical pulse shape measurement was demonstrated with 3 ps time resolution, excellent power sensitivity and relative system simplicity. These experiments have opened up the field of temporal optics. Electro - optic sampling.

  2. Electro-optic device with gap-coupled electrode

    SciTech Connect

    Deri, Robert J.; Rhodes, Mark A.; Bayramian, Andrew J.; Caird, John A.; Henesian, Mark A.; Ebbers, Christopher A.

    2013-08-20

    An electro-optic device includes an electro-optic crystal having a predetermined thickness, a first face and a second face. The electro-optic device also includes a first electrode substrate disposed opposing the first face. The first electrode substrate includes a first substrate material having a first thickness and a first electrode coating coupled to the first substrate material. The electro-optic device further includes a second electrode substrate disposed opposing the second face. The second electrode substrate includes a second substrate material having a second thickness and a second electrode coating coupled to the second substrate material. The electro-optic device additionally includes a voltage source electrically coupled to the first electrode coating and the second electrode coating.

  3. TOD characterization of the Gatekeeper electro-optical security system

    NASA Astrophysics Data System (ADS)

    Gosselink, Guido; Anbeek, Hugo; Bijl, Piet; Hogervorst, Maarten A.

    2013-06-01

    The Triangle Orientation Discrimination (TOD) test method was applied to characterize thermal and visual range performance of the Gatekeeper Electro Optical Security System. Gatekeeper developed by Thales Nederland BV, is currently in use with the Royal Netherlands Navy. The system houses uncooled infrared and colour TV cameras providing up to 360° view in azimuth. The images displayed to the operator are automatically optimized based on the scene intensity distribution. Because of this built-in scene-based optimization, proper measurement of the system requires careful surround illumination of the TOD setup over a large part of the camera Field Of View. The tests provided very accurate threshold estimates with relatively small observer differences. The resulting TOD curves that characterize the sensor system in terms of acuity and contrast sensitivity can be used as input to a Target Acquisition model to predict range performance for operational scenarios.

  4. Optical analysis of electro-optical systems by MTF calculus

    NASA Astrophysics Data System (ADS)

    Barbarini, Elisa Signoreto; Dos Santos, Daniel, Jr.; Stefani, Mário Antonio; Yasuoka, Fátima Maria Mitsue; Castro Neto, Jarbas C.; Rodrigues, Evandro Luís Linhari

    2011-08-01

    One of the widely used methods for performance analysis of an optical system is the determination of the Modulation Transfer Function (MTF). The MTF represents a quantitative and direct measure of image quality, and, besides being an objective test, it can be used on concatenated optical system. This paper presents the application of software called SMTF (software modulation transfer function), built in C++ and Open CV platforms for MTF calculation on electro-optical system. Through this technique, it is possible to develop specific method to measure the real time performance of a digital fundus camera, an infrared sensor and an ophthalmological surgery microscope. Each optical instrument mentioned has a particular device to measure the MTF response, which is being developed. Then the MTF information assists the analysis of the optical system alignment, and also defines its resolution limit by the MTF graphic. The result obtained from the implemented software is compared with the theoretical MTF curve from the analyzed systems.

  5. Electro optical system to measure strains at high temperature

    NASA Technical Reports Server (NTRS)

    Sciammarella, Cesar A.

    1991-01-01

    The goals of this proposal were to develop a prototype of an electro-optics system for the measurement of strains in structures at high temperatures and to perform a test under field conditions. In the research task section, the topics addressed include: (1) correction of the effect of vibrations and thermal currents by means of an active compensation system; (2) reduction of the speckle noise by means of electronic filter and TV signal reconstruction circuit; (4) compensation of the rigid body motions by mounting the camera in a universal motion system; and (5) removal of phase errors left by the active compensation system by dynamic reading. In the design and construction section, the topics addressed include: (1) preliminary design; (2) final design; (3) software development; (4) signal conditioning; (5) data processing; (6) recorrelation of two holograms in the presence of rigid body motions; and (7) phase extraction using a computer generated image. Testing in the high temperature oven is also addressed.

  6. Electro-optic and radiation damage performance of the CIS115, an imaging sensor for the JANUS optical camera onboard JUICE

    NASA Astrophysics Data System (ADS)

    Soman, M. R.; Allanwood, E. A. H.; Holland, A. D.; Stefanov, K.; Pratlong, J.; Leese, M.; Gow, J. P. D.; Smith, D. R.

    2016-08-01

    The Jupiter Icy Moon Explorer (JUICE) has been officially adopted as the next Large class mission by the European Space Agency, with a launch date of 2022. The science payload includes an optical camera, JANUS, which will perform imaging and mapping observations of Jupiter, its moons and icy rings. A 13 slot filter wheel will be used to provide spectral information in order for the JANUS experiment to study the geology and physical properties of Ganymede, Europa and Io, and to investigate processes and structures in the atmosphere of Jupiter. The sensor selected for JANUS is the back-thinned CIS115, a 3 MPixel CMOS Image Sensor from e2v technologies. The CIS115 has a 4-Transistor pixel design with a pinned photodiode to improve signal to noise performance by reducing dark current and allowing for reset level subtraction. The JUICE mission will consist of an 8 year cruise phase followed by a 3 year science phase in the Jovian system. Models of the radiation environment throughout the JUICE mission predict that the End of Life (EOL) non-ionising damage will be equivalent to 1010 protons cm-2 (10 MeV) and the EOL ionising dose will be 100 krad(Si), once the shielding from the spacecraft and instrument design is taken into account. An extensive radiation campaign is therefore being carried out to qualify and characterise the CIS115 for JANUS, as well as other space and terrestrial applications. Radiation testing to take the CIS115 to twice the ionising dose and displacement damage levels was completed in 2015 and the change in sensor performance has been characterised. Good sensor performance has been observed following irradiation and a summary of the key results from the campaign using gamma irradiation (ionising dose) will be presented here, including its soft X-ray detection capabilities, flat-band voltage shift and readout noise. In 2016, further radiation campaigns on flight-representative CIS115s will be undertaken and their results will be disseminated in

  7. Conoscopic polarized interference applied in measuring uniaxial axis direction of electro-optic crystal

    NASA Astrophysics Data System (ADS)

    Liu, Yong; Jiang, Hongzhen; Zhang, Lin; Li, Dong; Liu, Xu; Zheng, Fanglan

    2016-10-01

    The crystal can be used to be electro-optic switch because of its electro-optic modulation. Generally the uniaxial axis of electro-optic crystal is perpendicular to the light injection surface. Due to the manufacturing precision, the uniaxial axis direction has a little angle with the normal of the light injection surface, which affects the electro-optic modulation ability. In conoscopic polarized inference, due to birefraction the ordinary ray and extraordinary ray from crystal interferes after the polarizer. The interference pattern of crystal component is circle fringes with dark cross. The center of interference pattern has relation to the uniaxial axis direction. Using digital camera to capture the pattern and the center position of interferogram can be determinate by image processing program. In repeatability experiments the rms of center position is around 1 pixel. To measure the uniaxial axis direction, the normal direction of the crystal component should also be accurately determinate. Michelson interference method is introduced to determinate the normal direction. If rotate the crystal component around the normal direction in conoscopic polarized interference, the track of interferogram center is a circle theoretically. The circle center is related to the normal direction of crystal component, and the radii is related to the angle uniaxial axis, which can be determinate by least square fitting method. Experiment result shows that the measuring precision can achieves several tens of microradians.

  8. Night Vision and Electro-Optics Technology Transfer, 1972-1981

    DTIC Science & Technology

    1981-09-15

    Figure 3 Image Intensifier (3-Stage) ............................................ 6 Figure 4 Advanced Image Intensifier with Microchannel Plate ...report, "Night Vision and Electro-Optics Technology Transfer 1972-1981," is threefold: To illustrate, through actual case histories , the potential for...screen as did the earlier devices; however, amplification of the image is achieved through the use of a single micro-channel plate (MCP). I1

  9. Fourier analysis: from cloaking to imaging

    NASA Astrophysics Data System (ADS)

    Wu, Kedi; Cheng, Qiluan; Wang, Guo Ping

    2016-04-01

    Regarding invisibility cloaks as an optical imaging system, we present a Fourier approach to analytically unify both Pendry cloaks and complementary media-based invisibility cloaks into one kind of cloak. By synthesizing different transfer functions, we can construct different devices to realize a series of interesting functions such as hiding objects (events), creating illusions, and performing perfect imaging. In this article, we give a brief review on recent works of applying Fourier approach to analysis invisibility cloaks and optical imaging through scattering layers. We show that, to construct devices to conceal an object, no constructive materials with extreme properties are required, making most, if not all, of the above functions realizable by using naturally occurring materials. As instances, we experimentally verify a method of directionally hiding distant objects and create illusions by using all-dielectric materials, and further demonstrate a non-invasive method of imaging objects completely hidden by scattering layers.

  10. Electro-optic high voltage sensor

    DOEpatents

    Davidson, James R.; Seifert, Gary D.

    2003-09-16

    A small sized electro-optic voltage sensor capable of accurate measurement of high voltages without contact with a conductor or voltage source is provided. When placed in the presence of an electric field, the sensor receives an input beam of electromagnetic radiation. A polarization beam displacer separates the input beam into two beams with orthogonal linear polarizations and causes one linearly polarized beam to impinge a crystal at a desired angle independent of temperature. The Pockels effect elliptically polarizes the beam as it travels through the crystal. A reflector redirects the beam back through the crystal and the beam displacer. On the return path, the polarization beam displacer separates the elliptically polarized beam into two output beams of orthogonal linear polarization. The system may include a detector for converting the output beams into electrical signals and a signal processor for determining the voltage based on an analysis of the output beams.

  11. Electro-optical tunable birefringent filter

    SciTech Connect

    Levinton, Fred M

    2012-01-31

    An electrically tunable Lyot type filter is a Lyot that include one or more filter elements. Each filter element may have a planar, solid crystal comprised of a material that exhibits birefringence and is electro-optically active. Transparent electrodes may be coated on each face of the crystal. An input linear light polarizer may be located on one side of the crystal and oriented at 45 degrees to the optical axis of the birefringent crystal. An output linear light polarizer may be located on the other side of the crystal and oriented at -45 degrees with respect to the optical axis of the birefringent crystal. When an electric voltage is applied between the electrodes, the retardation of the crystal changes and so does the spectral transmission of the optical filter.

  12. Passive electro optical materials and applications

    NASA Astrophysics Data System (ADS)

    Diekstall, K.; Gutu-Nelle, A.; Lauckner, J.; Lutz, F.; Mueller, S.; Seibold, G.; Schichl, H.; Volz, H.

    1980-12-01

    Electro-optical ceramics made of lead/lanthanum/zirconates/titanates (PLZT) can be economically manufactured by coprecipitation of the base materials and by vacuum sintering of the sintering of the green blocks. Magnesium additives reduce by half the operating voltage required to achieve an equal contrast ratio. Transparent electrodes deposited by sputtering tin-indium oxide remain transparent up to 2400 nm. The contrast ratio in the scattering mode amounts typically to 100 : 1 at 500 nm and 5 : 1 at 1000 nm, while in the birefrigence mode it amounts typically to 10,000 : 1 at 800 V/mm, at a thickness of 0.4 mm. Functional blocks were designed to demonstrate and test applications: a laser modular; a light intensity attenuator; welding protection goggles; and numerical displays. The first promising results with sputtered thin films indicate future suitability for displays. Multiple light modulators for opto-electronic nonimpact printing presently appear to be the most important application area.

  13. Characterization of crosslinked electro-optic polyimides

    NASA Astrophysics Data System (ADS)

    Meinhardt, Michael B.; Cahill, Paul A.; Seager, Carl H.; Beuhler, Allyson J.; Wargowski, David A.; Singer, Kenneth D.; Kowalczyk, Tony C.; Kosc, Tanya Z.; Ermer, Susan P.

    1994-05-01

    The electro-optical properties of UltradelR 9000D polyimides doped with DCM and DADC, a bis(carbazole) analog of DCM with improved thermal stability, are reported. Cure temperatures were restricted to 240 degree(s)C or less to minimize potential thermal degradation of these dyes. Low poling fields of 30 V/micrometers were used in these experiments and yielded r13 coefficients in the 0.1 - 0.8 pm/V range. Photothermal deflection measurements of dye-doped Ultradel 9000D samples showed low optical absorption losses in systems cured at 175 degree(s)C, but losses exceeded 20 dB/cm in samples cured at 300 degree(s)C.

  14. Electro-optical hybrid slip ring

    NASA Astrophysics Data System (ADS)

    Hong, En

    2005-11-01

    The slip ring is a rotary electrical interface, collector, swivel or rotary joint. It is a physical system that can perform continuous data transfer and data exchange between a stationary and a rotating structure. A slip ring is generally used to transfer data or power from an unrestrained, continuously rotating electro-mechanical system in real-time, thereby simplifying operations and eliminating damage-prone wires dangling from moving joints. Slip rings are widely used for testing, evaluating, developing and improving various technical equipment and facilities with rotating parts. They are widely used in industry, especially in manufacturing industries employing turbo machinery, as in aviation, shipbuilding, aerospace, defense, and in precise facilities having rotating parts such as medical Computerized Tomography (CT) and MRI scanners and so forth. Therefore, any improvement in slip ring technology can impact large markets. Research and development in this field will have broad prospects long into the future. The goal in developing the current slip ring technology is to improve and increase the reliability, stability, anti-interference, and high data fidelity between rotating and stationary structures. Up to now, there have been numerous approaches used for signal and data transfer utilizing a slip ring such as metal contacts, wires, radio transmission, and even liquid media. However, all suffer from drawbacks such as data transfer speed limitations, reliability, stability, electro-magnetic interference and durability. The purpose of the current research is to break through these basic limitations using an optical solution, thereby improving performance in current slip ring applications. This dissertation introduces a novel Electro-Optical Hybrid Slip Ring technology, which makes "through the air" digital-optical communication between stationary and rotating systems a reality with high data transfer speed, better reliability and low interference susceptibility

  15. Electro-optic high voltage sensor

    DOEpatents

    Davidson, James R.; Seifert, Gary D.

    2002-01-01

    A small sized electro-optic voltage sensor capable of accurate measurement of high levels of voltages without contact with a conductor or voltage source is provided. When placed in the presence of an electric field, the sensor receives an input beam of electromagnetic radiation into the sensor. A polarization beam displacer serves as a filter to separate the input beam into two beams with orthogonal linear polarizations. The beam displacer is oriented in such a way as to rotate the linearly polarized beams such that they enter a Pockels crystal having at a preferred angle of 45 degrees. The beam displacer is therefore capable of causing a linearly polarized beam to impinge a crystal at a desired angle independent of temperature. The Pockels electro-optic effect induces a differential phase shift on the major and minor axes of the input beam as it travels through the Pockels crystal, which causes the input beam to be elliptically polarized. A reflecting prism redirects the beam back through the crystal and the beam displacer. On the return path, the polarization beam displacer separates the elliptically polarized beam into two output beams of orthogonal linear polarization representing the major and minor axes. The system may include a detector for converting the output beams into electrical signals, and a signal processor for determining the voltage based on an analysis of the output beams. The output beams are amplitude modulated by the frequency of the electric field and the amplitude of the output beams is proportional to the magnitude of the electric field, which is related to the voltage being measured.

  16. A method to Fourier filter textured images

    SciTech Connect

    Hoffman, David K.; Gunaratne, Gemunu H.; Zhang, D. S.; Kouri, Donald J.

    2000-03-01

    An algorithm is introduced to extract an underlying image from a class of textures. It is assumed that the image is bandwidth limited and the noise is broad-band. The initial step of the algorithm extends the signal to a larger periodic image using ''Distributed Approximating Functionals.'' The second step introduces a low-pass filter which allows the identification and elimination of the high-frequency components of the noise. The periodicity of the resulting image allows it to be Fourier filtered without aliasing. The feasibility of the algorithm is demonstrated on several noisy patterns generated in experiments and model systems. (c) 2000 American Institute of Physics.

  17. Fourier Plane Image Combination by Feathering

    NASA Astrophysics Data System (ADS)

    Cotton, W. D.

    2017-09-01

    Astronomical objects frequently exhibit structure over a wide range of scales whereas many telescopes, especially interferometer arrays, only sample a limited range of spatial scales. To properly image these objects, images from a set of instruments covering the range of scales may be needed. These images then must be combined in a manner to recover all spatial scales. This paper describes the feathering technique for image combination in the Fourier transform plane. Implementations in several packages are discussed and example combinations of single dish and interferometric observations of both simulated and celestial radio emission are given.

  18. Photoinduced electro-optics measurements of biosilica transformation to cristobalite

    SciTech Connect

    Fuchs, Ido; Aluma, Yaniv; Ilan, Micha; Kityk, Iwan; Mastai, Yitzhak

    2015-03-15

    In this paper we studied the photoinduced electro optics effects in the thermal transformation process of biosilica to cristobalite, at a relatively low temperature and ambient pressure. This process was characterized by a variety of standards techniques with emphasis on linear electro optic effect measurements. Overall we demonstrated that photoinduced electro optics measurements are very sensitive to the transformation from amorphous structure of silica in the natural sponge samples to laminar string morphology of cristobalite. With this technique we could probe the change in the samples chirality from achiral bio silica to chiral cristobalite structure. Furthermore it is shown that natural biosilica have photoinduced linear electro optics respond indicating the chiral natural of biosilica. - Graphical abstract: The phase transformation of biosilica from marine sponges to Cristobalite under thermal treatment was investigated using photoinduced electro optics measurements. The figure shows the changes of the electro-optic coefficient of cristobalite and biosilica. - Highlights: • We examine phase transformation of biosilica. • We report transition from amorphous biosilica to crystalline Cristobalite. • Biosilica transformation to Cristobalite at temperature of 850 °C. • Biosilica transformation is studied with photoinduced measurements. • We examine changes in the photoinduced linear electro optics properties.

  19. Determining electro-optic coefficients for lithium tantalate using an electro-optic scanning device

    SciTech Connect

    Casson, J. L.; Gahagan, K. T.; Robinson, J. M.; Scrymgeour, D. A.; Jain, R.

    2001-01-01

    We demonstrate a ferroelectric optical device based on single crystal LiTaO{sub 3} that can scan a laser beam from the visible to the infrared. It utilizes the electro-optic effect in the ferroelectric that has potentially high intrinsic response times of GHz. There are many applications to such scanning devices in the infrared such as optical switching, spectrometry, microscopy, and sensing. Lithium tantalate has two ferroelectric polarization states that are antiparallel (180{sup o}) to each other. The domain states can be reversed by applying an electric field of {approx}21 kV/mm at room temperature. By reversing the domain structure in the crystal, we can create domains in the crystal of almost any desired shape. By creating prism-shaped domain, we can create a ferroelectric deflector or scanner by applying either static or sweeping voltages across the crystal. This scanner is capable of scanning wavelengths from 0.4-5 {micro}m. The scanning performance varied from a total deflection angle of 13.38{sup o} at 1558 nm to 16.18{sup o} at 632.8 nm. Since the amount of deflection of the incoming light is determined by the applied voltage, the electro-optic coefficient and other fixed quantities, by measuring the deflection angle as a function of wavelength, the dispersion of the electro-optic coefficient in lithium tantalate can be determined. In these experiments, the scanner was characterized from the visible (632.8 nm) to midinfrared (1558 nm). Both extraordinary and the ordinary polarizations of light were used, in order to determine the electro-optic coefficients, r{sup 33} and r{sup 31}. Except for the values at 632.8 nm, these values of the electro-optic coefficients have not been previously reported. For lithium tantalate, r{sup 33} at 632.8 nm is reported in the literature as 30.2 pm/V. We found that this decreases to 27.1 pm/V at 1558 nm. For the extraordinary polarization, r{sup 13} varied from 7.55 pm/V (632.8 nm) to 6.84 pm/V (1558 nm).

  20. The role of fiber optics in mass spectrometer electro-optical ion detection

    NASA Technical Reports Server (NTRS)

    Norris, D. D.; Giffin, C. E.

    1976-01-01

    This paper describes the development of an electro-optical ion detector combining the best features of photographic and electrical ion detection (i.e., wide mass range coverage and low ion detection threshold respectively). A nineteen fold fiber optic image dissector is discussed which reformats the 1 mm x 361 mm mass spectrometer focal plane format to a 19 mm x 19 mm format suitable for vidicon imaging and electronic display of the data.

  1. Fourier removal of stripe artifacts in IRAS images

    NASA Technical Reports Server (NTRS)

    Van Buren, Dave

    1987-01-01

    By working in the Fourier plane, approximate removal of stripe artifacts in IRAS images can be effected. The image of interest is smoothed and subtracted from the original, giving the high-spatial-frequency part. This 'filtered' image is then clipped to remove point sources and then Fourier transformed. Subtracting the Fourier components contributing to the stripes in this image from the Fourier transform of the original and transforming back to the image plane yields substantial removal of the stripes.

  2. A new electro-optic waveguide architecture and the unprecedented devices it enables

    NASA Astrophysics Data System (ADS)

    Davis, Scott R.; Rommel, Scott D.; Farca, George; Anderson, Michael H.

    2008-04-01

    A new electro-optic waveguide platform, which provides unprecedented electro-optical phase delays (> 1mm), with very low loss (< 0.5 dB/cm) and rapid response time (sub millisecond), is presented. This technology, developed by Vescent Photonics, is based upon a unique liquid-crystal waveguide geometry, which exploits the tremendous electro-optic response of liquid crystals while circumventing historic limitations of liquid crystals. The exceedingly large optical phase delays accessible with this technology enable the design and construction of a new class of previously unrealizable photonic devices. Examples include: a 1-D non-mechanical, analog beamsteerer with an 80° field of regard, a chip-scale widely tunable laser, a chip-scale Fourier transform spectrometer (< 5 nm resolution demonstrated), widely tunable micro-ring resonators, tunable lenses, ultra-low power (< 5 microWatts) optical switches, true optical time delay (up to 10 ns), and many more. All of these devices may benefit from established manufacturing technologies and ultimately may be as inexpensive as a calculator display. Furthermore, this new integrated photonic architecture has applications in a wide array of commercial and defense markets including: remote sensing, micro-LADAR, OCT, laser illumination, phased array radar, optical communications, etc. Performance attributes of several example devices are presented.

  3. Electro-Optic Computing Architectures: Volume II. Components and System Design and Analysis

    DTIC Science & Technology

    1998-02-01

    The objective of the Electro - Optic Computing Architecture (EOCA) program was to develop multi-function electro - optic interfaces and optical...interconnect units to enhance the performance of parallel processor systems and form the building blocks for future electro - optic computing architectures...Specifically, three multi-function interface modules were targeted for development - an Electro - Optic Interface (EOI), an Optical Interconnection Unit

  4. ISAR Imaging Using Fourier and Wavelet Transforms

    DTIC Science & Technology

    2007-12-01

    5 B. SCATTERING FROM A SPHERE . . . . . . . . . . . . . . . . 7 C. IMAGING FROM WEAK-SCATTERER FAR-FIELD DATA USING FOURIER ANALYSIS ...independent of weather conditions, in day or night. With the advent of powerful digital signal processing algorithms, multidimensional signal analysis ...a very long antenna by signal analysis [Ref. 2]. The ability to view or capture a scene improves with a larger aperture (in a binocular or camera), a

  5. Photoinduced electro-optics measurements of biosilica transformation to cristobalite

    NASA Astrophysics Data System (ADS)

    Fuchs, Ido; Aluma, Yaniv; Ilan, Micha; Kityk, Iwan; Mastai, Yitzhak

    2015-03-01

    In this paper we studied the photoinduced electro optics effects in the thermal transformation process of biosilica to cristobalite, at a relatively low temperature and ambient pressure. This process was characterized by a variety of standards techniques with emphasis on linear electro optic effect measurements. Overall we demonstrated that photoinduced electro optics measurements are very sensitive to the transformation from amorphous structure of silica in the natural sponge samples to laminar string morphology of cristobalite. With this technique we could probe the change in the samples chirality from achiral bio silica to chiral cristobalite structure. Furthermore it is shown that natural biosilica have photoinduced linear electro optics respond indicating the chiral natural of biosilica.

  6. Terahertz wave electro-optic measurements with optical spectral filtering

    SciTech Connect

    Ilyakov, I. E. Shishkin, B. V.; Kitaeva, G. Kh.; Akhmedzhanov, R. A.

    2015-03-23

    We propose electro-optic detection techniques based on variations of the laser pulse spectrum induced during pulse co-propagation with terahertz wave radiation in a nonlinear crystal. Quantitative comparison with two other detection methods is made. Substantial improvement of the sensitivity compared to the standard electro-optic detection technique (at high frequencies) and to the previously shown technique based on laser pulse energy changes is demonstrated in experiment.

  7. Intrinsic optical modulation mechanism in electro-optic crystals

    NASA Astrophysics Data System (ADS)

    Garzarella, A.; Hinton, R. J.; Qadri, S. B.; Wu, Dong Ho

    2008-06-01

    An intrinsic mechanism of optical intensity modulation occurring in electro-optic devices such as field sensors and modulators under applied fields is described. The optical modulation results from interactions between internally generated Fizeau interference patterns and electro-optic effects within the nonlinear crystal. Our results indicate that when phase matched with the conventional polarimetric signal, the intrinsic modulation mechanism can nearly double device sensitivity.

  8. Highly Sensitive Electro-Optic Modulators

    SciTech Connect

    DeVore, Peter S

    2015-10-26

    There are very important diagnostic and communication applications that receive faint electrical signals to be transmitted over long distances for capture. Optical links reduce bandwidth and distance restrictions of metal transmission lines; however, such signals are only weakly imprinted onto the optical carrier, resulting in low fidelity transmission. Increasing signal fidelity often necessitates insertion of radio-frequency (RF) amplifiers before the electro-optic modulator, but (especially at high frequencies) RF amplification results in large irreversible distortions. We have investigated the feasibility of a Sensitive and Linear Modulation by Optical Nonlinearity (SALMON) modulator to supersede RF-amplified modulators. SALMON uses cross-phase modulation, a manifestation of the Kerr effect, to enhance the modulation depth of an RF-modulated optical wave. This ultrafast process has the potential to result in less irreversible distortions as compared to a RF-amplified modulator due to the broadband nature of the Kerr effect. Here, we prove that a SALMON modulator is a feasible alternative to an RFamplified modulator, by demonstrating a sensitivity enhancement factor greater than 20 and significantly reduced distortion.

  9. Electro-optical spin measurement system

    NASA Technical Reports Server (NTRS)

    Fodale, Robert (Inventor); Hampton, Herbert R. (Inventor)

    1990-01-01

    An electro-optical spin measurement system for a spin model in a spin tunnel includes a radio controlled receiver/transmitter, targets located on the spin model, optical receivers mounted around the perimeter of the spin tunnel and the base of the spin tunnel for receiving data from the targets, and a control system for accumulating data from the radio controlled receiver and receivers. Six targets are employed. The spin model includes a fuselage, wings, nose, and tail. Two targets are located under the fuselage of the spin model at the nose tip and tail. Two targets are located on the side of the fuselage at the nose tip and tail, and a target is located under each wing tip. The targets under the fuselage at the nose tip and tail measure spin rate of the spin model, targets on the side of the fuselage at the nose tip and tail measure angle of attack of the spin model, and the targets under the wing tips measure roll angle of the spin model. Optical receivers are mounted at 90 degree increments around the periphery of the spin tunnel to determine angle of attack and roll angle measurements of the spin model. Optical receivers are also mounted at the base of the spin tunnel to define quadrant and position of the spin model and to determine the spin rate of the spin model.

  10. Applications of lasers and electro-optics

    NASA Astrophysics Data System (ADS)

    Tan, B. C.; Low, K. S.; Chen, Y. H.; Ahmad, Harith; Tou, T. Y.

    Supported by the IRPA Programme on Laser Technology and Applications, many types of lasers have been designed, constructed and applied in various areas of science, medicine and industries. Amongst these lasers constructed were high power carbon dioxide lasers, rare gas halide excimer lasers, solid state Neodymium-YAG lasers, nitrogen lasers, flashlamp pumped dye lasers and nitrogen and excimer laser pumped dye lasers. These lasers and the associated electro-optics system, some with computer controlled, are designed and developed for the following areas of applications: (1) industrial applications of high power carbon dioxide lasers for making of i.c. components and other materials processing purposes -- prototype operational systems have been developed; (2) Medical applications of lasers for cancer treatment using the technique of photodynamic therapy -- a new and more effective treatment protocol has been proposed; (3) agricultural applications of lasers in palm oil and palm fruit-fluorescence diagnostic studies -- fruit ripeness signature has been developed and palm oil oxidation level were investigated; (4) development of atmospheric pollution monitoring systems using laser lidar techniques -- laboratory scale systems were developed; and (5) other applications of lasers including laser holographic and interferometric methods for the non destructive testing of materials.

  11. Electro-optics of perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Lin, Qianqian; Armin, Ardalan; Nagiri, Ravi Chandra Raju; Burn, Paul L.; Meredith, Paul

    2015-02-01

    Organohalide-perovskite solar cells have emerged as a leading next-generation photovoltaic technology. However, despite surging efficiencies, many questions remain unanswered regarding the mechanisms of operation. Here we report a detailed study of the electro-optics of efficient CH3NH3PbI3-perovskite-only planar devices. We report the dielectric constants over a large frequency range. Importantly, we found the real part of the static dielectric constant to be ∼70, from which we estimate the exciton-binding energy to be of order 2 meV, which strongly indicates a non-excitonic mechanism. Also, Jonscher's Law behaviour was consistent with the perovskite having ionic character. Accurate knowledge of the cell's optical constants allowed improved modelling and design, and using this information we fabricated an optimized device with an efficiency of 16.5%. The optimized devices have ∼100% spectrally flat internal quantum efficiencies and minimal bimolecular recombination. These findings establish systematic design rules to achieve silicon-like efficiencies in simple perovskite solar cells.

  12. Identification of handheld objects for electro-optic/FLIR applications

    NASA Astrophysics Data System (ADS)

    Moyer, Steve K.; Flug, Eric; Edwards, Timothy C.; Krapels, Keith A.; Scarbrough, John

    2004-08-01

    This paper describes research on the determination of the fifty-percent probability of identification cycle criterion (N50) for two sets of handheld objects. The first set consists of 12 objects which are commonly held in a single hand. The second set consists of 10 objects commonly held in both hands. These sets consist of not only typical civilian handheld objects but also objects that are potentially lethal. A pistol, a cell phone, a rocket propelled grenade (RPG) launcher, and a broom are examples of the objects in these sets. The discrimination of these objects is an inherent part of homeland security, force protection, and also general population security. Objects were imaged from each set in the visible and mid-wave infrared (MWIR) spectrum. Various levels of blur are then applied to these images. These blurred images were then used in a forced choice perception experiment. Results were analyzed as a function of blur level and target size to give identification probability as a function of resolvable cycles on target. These results are applicable to handheld object target acquisition estimates for visible imaging systems and MWIR systems. This research provides guidance in the design and analysis of electro-optical systems and forward-looking infrared (FLIR) systems for use in homeland security, force protection, and also general population security.

  13. Development of electro-optical instrumentation for reactor safety studies

    SciTech Connect

    Turko, B.T.; Kolbe, W.F.; Leskovar, B.; Sun, R.K.

    1980-11-01

    The development of new electro-optical instrumentation for reactor safety studies is described. The system measures the thickness of the water film and droplet size and velocity distributions which would be encountered in the annular two-phase flow in a reactor cooling system. The water film thickness is measured by a specially designed capacitance system with a short time constant. Water droplet size and velocity are measured by a subsystem consisting of a continuously pulsed laser light source, a vidicon camera, a video recorder, and an automatic image analyzer. An endoscope system attached to the video camera is used to image the droplets. Each frame is strobed with two accurately spaced uv light pulses, from two sequentially fired nitrogen lasers. The images are stored in the video disk recorder. The modified automatic image analyzer is programmed to digitize the droplet size and velocity distributions. Many special optical, mechanical and electronic system components were designed and fabricated. They are described in detail, together with calibration charts and experimental results.

  14. Hunting Sea Mines with UUV-Based Magnetic and Electro-Optic Sensors

    DTIC Science & Technology

    2010-06-01

    results from a short-range bottom-looking sonar, with all three sensors co- residing and operating simultaneously on an Unmanned Underwater Vehicle (UUV... underwater marine environment while operating onboard autonomous underwater vehicles (AUVs) [1], [2]. Under the current concept of operations, AUV...Figure 1(a). It hosts a multi-sensor suite including the RTG [3-4] along with a bottom looking sonar, and an Underwater Electro-Optic Imager (EOI

  15. Polycrystalline PLZT/ITO Ceramic Electro-Optic Phase Gratings: Electro- Optically Reconfigurable Diffractive Devices for Free-Space and In-Wafer Interconnects

    DTIC Science & Technology

    1994-09-01

    free-space and waveguide interconnects is investigated through the fabrication, testing and modeling of polycrystalline PLZT/ITO ceramic electro - optic phase...only gratings. PLZT Diffraction grating, Electro - optic diffraction grating, Optical switching, Optical interconnects, Reconfigurable interconnect

  16. Electro-Optical Design for Efficient Visual Communication

    NASA Technical Reports Server (NTRS)

    Huck, Friedrich O.; Fales, Carl L.; Jobson, Daniel J.; Rahman, Zia-Ur

    1995-01-01

    Visual communication, in the form of telephotography and television, for example, can be regarded as efficient only if the amount of information that it conveys about the scene to the observer approaches the maximum possible and the associated cost approaches the minimum possible. Elsewhere we have addressed the problem of assessing the end to end performance of visual communication systems in terms of their efficiency in this sense by integrating the critical limiting factors that constrain image gathering into classical communications theory. We use this approach to assess the electro-optical design of image gathering devices as a function of the f number and apodization of the objective lens and the aperture size and sampling geometry of the phot-detection mechanism. Results show that an image gathering device that is designed to optimize information capacity performs similarly to the human eye. For both, the performance approaches the maximum possible, in terms of the efficiency with which the acquired information can be transmitted as decorrelated data, and the fidelity, sharpness, and clearity with which fine detail can be restored.

  17. Underwater electro-optical system for mine identification

    NASA Astrophysics Data System (ADS)

    Strand, Michael P.

    1995-06-01

    The Electro-Optic Identification (EOID) Sensors project is developing a Laser Visual Iidentification Sensor (LVIS) for identification of proud, partially buried, and moored mines in shallow water/very shallow water. LVIS will be deployed in small diameter underwater vehicles, including unmanned underwater vehicles (UUVs). Since the mission is mine identification, LVIS must: a) deliver high quality images in turbid coastal waters, while b) being compatible with the size and power constraints imposed by the intended deployment platforms. This project is sponsored by the Office of Naval Research, as a part of the AOA Mine Reconnaissance/Hunter program. High quality images which retain target detail and contrast are required for mine identification. LVIS will be designed to produce images of minelike contacts (MLC) of sufficient quality to allow identification while operating in turbid coastal waters from a small diameter UUV. Technology goals for the first generation LVIS are a) identification range up to 40 feet for proud, partially buried, and moored MLCs under coastal water conditions; b) day/night operation from a UUV operating at speeds up to 4 knots; c) power consumption less than 500 watts, with 275 watts being typical; and d) packaged within a 32-inch long portion of a 21-inch diameter vehicle section.

  18. Measurement of spatio-temporal field distribution of THz pulses in electro-optic crystal by interferometry method

    SciTech Connect

    Chizhov, P A; Ushakov, A A; Bukin, V V; Garnov, S V

    2015-05-31

    We propose a scheme for measuring the spatial distribution of the THz pulse electric field strength in an electro-optic crystal using optical interferometry. The resulting images of the field distribution from a test source with a spherical wave front are presented. (extreme light fields and their applications)

  19. Novel electro-optical coupling technique for magnetic resonance-compatible positron emission tomography detectors.

    PubMed

    Olcott, Peter D; Peng, Hao; Levin, Craig S

    2009-01-01

    A new magnetic resonance imaging (MRI)-compatible positron emission tomography (PET) detector design is being developed that uses electro-optical coupling to bring the amplitude and arrival time information of high-speed PET detector scintillation pulses out of an MRI system. The electro-optical coupling technology consists of a magnetically insensitive photodetector output signal connected to a nonmagnetic vertical cavity surface emitting laser (VCSEL) diode that is coupled to a multimode optical fiber. This scheme essentially acts as an optical wire with no influence on the MRI system. To test the feasibility of this approach, a lutetium-yttrium oxyorthosilicate crystal coupled to a single pixel of a solid-state photomultiplier array was placed in coincidence with a lutetium oxyorthosilicate crystal coupled to a fast photomultiplier tube with both the new nonmagnetic VCSEL coupling and the standard coaxial cable signal transmission scheme. No significant change was observed in 511 keV photopeak energy resolution and coincidence time resolution. This electro-optical coupling technology enables an MRI-compatible PET block detector to have a reduced electromagnetic footprint compared with the signal transmission schemes deployed in the current MRI/PET designs.

  20. The electro-optical and electrochromic properties of electrolyte-liquid crystal dispersions

    NASA Astrophysics Data System (ADS)

    Cupelli, Daniela; De Filpo, Giovanni; Chidichimo, Giuseppe; Nicoletta, Fiore Pasquale

    2006-07-01

    Liquid crystals are known to exhibit a reversible color change by applying a direct current electric field, if a small amount of quaternary ammonium salts is dissolved into them. Applications of such an electrochromic liquid crystal cell have been proposed as interesting laser-addressed writing and image storage devices. Liquid crystal dispersions are composite materials formed by liquid crystal droplets embedded in either a polymer or a monomer matrix. Thin films of liquid crystal dispersions can be turned from an opaque to a transparent state by application of a suitable alternating current electric field. Herein, we report our investigations on electrolyte-liquid crystal dispersions, which show independent electro-optical and electrochromic properties characterized by fast bleaching times. This cell involves the reorientation of liquid crystal molecules, trapped in droplets, for the electro-optical changes from the opaque to transparent state and the formation of complexes at the cathode, between the positive ions of electrolyte and liquid crystal dispersed in the matrix, for the electrochromic changes from the bleached to colored state. The device is able to change its electro-optical transmittance within few milliseconds and its color within few seconds.

  1. Configuration of electro-optic fire source detection system

    NASA Astrophysics Data System (ADS)

    Fabian, Ram Z.; Steiner, Zeev; Hofman, Nir

    2007-04-01

    The recent fighting activities in various parts of the world have highlighted the need for accurate fire source detection on one hand and fast "sensor to shooter cycle" capabilities on the other. Both needs can be met by the SPOTLITE system which dramatically enhances the capability to rapidly engage hostile fire source with a minimum of casualties to friendly force and to innocent bystanders. Modular system design enable to meet each customer specific requirements and enable excellent future growth and upgrade potential. The design and built of a fire source detection system is governed by sets of requirements issued by the operators. This can be translated into the following design criteria: I) Long range, fast and accurate fire source detection capability. II) Different threat detection and classification capability. III) Threat investigation capability. IV) Fire source data distribution capability (Location, direction, video image, voice). V) Men portability. ) In order to meet these design criteria, an optimized concept was presented and exercised for the SPOTLITE system. Three major modular components were defined: I) Electro Optical Unit -Including FLIR camera, CCD camera, Laser Range Finder and Marker II) Electronic Unit -including system computer and electronic. III) Controller Station Unit - Including the HMI of the system. This article discusses the system's components definition and optimization processes, and also show how SPOTLITE designers successfully managed to introduce excellent solutions for other system parameters.

  2. Electro-optic time lens model for femtosecond pulses

    NASA Astrophysics Data System (ADS)

    Marinho, Francisco J.; Bernardo, Luís M.

    2008-04-01

    We propose an electro-optic time-lens (EOTL) model based on the coupled-mode theory. The model describes the propagation of a femtosecond pulse in an electro-optical crystal with parabolic refractive index modulation by a microwave. The proposed model integrates the second order dispersion approximation (β II ≠ 0) and takes into consideration the possible mismatch between the microwave phase velocity and the pulse group velocity. The coupled-mode theory uses the Hermite-Gaussian functions which are the modes of an ideal electro-optic time-lens. The model characterizes completely the performances of EOTL, including the aberrations, and it establishes the maximum velocity mismatch for which the pulse profile propagates through the crystal without significant distortion. The theoretical model is numerically implement considering the propagation of a short pulse in a Litium Niobate time-lens.

  3. Direct Absorption Spectroscopy with Electro-Optic Frequency Combs

    NASA Astrophysics Data System (ADS)

    Fleisher, Adam J.; Long, David A.; Plusquellic, David F.; Hodges, Joseph T.

    2017-06-01

    The application of electro-optic frequency combs to direct absorption spectroscopy has increased research interest in high-agility, modulator-based comb generation. This talk will review common architectures for electro-optic frequency comb generators as well as describe common self-heterodyne and multi-heterodyne (i.e., dual-comb) detection approaches. In order to achieve a sufficient signal-to-noise ratio on the recorded interferogram while allowing for manageable data volumes, broadband electro-optic frequency combs require deep coherent averaging, preferably in real-time. Applications such as cavity-enhanced spectroscopy, precision atomic and molecular spectroscopy, as well as time-resolved spectroscopy will be introduced. D.A. Long et al., Opt. Lett. 39, 2688 (2014) A.J. Fleisher et al., Opt. Express 24, 10424 (2016)

  4. Embodiment of Learning in Electro-Optical Signal Processors.

    PubMed

    Hermans, Michiel; Antonik, Piotr; Haelterman, Marc; Massar, Serge

    2016-09-16

    Delay-coupled electro-optical systems have received much attention for their dynamical properties and their potential use in signal processing. In particular, it has recently been demonstrated, using the artificial intelligence algorithm known as reservoir computing, that photonic implementations of such systems solve complex tasks such as speech recognition. Here, we show how the backpropagation algorithm can be physically implemented on the same electro-optical delay-coupled architecture used for computation with only minor changes to the original design. We find that, compared to when the backpropagation algorithm is not used, the error rate of the resulting computing device, evaluated on three benchmark tasks, decreases considerably. This demonstrates that electro-optical analog computers can embody a large part of their own training process, allowing them to be applied to new, more difficult tasks.

  5. Embodiment of Learning in Electro-Optical Signal Processors

    NASA Astrophysics Data System (ADS)

    Hermans, Michiel; Antonik, Piotr; Haelterman, Marc; Massar, Serge

    2016-09-01

    Delay-coupled electro-optical systems have received much attention for their dynamical properties and their potential use in signal processing. In particular, it has recently been demonstrated, using the artificial intelligence algorithm known as reservoir computing, that photonic implementations of such systems solve complex tasks such as speech recognition. Here, we show how the backpropagation algorithm can be physically implemented on the same electro-optical delay-coupled architecture used for computation with only minor changes to the original design. We find that, compared to when the backpropagation algorithm is not used, the error rate of the resulting computing device, evaluated on three benchmark tasks, decreases considerably. This demonstrates that electro-optical analog computers can embody a large part of their own training process, allowing them to be applied to new, more difficult tasks.

  6. Night vision and electro-optics technology transfer, 1972 - 1981

    NASA Astrophysics Data System (ADS)

    Fulton, R. W.; Mason, G. F.

    1981-09-01

    The purpose of this special report, 'Night Vision and Electro-Optics Technology Transfer 1972-1981,' is threefold: To illustrate, through actual case histories, the potential for exploiting a highly developed and available military technology for solving non-military problems. To provide, in a layman's language, the principles behind night vision and electro-optical devices in order that an awareness may be developed relative to the potential for adopting this technology for non-military applications. To obtain maximum dollar return from research and development investments by applying this technology to secondary applications. This includes, but is not limited to, applications by other Government agencies, state and local governments, colleges and universities, and medical organizations. It is desired that this summary of Technology Transfer activities within Night Vision and Electro-Optics Laboratory (NV/EOL) will benefit those who desire to explore one of the vast technological resources available within the Defense Department and the Federal Government.

  7. An electro-optic resonant modulator for coherent optical communication

    NASA Technical Reports Server (NTRS)

    Robinson, D. L.; Chen, C.-C.; Hemmati, H.

    1991-01-01

    A resonant cavity electro-optic phase modulator has been designed and implemented to operate at a data rate of 10 Mbps. The modulator consists of an electro-optic crystal located in a highly resonant cavity. The cavity is electro-optically switched on and off resonance, and the phase dispersion near the cavity resonance provides the output phase modulation. The performance of the modulator was measured by first heterodyne detecting the signal to an intermediate frequency, and measuring the spectral characteristics using an RF spectrum analyzer. The measured phase shift is shown to be in good agreement with the theoretical predictions. Further theoretical analysis shows that the design of the modulator can be scaled to operate at 100 Mbps.

  8. 10-Mbps electro-optic resonant phase modulator

    NASA Technical Reports Server (NTRS)

    Robinson, D. L.; Chen, Chien-Chung; Hemmati, Hamid

    1993-01-01

    A resonant cavity electro-optic phase modulator has been designed and implemented to operate at a data rate of 10 Mbps. The modulator consists of an electro-optic crystal located in a highly resonant cavity. The cavity is electro-optically switched on and off resonance, and the phase dispersion near the cavity resonance provides the output phase modulation. The performance of the modulator was measured by first heterodyne-detecting the signal to an intermediate frequency and then measuring the spectral characteristics using an rf spectrum analyzer. The measured phase shift is shown to be in good agreement with the theoretical predictions. Further theoretical analysis shows that the design of the modulator can be scaled to operate at 100 Mbps.

  9. Integrated Optical Combinatorial Logic Using Electro-Optic Bragg Gratings

    NASA Astrophysics Data System (ADS)

    Arrathoon, R.; Schroeder, E. R.; Westervelt, F.

    1985-09-01

    Three classes of integrated optical devices suitable for implementing general combinatorial logic are discussed. The categories considered are electric-electric-optic (EEO), electric-optic-optic (E00), and optic-optic-optic (000). Existing gate geometries based on electro-optic Bragg gratings are modified to permit the realization of the NOT, NAND, OR, NOR, and inhibition functions. A full-adder based entirely on electro-optic Bragg gratings is developed, and the device is compared to current VLSI technology in terms of size and speed. The use of programmable logic arrays (PLA's)for implementing general combinatorial logic is discussed. The paper concludes with a proposal for using electro-optic Bragg gratings to construct an integrated optical PLA.

  10. Imaging photonic crystals using Fourier plane imaging and Fourier ptychographic microscopy techniques implemented with a computer controlled hemispherical digital condenser

    NASA Astrophysics Data System (ADS)

    Sen, Sanchari; Desai, Darshan B.; Alsubaie, Meznh H.; Zhelyeznyakov, Maksym V.; Molina, L.; Sarraf, Hamed Sari; Bernussi, Ayrton A.; Peralta, Luis Grave de

    2017-01-01

    Fourier plane imaging (FPIM) and Fourier ptychographic (FPM) microscopy techniques were used to image photonic crystals. A computer-controlled hemispherical digital condenser provided required sample illumination with variable inclination. Notable improvement in image resolution was obtained with both methods. However, it was determined that the FPM technique cannot surpass the Rayleigh resolution limit when imaging photonic crystals.

  11. Integral imaging with Fourier-plane recording

    NASA Astrophysics Data System (ADS)

    Martínez-Corral, M.; Barreiro, J. C.; Llavador, A.; Sánchez-Ortiga, E.; Sola-Pikabea, J.; Scrofani, G.; Saavedra, G.

    2017-05-01

    Integral Imaging is well known for its capability of recording both the spatial and the angular information of threedimensional (3D) scenes. Based on such an idea, the plenoptic concept has been developed in the past two decades, and therefore a new camera has been designed with the capacity of capturing the spatial-angular information with a single sensor and after a single shot. However, the classical plenoptic design presents two drawbacks, one is the oblique recording made by external microlenses. Other is loss of information due to diffraction effects. In this contribution report a change in the paradigm and propose the combination of telecentric architecture and Fourier-plane recording. This new capture geometry permits substantial improvements in resolution, depth of field and computation time

  12. Electro-optically spectrum tailorable intracavity optical parametric oscillator.

    PubMed

    Chung, H P; Chang, W K; Tseng, C H; Geiss, R; Pertsch, T; Chen, Y H

    2015-11-15

    We report a unique, pulsed intracavity optical parametric oscillator (IOPO) whose output spectrum is electro-optically (EO) tailorable based on an aperiodically poled lithium niobate (APPLN) working simultaneously as an optical parametric gain medium and an active gain spectrum filter in the system. We have successfully obtained from the IOPO the emission of single to multiple narrow-line signal spectral peaks in a near-infrared (1531 nm) band simply by electro-optic control. The power spectral density of the EO tailored signal can be enhanced by up to 10 times over the original (nontailored) signal.

  13. Algorithms of electro-optical effect calculation in nanodisperse systems

    NASA Astrophysics Data System (ADS)

    Bregman, A. M.; Petrov, M. P.; Trusov, A. A.; Voitylov, A. V.; Vojtylov, V. V.

    2017-07-01

    Electro-optical techniques are widely used to study nanodisperse systems and obtain geometrical, electrical, and optical characteristics of particles in the suspension. The theory that describes electro-optical effects in nanodisperse systems employs several generic relations which could benefit from fast numerical calculations. The presented Taylor series expansion and differential equations allow to perform such numerical calculations fast and with a pre-defined accuracy. To take into account the polydispersity of the particles in the solution the optical properties of particles need to be taken into account. The theory that allows to do this is presented.

  14. Electro-optic sampling of transient electric fields from charged particle beams

    NASA Astrophysics Data System (ADS)

    Fitch, Michael James

    The passage of a relativistic charged particle beam bunch through a structure is accompanied by transient electromagnetic fields. By causality, these fields must be behind the bunch, and are called ``wakefields.'' The wakefields act back on the beam, and cause instabilities such as the beam break-up instability, and the head-tail instability, which limit the luminosity of linear colliders. The wakefields are particularly important for short bunches with high charge. A great deal of effort is devoted to analytical and numerical calculations of wakefields, and wakefield effects. Experimental numbers are needed. In this thesis, we present measurements of the transient electric fields induced by a short high-charge electron bunch passing through a 6-way vacuum cross. These measurements are performed in the time domain using electro-optic sampling with a time resolution of approximately 5 picoseconds. With different orientations of the electro-optic crystal, we have measured different vector components of the electric field. The Fourier transform of the time-domain data yields the product of the beam impedance with the excitation spectrum of the bunch. Since the bunch length is known from streak camera measurements, the k loss factor is directly obtained. There is reasonably good agreement between the experimental k loss factor with calculations from the code MAFIA. To our knowledge, this is the first direct measurement of the k loss factor for bunch lengths shorter than one millimeter (rms). We also present results of magnetic bunch compression (using a dipole chicane) of a high-charge photoinjector beam for two different UV laser pulse lengths on the photocathode. At best compression, a 13.87 nC bunch was compressed to 0.66 mm (2.19 ps) rms, or a peak current of 3 kA. Other results from the photoinjector are given, and the laser system for photocathode excitation and electro- optic sampling is described.

  15. Imaging Fourier transform spectrometry of chemical plumes

    NASA Astrophysics Data System (ADS)

    Bradley, Kenneth C.; Gross, Kevin C.; Perram, Glen P.

    2009-05-01

    A midwave infrared (MWIR) imaging Fourier transform spectrometer (FTS), the Telops FIRST-MWE (Field-portable Imaging Radiometric Spectrometer Technology - Midwave Extended) has been utilized for the standoff detection and characterization of chemical plumes. Successful collection and analysis of MWIR hyperspectral imagery of jet engine exhaust has allowed us to produce spatial profiles of both temperature and chemical constituent concentrations of exhaust plumes. Successful characterization of this high temperature combustion event has led to the collection and analysis of hyperspectral imagery of lower temperature emissions from industrial smokestacks. This paper presents MWIR data from remote collection of hyperspectral imagery of methyl salicilate (MeS), a chemical warfare agent simulant, during the Chemical Biological Distributed Early Warning System (CBDEWS) test at Dugway Proving Grounds, UT in 2008. The data did not contain spectral lines associated with emission of MeS. However, a few broad spectral features were present in the background-subtracted plume spectra. Further analysis will be required to assign these features, and determine the utility of MWIR hyperspectral imagery for analysis of chemical warfare agent plumes.

  16. Electro-Optical Sensing Apparatus and Method for Characterizing Free-Space Electromagnetic Radiation

    DOEpatents

    Zhang, Xi-Cheng; Libelo, Louis Francis; Wu, Qi

    1999-09-14

    Apparatus and methods for characterizing free-space electromagnetic energy, and in particular, apparatus/method suitable for real-time two-dimensional far-infrared imaging applications are presented. The sensing technique is based on a non-linear coupling between a low-frequency electric field and a laser beam in an electro-optic crystal. In addition to a practical counter-propagating sensing technique, a co-linear approach is described which provides longer radiated field--optical beam interaction length, thereby making imaging applications practical.

  17. Development of New Electro-Optic and Acousto-Optic Materials.

    DTIC Science & Technology

    1983-11-01

    Improved materials are required for active optical devices, including electro - optic and acousto-optic modulators, switches and tunable filters, as...many microwave applications. In addition, electro - optic and acousto-optic devices are materials limited because the materials currently available are...these materials for applications involving the electro - optic effect, degenerate four-wave mixing and surface acoustic wave technology.

  18. Parallel image registration method for snapshot Fourier transform imaging spectroscopy

    NASA Astrophysics Data System (ADS)

    Zhang, Yu; Zhu, Shuaishuai; Lin, Jie; Zhu, Feijia; Jin, Peng

    2017-08-01

    A fast and precise registration method for multi-image snapshot Fourier transform imaging spectroscopy is proposed. This method accomplishes registration of an image array using the positional relationship between homologous points in the subimages, which are obtained offline by preregistration. Through the preregistration process, the registration problem is converted to the problem of using a registration matrix to interpolate subimages. Therefore, the hardware interpolation of graphics processing unit (GPU) texture memory, which has speed advantages for its parallel computing, can be used to significantly enhance computational efficiency. Compared to a central processing unit, GPU performance showed ˜27 times acceleration in registration efficiency.

  19. Solid state electro-optic color filter and iris

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Test results obtained have confirmed the practicality of the solid state electro-optic filters as an optical control element in a television system. Neutral-density control range in excess of 1000:1 has been obtained on sample filters. Test results, measurements in a complete camera system, discussions of problem areas, analytical comparisons, and recommendations for future investigations are included.

  20. Laser Electro-Optic Engineering Technology. Florida Vocational Program Guide.

    ERIC Educational Resources Information Center

    University of South Florida, Tampa. Dept. of Adult and Vocational Education.

    This program guide identifies particular considerations in the organization, operation, and evaluation of laser electro-optic engineering technology programs. Contents include an occupational description and information on the following: program content, including a curriculum framework that details major concepts and intended outcomes and a list…

  1. Laser Electro-Optic Technology. Florida Vocational Program Guide.

    ERIC Educational Resources Information Center

    University of South Florida, Tampa. Dept. of Adult and Vocational Education.

    This program guide identifies primary considerations in the organization, operation, and evaluation of a laser electro-optic technology program. An occupational description and program content are presented. A curriculum framework specifies the exact course title, course number, levels of instruction, major course content, laboratory activities,…

  2. Laser Electro-Optic Engineering Technology. Florida Vocational Program Guide.

    ERIC Educational Resources Information Center

    University of South Florida, Tampa. Dept. of Adult and Vocational Education.

    This program guide identifies particular considerations in the organization, operation, and evaluation of laser electro-optic engineering technology programs. Contents include an occupational description and information on the following: program content, including a curriculum framework that details major concepts and intended outcomes and a list…

  3. Laser Electro-Optic Technology. Florida Vocational Program Guide.

    ERIC Educational Resources Information Center

    University of South Florida, Tampa. Dept. of Adult and Vocational Education.

    This program guide identifies primary considerations in the organization, operation, and evaluation of a laser electro-optic technology program. An occupational description and program content are presented. A curriculum framework specifies the exact course title, course number, levels of instruction, major course content, laboratory activities,…

  4. Terrain-aided localization using electro-optical sensing (TALEOS)

    NASA Astrophysics Data System (ADS)

    Collins, Peter R. C.; Stephens, Arthur S.; Greenway, Phil; Deaves, Rob H.; Priestley, M. D. J.; Bullen, Mark

    1997-06-01

    The next generation of weapons systems will benefit from an array of new technologies which, when integrated, will provide the capability of accurately selecting the correct target. For example, target image features can be extracted from high resolution satellite data and this information can be fused with feature positions obtained from a weapon's imaging sensor. This will allow automatic target recognition to be performed. Terrain aided localization using electro-optical sensing (TALEOS) is a robust method of enhancing the performance of an imaging system through the exploitation of other sources of information. The primary image processing technique used in TALEOS is model-matching. The objective of model-matching is to discover the 3D position and orientation of an object (the model) with respect to the sensor reference frame by performing a match with corresponding features. In TALEOS, the model is derived from remotely sensed data and contains information about potentially observable features which might be extracted from the image. Embedded in this extended model is information about specific targets, including their known or estimated position, and features which characterize them. The Sowerby Research Center terrain model facility was used to gather realistic imagery. The terrain model is a 300:1 scale model of a 25 square kilometer area of real terrain. An overhead gantry system carries a video camera over the model enabling a wide variety of flight scenarios to be simulated experimentally. By a combination of special paint schemes and video inversion, pictures of the terrain model can provide a realistic simulation of infrared imagery. An image database was simulated using an overhead view of the model as if seen from a 'satellite' or reconnaissance aircraft. This imagery was utilized to evaluate the performance of the TALEOS technique for comparison with theoretical results. TALEOS integrates the data from the image processing subsystem with data from

  5. Electro-optics technology for a new generation of military and law enforcement small equipment

    NASA Astrophysics Data System (ADS)

    Giunti, C.; Cocchi, A.; Bardazzi, R.; Calamai, L.; Sabatini, M.; Torniai, E.; Livi, M.; Toccafondi, C.; Maestrini, M.; Santini, N.

    2007-10-01

    In the framework of a modernization program, supported by Italian Army, Galileo Avionica (a Finmeccanica company) has developed a family of small equipments based on suites of electro-optics sensors. These modules, designed and built by GA, range from uncooled V0x 25 micron thermal imagers, small and very compact laser rangefinders, CMOS Visible sensors to the last generation of colour OLED microdisplay based visual units. All the EO assemblies are integrated to form very small and lightweight Integrated Sight, a Multi Function Target Locator, and Dynamic Aiming System. Even if the equipments have been developed for military applications many other applications such as law enforcements or surveillance can be envisaged.

  6. Electro-optical logic application of multimode interference coupler by multivalued controlling.

    PubMed

    Zhou, Haifeng; Wang, Wanjun; Yang, Jianyi; Wang, Minghua; Jiang, Xiaoqing

    2011-05-20

    Electro-optical hybrid logic is a potential solution to implement both electrical and optical signal processing, which receives analog or digital, electrical or optical signals and produces logic signals in a desired manner. In light of the transfer matrix theory, we found that one can steer light into different output ports of a multimode interference coupler by controlling the phases in a multivalued manner on the image-extended arms. This implementation acts as an analog-to-digital convertor from electric domain to optical domain. Also, an electrical-to-optical 2-to-2(2) binary-coded decoder is described and examined by the 3D beam propagation method.

  7. Invariant electro-optical system for deflection measurement of floating docks

    NASA Astrophysics Data System (ADS)

    Gorbachev, Alexey A.; Hoang, Anh Phuong

    2017-06-01

    An electro-optical system for deflection measurement of floating docks is represented in this paper. This system contains a base unit with two measurement channels observing opposite directions of the dock. It also includes a set of reference marks and an industrial computer. The measurement unit contains of a camera with long focal-length lens and a beam splitter. The effect of the beam splitter turning point on the image position of the reference mark on the camera is analyzed as well in this paper.

  8. Prototype positron emission tomography insert with electro-optical signal transmission for simultaneous operation with MRI

    NASA Astrophysics Data System (ADS)

    Olcott, Peter; Kim, Ealgoo; Hong, Keyjo; Lee, Brian J.; Grant, Alexander M.; Chang, Chen-Ming; Glover, Gary; Levin, Craig S.

    2015-05-01

    The simultaneous acquisition of PET and MRI data shows promise to provide powerful capabilities to study disease processes in human subjects, guide the development of novel treatments, and monitor therapy response and disease progression. A brain-size PET detector ring insert for an MRI system is being developed that, if successful, can be inserted into any existing MRI system to enable simultaneous PET and MRI images of the brain to be acquired without mutual interference. The PET insert uses electro-optical coupling to relay all the signals from the PET detectors out of the MRI system using analog modulated lasers coupled to fiber optics. Because the fibers use light instead of electrical signals, the PET detector can be electrically decoupled from the MRI making it partially transmissive to the RF field of the MRI. The SiPM devices and low power lasers were powered using non-magnetic MRI compatible batteries. Also, the number of laser-fiber channels in the system was reduced using techniques adapted from the field of compressed sensing. Using the fact that incoming PET data is sparse in time and space, electronic circuits implementing constant weight codes uniquely encode the detector signals in order to reduce the number of electro-optical readout channels by 8-fold. Two out of a total of sixteen electro-optical detector modules have been built and tested with the entire RF-shielded detector gantry for the PET ring insert. The two detectors have been tested outside and inside of a 3T MRI system to study mutual interference effects and simultaneous performance with MRI. Preliminary results show that the PET insert is feasible for high resolution simultaneous PET/MRI imaging for applications in the brain.

  9. A new generation of previously unrealizable photonic devices as enabled by a unique electro-optic waveguide architecture

    NASA Astrophysics Data System (ADS)

    Davis, Scott R.; Rommel, Scott D.; Farca, George; Anderson, Michael H.

    2008-08-01

    A new electro-optic waveguide platform, which provides unprecedented electro-optical phase delays (> 1mm), with very low loss (< 0.5 dB/cm) and rapid response time (sub millisecond), is presented. This technology, developed by Vescent Photonics, is based upon a unique liquid-crystal waveguide geometry, which exploits the tremendous electro-optic response of liquid crystals while circumventing historic limitations of liquid crystals. The exceedingly large optical phase delays accessible with this technology enable the design and construction of a new class of previously unrealizable photonic devices. Examples include: a 1-D non-mechanical, analog beamsteerer with an 80° field of regard, a chip-scale widely tunable laser, a chip-scale Fourier transform spectrometer (< 5 nm resolution demonstrated), widely tunable micro-ring resonators, tunable lenses, ultra-low power (< 5 microWatts) optical switches, true optical time delay (up to 10 ns), and many more. All of these devices may benefit from established manufacturing technologies and ultimately may be as inexpensive as a calculator display. Furthermore, this new integrated photonic architecture has applications in a wide array of commercial and defense markets including: remote sensing, micro-LADAR, OCT, laser illumination, phased array radar, optical communications, etc. Performance attributes of several example devices are presented.

  10. Generalized Fourier slice theorem for cone-beam image reconstruction.

    PubMed

    Zhao, Shuang-Ren; Jiang, Dazong; Yang, Kevin; Yang, Kang

    2015-01-01

    The cone-beam reconstruction theory has been proposed by Kirillov in 1961, Tuy in 1983, Feldkamp in 1984, Smith in 1985, Pierre Grangeat in 1990. The Fourier slice theorem is proposed by Bracewell 1956, which leads to the Fourier image reconstruction method for parallel-beam geometry. The Fourier slice theorem is extended to fan-beam geometry by Zhao in 1993 and 1995. By combining the above mentioned cone-beam image reconstruction theory and the above mentioned Fourier slice theory of fan-beam geometry, the Fourier slice theorem in cone-beam geometry is proposed by Zhao 1995 in short conference publication. This article offers the details of the derivation and implementation of this Fourier slice theorem for cone-beam geometry. Especially the problem of the reconstruction from Fourier domain has been overcome, which is that the value of in the origin of Fourier space is 0/0. The 0/0 type of limit is proper handled. As examples, the implementation results for the single circle and two perpendicular circle source orbits are shown. In the cone-beam reconstruction if a interpolation process is considered, the number of the calculations for the generalized Fourier slice theorem algorithm is O(N^4), which is close to the filtered back-projection method, here N is the image size of 1-dimension. However the interpolation process can be avoid, in that case the number of the calculations is O(N5).

  11. Electro-optical polycrystalline barium lanthanum titanium niobate

    SciTech Connect

    Mehrotra, A.K.

    1991-02-19

    This patent describes a transparent electro-optic article. It comprises: of a barium lanthanum titanium niobate wherein substantially all grains are of a grain size between about 2 and about 20 micron, the article has a pore volume of less than about 1 percent, and the article has a grain size of between about 2 and about 20 microns. This patent also describes a method of forming transparent electro-optical barium lanthanum titanium niobate. It comprises: providing particles of barium carbonate, lanthanum oxide, titanium oxide, and niobium oxide, calcining the particles, sintering the calcined particles at a temperature of between about 1200{degrees} C and 1300{degrees} C. and a vacuum of between about 10{sup {minus}3} and 10{sup {minus}4} torr while under pressure to form a sintered mass, cooling the sintered mass, slicing the mass to form wafers, heating the wafers in an oxidizing atmosphere.

  12. Automatic laser glare suppression in electro-optical sensors.

    PubMed

    Ritt, Gunnar; Eberle, Bernd

    2015-01-05

    Progress in laser technology has led to very compact but nevertheless powerful laser sources. In the visible and near infrared spectral region, lasers of any wavelength can be purchased. Continuous wave laser sources pose an especially serious threat to the human eye and electro-optical sensors due to their high proliferation and easy availability. The manifold of available wavelengths cannot be covered by conventional safety measures like absorption or interference filters. We present a protection concept for electro-optical sensors to suppress dazzling in the visible spectral region. The key element of the concept is the use of a digital micromirror device (DMD) in combination with wavelength multiplexing. This approach allows selective spectral filtering in defined regions of interest in the scene. The system offers the possibility of automatic attenuation of dazzling laser radiation.

  13. Automatic Laser Glare Suppression in Electro-Optical Sensors

    PubMed Central

    Ritt, Gunnar; Eberle, Bernd

    2015-01-01

    Progress in laser technology has led to very compact but nevertheless powerful laser sources. In the visible and near infrared spectral region, lasers of any wavelength can be purchased. Continuous wave laser sources pose an especially serious threat to the human eye and electro-optical sensors due to their high proliferation and easy availability. The manifold of available wavelengths cannot be covered by conventional safety measures like absorption or interference filters. We present a protection concept for electro-optical sensors to suppress dazzling in the visible spectral region. The key element of the concept is the use of a digital micromirror device (DMD) in combination with wavelength multiplexing. This approach allows selective spectral filtering in defined regions of interest in the scene. The system offers the possibility of automatic attenuation of dazzling laser radiation. PMID:25569754

  14. Electro-optic techniques in electron beam diagnostics

    SciTech Connect

    van Tilborg, Jeroen; Toth, Csaba; Matlis, Nicholas; Plateau, Guillaume; Leemans, Wim

    2011-06-17

    Electron accelerators such as laser wakefield accelerators, linear accelerators driving free electron lasers, or femto-sliced synchrotrons, are capable of producing femtosecond-long electron bunches. Single-shot characterization of the temporal charge profile is crucial for operation, optimization, and application of such accelerators. A variety of electro-optic sampling (EOS) techniques exists for the temporal analysis. In EOS, the field profile from the electron bunch (or the field profile from its coherent radiation) will be transferred onto a laser pulse co-propagating through an electro-optic crystal. This paper will address the most common EOS schemes and will list their advantages and limitations. Strong points that all techniques share are the ultra-short time resolution (tens of femtoseconds) and the single-shot capabilities. Besides introducing the theory behind EOS, data from various research groups is presented for each technique.

  15. Electro-optic and Acousto-optic Laser Beam Scanners

    NASA Astrophysics Data System (ADS)

    Römer, G. R. B. E.; Bechtold, P.

    Optical solid state deflectors rely on the electro-optical or acousto-optic effect. These Electro-Optical Deflectors (EODs) and Acousto-Optical Deflectors (AODs) do not contain moving parts and therefore exhibit high deflection velocities and are free of drawbacks associated with mechanical scanners. A description of the principles of operation of EODs and AODs is presented. In addition, characteristics, properties and the (dis)advantages of EODs and AODs, when compared to mirror based mechanical deflectors, is discussed. Deflection angles, speed and accuracy are discussed in terms of resolvable spots and related quantities. Also, response time, damage threshold, efficiency and the type and magnitude of beam distortions is addressed. Optical deflectors are characterized by high angular deflection velocities, but small deflection angles. Whereas mechanical mechanical scanners are characterized by relatively small deflection velocities, but large deflection angles. Arranging an optical deflector and a mechanical scanner in series allows to take advantage of the best of both worlds.

  16. Fan beam image reconstruction with generalized Fourier slice theorem.

    PubMed

    Zhao, Shuangren; Yang, Kang; Yang, Kevin

    2014-01-01

    For parallel beam geometry the Fourier reconstruction works via the Fourier slice theorem (or central slice theorem, projection slice theorem). For fan beam situation, Fourier slice can be extended to a generalized Fourier slice theorem (GFST) for fan-beam image reconstruction. We have briefly introduced this method in a conference. This paper reintroduces the GFST method for fan beam geometry in details. The GFST method can be described as following: the Fourier plane is filled by adding up the contributions from all fanbeam projections individually; thereby the values in the Fourier plane are directly calculated for Cartesian coordinates such avoiding the interpolation from polar to Cartesian coordinates in the Fourier domain; inverse fast Fourier transform is applied to the image in Fourier plane and leads to a reconstructed image in spacial domain. The reconstructed image is compared between the result of the GFST method and the result from the filtered backprojection (FBP) method. The major differences of the GFST and the FBP methods are: (1) The interpolation process are at different data sets. The interpolation of the GFST method is at projection data. The interpolation of the FBP method is at filtered projection data. (2) The filtering process are done in different places. The filtering process of the GFST is at Fourier domain. The filtering process of the FBP method is the ramp filter which is done at projections. The resolution of ramp filter is variable with different location but the filter in the Fourier domain lead to resolution invariable with location. One advantage of the GFST method over the FBP method is in short scan situation, an exact solution can be obtained with the GFST method, but it can not be obtained with the FBP method. The calculation of both the GFST and the FBP methods are at O(N^3), where N is the number of pixel in one dimension.

  17. Electro-optical switching of liquid crystals of graphene oxide

    NASA Astrophysics Data System (ADS)

    Song, Jang-Kun

    Electric field effects on aqueous graphene-oxide (GO) dispersions are reviewed in this chapter. In isotropic and biphasic regimes of GO dispersions, in which the inter-particle friction is low, GO particles sensitively respond to the application of electric field, producing field-induced optical birefringence. The electro-optical sensitivity dramatically decreases as the phase transits to the nematic phase; the increasing inter-particle friction hinders the rotational switching of GO particles. The corresponding Kerr coefficient reaches the maximum near the isotropic to biphasic transition concentration, at which the Kerr coefficient is found be c.a. 1:8 · 10-5 mV-2, the highest value ever reported in all Kerr materials. The exceptionally large Kerr effect arises from the Maxwell- Wagner polarization of GO particles with an extremely large aspect ratio and a thick electrical double layer (EDL). The polarization sensitively depends on the ratio of surface and bulk conductivities in dispersions. As a result, low ion concentration in bulk solvent is highly required to achieve a quality electro-optical switching in GO dispersions. Spontaneous vinylogous carboxylic reaction in GO particles produces H+ ions, resulting in spontaneous degradation of electro-optical response with time, hence the removal of residual ions by using a centrifuge cleaning process significantly improves the electro-optical sensitivity. GO particle size is another important parameter for the Kerr coefficient and the response time. The best performance is observed in a GO dispersion with c.a. 0.5 μm mean size. Dielectrophoretic migration of GO particles can be also used to manipulate GO particles in solution. Using these unique features of GO dispersions, one can fabricate GO liquid crystal devices similar to conventional liquid crystal displays; the large Kerr effect allows fabricating a low power device working at extremely low electric fields.

  18. A final look at LDEF electro-optic systems components

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1995-01-01

    Postrecovery characteristics of LDEF electro-optic components from the GTRI tray are compared with their prelaunch characteristics and with the characteristics of similar components from related experiments. Components considered here include lasers, light-emitting diodes, semiconducting radiation detectors and arrays, optical substrates, filters, and mirrors, and specialized coatings. Our understanding of the physical effects resulting from low earth orbit are described, and guidelines and recommendations for component and materials choices are presented.

  19. Electro-optical characterization of GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Olsen, Larry C.; Dunham, Glen; Addis, F. W.; Huber, Dan; Daling, Dave

    1987-01-01

    The electro-optical characterization of gallium arsenide p/n solar cells is discussed. The objective is to identify and understand basic mechanisms which limit the performance of high efficiency gallium arsenide solar cells. The approach involves conducting photoresponse and temperature dependent current-voltage measurements, and interpretation of the data in terms of theory to determine key device parameters. Depth concentration profiles are also utilized in formulating a model to explain device performance.

  20. Electro-Optic Characterisation of Extremely Wide Bandwidth Electrical Signals

    DTIC Science & Technology

    1993-02-01

    In this report an ultrafast electro - optic sampling system suitable for applications such as device characterisation is described. The aperture time of the sampler is calculated to be about 290 fs, implying an attainable device bandwidth in excess of 300 GHz. The sampler was characterised using a test pulse with approximately 12 GHz of frequency content, and the results compared to those obtained from an 18 GHz digital sampling oscilloscope. Signal Processing, Bandwidth, Frequencies, Oscilloscopes.

  1. Electro-Optics and Millimeter-Wave Technology in Japan.

    DTIC Science & Technology

    1987-05-01

    has an input sensitivity of -20 dB. e 6 GHz static divide by 4 prescaler will be commercially available by late 1986. # R&D continues on a dynamic ...Electro-Optics Center Aeronautical Laboratories Dr. Ken J. Ando Mr. Mitchell B. Mellen Defense Advanced Research B-K Dynamics , Inc. Pro.iect Agency...Product Systems (MIPS) which makes personal computers and automation systems, and the Mecatronics Group which makes printers and 3.5 inch disks. One half

  2. Electro-Optical Platform for the Manipulation of Live Cells

    DTIC Science & Technology

    2002-10-02

    Electro-Optical Platform for the Manipulation of Live Cells† M. Ozkan,‡ T. Pisanic,§ J. Scheel,| C. Barlow,| S. Esener,‡ and S. N. Bhatia...revolutionized our understanding of living systems. DNA microarrays, catalytic RNA arrays, and protein arrays are all a consequence of innovations in...engineering at the micro- and nanoscales. Here, we extend this paradigm to the fabrication of live mammalian cell arrays that can be used to investigate

  3. Dielectrically induced sensitivity enhancements in electro-optic field sensors

    NASA Astrophysics Data System (ADS)

    Garzarella, A.; Qadri, S. B.; Wieting, Terence J.; Wu, Dong Ho; Hinton, R. J.

    2007-04-01

    The sensitivity of an electro-optic (EO) field sensor depends inversely on the dielectric constant of the nonlinear crystal. In EO sensors based on lithium niobate the effective value of this dielectric constant is affected by dielectric relaxation effects and is identified with its smaller, high-frequency component. Because of this effect, the EO modulation is significantly enhanced, thus improving the field strength sensitivity.

  4. Visualizing Sound with an Electro-Optical Eardrum

    NASA Astrophysics Data System (ADS)

    Truncale, Nicholas P.; Graham, Michelle T.

    2014-02-01

    As science educators, one of our important responsibilities is ensuring students possess the proper tools and accommodations to examine phenomena in a laboratory setting. It is our job to innovate methods enabling students with disabilities to participate in all aspects of investigations. This article describes an experimental accommodation allowing a deaf student to determine and plot the sensitivity of an electro-optical eardrum in the sound range of 10-150 Hz.

  5. Monocular electro-optical stereo scanner

    NASA Technical Reports Server (NTRS)

    Vermillion, C.; Maurer, H.; Salomonson, V.; Cote, C.; Catena, J.; Rampariyan, H.; Smith, J.

    1988-01-01

    MEOSS is a single optics and single spectral band camera. Three CCD's working in pushbroom mode are mounted perpendicular to the flight direction on a common focal plate. Their oblique views of + and - 23 degrees forward and backward, as well as nadir oriented, lead to threefold stereoscopic images. This principle allows a nearly simultaneous generation of all three images of a stereo triplet. The time gap between the forward and aft looking images guarantees constant illumination conditions. The ground resolution of MEOSS will be 52 by 80 m ground pixel size, height resolution of 55 m and swath width of 255 km. The drifting ground coverage pattern of MEOSS is unique compared to polar orbiting satellites and will allow images of an area to be taken at different times of the day. A scene will consist of 3144 scan lines, with each having 3236 pixels. The data will be received by the Deep Space Network of JPL Goldstone and mailed to Goddard.

  6. Electro-optic product design for manufacture: where next?

    NASA Astrophysics Data System (ADS)

    Barr, John R. M.; MacDonald, M.; Jeffery, G.; Troughton, M.

    2016-10-01

    Manufacturing of electro-optic products for military environments poses a large number of apparently intractable and mutually contradictory problems. The ability to successfully engage in this area presents an intellectual challenge of a high order. The Advanced Targeting Sector of Leonardo's Airborne and Space Systems Division, based in Edinburgh, has developed a successful range of electro-optic products and transitioned these into a volume, and high value, manufacturing environment. As products cycle through the design process, there has been strong feedback from users, suppliers, and most importantly from our manufacturing organization, that has driven evolution of our design practices. It is fair to say that recent pointer trackers and lasers bear little resemblance to those designed and built 10 years ago. Looking ahead, this process will only continue. There are interesting technologies that will drive improvements in manufacturability, reliability and usability of electro-optic products. Examples might include freeform optics, additive manufacture of metal components, and laser welding of optics to metals, to name but a few. These have uses across our product portfolio and, when sufficiently matured, will have a major impact on the product quality and reliability

  7. Electro--optical simulation of diffraction in solar cells.

    PubMed

    Peters, Marius; Rüdiger, Marc; Bläsi, Benedikt; Platzer, Werner

    2010-11-08

    A simulation method is presented and evaluated for simulating two- and three dimensional wave optical effects in crystalline silicon solar cells. Due to a thickness in the 100 µm range, optical properties of these solar cells typically are simulated, primarily through the use of ray-tracing. Recently, diffractive elements such as gratings or photonic crystals have been investigated for their application in crystalline silicon solar cells, making it necessary to consider two- and three dimensional wave optical effects. The presented approach couples a rigorous wave optical simulation to a semiconductor device simulation. In a first step, characteristic parameters, simulated for a reference setup using the electro-optical method and the standard procedure are compared. Occurring differences provide a measure to quantify the errors of the electro-optical method. These errors are below 0.4% relative. In a second step the electro-optical method is used to simulate a crystalline silicon solar cell with a back side diffractive grating. It is found that the grating enhances to short circuit current density jSC of the solar cell by more than 1 mA/cm².

  8. Innovative, Inexpensive Etching Technique Developed for Polymer Electro- Optical Structures

    NASA Technical Reports Server (NTRS)

    Nguyen, Hung D.

    1999-01-01

    Electro-optic, polymer-based integrated optic devices for high-speed communication and computing applications offer potentially significant advantages over conventional inorganic electro-optic crystals. One key area of integrated optical technology--primary processing and fabrication--may particularly benefit from the use of polymer materials. However, as efforts concentrate on the miniaturization of electro-integrated circuit pattern geometries, the ability to etch fine features and smoothly sloped sidewalls is essential to make polymers useful for electro-integrated circuit applications. There are many existing processes available to etch polymer materials, but they all yield nearly vertical sidewalls. Vertical sidewalls are too difficult to reliably cover with a metal layer, and incomplete metalization degrades microwave performance, particularly at high frequency. However, obtaining a very sloped sidewall greatly improves the deposition of metal on the sidewall, leading to low-loss characteristics, which are essential to integrating these devices in highspeed electro-optic modulators. The NASA Lewis Research Center has developed in-house an inexpensive etching technique that uses a photolithography method followed by a simple, wet chemical etching process to etch through polymer layers. In addition to being simpler and inexpensive, this process can be used to fabricate smoothly sloped sidewalls by using a commercial none rodible mask: Spin-On-Glass. A commercial transparent material, Spin-On-Glass, uses processes and equipment similar to that for photoresist techniques.

  9. Polymer waveguide systems for nonlinear and electro-optic applications

    NASA Astrophysics Data System (ADS)

    Pantelis, Philip; Hill, Julian R.; Kashyap, Raman

    1991-12-01

    Waveguides with photochromic or electro-optic properties have been fabricated by a new technique using spin coating of polymers, or guest/host-polymer systems, on to grooves etched in an indium phosphide wafer. Monomoded waveguides at 633 nm, and at 1320 and 1550 nm (wavelengths of telecommunications interest) have been fabricated. These guides have good quality cleaved ends which allow efficient coupling of light from monomoded standard lensed silica fibers. An example of an electro-optic application is given in the form of a phase modulator. This device uses a side-chain polymer as the waveguide core that develops linear electro-optic properties following an electric field alignment process. It was found to have a switching voltage of 30 V, for a (pi) phase change, and had a total insertion loss of 9.4 dB. Waveguides with photochromic properties have also been produced using Aberchrome 670 (a commercially available fulgide) as a guest in a poly(methyl methacrylate) polymer host. Refractive index, optical loss, photochromic activity, and film forming properties of differing concentrations of guest (up to 20% concentration by weight) have been measured and are reported.

  10. Electro-optically actuated liquid-lens zoom

    NASA Astrophysics Data System (ADS)

    Pütsch, O.; Loosen, P.

    2012-06-01

    Progressive miniaturization and mass market orientation denote a challenge to the design of dynamic optical systems such as zoom-lenses. Two working principles can be identified: mechanical actuation and application of active optical components. Mechanical actuation changes the focal length of a zoom-lens system by varying the axial positions of optical elements. These systems are limited in speed and often require complex coupled movements. However, well established optical design approaches can be applied. In contrast, active optical components change their optical properties by varying their physical structure by means of applying external electric signals. An example are liquidlenses which vary their curvatures to change the refractive power. Zoom-lenses benefit from active optical components in two ways: first, no moveable structures are required and second, fast response characteristics can be realized. The precommercial development of zoom-lenses demands simplified and cost-effective system designs. However the number of efficient optical designs for electro-optically actuated zoom-lenses is limited. In this paper, the systematic development of an electro-optically actuated zoom-lens will be discussed. The application of aberration polynomials enables a better comprehension of the primary monochromatic aberrations at the lens elements during a change in magnification. This enables an enhanced synthesis of the system behavior and leads to a simplified zoom-lens design with no moving elements. The change of focal length is achieved only by varying curvatures of targeted integrated electro-optically actuated lenses.

  11. Innovative, Inexpensive Etching Technique Developed for Polymer Electro- Optical Structures

    NASA Technical Reports Server (NTRS)

    Nguyen, Hung D.

    1999-01-01

    Electro-optic, polymer-based integrated optic devices for high-speed communication and computing applications offer potentially significant advantages over conventional inorganic electro-optic crystals. One key area of integrated optical technology--primary processing and fabrication--may particularly benefit from the use of polymer materials. However, as efforts concentrate on the miniaturization of electro-integrated circuit pattern geometries, the ability to etch fine features and smoothly sloped sidewalls is essential to make polymers useful for electro-integrated circuit applications. There are many existing processes available to etch polymer materials, but they all yield nearly vertical sidewalls. Vertical sidewalls are too difficult to reliably cover with a metal layer, and incomplete metalization degrades microwave performance, particularly at high frequency. However, obtaining a very sloped sidewall greatly improves the deposition of metal on the sidewall, leading to low-loss characteristics, which are essential to integrating these devices in highspeed electro-optic modulators. The NASA Lewis Research Center has developed in-house an inexpensive etching technique that uses a photolithography method followed by a simple, wet chemical etching process to etch through polymer layers. In addition to being simpler and inexpensive, this process can be used to fabricate smoothly sloped sidewalls by using a commercial none rodible mask: Spin-On-Glass. A commercial transparent material, Spin-On-Glass, uses processes and equipment similar to that for photoresist techniques.

  12. Lasers and electro-optic technology in natural resource management

    NASA Astrophysics Data System (ADS)

    Greer, Jerry D.

    1991-03-01

    As pressure on our limited land base continues to increase managers of public lands must have more accurate information within a shorter time to make logical defensible decisions which are acceptable to the public. Remote sensing technology provides many tools required to gather much of the information used by decision makers. Some of the most important remote sensing tools are based on laser and electro-optical technology. This paper provides an overview of some applications of laser and electro-optical devices by managers of natural resources. It is important for workers in other fields to be aware of the problems and needs of resource managers as it is important for resource managers to be knowledgeable about developments in technical areas. Sharing information will promote opportunities to develop new tools and improve the effectiveness and efficiency of management. Personal knowledge and literature searches provide examples. While the variety of uses in somewhat limited their importance is increasing as managers and analysts become more accustomed to using products of this technology. Lasers and electro-optical instruments will continue to be a very important part of our data collection process. 2. 0

  13. Quadratic electro-optic Kerr effect in doped graphene

    NASA Astrophysics Data System (ADS)

    Margulis, Vl A.; Muryumin, E. E.; Gaiduk, E. A.

    2017-06-01

    We theoretically investigate one of the third-order nonlinear optical (NLO) effects, namely, the quadratic electro-optic Kerr effect (EOKE), in doped graphene. To avoid the screening of an in-plane external dc electric field by the graphene’s electrons, we propose to use ‘low-amplitude’ (≲ 10 {kV} cm-1) terahertz radiation pulses focused onto the graphene sample collinearly with a normally incident optical beam of frequency ω. Using the Dirac cone approximation for the π-electron energy bands of graphene, we calculate the real part of the effective third-order NLO susceptibility {χ }(3)(-ω ;0,0,ω ), describing the EOKE in doped graphene under the above conditions. The results obtained show that a large electro-optic modulation of the graphene’s refractive index n (up to {{Δ }}n≈ 0.1) can be achieved by proper tuning the Fermi level {E}{{F}} of charge carriers in the graphene sample via electrostatic gating. Furthemore, a change of sign of the electro-optic Kerr coefficient of doped graphene can occur in the spectral range below the photon energy threshold value of 2{E}{{F}}, corresponding to the onset of the fundamental (single-photon) interband absorption in the graphene. These theoretical findings open up new opportunities for practical exploitation of the EOKE in graphene-based NLO devices.

  14. Electro-optic voltage sensor with Multiple Beam Splitting

    DOEpatents

    Woods, Gregory K.; Renak, Todd W.; Crawford, Thomas M.; Davidson, James R.

    2000-01-01

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages without use of the dedicated voltage dividing hardware. The invention achieves voltage measurement without significant error contributions from neighboring conductors or environmental perturbations. The invention employs a transmitter, a sensor, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor. Within the sensor the beam undergoes the Pockels electro-optic effect. The electro-optic effect produces a modulation of the beam's polarization, which is in turn converted to a pair of independent conversely-amplitude-modulated signals, from which the voltage of the E-field is determined by the signal processor. The use of converse AM signals enables the signal processor to better distinguish signal from noise. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  15. Electro-optic voltage sensor with beam splitting

    DOEpatents

    Woods, Gregory K.; Renak, Todd W.; Davidson, James R.; Crawford, Thomas M.

    2002-01-01

    The invention is a miniature electro-optic voltage sensor system capable of accurate operation at high voltages without use of the dedicated voltage dividing hardware typically found in the prior art. The invention achieves voltage measurement without significant error contributions from neighboring conductors or environmental perturbations. The invention employs a transmitter, a sensor, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor. Within the sensor the beam undergoes the Pockels electro-optic effect. The electro-optic effect produces a modulation of the beam's polarization, which is in turn converted to a pair of independent conversely-amplitude-modulated signals, from which the voltage of the E-field is determined by the signal processor. The use of converse AM signals enables the signal processor to better distinguish signal from noise. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  16. Design of a multi-point microwave interferometer using the electro-optic effect

    NASA Astrophysics Data System (ADS)

    Specht, Paul E.; Cooper, Marcia A.; Jilek, Brook A.

    2017-01-01

    A multi-point microwave interferometer (MPMI) concept is presented for non-invasively monitoring the internal transit of a shock, detonation, or reaction front in energetic media. The concept utilizes an electro-optic (EO) crystal to impart a time-varying phase lag onto a laser with a microwave signal. Polarization optics convert this phase lag into an amplitude modulation. A heterodyne interferometer compares the modulated laser beam to a constant reference. This enables the detection of changes in the modulating microwave frequency generated by the motion of the measurement surface. The design is scalable and makes use of the established construction and analysis methods employed in photonic Doppler velocimetry (PDV). The technical challenges associated with the concept are the frequency stability of the lasers, the amount of light return after EO modulation, and the frequency uncertainty of fast Fourier transform (FFT) methods.

  17. Fast interrogation of fiber Bragg grating sensors using electro-optic dual optical frequency combs

    NASA Astrophysics Data System (ADS)

    Bonilla-Manrique, O. E.; Garcia-Souto, J. A.; Martin-Mateos, P.; Jerez-Gonzalez, B.; Acedo, P.

    2015-09-01

    In this document, a FBG interrogation system based on a multimode optical source and a direct read-out is proposed for measuring fast phenomena such as vibrations and ultrasounds. The system is based on an electro-optic dual optical frequency-comb. This architecture allows the configuration of the multimode optical source parameters such as the number of modes that are within the reflected spectrum (FWHM) of the FBG. Results are presented for the dual-comb operating under optimized control when mapping these optical modes onto detectable tones of multiples of 100 kHz around a centre radiofrequency tone (40 MHz). Dynamic strain is induced onto the fiber through an actuator, which generates changes in the reflected wavelength of the FBG and in turn the modes within the reflected spectrum. The electrical signals are analyzed using fast Fourier transform algorithms allowing identification of the vibrations.

  18. PREFACE: Colloidal and molecular electro-optics Colloidal and molecular electro-optics

    NASA Astrophysics Data System (ADS)

    Palberg, Thomas; Löwen, Hartmut

    2010-12-01

    The Kerr effect, also known as the quadratic electro-optic effect, was discovered more than a hundred years ago by John Kerr, a Scottish physicist [1]. It describes the change in the refractive index of a material in response to an applied electric field. Around 1950 its application swayed from simple to complex fluids. A strong contribution was made through a number of seminal papers by the French polymer scientist H Benoit [2-4]. These and others initiated wide interest from researchers working on macromolecular solutions or colloidal dispersions. Experimental activities were further boosted by the advent of the laser and theoretical approaches strongly drew from growing computer power. Use of AC or pulsed field techniques, as well as of inhomogeneous fields, including laser tweezers, studies of electrophoretic, dielectrophoretic, electro-osmotic and other types of motion by advanced optical methods and combinations with other external fields have had the greatest impact on our understanding of the electric field induced optical properties of soft matter systems. Today the field has matured and its techniques are broadly employed as versatile tools with applications ranging from biological systems to electronic ink. Fundamental interest still continues but more and more side branches have evolved fruitfully. This collection of papers was, therefore, brought together to take a fresh look at this traditional field. Further, we are to celebrate 35 years of a successful conference series, ELOPTO, with the last one held at Waldthausen Castle hosted by the Johannes Gutenberg University, MainzNote1 and the DFG Collaborative Research Centre TR6 'Physics of colloidal dispersions in external fields'Note2. In this issue we have collected the articles of some of the leading experts in the area, well garnished with novel approaches and clever ideas by younger colleagues. With our selection we hope to cover a representative spectrum of the ongoing research, catch the most

  19. Development of an Imaging Fourier Transform Spectrometer

    DTIC Science & Technology

    1986-05-01

    13. Smith, Warren J. Modern Optical Engineering . McGraw Hill Book Company, New York, 1966. 14. Sanderson, R. B. "Fourier Spectroscopy." Molecular...DOWNGRADIP,.G SCHEDU.E 4 PERFORMING ORGANIZATION REPORT NUMBERIS) AEDC-TR-86-17 6a. NAME OF PERFORMING ORGANIZATION ~ h Arnold Engineering L...PREFACE The work reported herein was conducted by the Arnold Engineering Development Center (AEDC), Air Force Systems Command (AFSC), from October

  20. An optical-fiber-scale electro-optic probe for minimally invasive high-frequency field sensing.

    PubMed

    Lee, Dong-Joon; Whitaker, John F

    2008-12-22

    A sub-millimeter-dimension electro-optic probe that provides enhanced scanning accessibility with significantly less intrusiveness than metal-based or even other dielectric probes during electromagnetic characterization of microwave devices is presented. The quantitative and qualitative relative invasiveness of the probe on the operation of an example antenna device-under-test is explored with respect to previously demonstrated fiber and wafer electro-optic sensors. We also demonstrate that the miniaturized probe, with a diameter of 125 microm, can be used to reconstruct the three orthogonal vector components of near-electric fields without the need for different probe crystals or multiple calibration procedures. Finally, the advantages of the reduced size and invasiveness of the new micro-scale probe are demonstrated through the enhanced resolution of detailed images extracted from planar antennas, as well as the capability of reaching into circuit locations heretofore inaccessible.

  1. Fourier domain OCT imaging of American cockroach nervous system

    NASA Astrophysics Data System (ADS)

    Wyszkowska, Joanna; Gorczynska, Iwona; Ruminski, Daniel; Karnowski, Karol; Kowalczyk, Andrzej; Stankiewicz, Maria; Wojtkowski, Maciej

    2012-01-01

    In this pilot study we demonstrate results of structural Fourier domain OCT imaging of the nervous system of Periplaneta americana L. (American cockroach). The purpose of this research is to develop an OCT apparatus enabling structural imaging of insect neural system. Secondary purpose of the presented research is to develop methods of the sample preparation and handling during the OCT imaging experiments. We have performed imaging in the abdominal nerve cord excised from the American cockroach. For this purpose we have developed a Fourier domain / spectral OCT system operating at 820 nm wavelength range.

  2. Fourier Spectral Filter Array for Optimal Multispectral Imaging.

    PubMed

    Jia, Jie; Barnard, Kenneth J; Hirakawa, Keigo

    2016-04-01

    Limitations to existing multispectral imaging modalities include speed, cost, range, spatial resolution, and application-specific system designs that lack versatility of the hyperspectral imaging modalities. In this paper, we propose a novel general-purpose single-shot passive multispectral imaging modality. Central to this design is a new type of spectral filter array (SFA) based not on the notion of spatially multiplexing narrowband filters, but instead aimed at enabling single-shot Fourier transform spectroscopy. We refer to this new SFA pattern as Fourier SFA, and we prove that this design solves the problem of optimally sampling the hyperspectral image data.

  3. Production Testing Of Electro-Optical Systems

    NASA Astrophysics Data System (ADS)

    Nash, S. L.

    1982-12-01

    Hughes Aircraft Company builds a variety of Electra-Optical Systems within its Manufacturing Division in El Segundo, California. The magnitude of the testing function within the manufacturing cycle of these systems, whether they are a Laser Fire Control System, a Thermal Imaging System, or some type of dedicated electronics, is almost beyond measure. Whereas testing was once quite simple, today's more complex products demand more complex test strategies. In our typical manufacturing cycle, there are at least nine (9) separate areas in which testing related to the product (end-item) may be performed. In this paper, an overview of these test areas will be discussed along with same of the considerations that are necessary for a logical manufacturing test strategy.

  4. Night Vision And Electro-Optics Laboratory (NVEOL) Performance Model And Its Use

    NASA Astrophysics Data System (ADS)

    Hoover, C.; Ratches, J.; Shields, F.; Mayo, K.

    1982-06-01

    This paper discusses the major design tools utilized at the Night Vision and Electro-Optics Laboratory (NVEOL) for analyzing electro-optical sensor systems. The Thermal Static Performance Model is described as an example of the methods used. The other systems models are based on the same concepts both in analysis and computer programming. The basic approach for all the laboratory and field models is tied to measurement techniques. The models provide a set of tools to write specifications, design systems and analyze requirements. The basic thermal model code, its use, and limitations will be explained. The current version utilized at NVEOL makes use of an interactive input data structure, and includes a graphics package for field performance. Similiar models exist for image intensifiers (II), television (TV), and aided/unaided eye. These models however are not as widely used and therefore have not received the same level of resources as the thermal models. All of these models enable one to predict performance against a variety of target configurations and atmospheric conditions including smoke. The use of the computer programs is illustra-ted.

  5. Dual-Mode Electro-Optical Techniques for Biosensing Applications: A Review

    PubMed Central

    Johnson, Steven

    2017-01-01

    The monitoring of biomolecular interactions is a key requirement for the study of complex biological processes and the diagnosis of disease. Technologies that are capable of providing label-free, real-time insight into these interactions are of great value for the scientific and clinical communities. Greater understanding of biomolecular interactions alongside increased detection accuracy can be achieved using technology that can provide parallel information about multiple parameters of a single biomolecular process. For example, electro-optical techniques combine optical and electrochemical information to provide more accurate and detailed measurements that provide unique insights into molecular structure and function. Here, we present a comparison of the main methods for electro-optical biosensing, namely, electrochemical surface plasmon resonance (EC-SPR), electrochemical optical waveguide lightmode spectroscopy (EC-OWLS), and the recently reported silicon-based electrophotonic approach. The comparison considers different application spaces, such as the detection of low concentrations of biomolecules, integration, the tailoring of light-matter interaction for the understanding of biomolecular processes, and 2D imaging of biointeractions on a surface. PMID:28880211

  6. Dual-Mode Electro-Optical Techniques for Biosensing Applications: A Review.

    PubMed

    Juan-Colás, José; Johnson, Steven; Krauss, Thomas F

    2017-09-07

    The monitoring of biomolecular interactions is a key requirement for the study of complex biological processes and the diagnosis of disease. Technologies that are capable of providing label-free, real-time insight into these interactions are of great value for the scientific and clinical communities. Greater understanding of biomolecular interactions alongside increased detection accuracy can be achieved using technology that can provide parallel information about multiple parameters of a single biomolecular process. For example, electro-optical techniques combine optical and electrochemical information to provide more accurate and detailed measurements that provide unique insights into molecular structure and function. Here, we present a comparison of the main methods for electro-optical biosensing, namely, electrochemical surface plasmon resonance (EC-SPR), electrochemical optical waveguide lightmode spectroscopy (EC-OWLS), and the recently reported silicon-based electrophotonic approach. The comparison considers different application spaces, such as the detection of low concentrations of biomolecules, integration, the tailoring of light-matter interaction for the understanding of biomolecular processes, and 2D imaging of biointeractions on a surface.

  7. LLNL electro-optical mine detection program

    SciTech Connect

    Anderson, C.; Aimonetti, W.; Barth, M.; Buhl, M.; Bull, N.; Carter, M.; Clark, G.; Fields, D.; Fulkerson, S.; Kane, R.

    1994-09-30

    Under funding from the Advanced Research Projects Agency (ARPA) and the US Marine Corps (USMC), Lawrence Livermore National Laboratory (LLNL) has directed a program aimed at improving detection capabilities against buried mines and munitions. The program has provided a national test facility for buried mines in arid environments, compiled and distributed an extensive data base of infrared (IR), ground penetrating radar (GPR), and other measurements made at that site, served as a host for other organizations wishing to make measurements, made considerable progress in the use of ground penetrating radar for mine detection, and worked on the difficult problem of sensor fusion as applied to buried mine detection. While the majority of our effort has been concentrated on the buried mine problem, LLNL has worked with the U.S.M.C. on surface mine problems as well, providing data and analysis to support the COBRA (Coastal Battlefield Reconnaissance and Analysis) program. The original aim of the experimental aspect of the program was the utilization of multiband infrared approaches for the detection of buried mines. Later the work was extended to a multisensor investigation, including sensors other than infrared imagers. After an early series of measurements, it was determined that further progress would require a larger test facility in a natural environment, so the Buried Object Test Facility (BOTF) was constructed at the Nevada Test Site. After extensive testing, with sensors spanning the electromagnetic spectrum from the near ultraviolet to radio frequencies, possible paths for improvement were: improved spatial resolution providing better ground texture discrimination; analysis which involves more complicated spatial queueing and filtering; additional IR bands using imaging spectroscopy; the use of additional sensors other than IR and the use of data fusion techniques with multi-sensor data; and utilizing time dependent observables like temperature.

  8. Fast Fourier single-pixel imaging via binary illumination.

    PubMed

    Zhang, Zibang; Wang, Xueying; Zheng, Guoan; Zhong, Jingang

    2017-09-20

    Fourier single-pixel imaging (FSI) employs Fourier basis patterns for encoding spatial information and is capable of reconstructing high-quality two-dimensional and three-dimensional images. Fourier-domain sparsity in natural scenes allows FSI to recover sharp images from undersampled data. The original FSI demonstration, however, requires grayscale Fourier basis patterns for illumination. This requirement imposes a limitation on the imaging speed as digital micro-mirror devices (DMDs) generate grayscale patterns at a low refreshing rate. In this paper, we report a new strategy to increase the speed of FSI by two orders of magnitude. In this strategy, we binarize the Fourier basis patterns based on upsampling and error diffusion dithering. We demonstrate a 20,000 Hz projection rate using a DMD and capture 256-by-256-pixel dynamic scenes at a speed of 10 frames per second. The reported technique substantially accelerates image acquisition speed of FSI. It may find broad imaging applications at wavebands that are not accessible using conventional two-dimensional image sensors.

  9. Digital image pattern recognition system using normalized Fourier transform and normalized analytical Fourier-Mellin transform

    NASA Astrophysics Data System (ADS)

    Vélez-Rábago, Rodrigo; Solorza-Calderón, Selene; Jordan-Aramburo, Adina

    2016-12-01

    This work presents an image pattern recognition system invariant to translation, scale and rotation. The system uses the Fourier transform to achieve the invariance to translation and the analytical Forier-Mellin transform for the invariance to scale and rotation. According with the statistical theory of box-plots, the pattern recognition system has a confidence level at least of 95.4%.

  10. Electro-optic crystal mosaics for the generation of terahertz radiation

    DOEpatents

    Carrig, T.J.; Taylor, A.J.; Stewart, K.R.

    1996-08-06

    Apparatus for the generation of high energy terahertz radiation is presented and comprises laser means effective to produce subpicosecond optical pulses and a mosaic comprising a plurality of planar electro-optic crystals fastened together edge to edge in the form of a grid. The electro-optic crystals are in optical communication with the subpicosecond optical pulses, and behave as a single large electro-optic crystal, producing high energy terahertz radiation by way of optical rectification. 5 figs.

  11. Electro-optic crystal mosaics for the generation of terahertz radiation

    DOEpatents

    Carrig, Timothy J.; Taylor, Antoinette J.; Stewart, Kevin R.

    1996-01-01

    Apparatus for the generation of high energy terahertz radiation is presented and comprises laser means effective to produce subpicosecond optical pulses and a mosaic comprising a plurality of planar electro-optic crystals fastened together edge to edge in the form of a grid. The electro-optic crystals are in optical communication with the subpicosecond optical pulses, and behave as a single large electro-optic crystal, producing high energy terahertz radiation by way of optical rectification.

  12. Stoichiometric Lithium Niobate (SLN) Based Linearized Electro-Optic (EO) Modulator

    DTIC Science & Technology

    2006-01-01

    AFRL-SN-RS-TR-2006-15 Final Technical Report January 2006 STOICHIOMETRIC LITHIUM NIOBATE (SLN) BASED LINEARIZED ELECTRO - OPTIC (EO...LITHIUM NIOBATE (SLN) BASED LINEARIZED ELECTRO - OPTIC (EO) MODULATOR 6. AUTHOR(S) Dr Stuart Kingsley, Dr Sri Sriram 5. FUNDING NUMBERS C...SUBJECT TERMS electro - optic modulator, linearization, directional coupler, variable coupling, optical waveguide, Mach-Zehnder, photonic link, lithium

  13. Electro-Optic Properties of Holographically Patterned, Polymer Stabilized Cholesteric Liquid Crystals (Preprint)

    DTIC Science & Technology

    2007-01-01

    Electro - optic properties of cholesteric liquid crystals with holographically patterned polymer stabilization were examined. It is hypothesized that...enhanced electro - optic properties of the final device. Prior to holographic patterning, polymer stabilization with large elastic memory was generated by way... electro - optic properties appear to stem from a single dimension domain size increase, which allows for a reduction in the LC/polymer interaction.

  14. Nonlinear Optical Acrylic Polymers and Use Thereof in Optical and Electro-Optic Devices

    DTIC Science & Technology

    1992-01-07

    COVERED 4. TITLE AND SUBTITLE Nonlinear Optical Acrylic Polymers and Use Thereof in Optical and Electro - Optic Devices 5a. CONTRACT NUMBER 5b. GRANT...generators, computational devices and the like. 15. SUBJECT TERMS optical devices, electro - optical devices, optical signal processing...THEREOF IN OPTICAL AND ELECTRO - OPTIC DEVICES [75] Inventors: Le*lie H. Sperling, Bethlehem; Clarence J. Murphy, Stroudsburg; Warren A. Rosen

  15. Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS): Imaging and Tracking Capability

    NASA Technical Reports Server (NTRS)

    Zhou, D. K.; Larar, A. M.; Liu, Xu; Reisse, R. A.; Smith, W. L.; Revercomb, H. E.; Bingham, G. E.; Zollinger, L. J.; Tansock, J. J.; Huppi, Ronald J.

    2007-01-01

    The geosynchronous-imaging Fourier transform spectrometer (GIFTS) engineering demonstration unit (EDU) is an imaging infrared spectrometer designed for atmospheric soundings. It measures the infrared spectrum in two spectral bands (14.6 to 8.8 microns, 6.0 to 4.4 microns) using two 128 128 detector arrays with a spectral resolution of 0.57/cm with a scan duration of approx. 11 seconds. From a geosynchronous orbit, the instrument will have the capability of taking successive measurements of such data to scan desired regions of the globe, from which atmospheric status, cloud parameters, wind field profiles, and other derived products can be retrieved. The GIFTS EDU provides a flexible and accurate testbed for the new challenges of the emerging hyperspectral era. The EDU ground-based measurement experiment, held in Logan, Utah during September 2006, demonstrated its extensive capabilities and potential for geosynchronous and other applications (e.g., Earth observing environmental measurements). This paper addresses the experiment objectives and overall performance of the sensor system with a focus on the GIFTS EDU imaging capability and proof of the GIFTS measurement concept.

  16. MTF measurements on real time for performance analysis of electro-optical systems

    NASA Astrophysics Data System (ADS)

    Stuchi, Jose Augusto; Signoreto Barbarini, Elisa; Vieira, Flavio Pascoal; dos Santos, Daniel, Jr.; Stefani, Mário Antonio; Yasuoka, Fatima Maria Mitsue; Castro Neto, Jarbas C.; Linhari Rodrigues, Evandro Luis

    2012-06-01

    The need of methods and tools that assist in determining the performance of optical systems is actually increasing. One of the most used methods to perform analysis of optical systems is to measure the Modulation Transfer Function (MTF). The MTF represents a direct and quantitative verification of the image quality. This paper presents the implementation of the software, in order to calculate the MTF of electro-optical systems. The software was used for calculating the MTF of Digital Fundus Camera, Thermal Imager and Ophthalmologic Surgery Microscope. The MTF information aids the analysis of alignment and measurement of optical quality, and also defines the limit resolution of optical systems. The results obtained with the Fundus Camera and Thermal Imager was compared with the theoretical values. For the Microscope, the results were compared with MTF measured of Microscope Zeiss model, which is the quality standard of ophthalmological microscope.

  17. Implementation of spatial overlap modulation nonlinear optical microscopy using an electro-optic deflector

    PubMed Central

    Isobe, Keisuke; Kawano, Hiroyuki; Kumagai, Akiko; Miyawaki, Atsushi; Midorikawa, Katsumi

    2013-01-01

    A spatial overlap modulation (SPOM) technique is a nonlinear optical microscopy technique which enhances the three-dimensional spatial resolution and rejects the out-of-focus background limiting the imaging depth inside a highly scattering sample. Here, we report on the implementation of SPOM in which beam pointing modulation is achieved by an electro-optic deflector. The modulation and demodulation frequencies are enhanced to 200 kHz and 400 kHz, respectively, resulting in a 200-fold enhancement compared with the previously reported system. The resolution enhancement and suppression of the out-of-focus background are demonstrated by sum-frequency-generation imaging of pounded granulated sugar and deep imaging of fluorescent beads in a tissue-like phantom, respectively. PMID:24156055

  18. Fractional Fourier transform in temporal ghost imaging with classical light

    SciTech Connect

    Setaelae, Tero; Shirai, Tomohiro; Friberg, Ari T.

    2010-10-15

    We investigate temporal, second-order classical ghost imaging with long, incoherent, scalar plane-wave pulses. We prove that in rather general conditions, the intensity correlation function at the output of the setup is given by the fractional Fourier transform of the temporal object. In special cases, the correlation function is shown to reduce to the ordinary Fourier transform and the temporal image of the object. Effects influencing the visibility and the resolution are considered. This work extends certain known results on spatial ghost imaging into the time domain and could find applications in temporal tomography of pulses.

  19. Nanosecond Electro-Optic Switching of a Liquid Crystal

    NASA Astrophysics Data System (ADS)

    Borshch, Volodymyr; Shiyanovskii, Sergij V.; Lavrentovich, Oleg D.

    2013-09-01

    Electrically induced reorientation of nematic liquid crystal (NLC) molecules caused by dielectric anisotropy of the material is a fundamental phenomenon widely used in modern technologies. Its Achilles heel is a slow (millisecond) relaxation from the field-on to the field-off state. We present an electro-optic effect in an NLC with a response time of about 30 ns to both the field-on and field-off switching. This effect is caused by the electric field induced modification of the order parameters and does not require reorientation of the optic axis (director).

  20. Simple electro-optically controlled dual-axis sun tracker

    SciTech Connect

    Lynch, W.A.; Salameh, Z.M. )

    1990-01-01

    This paper describes the design of a sun tracker which uses two electro-optic sensors and a small, low-cost electronic control circuit. One sensor is a four-cell pyramid which is mounted on the tracker plane. The second sensor is a sunlight beam sensor which is fixed facing south. The control circuit tracking resolution is within 0.1 degrees. This system minimizes wandering on partially overcast days. It will never make multiple revolutions or face down towards the ground. Power MOSFETS (Metal Oxide Semiconductor Field Effect Transistors) are used to drive high-torque DC gearbox motors.

  1. Deposited silicon high-speed integrated electro-optic modulator.

    PubMed

    Preston, Kyle; Manipatruni, Sasikanth; Gondarenko, Alexander; Poitras, Carl B; Lipson, Michal

    2009-03-30

    We demonstrate a micrometer-scale electro-optic modulator operating at 2.5 Gbps and 10 dB extinction ratio that is fabricated entirely from deposited silicon. The polycrystalline silicon material exhibits properties that simultaneously enable high quality factor optical resonators and sub-nanosecond electrical carrier injection. We use an embedded p(+)n(-)n(+) diode to achieve optical modulation using the free carrier plasma dispersion effect. Active optical devices in a deposited microelectronic material can break the dependence on the traditional single layer silicon-on-insulator platform and help lead to monolithic large-scale integration of photonic networks on a microprocessor chip.

  2. Polymeric waveguide prism-based electro-optic beam deflector

    NASA Astrophysics Data System (ADS)

    Sun, Lin; Kim, Jin-ha; Jang, Chiou-Hung; An, Dechang; Lu, Xuejun; Zhou, Qingjun; Taboada, John M.; Chen, Ray T.; Maki, Jeffery J.; Tang, Suning; Zhang, Hua; Steier, William H.; Zhang, Cheng H.; Dalton, Larry R.

    2001-07-01

    Beam steering devices without moving parts are highly desirable for their potential application in emerging optical technologies such as holographic optical storage systems, all optical networks, and optical switches. We demonstrate a thin-film waveguide beam deflector device that consists of an electro-optic prism array within a polymer waveguide. An electrode structure defines the prism array within the planar waveguide. The deflection efficiency of 28 mrad/kV and the maximum deflection angle of +/- 8.4 mrad at +/- 300 V are obtained for this demonstration device. Further optimization of electrode-field poling and processing is likely to improve these results by at least an order of magnitude.

  3. Electro optical tuning of Tamm-plasmon exciton-polaritons

    NASA Astrophysics Data System (ADS)

    Gessler, J.; Baumann, V.; Emmerling, M.; Amthor, M.; Winkler, K.; Höfling, S.; Schneider, C.; Kamp, M.

    2014-11-01

    We report on electro optical tuning of the emission from GaAs quantum wells resonantly coupled to a Tamm-plasmon mode in a hybrid metal/dielectric structure. The structures were studied via momentum resolved photoluminescence and photoreflectance spectroscopy, and the surface metal layer was used as a top gate, which allowed for a precise tuning of the quantum well emission via the quantum confined Stark effect. By tuning the resonance, we were able to observe the characteristic anticrossing behavior of a polaritonic emission in the strong light-matter coupling regime, yielding a Rabi splitting of (9.2 ± 0.2) meV.

  4. Electro-Optical Modulator Bias Control Using Bipolar Pulses

    NASA Technical Reports Server (NTRS)

    Farr, William; Kovalik, Joseph

    2007-01-01

    An improved method has been devised for controlling the DC bias applied to an electro-optical crystal that is part of a Mach-Zehnder modulator that generates low-duty-cycle optical pulses for a pulse-position modulation (PPM) optical data-communication system. In such a system, it is desirable to minimize the transmission of light during the intervals between pulses, and for this purpose, it is necessary to maximize the extinction ratio of the modulator (the ratio between the power transmitted during an "on" period and the power transmitted during an "off" period). The present method is related to prior dither error feedback methods, but unlike in those methods, there is no need for an auxiliary modulation subsystem to generate a dithering signal. Instead, as described below, dither is effected through alternation of the polarity of the modulation signal. The upper part of Figure 1 schematically depicts a Mach-Zehnder modulator. The signal applied to the electro-optical crystal consists of a radio-frequency modulating pulse signal, VRF, superimposed on a DC bias Vbias. Maximum extinction occurs during the off (VRF = 0) period if Vbias is set at a value that makes the two optical paths differ by an odd integer multiple of a half wavelength so that the beams traveling along the two paths interfere destructively at the output beam splitter. Assuming that the modulating pulse signal VRF has a rectangular waveform, maximum transmission occurs during the "on" period if the amplitude of VRF is set to a value, V , that shifts the length of the affected optical path by a half wavelength so that now the two beams interfere constructively at the output beam splitter. The modulating pulse signal is AC-coupled from an amplifier to the electro-optical crystal. Sometimes, two successive pulses occur so close in time that the operating point of the amplifier drifts, one result being that there is not enough time for the signal level to return to ground between pulses. Also, the

  5. Infrared electro-optical detector to rescue humans

    NASA Astrophysics Data System (ADS)

    Ysi-Zarco, Paulo; Castro Ramos, Jorge; Gordiano-Alvarado, Gabriel

    2004-10-01

    We designed and built an electro-optical sensor to detect human bodies. The aim of this paper is to describe a device to make easier the localization of lost people in natural disasters or in dangerous environments. The detection is realized in base of the infrared radiation emitted by the human body. We employ point commercial pyloric quantum sensors, the electronic assembly integrates the captured infrared energy by using low noise chip. The optical device include a Cassegrain antenna, a diffraction grating which besides to choose in automatic way the correct wavelength emitted by the human body, it is useful as optical filter.

  6. Electro optical tuning of Tamm-plasmon exciton-polaritons

    SciTech Connect

    Gessler, J.; Baumann, V.; Emmerling, M.; Amthor, M.; Winkler, K.; Schneider, C.; Kamp, M.; Höfling, S.

    2014-11-03

    We report on electro optical tuning of the emission from GaAs quantum wells resonantly coupled to a Tamm-plasmon mode in a hybrid metal/dielectric structure. The structures were studied via momentum resolved photoluminescence and photoreflectance spectroscopy, and the surface metal layer was used as a top gate, which allowed for a precise tuning of the quantum well emission via the quantum confined Stark effect. By tuning the resonance, we were able to observe the characteristic anticrossing behavior of a polaritonic emission in the strong light-matter coupling regime, yielding a Rabi splitting of (9.2 ± 0.2) meV.

  7. The Deposition of Electro-Optic Films on Semiconductors

    DTIC Science & Technology

    1993-10-08

    Electro - optic properties of KNbO3 films on MgO are found to be similar to bulk, although the scattering losses are very high for these films. In comparison KNbO3 films grown on KTaO3 exhibit low losses of less than 8 dB, while losses for films on spinel showed to be in between those two. The variety of substrates provide us with differences in lattice mismatch, refractive index mismatch, surface morphologies, and microstructure, all of which influence loss

  8. Electro-optic analyzer of angular momentum hyperentanglement

    PubMed Central

    Wu, Ziwen; Chen, Lixiang

    2016-01-01

    Characterizing a high-dimensional entanglement is fundamental in quantum information applications. Here, we propose a theoretical scheme to analyze and characterize the angular momentum hyperentanglement that two photons are entangled simultaneously in spin and orbital angular momentum. Based on the electro-optic sampling with a proposed hyper-entanglement analyzer and the simple matrix operation using Cramer rule, our simulations show that it is possible to retrieve effectively both the information about the degree of polarization entanglement and the spiral spectrum of high-dimensional orbital angular momentum entanglement. PMID:26911530

  9. Introduction into service of mature pushbroom electro-optic sensors

    NASA Astrophysics Data System (ADS)

    Brownie, Ralph S.

    2000-11-01

    Pushbroom Electro-Optic sensors have been developed and brought into full production, entering service in year 2000 on RAF Jaguar and Belgian Air Force F-16. The use of fiber- optic gyroscopes, closely coupled to the focal plane electronics, permits correction of all motion effects and provides practical high quality, stereo imagery at high V/H ratios. This paper describes technical features and samples of imagery from a scalable range of sensors incorporating focal lengths from 38mm to 900mm and operating throughout the full flight envelope of modern fighter aircraft.

  10. Electro-optic probe measurements of electric fields in plasmas.

    PubMed

    Nishiura, M; Yoshida, Z; Mushiake, T; Kawazura, Y; Osawa, R; Fujinami, K; Yano, Y; Saitoh, H; Yamasaki, M; Kashyap, A; Takahashi, N; Nakatsuka, M; Fukuyama, A

    2017-02-01

    The direct measurements of high-frequency electric fields in a plasma bring about significant advances in the physics and engineering of various waves. We have developed an electro-optic sensor system based on the Pockels effect. Since the signal is transmitted through an optical fiber, the system has high tolerance for electromagnetic noises. To demonstrate its applicability to plasma experiments, we report the first result of measurement of the ion-cyclotron wave excited in the RT-1 magnetosphere device. This study compares the results of experimental field measurements with simulation results of electric fields in plasmas.

  11. Electro-optic probe measurements of electric fields in plasmas

    NASA Astrophysics Data System (ADS)

    Nishiura, M.; Yoshida, Z.; Mushiake, T.; Kawazura, Y.; Osawa, R.; Fujinami, K.; Yano, Y.; Saitoh, H.; Yamasaki, M.; Kashyap, A.; Takahashi, N.; Nakatsuka, M.; Fukuyama, A.

    2017-02-01

    The direct measurements of high-frequency electric fields in a plasma bring about significant advances in the physics and engineering of various waves. We have developed an electro-optic sensor system based on the Pockels effect. Since the signal is transmitted through an optical fiber, the system has high tolerance for electromagnetic noises. To demonstrate its applicability to plasma experiments, we report the first result of measurement of the ion-cyclotron wave excited in the RT-1 magnetosphere device. This study compares the results of experimental field measurements with simulation results of electric fields in plasmas.

  12. Electro-optic analyzer of angular momentum hyperentanglement.

    PubMed

    Wu, Ziwen; Chen, Lixiang

    2016-02-25

    Characterizing a high-dimensional entanglement is fundamental in quantum information applications. Here, we propose a theoretical scheme to analyze and characterize the angular momentum hyperentanglement that two photons are entangled simultaneously in spin and orbital angular momentum. Based on the electro-optic sampling with a proposed hyper-entanglement analyzer and the simple matrix operation using Cramer rule, our simulations show that it is possible to retrieve effectively both the information about the degree of polarization entanglement and the spiral spectrum of high-dimensional orbital angular momentum entanglement.

  13. Radiation resistance of electro-optic polymer-based modulators

    NASA Astrophysics Data System (ADS)

    Taylor, Edward W.; Nichter, James E.; Nash, Fazio D.; Haas, Franz; Szep, Attila A.; Michalak, Richard J.; Flusche, Brian M.; Cook, Paul R.; McEwen, Tom A.; McKeon, Brian F.; Payson, Paul M.; Brost, George A.; Pirich, Andrew R.; Castaneda, Carlos; Tsap, Boris; Fetterman, Harold R.

    2005-05-01

    Mach-Zehnder interferometric electro-optic polymer modulators composed of highly nonlinear phenyltetraene bridge-type chromophores within an amorphous polycarbonate host matrix were investigated for their resistance to gamma rays and 25.6 MeV protons. No device failures were observed and the majority of irradiated modulators exhibited decreases in half-wave voltage and optical insertion losses compared to nonirradiated control samples undergoing aging processes. Irradiated device responses were attributed to scission, cross-linking, and free volume processes. The data suggests that strongly poled devices are less likely to de-pole under the influence of ionizing radiation.

  14. Benchmarking of Electro-Optic Monitors for Femtosecond Electron Bunches

    SciTech Connect

    Berden, G.; Meer, A. F. G. van der; Gillespie, W. A.; Phillips, P. J.; Jamison, S. P.; Knabbe, E.-A.; Schlarb, H.; Schmidt, B.; Schmueser, P.; Steffen, B.; MacLeod, A. M.

    2007-10-19

    The longitudinal profiles of ultrashort relativistic electron bunches at the soft x-ray free-electron laser FLASH have been investigated using two single-shot detection schemes: an electro-optic (EO) detector measuring the Coulomb field of the bunch and a radio-frequency structure transforming the charge distribution into a transverse streak. A comparison permits an absolute calibration of the EO technique. EO signals as short as 60 fs (rms) have been observed, which is a new record in the EO detection of single electron bunches and close to the limit given by the EO material properties.

  15. Benchmarking of electro-optic monitors for femtosecond electron bunches.

    PubMed

    Berden, G; Gillespie, W A; Jamison, S P; Knabbe, E-A; MacLeod, A M; van der Meer, A F G; Phillips, P J; Schlarb, H; Schmidt, B; Schmüser, P; Steffen, B

    2007-10-19

    The longitudinal profiles of ultrashort relativistic electron bunches at the soft x-ray free-electron laser FLASH have been investigated using two single-shot detection schemes: an electro-optic (EO) detector measuring the Coulomb field of the bunch and a radio-frequency structure transforming the charge distribution into a transverse streak. A comparison permits an absolute calibration of the EO technique. EO signals as short as 60 fs (rms) have been observed, which is a new record in the EO detection of single electron bunches and close to the limit given by the EO material properties.

  16. Hybrid silicon-vanadium dioxide electro-optic modulators

    NASA Astrophysics Data System (ADS)

    Miller, Kevin J.; Markov, Petr; Marvel, Robert E.; Haglund, Richard F.; Weiss, Sharon M.

    2016-03-01

    Small-footprint, low-power devices that can modulate optical signals at THz speeds would transform next-generation onchip photonics. We describe a hybrid silicon-vanadium dioxide (Si-VO2) electro-optic ring resonator modulator as a candidate platform for achieving this performance benchmark. Vanadium dioxide (VO2) is a strongly correlated material exhibiting a semiconductor-to-metal transition (SMT) accompanied by large changes in electrical and optical properties. While VO2 can be switched optically on a sub-picosecond time scale, the ultimate electrical switching speed remains to be determined. In a 5 μm radius Si-VO2 ring resonator, we achieve 1.5 dB modulation in response to a 10 ns square voltage pulse of 2.5 V. In the steady state regime, we report a modulation depth of 10 dB. The larger modulation depth at longer timescales is attributed to a Joule heating contribution. Experimental results, corroborated by FDTD simulations, reveal the relationship between the portion of a VO2 patch undergoing the SMT and the resulting effects on the Si-VO2 device performance. This work indicates that with further reduction of VO2 patch sizes and increase in resonator Q factor, there is promise for the Si-VO2 ring resonator electro-optic modulator as a competitive option for on-chip photonics technology.

  17. Electron Bunch Shape Measurements Using Electro-optical Spectral Decoding

    NASA Astrophysics Data System (ADS)

    Borysenko, A.; Hiller, N.; Müller, A.-S.; Steffen, B.; Peier, P.; Ivanisenko, Y.; Ischebeck, R.; Schlott, V.

    Longitudinal diagnostics of the electron bunch shapes play a crucial role in the operation of linac-based light sources. Electro-optical techniques allow us to measure the longitudinal electron bunch profiles non-destructively on a shot-by-shot basis. Here we present results from measurements of electron bunches with a length of 200-900 fs rms at the Swiss FEL Injector Test Facility. All the measurements were done using an Yb-doped fibre laser system (with a central wavelength of a 1050 nm) and a GaP crystal. The technique of electro-optical spectral decoding (EOSD) was applied and showed great capabilities to measure bunch shapes down to around 370 fs rms. Measurements were performed for different electron energies to study the expected distortions of the measured bunch profile due to the energy-dependent widening of the electric field, which plays a role for low beam energies below and around 40 MeV. The studies provide valuable input for the design of the EOSD monitors for the compact linear accelerator FLUTE that is currently under commissioning at the Karslruhe Institute of Technology (KIT).

  18. Phase Matching Using the Linear Electro-Optic Effect

    NASA Astrophysics Data System (ADS)

    Cui, Zijian; Liu, Dean; Miao, Jie; Yang, Aihua; Zhu, Jianqiang

    2017-01-01

    Phase matching is a necessary condition for achieving high-efficiency optical-frequency conversion. To date, practical means of accomplishing phase matching in homogeneous crystals remain limited, despite considerable efforts. Herein, we report a new class of methods aimed at achieving quasiperfect phase matching, based on controllable birefringence produced via the linear electro-optic effect, termed "voltage-tuning phase matching." The wave vectors of the induced polarization and the generated fields can be matched and maintained along the direction of propagation by introducing an external electric field. We analyze the validity and feasibility of this method theoretically and demonstrate it experimentally by applying the linear electro-optic effect and fourth-harmonic generation simultaneously in a partially deuterated KH2PO4 crystal. Quasiperfect phase matching is achieved systematically over a temperature range of the initial phase-matching temperature ±2 ° C . Moreover, this method can overcome the limitation of the birefringence in traditional technologies and provides new functionalities for conventional nonlinear materials as well as low-birefringence and isotropic materials. This technology may significantly impact the study of optical-frequency conversion and has promise for a broad range of applications in nonlinear optics.

  19. Automatic building detection and 3D shape recovery from single monocular electro-optic imagery

    NASA Astrophysics Data System (ADS)

    Lavigne, Daniel A.; Saeedi, Parvaneh; Dlugan, Andrew; Goldstein, Norman; Zwick, Harold

    2007-04-01

    The extraction of 3D building geometric information from high-resolution electro-optical imagery is becoming a key element in numerous geospatial applications. Indeed, producing 3D urban models is a requirement for a variety of applications such as spatial analysis of urban design, military simulation, and site monitoring of a particular geographic location. However, almost all operational approaches developed over the years for 3D building reconstruction are semiautomated ones, where a skilled human operator is involved in the 3D geometry modeling of building instances, which results in a time-consuming process. Furthermore, such approaches usually require stereo image pairs, image sequences, or laser scanning of a specific geographic location to extract the 3D models from the imagery. Finally, with current techniques, the 3D geometric modeling phase may be characterized by the extraction of 3D building models with a low accuracy level. This paper describes the Automatic Building Detection (ABD) system and embedded algorithms currently under development. The ABD system provides a framework for the automatic detection of buildings and the recovery of 3D geometric models from single monocular electro-optic imagery. The system is designed in order to cope with multi-sensor imaging of arbitrary viewpoint variations, clutter, and occlusion. Preliminary results on monocular airborne and spaceborne images are provided. Accuracy assessment of detected buildings and extracted 3D building models from single airborne and spaceborne monocular imagery of real scenes are also addressed. Embedded algorithms are evaluated for their robustness to deal with relatively dense and complicated urban environments.

  20. Electro-Optics of an Experimental Quantum-Optical Photometer

    NASA Astrophysics Data System (ADS)

    Solomos, N. H.

    2010-07-01

    The first working version of a new ultrafast three-beam photon counting photometer (QOP) has been materialized and demonstrated by the Applied Physics / Electro-optics Laboratory of the Hellenic Naval Academy in Piraeus. The QOP has been installed on the new 0.51m TVD telescope. The instrument is currently being used for quantum-optical study of atmospheric transmission in green monochromatic light over slant paths, at the RFK/Eudoxos Observatories. Actively quenched Single Photon Avalanche Diode detectors can be interchangeably deployed in addition to PMTs and LLL-CCDs. It is also intended for the testing of various approaches for solving the difficult problem of coupling light efficiently to the very small sensitive areas of SPADS, either using fiber couplers, or novel technologies like dedicated fiber tapers. Some particulars of the instrument design philosophy and its optomechanical construction are very briefly mentioned further below. However, it is appropriate to comment, firstly, on its purpose/rationale: The successful formalism of Glauber that led to the quantum-optical framework pertinent to the study of light in the terrestrial laboratories could, perhaps, be proven equally fruitful if applied to celestial light as well. Adopting the new idea of describing an arbitrary light state in terms of coherence functions, it is easily concluded that conventional astronomical instrumentation measures only spatial (imaging) or temporal (spectroscopy) coherence properties of the incoming photon stream. However, higher order spatiotemporal coherence (manifested as correlations among separated photon detection events) convey blueprints of the emission mechanism itself or even of the photon scattering history written in the course of the long path from the emitter to the telescope. To extract this information, high photon fluxes and unprecedented timing resolutions are needed. Our gradual entrance to the era of Extremely Large Telescopes combined with certain new

  1. Comparative analysis of imaging configurations and objectives for Fourier microscopy.

    PubMed

    Kurvits, Jonathan A; Jiang, Mingming; Zia, Rashid

    2015-11-01

    Fourier microscopy is becoming an increasingly important tool for the analysis of optical nanostructures and quantum emitters. However, achieving quantitative Fourier space measurements requires a thorough understanding of the impact of aberrations introduced by optical microscopes that have been optimized for conventional real-space imaging. Here we present a detailed framework for analyzing the performance of microscope objectives for several common Fourier imaging configurations. To this end, we model objectives from Nikon, Olympus, and Zeiss using parameters that were inferred from patent literature and confirmed, where possible, by physical disassembly. We then examine the aberrations most relevant to Fourier microscopy, including the alignment tolerances of apodization factors for different objective classes, the effect of magnification on the modulation transfer function, and vignetting-induced reductions of the effective numerical aperture for wide-field measurements. Based on this analysis, we identify an optimal objective class and imaging configuration for Fourier microscopy. In addition, the Zemax files for the objectives and setups used in this analysis have been made publicly available as a resource for future studies.

  2. Coherent synthetic imaging using multi-aperture scanning Fourier ptychography

    NASA Astrophysics Data System (ADS)

    Xie, Zongliang; Ma, Haotong; Qi, Bo; Ren, Ge

    2016-10-01

    The high resolution is what the synthetic aperture technique quests for. In this paper, we propose an approach of coherent synthetic imaging with sparse aperture systems using multi-aperture scanning Fourier ptychography algorithm, which can further improve the resolution of sparse aperture systems. The reported technique first acquires a series of raw images by scanning a sparse aperture system and then the captured images are used to synthesize a larger spectrum in the frequency domain using aperture-scanning Fourier ptychography algorithm. The system's traveling circumvent its diffraction limit so that a super-resolution image can be obtained. Numerical simulation demonstrates the validity. The technique proposed in this paper may find wide applications in synthetic aperture imaging and astronomy.

  3. Coherent electromagnetic field imaging through Fourier transform heterodyne

    SciTech Connect

    Cooke, B.J.; Laubscher, B.E.; Olivas, N.L.; Goeller, R.M.; Cafferty, M.; Briles, S.D.; Galbraith, A.E. |; Grubler, A.C. |

    1998-12-31

    The authors present a detection process capable of directly imaging the transverse amplitude, phase, and if desired, Doppler shift of coherent electromagnetic fields. Based on coherent detection principles governing conventional heterodyned RADAR/LIDAR systems, Fourier Transform Heterodyne (FTH) incorporates transverse spatial encoding of the local oscillator for image capture. Appropriate selection of spatial encoding functions, or basis set, allows image retrieval by way of classic Fourier manipulations. Of practical interest: (1) imaging is accomplished on a single element detector requiring no additional scanning or moving components, and (2) a wide variety of appropriate spatial encoding functions exist that may be adaptively configured in real-time for applications requiring optimal detection. In this paper, they introduce the underlying principles governing FTH imaging, followed by demonstration of concept via a simple experimental setup based on a HeNe laser and a 69 element spatial phase modulator.

  4. Electro-optical deflectors as a method of beam smoothing for Inertial Confinement Fusion

    SciTech Connect

    Rothenberg, J.E.

    1997-01-01

    The electro-optic deflector is analyzed and compared to smoothing by spectral dispersion for efficacy as a beam smoothing method for ICF. It is found that the electro-optic deflector is inherently somewhat less efficient when compared either on the basis of equal peak phase modulation or equal generated bandwidth.

  5. Ferroelectric Tungsten Bronze Bulk Crystals and Epitaxial Thin Films for Electro-Optic Device Applications

    DTIC Science & Technology

    1984-07-01

    improved, they show a considerable enhancement in electro - optic and photorefractive properties, specifically for Ce(3+)-doped SBN:60 crystals. The...concentration of impurity ions increased. Undoped SBN:60 single crystals have also been grown and they are almost striation-free and exhibit excellent electro - optic properties.

  6. A LATTICE THEORY OF THE ELECTRO-OPTIC EFFECTS IN SEMICONDUCTORS.

    DTIC Science & Technology

    A unified lattice theory of the electro - optic effect in semiconductor crystals, which encompasses the piezo-electric and elasto-optic effects, is...presented. Expressions are derived for the constant stress and constant strain electro - optic coefficients and the results are specialized to crystals of the zincblende structure. (Author)

  7. Electro-optic study of PZT ferroelectric ceramics using modulation of reflected light

    NASA Astrophysics Data System (ADS)

    Kniazkov, A. V.

    2016-04-01

    Electro-optic coefficients of variations in the refractive index of PZT and PLZT ceramic materials induced by ac electric field are estimated using modulation of reflected light. The electro-optic coefficients of PLZT ceramics measured with the aid of conventional birefringence using the phase shift of transmitted radiation and the proposed method of birefringence using the modulation of reflected light are compared.

  8. A novel electro-optical pump-probe system for bioelectromagnetic investigations

    NASA Astrophysics Data System (ADS)

    De Angelis, Annalisa; Couderc, Vincent; Leproux, Philippe; Labruyère, Alexis; Tonello, Alessandro; El Amari, Saad; Arnaud-Cormos, Delia; Leveque, Philippe

    2012-10-01

    In the area of bioelectromagnetic studies there is a growing interest to understand the mechanisms leading to nanosecond electric fields induced electroporation. Real-time imaging techniques at molecular level could probably bring further advances on how electric fields interact with living cells. However the investigations are limited by the present-day lack of these kinds of advanced instrumentations. In this context, we present an innovative electro-optical pump-probe system. The aim of our project is to provide a performing and compact device for electrical stimulation and multiplex Coherent anti-Stokes Raman Scattering (M-CARS) imaging of biological cells at once. The system consists of a 1064 nm sub-nanosecond laser source providing both a monochromatic pump and a polychromatic Stokes optical beam used in a CARS process, as well as the trigger beam for the optoelectronic switching-based electrical pulse generator. The polychromatic Stokes beam (from 600 to 1700 nm) results from a supercontinuum generation in a photonic crystal fiber (PCF). A detailed spectro-temporal characterization of such a broadband spectrum shows the impact of the nonlinear propagation in the fiber on the Stokes wave. Despite the temporal distortions observable on Stokes pulse profiles, their spectral synchronization with the pump pulse remains possible and efficient in the interesting region between 1100 nm and 1700 nm. The electrical stimulation device consists of a customized generator combining microstrip-line technology and laser-triggered photoconductive semiconductor switches. Our experimental characterization highlights the capability for such a generator to control the main pulse parameters (profile, amplitude and duration) and to be easily synchronized with the imaging system. We finally test and calibrate the system by means of a KDP crystal. The preliminary results suggest that this electro-optical system provides a suitable tool for real-time investigation of

  9. Optical stress sensor based on electro-optic compensation for photoelastic birefringence in a single crystal

    SciTech Connect

    Li Changsheng

    2011-09-20

    An optical stress sensor is proposed by using a single crystal with both electro-optic and photoelastic effects. Different from previous crystal-based stress sensors, the proposed sensor is based on electro-optic compensation for stress-induced birefringence and does not need an additional quarter-wave plate or modulator, because the stress-sensing element is simultaneously used as an electro-optic compensator. Candidate sensing materials include electro-optic crystals of the 3 m symmetry group and all glass with large Kerr coefficients. A primary experiment has demonstrated that the stress-induced birefringence in lithium niobate crystal can be compensated by its electro-optic birefringence. The proposed stress sensor is compact and low cost, and it is possible to achieve closed-loop stress measurement.

  10. Fourier-ring descriptor to characterize rare circulating cells from images generated using immunofluorescence microscopy.

    PubMed

    Emerson, Tegan; Kirby, Michael; Bethel, Kelly; Kolatkar, Anand; Luttgen, Madelyn; O'Hara, Stephen; Newton, Paul; Kuhn, Peter

    2015-03-01

    We address the problem of subclassification of rare circulating cells using data driven feature selection from images of candidate circulating tumor cells from patients diagnosed with breast, prostate, or lung cancer. We determine a set of low level features which can differentiate among candidate cell types. We have implemented an image representation based on concentric Fourier rings (FRDs) which allow us to exploit size variations and morphological differences among cells while being rotationally invariant. We discuss potential clinical use in the context of treatment monitoring for cancer patients with metastatic disease.

  11. An innovative procedure for calibration of strapdown electro-optical sensors onboard unmanned air vehicles.

    PubMed

    Fasano, Giancarmine; Accardo, Domenico; Moccia, Antonio; Rispoli, Attilio

    2010-01-01

    This paper presents an innovative method for estimating the attitude of airborne electro-optical cameras with respect to the onboard autonomous navigation unit. The procedure is based on the use of attitude measurements under static conditions taken by an inertial unit and carrier-phase differential Global Positioning System to obtain accurate camera position estimates in the aircraft body reference frame, while image analysis allows line-of-sight unit vectors in the camera based reference frame to be computed. The method has been applied to the alignment of the visible and infrared cameras installed onboard the experimental aircraft of the Italian Aerospace Research Center and adopted for in-flight obstacle detection and collision avoidance. Results show an angular uncertainty on the order of 0.1° (rms).

  12. Characterization of coplanar poled electro optic polymer films for Si-photonic devices with multiphoton microscopy

    SciTech Connect

    Himmelhuber, R. Mehravar, S. S.; Herrera, O. D.; Demir, V.; Kieu, K.; Norwood, R. A.; Peyghambarian, N.; Luo, J.; Jen, A. K.-Y.

    2014-04-21

    We imaged coplanar poled electro optic (EO) polymer films on transparent substrates with a multiple-photon microscope in reflection and correlated the second-harmonic light intensity with the results of Pockels coefficient (r{sub 33}) measurements. This allowed us to make quantitative measurements of poled polymer films on non-transparent substrates like silicon, which are not accessible with traditional Pockels coefficient measurement techniques. Phase modulators consisting of silicon waveguide devices with EO polymer claddings with a known Pockels coefficient (from V{sub π} measurements) were used to validate the correlation between the second-harmonic signal and r{sub 33}. This also allowed us to locally map the r{sub 33} coefficient in the poled area.

  13. Ground-based electro-optical detection of artificial satellites in daylight from reflected sunlight

    NASA Astrophysics Data System (ADS)

    Rork, E. W.; Lin, S. S.; Yakutis, A. J.

    1982-05-01

    An electro-optical sensor consisting of the ETS 31-inch f/5 telescope, a readily-available silicon vidicon TV camera, and a video signal processing system was used to acquire and track low altitude satellites in daylight from reflected sunlight. The limiting magnitude was 8m3. In demonstrating this, a total of 20 satellite tracks on 18 different satellites was achieved in full daylight during one day, and accurate precision positional data on 13 of the tracks were sent to the NORAD Space Defense Center. This demonstrated proof-of-concept might provide an enhanced GEODSS daylight operation. In connection with experiments in daylight space surveillance, an atmospheric phenomenon was encountered which consists primarily of point images, apparently windblown, moving through the field-of-view. The leading candidates are seed vehicles, insects, and ice crystals. A parallax technique has been demonstrated to separate these objects, dubbed "angels,' from artificial satellites.

  14. An Innovative Procedure for Calibration of Strapdown Electro-Optical Sensors Onboard Unmanned Air Vehicles

    PubMed Central

    Fasano, Giancarmine; Accardo, Domenico; Moccia, Antonio; Rispoli, Attilio

    2010-01-01

    This paper presents an innovative method for estimating the attitude of airborne electro-optical cameras with respect to the onboard autonomous navigation unit. The procedure is based on the use of attitude measurements under static conditions taken by an inertial unit and carrier-phase differential Global Positioning System to obtain accurate camera position estimates in the aircraft body reference frame, while image analysis allows line-of-sight unit vectors in the camera based reference frame to be computed. The method has been applied to the alignment of the visible and infrared cameras installed onboard the experimental aircraft of the Italian Aerospace Research Center and adopted for in-flight obstacle detection and collision avoidance. Results show an angular uncertainty on the order of 0.1° (rms). PMID:22315559

  15. Grid-Independent Compressive Imaging and Fourier Phase Retrieval

    ERIC Educational Resources Information Center

    Liao, Wenjing

    2013-01-01

    This dissertation is composed of two parts. In the first part techniques of band exclusion(BE) and local optimization(LO) are proposed to solve linear continuum inverse problems independently of the grid spacing. The second part is devoted to the Fourier phase retrieval problem. Many situations in optics, medical imaging and signal processing call…

  16. Grid-Independent Compressive Imaging and Fourier Phase Retrieval

    ERIC Educational Resources Information Center

    Liao, Wenjing

    2013-01-01

    This dissertation is composed of two parts. In the first part techniques of band exclusion(BE) and local optimization(LO) are proposed to solve linear continuum inverse problems independently of the grid spacing. The second part is devoted to the Fourier phase retrieval problem. Many situations in optics, medical imaging and signal processing call…

  17. Electro-optical and Magneto-optical Sensing Apparatus and Method for Characterizing Free-space Electromagnetic Radiation

    DOEpatents

    Zhang, Xi-Cheng; Riordan, Jenifer Ann; Sun, Feng-Guo

    2000-08-29

    Apparatus and methods for characterizing free-space electromagnetic energy, and in particular, apparatus/method suitable for real-time two-dimensional far-infrared imaging applications are presented. The sensing technique is based on a non-linear coupling between a low-frequency electric (or magnetic) field and a laser beam in an electro-optic (or magnetic-optic) crystal. In addition to a practical counter-propagating sensing technique, a co-linear approach is described which provides longer radiated field-optical beam interaction length, thereby making imaging applications practical.

  18. Visible Imaging Fourier Transform Spectrometer: Design and Calibration

    SciTech Connect

    Wishnow, E H; Wurtz, R; Blais-Ouellette, S; Cook, K H; Carr, D; Lewis, I; Grandmont, F; Stubbs, C W

    2002-09-19

    We present details of the design, operation and calibration of an astronomical visible-band imaging Fourier transform spectrometer (IFTS). This type of instrument produces a spectrum for every pixel in the field of view where the spectral resolution is flexible. The instrument is a dual-input/dual-output Michelson interferometer coupled to the 3.5 meter telescope at the Apache Point Observatory. Imaging performance and interferograms and spectra from calibration sources and standard stars are discussed.

  19. A comparative image analysis of radial Fourier-Chebyshev moments

    NASA Astrophysics Data System (ADS)

    Li, Bo

    2017-08-01

    On the basis of the discrete Fourier functions and the discrete Chebyshev polynomials, a new set of radial orthogonal moment functions were presented. The new moments construct a new discrete orthogonal plane, and take a new sampling method that overcomes the default of classical method, which can be effectively used in the image analysis. The experimental results show that the new radial moments are superior to the conventional moments in image reconstruction and computing efficiency.

  20. Electro-optic Laser-Sampled Neutron Detector

    SciTech Connect

    J. Kenneth Shultis; Douglas McGregor

    2009-11-30

    A new method of detecting radiation which can allow for long distance measurements is being investigated. The device is primarily for neutrons detection althought it could, in principle, be used for gamma ray detection. The neutron detection medium is a solid, transparent, electro-optical material, such as lithium niobate, lithium tantalite, or barium borate. Crystals of these materials act as optical gates to laser light, allowing light to pass through only when a neutron interaction occurs in the crystal. Typical light detection devices, such as CCD cameras or photomultiplier tubes, can be used to signal when light passes through the crystal. The overall goal of the project is to investigate the feasibility of such devices for the detection of neutron radiation and to quantify their capabilities and limitations.

  1. Electro-Optical Plasmonic Switch Based On Graphene

    NASA Astrophysics Data System (ADS)

    Park, Suk-Young; Moon, Kyungsun

    2014-03-01

    We have studied an electro-optical plasmonic waveguide, which controls the transmission of incident light by switching the coupling of the surface plasmon polariton (SPP) localized on graphene. It has been previously shown that the propagation length of the SPP localized on the copper surface can be effectively reduced by a factor of two or three by applying external bias potential. In our study, we have demonstrated that the propagation length of the SPP localized on graphene can be dramatically reduced by a factor of ten or so and the wavelength of SPP can be reduced by several hundredths of the incident light as well. This may help develop a nano-scale plasmonic switch. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2012R1A1A2006927).

  2. Solid state electro-optic color filter and iris

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A pair of solid state electro-optic filters (SSEF) in a binocular holder were designed and fabricated for evaluation of field sequential stereo TV applications. The electronic circuitry for use with the stereo goggles was designed and fabricated, requiring only an external video input. A polarizing screen suitable for attachment to various size TV monitors for use in conjunction with the stereo goggles was designed and fabricated. An improved engineering model 2 filter was fabricated using the bonded holder technique developed previously and integrated to a GCTA color TV camera. An engineering model color filter was fabricated and assembled using PLZT control elements. In addition, a ruggedized holder assembly was designed, fabricated and tested. This assembly provides electrical contacts, high voltage protection, and support for the fragile PLZT disk, and also permits mounting and optical alignment of the associated polarizers.

  3. Electro-optically tunable diffraction grating with photoaligned liquid crystals

    NASA Astrophysics Data System (ADS)

    Węgłowski, Rafał; Kozanecka-Szmigiel, Anna; Piecek, Wiktor; Konieczkowska, Jolanta; Schab-Balcerzak, Ewa

    2017-10-01

    This work shows the possibility of fabricating one- and two-dimensional diffraction structures based on liquid crystals photoaligned with the layers of photosensitive azobenzene poly(ester imide). The gratings involve a micron-sized planar-twisted nematic alignment. The diffraction efficiency of these gratings is controlled by a uniform electric field applied across the cell. The electro-optical measurements showed short switching times (0.8 ms and 7 ms for τrise and τdecay respectively) and low driving electric fields (1 . 5 V / μm) of 1st order diffracted light. The LC grating is regarded as an amplitude grating in the low electric field region and a phase grating in the high electric field region. Moreover the diffraction efficiency is polarization-independent in the wide range of external electric fields.

  4. Ultra Broadband High Sensitivity Electro-optic Field Sensors

    NASA Astrophysics Data System (ADS)

    Wieting, Terence J.; Qadri, Syed B.; Wu, Dong Ho

    2004-03-01

    We have carried out electro-optics experiments for the development of high sensitivity EO field sensors that detect electric fields noninvasively over a very broad frequency range. Presently we have obtained a maximum field sensitivity about 2 mV/m and the sensor has been tested over the frequency range of 0.1 Hz -200 MHz. We have used various EO materials, which include LiNbO_3, (Sr,Ba)Nb_2O_6, and DAST. Currently we are testing the sensors at frequencies of 200 MHz through 50 GHz, and also improving the sensors to achieve the field sensitivity to be better than 2 μ V/m. We found that even a small variation of materials properties greatly alters the sensors characteristics. We will present detailed sensor's characteristics that are obtained with various materials' chemical and physical properties.

  5. Electro-optical seasonal weather and gender data collection

    NASA Astrophysics Data System (ADS)

    McCoppin, Ryan; Koester, Nathan; Rude, Howard N.; Rizki, Mateen; Tamburino, Louis; Freeman, Andrew; Mendoza-Schrock, Olga

    2013-05-01

    This paper describes the process used to collect the Seasonal Weather And Gender (SWAG) dataset; an electro-optical dataset of human subjects that can be used to develop advanced gender classification algorithms. Several novel features characterize this ongoing effort (1) the human subjects self-label their gender by performing a specific action during the data collection and (2) the data collection will span months and even years resulting in a dataset containing realistic levels and types of clothing corresponding to the various seasons and weather conditions. It is envisioned that this type of data will support the development and evaluation of more robust gender classification systems that are capable of accurate gender recognition under extended operating conditions.

  6. Solid state electro-optic color filter and iris

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The electro-optic properties of lanthanum-modified lead zirconate titanate (PLZT) ferroelectric ceramic material are evaluated when utilized as a variable density and/or spectral filter in conjunction with a television scanning system. Emphasis was placed on the development of techniques and procedures for processing the PLZT disks and for applying efficient electrode structures. A number of samples were processed using different combinations of cleaning, electrode material, and deposition process. Best overall performance resulted from the direct evaporation of gold over chrome electrodes. A ruggedized mounting holder assembly was designed, fabricated, and tested. The assembly provides electrical contacts, high voltage protection, and support for the fragile PLZT disk, and permits mounting and optical alignment of the associated polarizers. Operational measurements of a PLZT sample mounted in the holder assembly were performed in conjunction with a television camera and the associated drive circuits. The data verified achievement of the elimination of the observed white-line effect.

  7. Degradation of electro-optic components aboard LDEF

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1993-01-01

    Remeasurement of the properties of a set of electro-optic components exposed to the low-earth environment aboard the Long Duration Exposure Facility (LDEF) indicates that most components survived quite well. Typical components showed some effects related to the space environment unless well protected. The effects were often small but significant. Results for semiconductor infrared detectors, lasers, and LED's, as well as filters, mirrors, and black paints are described. Semiconductor detectors and emitters were scarred but reproduced their original characteristics. Spectral characteristics of multi-layer dielectric filters and mirrors were found to be altered and degraded. Increased absorption in black paints indicates an increase in absorption sites, giving rise to enhanced performance as coatings for baffles and sunscreens.

  8. Giant electro-optic effect in nanodisordered KTN crystals.

    PubMed

    Chang, Yun-Ching; Wang, Chao; Yin, Shizhuo; Hoffman, Robert C; Mott, Andrew G

    2013-11-15

    The electro-optic (EO) effect in nanodisordered potassium tantalate niobate (KTN) crystal is quantitatively investigated. It is found out that the EO coefficient of nanodisordered KTN crystal depends not only on the cooling temperature but also on the cooling rate. A larger EO coefficient can be obtained by employing a faster cooling rate. A Kerr EO efficient (s(11) - s(12) = 6.94 × 10(-14) m(2)/V(2)) is obtained at a cooling rate of 0.45 °C/s. The enhanced EO efficient by employing a faster cooling rate will be greatly beneficial for a variety of applications such as laser Q switches, laser pulse shaping, high-speed optical shutters, and modulating retroreflectors.

  9. Electro-optical terrain reflectance modeling - A perspective

    NASA Technical Reports Server (NTRS)

    Smith, J. A.; Cooper, K. D.; Strahler, A. H.

    1984-01-01

    Electro-optical terrain reflectance modeling is one of the components required in the overall capability to simulate remote sensing measurement systems as an aid to the sensor or information processing designer. Given that sensor fields-of-view may vary from a few centimeters to several meters and that measurement devices may be placed at varying heights above the terrain surface, modeling of complex combinations of terrain classes or media with respect to both vertical and horizontal scales may be required. This paper addresses the issue of combining modeling approaches for different classes of materials in the optical regime and recommends a more formal approach to the radiative characterization of media properties as well as the calculation of the bidirectional reflectance distribution functions.

  10. Multiplexed Saturation Spectroscopy with Electro-Optic Frequency Combs

    NASA Astrophysics Data System (ADS)

    Long, David A.; Fleisher, Adam J.; Plusquellic, David F.; Hodges, Joseph T.

    2017-06-01

    Electro-optic frequency combs recently have been applied to a wide range of physical and spectroscopic measurements because of attributes including, simplicity, robustness, flexibility, phase coherence, and high spectral power density. As an illustrative example, I will focus upon multiplexed saturation spectroscopy of atomic potassium (^{39}K) using ultra-high resolution frequency combs which contain up to a million individual teeth with spacings between 2 kHz and 2 MHz. Through the use of a self-heterodyne detection method, we have been able to simultaneously observe phenomena such as hole burning, hyperfine pumping, and electromagnetically induced transparency. I will discuss these measurements as well as future applications in molecular and atomic spectroscopy.

  11. Electro-optical switching and memory display device

    NASA Astrophysics Data System (ADS)

    Skotheim, T. A.; Ogrady, W. E.; Linkous, C. A.

    1983-12-01

    An electro-optical display device is described having a housing including one transparent wall and at least one other wall. Counter electrodes are positioned on the transparent wall and display electrodes are positioned on the other wall with both electrodes in electrically conductive relationship with an electrolyte. Circuits means are connected to the display and counter electrodes to apply different predetermined control potentials between them. The display electrodes are covered with a thin electrically conductive polymer film that is characterized according to the invention by having embedded in it pigment molecules as counter ions. The display device is operable to be switched to a plurality of different visual color states at an exceptionally rapid switching rate while each of the color states is characterized by possessing good color intensity and definition.

  12. Hyper-branched polymer for electro-optic applications

    NASA Astrophysics Data System (ADS)

    Piao, Xianqing; Mori, Yuichi; Zhang, Xianmin; Inoue, Shinichiro; Yokoyama, Shiyoshi

    2010-02-01

    In the present work, the hyper-branched (HB) polymer is utilized as a host material to efficiently incorporate the nonlinear optical chromophore. The HB polymer and toluene diisocyanate (2, 4-TDI) formed 3-D networks, and the typical FTC or CF3-Ph-FTC chromophores were introduced to investigate the electro-optic activity (r33). At the same time, poling behavior of NLO chromophores in the traditional poly methyl methacrylate (PMMA) and Poly MMA-MOI side-chain polymers were also included in this work for comparison. For FTC doped composites, the r33 reached over 80 pm/V in 3-D network matrix, while the value of r33 maximized at about 45 pm/V in traditional PMMA host and 70 pm/V in side-chain polymers. In addition, the measurement of poling process, poling efficiency, and thermal stability for the real application were also investigated.

  13. A very sensitive electro-optical simultaneous ion detection system

    NASA Astrophysics Data System (ADS)

    1982-02-01

    A fully operational, electro-optical system for simultaneous detection is discussed. This system is applied for the simultaneous detection of fragment mass spectra, obtained by collision activated dissociation experiments. The detector itself consists of two chevron channelplates, phospher screen, fiber optics, camera objective and photodiode array. If forms part of an extensive information system, which controls the photodiode array and performs data processing as for example background subtraction and correction of the spectrum for spatial sensitivity variations of the detector. The detection system is characterized by a very low noise rate with an average value of about one dark ion per 250 s for each mass peak in the spectrum. The dynamic range of peak heights in a simultaneously detected spectrum can be up to 2.3 x 10 to the 4th power at a signal to noise ratio of 1. The reproducibility of peak area measurements is better than 20% over the entire length of the detector.

  14. 1-D ELECTRO-OPTIC BEAM STEERING DEVICE.

    PubMed

    Wang, Wei-Chih; Tsui, Chi Leung

    2011-06-05

    In this paper, we present the design and fabrication of a 1D beam steering device based on planar electro-optic thermal-plastic prisms and a collimator lens array. With the elimination of moving parts, the proposed device is able to overcome the mechanical limitations of present scanning devices, such as fatigue and low operating frequency, while maintaining a small system footprint (~0.5mm×0.5mm). From experimental data, our prototype device is able to achieve a maximum deflection angle of 5.6° for a single stage prism design and 29.2° for a cascaded three prisms stage design. The lens array shows a 4µm collimated beam diameter.

  15. 1-D ELECTRO-OPTIC BEAM STEERING DEVICE

    PubMed Central

    Wang, Wei-Chih; Tsui, Chi Leung

    2011-01-01

    In this paper, we present the design and fabrication of a 1D beam steering device based on planar electro-optic thermal-plastic prisms and a collimator lens array. With the elimination of moving parts, the proposed device is able to overcome the mechanical limitations of present scanning devices, such as fatigue and low operating frequency, while maintaining a small system footprint (~0.5mm×0.5mm). From experimental data, our prototype device is able to achieve a maximum deflection angle of 5.6° for a single stage prism design and 29.2° for a cascaded three prisms stage design. The lens array shows a 4µm collimated beam diameter. PMID:22199458

  16. Electro-optical switching and memory display device

    DOEpatents

    Skotheim, Terje A.; O'Grady, William E.; Linkous, Clovis A.

    1986-01-01

    An electro-optical display device having a housing with wall means including one transparent wall and at least one other wall. Counter electrodes are positioned on the transparent wall and display electrodes are positioned on the other wall with both electrodes in electrically conductive relationship with an electrolyte. Circuit means are connected to the display and counter electrodes to apply different predetermined control potentials between them. The display electrodes are covered with a thin electrically conductive polymer film that is characterized according to the invention by having embedded in it pigment molecules as counter ions. The display device is operable to be switched to a plurality of different visual color states at an exceptionally rapid switching rate while each of the color states is characterized by possessing good color intensity and definition.

  17. Electro-optical switching and memory display device

    DOEpatents

    Skotheim, T.A.; O'Grady, W.E.; Linkous, C.A.

    1983-12-29

    An electro-optical display device having a housing with wall means including one transparent wall and at least one other wall. Counter electrodes are positioned on the transparent wall and display electrodes are positioned on the other wall with both electrodes in electrically conductive relationship with an electrolyte. Circuits means are connected to the display and counter electrodes to apply different predetermined control potentials between them. The display electrodes are covered with a thin electrically conductive polymer film that is characterized according to the invention by having embedded in it pigment molecules as counter ions. The display device is operable to be switched to a plurality of different visual color states at an exceptionally rapid switching rate while each of the color states is characterized by possessing good color intensity and definition.

  18. The Sharper Image: Implementing a Fast Fourier Transform (FFT) to Enhance a Video-Captured Image.

    DTIC Science & Technology

    1994-01-01

    mathematical system to quantitatively analyze and compare complex wave forms. In 1307, Baron Jean - Baptiste - Joseph Fourier proved that any periodic wave can be...HOVEY ROAD, PENSACOLA, FL 32508-1046 NAMRL Special Report 94-1 THE SHARPER IMAGE: 16 IMPLEMENTING A FAST FOURIER TRANSFORM (FFT) TO ENHANCE A VIDEO...most visually impaired persons fail to discern the higher spatial frequencies present in an image. Based on the Fourier analysis of vision, Peli et al

  19. Design principles and realization of electro-optical circuit boards

    NASA Astrophysics Data System (ADS)

    Betschon, Felix; Lamprecht, Tobias; Halter, Markus; Beyer, Stefan; Peterson, Harry

    2013-02-01

    The manufacturing of electro-optical circuit boards (EOCB) is based to a large extent on established technologies. First products with embedded polymer waveguides are currently produced in series. The range of applications within the sensor and data communication markets is growing with the increasing maturity level. EOCBs require design flows, processes and techniques similar to existing printed circuit board (PCB) manufacturing and appropriate for optical signal transmission. A key aspect is the precise and automated assembly of active and passive optical components to the optical waveguides which has to be supported by the technology. The design flow is described after a short introduction into the build-up of EOCBs and the motivation for the usage of this technology within the different application fields. Basis for the design of EOCBs are the required optical signal transmission properties. Thereafter, the devices for the electro-optical conversion are chosen and the optical coupling approach is defined. Then, the planar optical elements (waveguides, splitters, couplers) are designed and simulated. This phase already requires co-design of the optical and electrical domain using novel design flows. The actual integration of an optical system into a PCB is shown in the last part. The optical layer is thereby laminated to the purely electrical PCB using a conventional PCB-lamination process to form the EOCB. The precise alignment of the various electrical and optical layers is thereby essential. Electrical vias are then generated, penetrating also the optical layer, to connect the individual electrical layers. Finally, the board has to be tested electrically and optically.

  20. Quantification of helicopter rotor downwash effects on electro-optical defensive aids suites

    NASA Astrophysics Data System (ADS)

    Seiffer, Dirk P.; Eisele, Christian; Henriksson, Markus; Sjöqvist, Lars; Möller, Sebastian; Togna, Fabio; Velluet, Marie-Thérèse

    2015-10-01

    The performance of electro-optical platform protection systems can be degraded significantly by the propagation environment around the platform. This includes aero-optical effects and zones of severe turbulence generated by engine exhausts. For helicopters rotor tip vortices and engine exhaust gases that are pressed down by the rotor airflow form the so called downwash phenomena. The downwash is a source for perturbations. A wide range of spatial and temporal fluctuations in the refractive index of air can occur. The perturbations from the turbulent flow cause detrimental effects on energy delivery, angle of arrival fluctuations, jam-code transmission, tracking accuracy and imaging performance in general. Therefore the effects may especially have a severe impact on the performance of laser-based protection systems like directed infrared countermeasures (DIRCM). The chain from passive missile detection and warning to obtaining an optical break-lock by the use of an active laser system will be influenced. To anticipate the installed performance of an electro-optical defensive aids suite (DAS) for helicopter platforms it is necessary to develop models for the prediction of the perturbations. Modelled results have to be validated against experimental findings. However, the data available in open literature on the effects of rotor downwash from helicopters on optical propagation is very limited. To collect necessary data and to obtain a first impression about the magnitude of occurring effects the European defence agency group (EDA) on "airborne platform effects on lasers and warning sensors (ALWS)" decided to design and perform a field trial on the premises of the Italian Air Force Flight Test Center in Pratica di Mare, Italy. ALWS is a technical arrangement under the Europa MoU among France, Germany, Italy, Sweden and the United Kingdom.

  1. Assessment of Spacecraft Operational Status Using Electro-Optical Predictive Techniques

    NASA Astrophysics Data System (ADS)

    Swann, D.; Klem, B.; McCoy, B.

    2010-09-01

    The current class of small satellite systems presents an analyst responsible for monitoring spacecraft operational status and early detection of detrimental anomalies with a broad variety of sensing and identification issues and challenges. Simple, small, cube-shaped satellites, without protruding solar panel appendages, may require enhanced preflight characterization processes to support monitoring by passive, remote, nonimaging optical sensors. This paper will describe spacecraft optical signature modeling and simulation techniques to develop sensing and identification algorithms for observing and characterizing key spacecraft features. The simulation results are based on electro-optical signatures apparent to nonimaging sensors, along with related observable features derived from multicolor and multiviewing aspect scenarios. This model and simulation analysis capability is used to support programs to monitor spacecraft performance status and identify anomalies associated with spacecraft damage/deterioration due to space debris or micrometeorite impact, thruster exhaust deposition or material aging. The development of state-of-the-art optical signature modeling tools to perform high-fidelity satellite models (such as the Air Force Academy FalconSat-5 or AFRL TacSat-3) simulations to characterize spectral radiant intensities apparent to passive, remote, nonresolved imaging sensors are described in detail. Simulations are performed for a comprehensive scenario range of natural (solar and earth) illumination and viewing conditions. Results are generated for comparing baseline, streamlined geometry models with the actual higher fidelity models that capture vehicle small-size hardware components and modifications. Output consisting of radiant intensity history apparent to ground-based sensor locations for vehicle trajectories that capture a comprehensive range of illumination conditions from the sun and underlying earth scene are presented for extensive spectral band

  2. Electro-optic comb based real time ultra-high sensitivity phase noise measurement system for high frequency microwaves.

    PubMed

    Kuse, N; Fermann, M E

    2017-06-06

    Recent progress in ultra low phase noise microwave generation indispensably depends on ultra low phase noise characterization systems. However, achieving high sensitivity currently relies on time consuming averaging via cross correlation, which sometimes even underestimates phase noise because of residual correlations. Moreover, extending high sensitivity phase noise measurements to microwaves beyond 10 GHz is very difficult because of the lack of suitable high frequency microwave components. In this work, we introduce a delayed self-heterodyne method in conjunction with sensitivity enhancement via the use of higher order comb modes from an electro-optic comb for ultra-high sensitivity phase noise measurements. The method obviates the need for any high frequency RF components and has a frequency measurement range limited only by the bandwidth (100 GHz) of current electro-optic modulators. The estimated noise floor is as low as -133 dBc/Hz, -155 dBc/Hz, -170 dBc/Hz and -171 dBc/Hz without cross correlation at 1 kHz, 10 kHz, 100 kHz and 1 MHz Fourier offset frequency for a 10 GHz carrier, respectively. Moreover, since no cross correlation is necessary, RF oscillator phase noise can be directly suppressed via feedback up to 100 kHz frequency offset.

  3. Hyperspectral imaging using the single-pixel Fourier transform technique

    NASA Astrophysics Data System (ADS)

    Jin, Senlin; Hui, Wangwei; Wang, Yunlong; Huang, Kaicheng; Shi, Qiushuai; Ying, Cuifeng; Liu, Dongqi; Ye, Qing; Zhou, Wenyuan; Tian, Jianguo

    2017-03-01

    Hyperspectral imaging technology is playing an increasingly important role in the fields of food analysis, medicine and biotechnology. To improve the speed of operation and increase the light throughput in a compact equipment structure, a Fourier transform hyperspectral imaging system based on a single-pixel technique is proposed in this study. Compared with current imaging spectrometry approaches, the proposed system has a wider spectral range (400-1100 nm), a better spectral resolution (1 nm) and requires fewer measurement data (a sample rate of 6.25%). The performance of this system was verified by its application to the non-destructive testing of potatoes.

  4. Hyperspectral imaging using the single-pixel Fourier transform technique

    PubMed Central

    Jin, Senlin; Hui, Wangwei; Wang, Yunlong; Huang, Kaicheng; Shi, Qiushuai; Ying, Cuifeng; Liu, Dongqi; Ye, Qing; Zhou, Wenyuan; Tian, Jianguo

    2017-01-01

    Hyperspectral imaging technology is playing an increasingly important role in the fields of food analysis, medicine and biotechnology. To improve the speed of operation and increase the light throughput in a compact equipment structure, a Fourier transform hyperspectral imaging system based on a single-pixel technique is proposed in this study. Compared with current imaging spectrometry approaches, the proposed system has a wider spectral range (400–1100 nm), a better spectral resolution (1 nm) and requires fewer measurement data (a sample rate of 6.25%). The performance of this system was verified by its application to the non-destructive testing of potatoes. PMID:28338100

  5. Experimental results from an airborne static Fourier transform imaging spectrometer.

    PubMed

    Ferrec, Yann; Taboury, Jean; Sauer, Hervé; Chavel, Pierre; Fournet, Pierre; Coudrain, Christophe; Deschamps, Joël; Primot, Jérôme

    2011-10-20

    A high étendue static Fourier transform spectral imager has been developed for airborne use. This imaging spectrometer, based on a Michelson interferometer with rooftop mirrors, is compact and robust and benefits from a high collection efficiency. Experimental airborne images were acquired in the visible domain. The processing chain to convert raw images to hyperspectral data is described, and airborne spectral images are presented. These experimental results show that the spectral resolution is close to the one expected, but also that the signal to noise ratio is limited by various phenomena (jitter, elevation fluctuations, and one parasitic image). We discuss the origin of those limitations and suggest solutions to circumvent them. © 2011 Optical Society of America

  6. Gradient-based image recovery methods from incomplete Fourier measurements.

    PubMed

    Patel, Vishal M; Maleh, Ray; Gilbert, Anna C; Chellappa, Rama

    2012-01-01

    A major problem in imaging applications such as magnetic resonance imaging and synthetic aperture radar is the task of trying to reconstruct an image with the smallest possible set of Fourier samples, every single one of which has a potential time and/or power cost. The theory of compressive sensing (CS) points to ways of exploiting inherent sparsity in such images in order to achieve accurate recovery using sub-Nyquist sampling schemes. Traditional CS approaches to this problem consist of solving total-variation (TV) minimization programs with Fourier measurement constraints or other variations thereof. This paper takes a different approach. Since the horizontal and vertical differences of a medical image are each more sparse or compressible than the corresponding TV image, CS methods will be more successful in recovering these differences individually. We develop an algorithm called GradientRec that uses a CS algorithm to recover the horizontal and vertical gradients and then estimates the original image from these gradients. We present two methods of solving the latter inverse problem, i.e., one based on least-square optimization and the other based on a generalized Poisson solver. After a thorough derivation of our complete algorithm, we present the results of various experiments that compare the effectiveness of the proposed method against other leading methods.

  7. Electro-Optic Effect in the PESO Acousto-Optic Modulator

    DTIC Science & Technology

    1994-11-09

    AD-A286 355 NAIC-ID(RS)T-0395-94 NATIONAL AIR INTELLIGENCE CENTER ELECTRO - OPTIC EFFECT IN THE PESO ACOUSTO-OPTIC MODULATOR by Tai Renzhong, Lu Futun...owing to coupling.betw;ee.elecuc grazing" and "acou- tic grating". Linear electro - optic effect in PESO modulator is helpful to the diffraction and...crystaO A-l/Am,ARjAb, anl / ar:.. thtta=30 and theta=900 . Along these two orientations. th;- electro - optic effect is restricted tcŽ the rn :-t m:,n e

  8. Secure communications of CAP-4 and OOK signals over MMF based on electro-optic chaos.

    PubMed

    Ai, Jianzhou; Wang, Lulu; Wang, Jian

    2017-09-15

    Chaos-based secure communication can provide a high level of privacy in data transmission. Here, we experimentally demonstrate secure signal transmission over two kinds of multimode fiber (MMF) based on electro-optic intensity chaos. High-quality synchronization is achieved in an electro-optic feedback configuration. Both 5  Gbit/s carrier-less amplitude/phase (CAP-4) modulation and 10  Gbit/s on-off key (OOK) signals are recovered efficiently in electro-optic chaos-based communication systems. Degradations of chaos synchronization and communication system due to mismatch of various hardware keys are also discussed.

  9. Theoretical and Experimental Studies of the Electro-Optic Effect: Toward a Microscopic Understanding.

    DTIC Science & Technology

    1981-08-01

    The electro - optic effect is investigated both theoretically and experimentally. The theoretical approach is based upon W.A. Harrison’s ’Bond-Orbital...Model’. The separate electronic and lattice contributions to the second-order, electro - optic susceptibility are examined within the context of this...frequency (dc) electric field is outlined. Finally, experimental measurements of the electro - optic effects in TeO2 and tl3AsAs3 have been performed and the results of these measurements are presented. (Author)

  10. Analysis of Electro-Optic Materials Properties on Guided Wave Devices

    DTIC Science & Technology

    1992-12-16

    AD-A262 787 APPLIED RESEARCH, INC, ANALYSIS OF ELECTRO - OPTIC MATERIALS PROPERTIES ON GUIDED WAVE DEVICES FINAL REPORT DTI 6700 ODYSSEY DR HUNTSVILLE...ALABAMA 35814-1220 s IMAR1893 APPROVED FOR PUKIC RE’.EASE DISTRIBUTION UNLIMlITED Applied Research Inc. ARI/92iR-048Z ANALYSIS OF ELECTRO - OPTIC MATERIALS...uNiT ATTN: Dr. 2aul Ashley-AMSMI-RD-~WS--CM ELEMENT NO 4 NO IAr SSiON No t1I TI TLE iciup SeawIfy 0Mft*G’I Analysis of Electro - optic Materials

  11. Electro-optical behavior of polymer dispersed blue phase liquid crystals

    NASA Astrophysics Data System (ADS)

    Kemiklioglu, E.; Chien, L.-C.

    2015-03-01

    We have investigated a new form of polymer dispersed liquid crystals (PDLC) electro-optical films comprised of blue phase liquid crystal and polymer prepared by the solvent evaporation method. In this method, polymer dispersed blue phase (PDBP) films, which were laminated between two indium-tin-oxidecoated conductive substrates, demonstrated two switching modes between light scattering and transparent states in response to an applied electric field across the film. The electro-optical properties of PDBP liquid crystals can be altered by changing the concentrations of liquid crystal and polymer. The compositions, film preparations, physical and morphological behaviors, and electro-optical properties of PDBP films are described.

  12. Full-field modeling of the longitudinal electro-optic probe.

    PubMed

    Freeman, J L; Jefferies, S R; Auld, B A

    1987-10-01

    Optical polarization changes and mode coupling due to spatially varying anisotropic perturbations in caused by electro-optic, acousto-optic, and other effects have been widely studied for both plane-wave and fiber mode propagation. A new optical S-parameter analysis of these effects, applicable to arbitrary optical field distributions, is presented. It is applied to evaluating the performance of the longitudinal electro-optic probe used for noninva-sively examining GaAs integrated circuits. Error in probe measurements of circuit voltage distributions can be characterized by considering the probe as a scanned electro-optic spatial filter.

  13. Fourier transform digital holographic adaptive optics imaging system

    PubMed Central

    Liu, Changgeng; Yu, Xiao; Kim, Myung K.

    2013-01-01

    A Fourier transform digital holographic adaptive optics imaging system and its basic principles are proposed. The CCD is put at the exact Fourier transform plane of the pupil of the eye lens. The spherical curvature introduced by the optics except the eye lens itself is eliminated. The CCD is also at image plane of the target. The point-spread function of the system is directly recorded, making it easier to determine the correct guide-star hologram. Also, the light signal will be stronger at the CCD, especially for phase-aberration sensing. Numerical propagation is avoided. The sensor aperture has nothing to do with the resolution and the possibility of using low coherence or incoherent illumination is opened. The system becomes more efficient and flexible. Although it is intended for ophthalmic use, it also shows potential application in microscopy. The robustness and feasibility of this compact system are demonstrated by simulations and experiments using scattering objects. PMID:23262541

  14. Fourier transform digital holographic adaptive optics imaging system.

    PubMed

    Liu, Changgeng; Yu, Xiao; Kim, Myung K

    2012-12-10

    A Fourier transform digital holographic adaptive optics imaging system and its basic principles are proposed. The CCD is put at the exact Fourier transform plane of the pupil of the eye lens. The spherical curvature introduced by the optics except the eye lens itself is eliminated. The CCD is also at image plane of the target. The point-spread function of the system is directly recorded, making it easier to determine the correct guide-star hologram. Also, the light signal will be stronger at the CCD, especially for phase-aberration sensing. Numerical propagation is avoided. The sensor aperture has nothing to do with the resolution and the possibility of using low coherence or incoherent illumination is opened. The system becomes more efficient and flexible. Although it is intended for ophthalmic use, it also shows potential application in microscopy. The robustness and feasibility of this compact system are demonstrated by simulations and experiments using scattering objects.

  15. Evaluation of active and passive polarimetric electro-optic imagery for civilian and military targets discrimination

    NASA Astrophysics Data System (ADS)

    Lavigne, Daniel A.; Breton, Mélanie; Pichette, Mario; Larochelle, Vincent; Simard, Jean-Robert

    2008-04-01

    Electro-optic (EO) imaging systems are commonly used to detect civilian and military targets during surveillance operations and search and rescue missions. Adding the polarization of light as additional information to such active and passive EO imaging systems may increase the target discrimination performance, as man made objects are known to depolarized light in different manner than natural background. However, while the polarization of light has been used and studied in the past for numerous applications, the understanding of the polarization phenomenology taking place with targets used in cluttered backgrounds requires additional experimentations. Specifically, the target contrast enhancement obtained by analyzing the polarization of the reflected light from either a direct polarized laser source as encountered in active imagers, or from natural ambient illumination, needs further investigation. This paper describes an investigation of the use of polarization-based imaging sensors to discriminate civilian and military targets against different backgrounds. Measurements were carried out using two custom-designed active and passive imaging systems operating in the near infrared (NIR) and the long-wave infrared (LWIR) spectral bands. Polarimetric signatures were acquired during two distinct trials that occurred in 2007, using specific civilian and military targets such as cars and military vehicles. Results demonstrate to what extent and under which illumination and environmental conditions the exploitation of active and passive polarimetric images is suitable to enable target detection and recognition for some events of interest, according to various specific scenarios.

  16. Electro-optic bandwidth manipulation of quantum light (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Karpinski, Michal; Jachura, Michal; Wright, Laura J.; Smith, Brian J.

    2016-04-01

    Spectral-temporal manipulation of optical pulses has enabled numerous developments within a broad range of research topics, ranging from fundamental science to practical applications. Within quantum optics spectral-temporal degree of freedom of light offers a promising platform for integrated photonic quantum information processing. An important challenge in experimentally realizing spectral-temporal manipulation of quantum states of light is the need for highly efficient manipulation tools. In this context the intrinsically deterministic electro-optic methods show great promise for quantum applications. We experimentally demonstrate application of electro-optic platform for spectral-temporal manipulation of ultrashort pulsed quantum light. Using techniques analogous to serrodyne frequency shifting we show active spectral translation of few-picosecond single photon pulses by up to 0.5 THz. By employing an approach based on an electro-optic time lens we demonstrate up to 6-fold spectral compression of heralded single photon pulses with efficiency that enables us to significantly increase single photon flux through a narrow bandpass filter. We realize the required temporal phase manipulation by driving a lithium niobate waveguided electrooptic modulator with 33 dBm sinusoidal RF field at the frequency of either 10 GHz or 40 GHz. We use a phase lock loop to temporally lock the RF field to the 80 MHz repetition rate of approximately 1 ps long optical pulses. Heralded single photon wavepackets are generated by means of spontaneous parametric down-conversion in potassium dihydrogen phosphate (KDP) crystal, which enables preparation of spectrally pure single photon wavepackets without the need for spectral filtering. Spectral shifting is achieved by locking single-photon pulses to the linear slope of sinusoidal 40 GHz RF phase modulation. We verify the spectral shift by performing spectrally resolved heralded single photon counting, using frequency-to-time conversion by

  17. Improved Image Reconstruction for Partial Fourier Gradient-Echo Echo-Planar Imaging (EPI)

    PubMed Central

    Chen, Nan-kuei; Oshio, Koichi; Panych, Lawrence P.

    2009-01-01

    The partial Fourier gradient-echo echo planar imaging (EPI) technique makes it possible to acquire high-resolution functional MRI (fMRI) data at an optimal echo time. This technique is especially important for fMRI studies at high magnetic fields, where the optimal echo time is short and may not be achieved with a full Fourier acquisition scheme. In addition, it has been shown that partial Fourier EPI provides better anatomic resolvability than full Fourier EPI. However, the partial Fourier gradient-echo EPI may be degraded by artifacts that are not usually seen in other types of imaging. Those unique artifacts in partial Fourier gradient-echo EPI, to our knowledge, have not yet been systematically evaluated. Here we use the k-space energy spectrum analysis method to understand and characterize two types of partial Fourier EPI artifacts. Our studies show that Type 1 artifact, originating from k-space energy loss, cannot be corrected with pure postprocessing, and Type 2 artifact can be eliminated with an improved reconstruction method. We propose a novel algorithm, that combines images obtained from two or more reconstruction schemes guided by k-space energy spectrum analysis, to generate partial Fourier EPI with greatly reduced Type 2 artifact. Quality control procedures for avoiding Type 1 artifact in partial Fourier EPI are also discussed. PMID:18383294

  18. Future electro-optical sensors and processing in urban operations

    NASA Astrophysics Data System (ADS)

    Grönwall, Christina; Schwering, Piet B.; Rantakokko, Jouni; Benoist, Koen W.; Kemp, Rob A. W.; Steinvall, Ove; Letalick, Dietmar; Björkert, Stefan

    2013-10-01

    In the electro-optical sensors and processing in urban operations (ESUO) study we pave the way for the European Defence Agency (EDA) group of Electro-Optics experts (IAP03) for a common understanding of the optimal distribution of processing functions between the different platforms. Combinations of local, distributed and centralized processing are proposed. In this way one can match processing functionality to the required power, and available communication systems data rates, to obtain the desired reaction times. In the study, three priority scenarios were defined. For these scenarios, present-day and future sensors and signal processing technologies were studied. The priority scenarios were camp protection, patrol and house search. A method for analyzing information quality in single and multi-sensor systems has been applied. A method for estimating reaction times for transmission of data through the chain of command has been proposed and used. These methods are documented and can be used to modify scenarios, or be applied to other scenarios. Present day data processing is organized mainly locally. Very limited exchange of information with other platforms is present; this is performed mainly at a high information level. Main issues that arose from the analysis of present-day systems and methodology are the slow reaction time due to the limited field of view of present-day sensors and the lack of robust automated processing. Efficient handover schemes between wide and narrow field of view sensors may however reduce the delay times. The main effort in the study was in forecasting the signal processing of EO-sensors in the next ten to twenty years. Distributed processing is proposed between hand-held and vehicle based sensors. This can be accompanied by cloud processing on board several vehicles. Additionally, to perform sensor fusion on sensor data originating from different platforms, and making full use of UAV imagery, a combination of distributed and

  19. Numerical modeling of LCD electro-optical performance

    NASA Astrophysics Data System (ADS)

    Woehler, Henning; Becker, Michael E.

    2002-06-01

    Realization of complex high information density LCDs and systematic optimization of their electro-optical and ergonomic performance would not be possible in the required time-frame without reliable numerical modeling of the electro-optical performance of such display devices. In this paper we outline the history of numerical LDC modeling starting with Berreman and van Doorn, finally arriving at modern state-of-the-art LCD-modeling in two and three dimensions. Numerical modeling of LCDs is carried out in two steps: first, the effect of the electrical field on the orientation of the liquid crystalline alignment has to be evaluated before the corresponding optical properties can be computed. Starting from LC-elasticity theory we present suitable numerical methods for computing various states of LC-deformation (stable, metastable, bistable, etc.) in one- dimensional problems Light propagation in layered anisotropic absorbing media is evaluated with methods that are based on Maxwell's equations (Berreman 4 X 4-matrix approach). This approach can be simplified to yield methods with reduced computing time and sufficient accuracy for many problems (e.g. extended Jones 2 X 2-matrix formalism). A finite element method with automatic mesh generation and refinement for computing accurate solutions in two- dimensional problems is presented and its application illustrated with examples (e.g. IPS-effect, VAN-cells, etc.). In two- and three-dimensional problems, i.e. in cells with lateral dimensions comparable to the cell thickness, a variety of different director configurations are possible for a given geometry and electrical driving and addressing, making the modeling more complicated. Moreover, local defects can occur, which should also be considered in the simulation. Suitable approaches for the director field calculation, i.e. the vector and the tensor approach, are discussed. The complexity of the problem increases considerably when a third dimension is added, e.g. the

  20. High-speed high-density holographic memory using electro-optic beam steering devices

    NASA Astrophysics Data System (ADS)

    Chao, Tien-Hsin; Zhou, Hanying; Reyes, George F.; Dragoi, Danut; Hanan, Jay

    2002-11-01

    An innovative compact holographic memory system will be presented. This system utilizes a new electro-optic (E-O) beam steering technology to achieve high-speed, high-density holographic data storage.

  1. Polarization-independent integrated electro-optic phase modulator in polymers

    NASA Astrophysics Data System (ADS)

    Braeuer, Andreas H.; Gase, Torsten; Erdmann, Lars; Dannberg, Peter; Karthe, Wolfgang

    1994-01-01

    Polymer multilayer waveguide technology was used to fabricate a polarization-independent phasemodulator. Refractive indices and electro-optic coefficient r33 of the materials used (Co. SANDOZ) were determined by waveguide methods.

  2. The Electronic and Electro-Optic Future of III-V Semiconductor Compounds.

    DTIC Science & Technology

    1978-12-01

    An assessment of material development of III-V compounds for electro - optic , microwave and millimeter wave technology is presented. Questions concerning material selection, needs and processing is addressed. (Author)

  3. Innovative 3D Visualization of Electro-optic Data for MCM

    DTIC Science & Technology

    2001-09-30

    The long-term goal is to develop innovative methods for transforming data taken by electro - optic and acoustic MCM sensors into graphical representations better suited to human interpretation, specifically to aid mine classification.

  4. Susceptibility of electro-optic components to degradation in a space environment.

    PubMed

    Blue, M D

    1996-11-01

    Possible causes of degradation of electro-optic systems operating in a space environment include not only the effects of radiation but also the effects of temperature, temperature cycling, atomic oxygen effects (for low-Earth orbits), micrometeoroid impacts, and contamination effects. For the majority of electro-optic components, the radiation environment in space does not present a significant problem. For a few components, or for electro-optic systems that must operate in a high radiation environment, special precautions must be observed. The effects of radiation, as well as other problems of the space environment, on electro-optic components, including recent results from the LDEF satellite experiments and some later measurements, are reviewed. Guidelines for materials and component selection shielding are presented.

  5. Tunable Optical Filters Having Electro-optic Whispering-gallery-mode Resonators

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy (Inventor); Ilchenko, Vladimir (Inventor); Matsko, Andrey B. (Inventor); Maleki, Lutfollah (Inventor)

    2006-01-01

    Tunable optical filters using whispering-gallery-mode (WGM) optical resonators are described. The WGM optical resonator in a filter exhibits an electro-optical effect and hence is tunable by applying a control electrical signal.

  6. Design and simulation of planar electro-optic switches in ferroelectrics

    NASA Astrophysics Data System (ADS)

    Krishnamurthi, Mahesh; Tian, Lili; Gopalan, Venkatraman

    2008-08-01

    Conceptual design and numerical simulation of two polarization dependent planar optical switches based on the electro-optic effect in ferroelectrics operating at 1.55 μm wavelength are presented. The first design is a 3×3 optical switch based entirely on electro-optic beam steering (prism) elements and ion-exchanged lenses for collimation. The second design is a 1×N optical switch based on a combination of electro-optic beam steering and electro-optic focusing (lens) elements. The scalability of this device has been improved by compensating the in-plane divergence of the laser. Analytical expressions for the dependence of scalability are presented.

  7. A Fourier dimensionality reduction model for big data interferometric imaging

    NASA Astrophysics Data System (ADS)

    Vijay Kartik, S.; Carrillo, Rafael E.; Thiran, Jean-Philippe; Wiaux, Yves

    2017-06-01

    Data dimensionality reduction in radio interferometry can provide savings of computational resources for image reconstruction through reduced memory footprints and lighter computations per iteration, which is important for the scalability of imaging methods to the big data setting of the next-generation telescopes. This article sheds new light on dimensionality reduction from the perspective of the compressed sensing theory and studies its interplay with imaging algorithms designed in the context of convex optimization. We propose a post-gridding linear data embedding to the space spanned by the left singular vectors of the measurement operator, providing a dimensionality reduction below image size. This embedding preserves the null space of the measurement operator and hence its sampling properties are also preserved in light of the compressed sensing theory. We show that this can be approximated by first computing the dirty image and then applying a weighted subsampled discrete Fourier transform to obtain the final reduced data vector. This Fourier dimensionality reduction model ensures a fast implementation of the full measurement operator, essential for any iterative image reconstruction method. The proposed reduction also preserves the independent and identically distributed Gaussian properties of the original measurement noise. For convex optimization-based imaging algorithms, this is key to justify the use of the standard ℓ2-norm as the data fidelity term. Our simulations confirm that this dimensionality reduction approach can be leveraged by convex optimization algorithms with no loss in imaging quality relative to reconstructing the image from the complete visibility data set. Reconstruction results in simulation settings with no direction dependent effects or calibration errors show promising performance of the proposed dimensionality reduction. Further tests on real data are planned as an extension of the current work. matlab code implementing the

  8. Imaging Fourier Transform Spectroscopy from a Space Based Platform -- The Herschel/SPIRE Fourier Transform Spectrometer

    NASA Astrophysics Data System (ADS)

    Spencer, Locke Dean

    The Herschel Space Observatory (Herschel), a flagship mission of the European Space Agency (ESA), is comprised of three cryogenically cooled instruments commissioned to explore the far-infrared/submillimetre universe. Herschel's remote orbit at the second Lagrangian point (L2) of the Sun-Earth system, and its cryogenic payload, impose a need for thorough instrument characterization and rigorous testing as there will be no possibility for any servicing after launch. The Spectral and Photometric Imaging Receiver (SPIRE) is one of the instrument payloads aboard Herschel and consists of a three band imaging photometer and a two band imaging spectrometer. The imaging spectrometer on SPIRE consists of a Mach-Zehnder (MZ)-Fourier transform spectrometer (FTS) coupled with bolometric detector arrays to form an imaging FTS (IFTS). This thesis presents experiments conducted to verify the performance of an IFTS system from a space based platform, Le. the use of the SPIRE IFTS within the Herschel space observatory. Prior to launch, the SPIRE instrument has undergone a series of performance verification tests conducted at the Rutherford Appleton Laboratory (RAL) near Oxford, UK. Canada is involved in the SPIRE project through provision of instrument development hardware and software, mission flight software, and support personnel. Through this thesis project I have been stationed at RAL for a period spanning fifteen months to participate in the development, performance verification, and characterization of both the SPIRE FTS and photometer instruments. This thesis discusses Fourier transform spectroscopy and related FTS data processing (Chapter 2). Detailed discussions are included on the spectral phase related to the FTS beamsplitter (Chapter 3), the imaging aspects of the SPIRE IFTS instrument (Chapter 4), and the noise characteristics of the SPIRE bolometer detector arrays as measured using the SPIRE IFTS (Chapter 5). This thesis presents results from experiments performed

  9. Influence of Electro-Acoustic Effects on the Electro-Optic Response of Charged Colloids.

    PubMed

    Dimitrov; Alekov; Stoimenova

    1999-12-15

    Low-frequencyanomalous electro-optic behavior of colloidal systems (sign reversal and deviations from Kerr low) is considered in the light of electrically induced acoustic modes. The latter were recently detected and investigated in samples of isotropic spherical particles. Their linear dependence on field intensity explains the low-field "permanent dipole" behavior of charged colloids. The coupling of anisotropy and density fluctuations results in the complicated frequency curves of the electro-optic responses of anisometric particles. Copyright 1999 Academic Press.

  10. High performance electro-optical modulator based on photonic crystal and graphene

    NASA Astrophysics Data System (ADS)

    Malekmohammad, M.; Asadi, R.

    2017-07-01

    An electro-optical modulator is demonstrated based on Fano-resonance effect in an out-of-plane illumination of one-dimensional slab photonic crystal composed of two graphene layers. It has been shown that high sensitivity of the Fano-resonance and electro-refractive tuning of graphene layers provides a suitable condition to obtain an electro-optical modulator with low energy consumption (8 pJ) with contrast of 0.4.

  11. Ferroelectric Tungsten Bronze Bulk Crystals and Epitaxial Thin Films for Electro-Optic Device Applications

    DTIC Science & Technology

    1983-05-01

    23 FERROELECTRIC TUNGSTEN BRONZE BULK CRYSTALS AND EPITAXIAL THIN FILMS FOR ELECTRO-OPTIC DEVICE APPLICATIONS 10 CO O Semi-Annual Technical... THIN FILMS FOR ELECTRO-OPTIC DEVICE APPLICATIONS s TV^C or REPORT * pcmoo COVCHCO Semi-Annual Tec1! Rpt #1 for period 09/30/82-03/31/83...months, considerable progress has been made in several areas, including single crystal and thin film growth and characteriza- tion. The new

  12. Acousto-Optic and Linear Electro-Optic Properties of Organic Polymeric Materials

    DTIC Science & Technology

    1989-04-27

    Naval Research Laboratory Washington, DC 20375-5000 NRL Memorandum Report 6454 od I3 Acousto - Optic and Linear Electro-Optic Properties of Organic...PROGRAM P1RC;EC7 ASK Arlington, VA 22217-5000 ELEMENT NO NO1 I1I TITLE (Include Security Classification) Acousto - Optic and Linear Electro-Optic...briefly discussing the important molecular properties for enhanced acousto ~ optic and electro-Ooptic ef fects and then relating these to "current

  13. Azo-Carbazole Polymethacrylates as Single-Component Electro-Optic Materials

    DTIC Science & Technology

    2007-11-02

    previously. Sample Preparation The n-variable spacer poly( azo carbazole) (PAC-n) polymers used in this study were cast as films onto transparent...electric field poling and photoinduced birefringence. Once an electro-optic thin film sandwich of azo polymer is brought to Tg , application of an...and coefficients obtained from curve fitting. Figure 1. Azo -carbazole polymer cast as a thin film (top), an electro-optic sandwich (center), and an

  14. An Electro-Optic Spatial Light Modulator for Thermoelastic Generation of Programmably Focused Ultrasound.

    DTIC Science & Technology

    1984-12-01

    The concept proposed is an electro - optic technique that would make it possible to spatially modulate a high power pulsed laser beam to thermoelastically induce focused ultrasound in a test material. Being a purely electro - optic device, the modulator, and therefore the depth at which the acoustic focus occurs, can be programmed electronically at electronic speeds. If successful, it would become possible to scan ultrasound continuously in three dimensions within the component or structure under test. (Author)

  15. Performance of electro-optical plasmonic ring resonators at telecom wavelengths.

    PubMed

    Randhawa, Sukanya; Lachèze, Sébastien; Renger, Jan; Bouhelier, Alexandre; de Lamaestre, Roch Espiau; Dereux, Alain; Quidant, Romain

    2012-01-30

    In this work we report on the characteristics of an electro-optical dielectric-loaded surface plasmon polariton waveguide ring resonator. By doping the dielectric host matrix with an electro-optical material and designing an appropriate set of planar electrodes, we measured a 16% relative change of transmission upon application of a controlled electric field. We have analyzed the temporal response of the device and conclude that electrostriction of the host matrix is playing a dominating role in the transmission response.

  16. Stabilized electro-optical airborne instrumentation platform (SEAIP)

    NASA Astrophysics Data System (ADS)

    Ricks, Timothy P.; Burton, Megan M.; Cruger, William; Reynolds, Robert

    2004-02-01

    Airborne testing of sensors presents unique challenges to the researcher. Prototype sensors are not typically configured for aircraft mounting, and testing requires comparative (truth) data for accurate sensor performance evaluation. The U.S. Army Redstone Technical Test Center (RTTC) has developed a large Stabilized Electro-optical Airborne Instrumentation Platform (SEAIP) for use with rotary wing aircraft as a sensor test bed. This system is designed to accommodate the rapid integration of multiple sensors into the gimbal, greatly reducing the time required to enter a sensor into testing. The SEAIP has been designed for use with UH-1 or UH-60 aircraft. It provides nominal 35 μradian (RMS) line-of-sight stabilization in two axes. Design has been optimized for support of multiple/large prototype (brassboard) sensors. Payload combinations up to 80 lbs can be accommodated. Gimbal angle ranges are large to permit flexibility for sensor pointing. Target acquisition may be done manually, or with the use of a GPS tracker. Non-visible targets may be engaged, and sensor information may be mapped real-time to digitized maps or photographs of the test area. Two SEAIP systems are currently used at RTTC. Numerous sensors have been successfully integrated and tested, including MMW, LADAR, IR, SAL, multi-spectral, visible, and night vision.

  17. Evaluation of the electro-optic direction sensor

    NASA Technical Reports Server (NTRS)

    Johnson, A. R.; Salomon, P. M.

    1973-01-01

    Evaluation of a no-moving-parts single-axis star tracker called an electro-optic direction sensor (EODS) concept is described and the results are given in detail. The work involved experimental evaluation of a breadboard sensor yielding results which would permit design of a prototype sensor for a specific application. The laboratory work included evaluation of the noise equivalent input angle of the sensor, demonstration of a technique for producing an acquisition signal, constraints on the useful field-of-view, and a qualitative evaluation of the effects of stray light. In addition, the potential of the silicon avalanche-type photodiode for this application was investigated. No benefit in noise figure was found, but the easily adjustable gain of the avalanche device was useful. The use of mechanical tuning of the modulating element to reduce voltage requirements was also explored. The predicted performance of EODS in both photomultiplier and solid state detector configurations was compared to an existing state-of-the-art star tracker.

  18. Electro-optical parameters of bond polarizability model for aluminosilicates.

    PubMed

    Smirnov, Konstantin S; Bougeard, Daniel; Tandon, Poonam

    2006-04-06

    Electro-optical parameters (EOPs) of bond polarizability model (BPM) for aluminosilicate structures were derived from quantum-chemical DFT calculations of molecular models. The tensor of molecular polarizability and the derivatives of the tensor with respect to the bond length are well reproduced with the BPM, and the EOPs obtained are in a fair agreement with available experimental data. The parameters derived were found to be transferable to larger molecules. This finding suggests that the procedure used can be applied to systems with partially ionic chemical bonds. The transferability of the parameters to periodic systems was tested in molecular dynamics simulation of the polarized Raman spectra of alpha-quartz. It appeared that the molecular Si-O bond EOPs failed to reproduce the intensity of peaks in the spectra. This limitation is due to large values of the longitudinal components of the bond polarizability and its derivative found in the molecular calculations as compared to those obtained from periodic DFT calculations of crystalline silica polymorphs by Umari et al. (Phys. Rev. B 2001, 63, 094305). It is supposed that the electric field of the solid is responsible for the difference of the parameters. Nevertheless, the EOPs obtained can be used as an initial set of parameters for calculations of polarizability related characteristics of relevant systems in the framework of BPM.

  19. An integrated Si-based electro-optical modulator

    NASA Astrophysics Data System (ADS)

    Sciuto, Antonella; Libertino, Sebania; Coffa, Salvotore; Coppola, Giuseppe

    2004-08-01

    Optical interconnects are, nowadays, considered a promising alternative to electrical ones and monolithic integration in Si is the only choice when high volumes, low fabrication costs and reduced spaces are needed. We fabricated an electro-optic Si-based modulator working at 1.5 um using a Bipolar Mode Field-Effect transistor integrated within a Si rib waveguide. The principle of operation is the light absorption by a plasma of free carrier that can be opportunely moved inside or outside the device optical channel by properly changing the bias. The optical channel of the modulator is embodied within its vertical electrical channel. The devices were fabricated using epitaxial Si wafers and standard clean room processing. The optical characterization in static conditions shows a modulation depth, defined as M=(POff-POn)/POff , of ~ 90 %. It was measured at 1.48 um using a laser diode source coupled with the modulator through a silica optical fiber. The dynamic electrical characterization provides an electrical switching time of ~10 ns. A modulation depth of 72 % is observed at 100kHz electrical modulation frequency.

  20. Electro-optic sampling of near-infrared waveforms

    NASA Astrophysics Data System (ADS)

    Keiber, Sabine; Sederberg, Shawn; Schwarz, Alexander; Trubetskov, Michael; Pervak, Volodymyr; Krausz, Ferenc; Karpowicz, Nicholas

    2016-03-01

    Access to the complete electric field evolution of a laser pulse is essential for attosecond science in general, and for the scrutiny and control of electron phenomena in solid-state physics specifically. Time-resolved field measurements are routine in the terahertz spectral range, using electro-optic sampling (EOS), photoconductive switches and field-induced second harmonic generation. EOS in particular features outstanding sensitivity and ease of use, making it the basis of time-resolved spectroscopic measurements for studying charge carrier dynamics and active optical devices. In this Letter, we show that careful optical filtering allows the bandwidth of this technique to be extended to wavelengths as short as 1.2 μm (230 THz) with half-cycle durations 2.3 times shorter than the sampling pulse. In a proof-of-principle application, we measure the influence of optical parametric amplification (OPA) on the electric field dynamics of a few-cycle near-infrared (NIR) pulse.

  1. Electro-optic materials by solid source MOCVD

    SciTech Connect

    Hiskes, R.; Dicarolis, S.A.; Fouquet, J.; Lu, Z.; Feigelson, R.S.; Route, R.K.; Leplingard, F.; Foster, C.M.

    1993-12-01

    The solid source MOCVD technique, employing a single powder vaporization source composed of mixed beta-diketonate metalorganic compounds, has been used to grow thin films of a variety of electro-optic materials, including lithium niobate, strontium barium niobate, and potassium niobate. Preliminary results for potassium niobate films indicate that a volatile potassium organometallic source can be synthesized useful for growing potassium niobate by MOCVD. High single phase (001) oriented strontium barium niobate films have been deposited which exhibit waveguiding behavior. The most extensive work has been done on lithium niobate deposited epitaxially on a variety of substrates. Oriented z-axis (001) films have been grown on c-axis sapphire with and without a (111) oriented platinum base electrode and on a bulk grown lithium niobate substrate. Films grown directly on c-axis sapphire at 700 C exhibit x-ray rocking curve linewidths as low as .044 degrees, nearly perfect in-plane orientation as determined by x-ray phi scans, and peak-to-peak surface roughness less than 40 {Angstrom}. Optical waveguiding has been demonstrated by single prism coupling technique on similar films 1175--2000 {Angstrom} thick grown at 500 C, with optical losses of approximately 2 db/cm at 632.8 nm measured over 3.5 cm long films. Polarization vs. electric field measurements on 1100 {Angstrom} thick films grown on platinum show a hysteresis loop indicating ferroelectric behavior.

  2. Image encryption techniques based on the fractional Fourier transform

    NASA Astrophysics Data System (ADS)

    Hennelly, B. M.; Sheridan, J. T.

    2003-11-01

    The fractional Fourier transform, (FRT), is a generalisation of the Fourier transform which allows domains of mixed spatial frequency and spatial information to be examined. A number of method have recently been proposed in the literature for the encryption of two dimensional information using optical systems based on the FRT. Typically, these methods require random phase screen keys to decrypt the data, which must be stored at the receiver and must be carefully aligned with the received encrypted data. We have proposed a new technique based on a random shifting or Jigsaw transformation. This method does not require the use of phase keys. The image is encrypted by juxtaposition of sections of the image in various FRT domains. The new method has been compared numerically with existing methods and shows comparable or superior robustness to blind decryption. An optical implementation is also proposed and the sensitivity of the various encryption keys to blind decryption is quantified. We also present a second image encryption technique, which is based on a recently proposed method of optical phase retrieval using the optical FRT and one of its discrete counterparts. Numerical simulations of the new algorithm indicates that the sensitivity of the keys is much greater than any of the techniques currently available. In fact the sensitivity appears to be so high that optical implementation, based on existing optical signal processing technology, may be impossible. However, the technique has been shown to be a powerful method of 2-D image data encryption.

  3. Common Aperture Techniques for Imaging Electro-Optical Sensors (CATIES).

    DTIC Science & Technology

    1980-02-01

    Feedback for the servo electronics and LED readout display signals are also obtained from these reference potentiometer voltages. The motor drive circuitry...Object Seoaration: .1927 inches IMA r;I;SEI’ARATION EFI. = 196 1/0 EFL SPEC. TN(󈧏t*..’) (1NCHIRS) *"(INCHES) VNtIV .031 31.53 31.5+0.63 N1󈧈 .01025

  4. Bandwidth enhancement of electro-optic field sensing using photonic down-mixing with harmonic sidebands.

    PubMed

    Lee, Dong-Joon; Whitaker, John F

    2008-09-15

    We demonstrate that harmonic sidebands of an electro-optic modulator's driving frequency can be used as the local oscillator in a photonic down-mixing process in order to significantly enhance the bandwidth of near-field, electro-optic, microwave measurements. The creation of second- and third-order-harmonic modulation sidebands on a laser-diode output are described, with heterodyne down-conversion of microwave signals taking place within an electro-optic sensor crystal. The measurement bandwidth of an electro-optic microwave probe can thus be enhanced by as much as a factor of three with respect to the use of conventional, fundamental-harmonic sidebands. Carrier-sideband analysis from the measured optical spectrum indicates that millimeter-wave-frequency local-oscillator sidebands can be created using a Ku-band electro-optic modulator and that the electro-optic-signal-modulation depth can be enhanced by suppressing the light-beam carrier component. Transverse near-field distributions from high frequency patch antennas are extracted using both second- and third-order-harmonic sidebands.

  5. Multifunctional metasurface lens for imaging and Fourier transform

    PubMed Central

    Wen, Dandan; Yue, Fuyong; Ardron, Marcus; Chen, Xianzhong

    2016-01-01

    A metasurface can manipulate light in a desirable manner by imparting local and space-variant abrupt phase change. Benefiting from such an unprecedented capability, the conventional concept of what constitutes an optical lens continues to evolve. Ultrathin optical metasurface lenses have been demonstrated based on various nanoantennas such as V-shape structures, nanorods and nanoslits. A single device that can integrate two different types of lenses and polarities is desirable for system integration and device miniaturization. We experimentally demonstrate such an ultrathin metasurface lens that can function either as a spherical lens or a cylindrical lens, depending on the helicity of the incident light. Helicity-controllable focal line and focal point in the real focal plane, as well as imaging and 1D/2D Fourier transforms, are observed on the same lens. Our work provides a unique tool for polarization imaging, image processing and particle trapping. PMID:27272601

  6. Medical Image Processing Using Real-Time Optical Fourier Technique

    NASA Astrophysics Data System (ADS)

    Rao, D. V. G. L. N.; Panchangam, Appaji; Sastry, K. V. L. N.; Material Science Team

    2001-03-01

    Optical Image Processing Techniques are inherently fast in view of parallel processing. A self-adaptive Optical Fourier Processing system using photo induced dichroism in a Bacteriorhodopsin film was experimentally demonstrated for medical image processing. Application of this powerful analog all-optical interactive technique for cancer diagnostics is illustrated with mammograms and Pap smears. Micro calcification clusters buried in surrounding tissue showed up clearly in the processed image. By playing with one knob, which rotates the analyzer in the optical system, either the micro calcification clusters or the surrounding dense tissue can be selectively displayed. Bacteriorhodopsin films are stable up to 140^oC and environmental friendly. As no interference is involved in the experiments, vibration isolation and even a coherent light source are not required. It may be possible to develop a low-cost rugged battery operated portable signal-enhancing magnifier.

  7. Fourier-Transform Ghost Imaging with Hard X Rays

    NASA Astrophysics Data System (ADS)

    Yu, Hong; Lu, Ronghua; Han, Shensheng; Xie, Honglan; Du, Guohao; Xiao, Tiqiao; Zhu, Daming

    2016-09-01

    Knowledge gained through x-ray crystallography fostered structural determination of materials and greatly facilitated the development of modern science and technology in the past century. However, it is only applied to crystalline structures and cannot resolve noncrystalline materials. Here we demonstrate a novel lensless Fourier-transform ghost imaging method with pseudothermal hard x rays that extends x-ray crystallography to noncrystalline samples. By measuring the second-order intensity correlation function of the light, Fourier-transform diffraction pattern of a complex amplitude sample is achieved at the Fresnel region in our experiment and the amplitude and phase distributions of the sample in the spatial domain are retrieved successfully. For the first time, ghost imaging is experimentally realized with x rays. Since a highly coherent x-ray source is not required, the method can be implemented with laboratory x-ray sources and it also provides a potential solution for lensless diffraction imaging with fermions, such as neutrons and electrons where intensive coherent sources usually are not available.

  8. Fourier-Transform Ghost Imaging with Hard X Rays.

    PubMed

    Yu, Hong; Lu, Ronghua; Han, Shensheng; Xie, Honglan; Du, Guohao; Xiao, Tiqiao; Zhu, Daming

    2016-09-09

    Knowledge gained through x-ray crystallography fostered structural determination of materials and greatly facilitated the development of modern science and technology in the past century. However, it is only applied to crystalline structures and cannot resolve noncrystalline materials. Here we demonstrate a novel lensless Fourier-transform ghost imaging method with pseudothermal hard x rays that extends x-ray crystallography to noncrystalline samples. By measuring the second-order intensity correlation function of the light, Fourier-transform diffraction pattern of a complex amplitude sample is achieved at the Fresnel region in our experiment and the amplitude and phase distributions of the sample in the spatial domain are retrieved successfully. For the first time, ghost imaging is experimentally realized with x rays. Since a highly coherent x-ray source is not required, the method can be implemented with laboratory x-ray sources and it also provides a potential solution for lensless diffraction imaging with fermions, such as neutrons and electrons where intensive coherent sources usually are not available.

  9. Electro-optical detector for use in a wide mass range mass spectrometer

    NASA Technical Reports Server (NTRS)

    Giffin, Charles E. (Inventor)

    1976-01-01

    An electro-optical detector is disclosed for use in a wide mass range mass spectrometer (MS), in the latter the focal plane is at or very near the exit end of the magnetic analyzer, so that a strong magnetic field of the order of 1000G or more is present at the focal plane location. The novel detector includes a microchannel electron multiplier array (MCA) which is positioned at the focal plane to convert ion beams which are focused by the MS at the focal plane into corresponding electron beams which are then accelerated to form visual images on a conductive phosphored surface. These visual images are then converted into images on the target of a vidicon camera or the like for electronic processing. Due to the strong magnetic field at the focal plane, in one embodiment of the invention, the MCA with front and back parallel ends is placed so that its front end forms an angle of not less than several degrees, preferably on the order of 10.degree.-20.degree., with respect to the focal plane, with the center line of the front end preferably located in the focal plane. In another embodiment the MCA is wedge-shaped, with its back end at an angle of about 10.degree.-20.degree. with respect to the front end. In this embodiment the MCA is placed so that its front end is located at the focal plane.

  10. Fractional Fourier Transform Applied to Digital Images Encryption

    NASA Astrophysics Data System (ADS)

    Vilardy, Juan M.; Torres, Cesar O.; Mattos, Lorenzo

    2008-04-01

    In the present paper a digital algorithm was developed to make phase encryption of digital indexed images to color using the fractional Fourier transform (the images in RGB are converted to indexed before to encrypt). The indexed images are represented by a matrix of M×N pixels (where M defines the height and N is the Width of the image) and a color map (it's a matrix of C×3 elements, where C indicates the colors number of the image and the number 3 indicates the three columns associated with the color components: Red, Green and Blue of each pixel of the matrix of M×N) associated to the matrix of pixels to suitably represent the color information of the image. The indexed image (matrix of M×N pixels) to encrypt is placed as the phase of a complex exponential, then is transformed three times and multiplied in intermediate steps by two random phase masks statistically independent thus to obtain the encrypted image, for decrypt the coding image the encryption procedure is applied in the inverse sense to the conjugated complex of the encrypted image, then is taken the negative of the phase of the resulting function of the decryption process and the original image is obtained this way that had been encrypted; For the color map equal procedure is applied in the encryption/decryption process described previously for the matrix of M×N pixels. In the implemented cryptographic algorithm five keys are used, constituted by three fractional orders and two random phase masks, all these keys are necessary for a correct decryption providing a dependability to the transference of images by means of the communications nets.

  11. The Discrete Fourier Transform on hexagonal remote sensing image

    NASA Astrophysics Data System (ADS)

    Li, Yalu; Ben, Jin; Wang, Rui; Du, Lingyu

    2016-11-01

    Global discrete grid system will subdivide the earth recursively to form a multi-resolution grid hierarchy with no Overlap and seamless which help build global uniform spatial reference datum and multi-source data processing mode which takes the position as the object and in the aspect of data structure supports the organization, process and analysis of the remote sensing big data. This paper adopts the base transform to realize the mutual transformation of square pixel and hexagonal pixel. This paper designs the corresponding discrete Fourier transform algorithm for any lattice. Finally, the paper show the result of the DFT of the remote sensing image of the hexagonal pixel.

  12. Tests of a compact static Fourier-transform imaging spectropolarimeter.

    PubMed

    Li, Jie; Gao, Bo; Qi, Chun; Zhu, Jingping; Hou, Xun

    2014-06-02

    A compact Fourier-transform imaging spectropolarimeter covering a 450-1000 nm spectral range is presented. The sensor, which is based on two birefringent retarders and a Wollaston interferometer, offers significant advantages over previous implementations. Specifically, with no internal moving parts, electrically controllable or micro polarization components, the full wavelength-dependent state of polarization, spectral and spatial information of a scene can be acquired simultaneously. Outdoor measurements of several cars and plants demonstrate the sensor's potential for color measurement, target identification, and agriculture monitoring applications.

  13. Grid-Based Fourier Transform Phase Contrast Imaging

    NASA Astrophysics Data System (ADS)

    Tahir, Sajjad

    Low contrast in x-ray attenuation imaging between different materials of low electron density is a limitation of traditional x-ray radiography. Phase contrast imaging offers the potential to improve the contrast between such materials, but due to the requirements on the spatial coherence of the x-ray beam, practical implementation of such systems with tabletop (i.e. non-synchrotron) sources has been limited. One recently developed phase imaging technique employs multiple fine-pitched gratings. However, the strict manufacturing tolerances and precise alignment requirements have limited the widespread adoption of grating-based techniques. In this work, we have investigated a technique recently demonstrated by Bennett et al. that utilizes a single grid of much coarser pitch. Our system consisted of a low power 100 microm spot Mo source, a CCD with 22 microm pixel pitch, and either a focused mammography linear grid or a stainless steel woven mesh. Phase is extracted from a single image by windowing and comparing data localized about harmonics of the grid in the Fourier domain. A Matlab code was written to perform the image processing. For the first time, the effects on the diffraction phase contrast and scattering amplitude images of varying grid types and periods, and of varying the window function type used to separate the harmonics, and the window widths, were investigated. Using the wire mesh, derivatives of the phase along two orthogonal directions were obtained and new methods investigated to form improved phase contrast images.

  14. Electro-Optical Payloads and CubeSat Missions for Earth and Space Science

    NASA Astrophysics Data System (ADS)

    Swenson, C.; Marchant, A.

    2015-12-01

    Small, low-power electro-optical scientific payloads are required if small satellites and CubeSats are to become significant enablers of new science. Although these are just one class of scientific instrumentation they have often played a key role in many scientific discoveries. The most significant advances in Earth and space science, over the next decade are most likely to derive from new observational techniques. The connection between advances in scientific understanding and technology has historically been demonstrated across many disciplines and time. In this paper we present a review of three such sensors and the associated CubeSat missions and scientific investigation enabled. Each mission involves a relatively recently developed small electro-optical sensor which is tightly integrated with the small satellite bus in to a "Science Craft". The first is the NSF funded OPAL mission which makes use of a high-sensitivity, hyper-spectral limb imager to observe the daytime O2 A-band (near 762nm) emission. These observations allow the temperature of the lower thermosphere to be determined and address questions on the energy budget and response of the thermosphere to geomagnetic storms. The second is the MeNISCuS mission Methane Nadir Imaging Spatial-heterodyne CubeSat Spectrometer which is a demonstration of the volume holographic grating (VHG) spatial heterodyne spectrometer developed under a NASA-sponsored STTR contract. Methane (CH4) is the second most important greenhouse gas and although burning methane produces less CO2 than oil or coal, methane's global warming potential is about ~30 times higher. As a result, if methane leak rates are greater than 3-5%, the warming potential will outweigh the benefit of reduced CO2. The sources of such leaks can be discovered using missions like MeNISCuS. The third instrument and mission is SEDI a CubeSat scaled Fabry-Perot spectrometer focused on a narrow band around the OI(630) red line for observing winds in the

  15. Electro-optic microdisk RF-wireless receiver

    NASA Astrophysics Data System (ADS)

    Hossein-Zadeh, Mani

    A self-homodyne photonic receiver for transmitted carrier wireless links is demonstrated. The key innovations in this photonic RF-receiver are the design and implementation of a resonant LiNbO3 microdisk electro-optic modulator and novel RF down-conversion techniques that exploit the sensitivity of the microdisk for efficient RF down-conversion in the optical domain. By careful RF and optical design, simultaneous photonic and RF resonance is achieved in a LiNbO3 microdisk modulator resulting in a sensitivity of -80 dBm at 14.6 GHz. Two photonic RF down-conversion techniques are proposed to extract the baseband information from a RF signal that has a transmitted carrier modulation format. In the first approach we use an optical filter to modify the optical output spectrum of the microdisk modulator. Photodetection of the subsequent optical signal generates the baseband photocurrent. In the second technique the RF carrier and sidebands are mixed through nonlinear optical modulation in the microdisk and the down-converted signal is detected using a photodetector. In both cases the bandwidth of the photodetector and electronic circuitry are limited to that of the baseband signal. Receiver operation is demonstrated by demodulating up to 100 Mb/s digital data from a 14.6 GHz RF carrier frequency. Power efficiency, small volume, light weight and elimination of high-speed electronic components are the main specifications of the photonic RF-receiver that make it useful for applications like wireless LANs, fiber-feed backbone networks or video distribution systems.

  16. Magnetic resonance image enhancement using stochastic resonance in Fourier domain.

    PubMed

    Rallabandi, V P Subramanyam; Roy, Prasun Kumar

    2010-11-01

    In general, low-field MRI scanners such as the 0.5- and 1-T ones produce images that are poor in quality. The motivation of this study was to lessen the noise and enhance the signal such that the image quality is improved. Here, we propose a new approach using stochastic resonance (SR)-based transform in Fourier space for the enhancement of magnetic resonance images of brain lesions, by utilizing an optimized level of Gaussian fluctuation that maximizes signal-to-noise ratio (SNR). We acquired the T1-weighted MR image of the brain in DICOM format. We processed the original MR image using the proposed SR procedure. We then tested our approach on about 60 patients of different age groups with different lesions, such as arteriovenous malformation, benign lesion and malignant tumor, and illustrated the image enhancement by using just-noticeable difference visually as well as by utilizing the relative enhancement factor quantitatively. Our method can restore the original image from noisy image and optimally enhance the edges or boundaries of the tissues, clarify indistinct structural brain lesions without producing ringing artifacts, as well as delineate the edematous area, active tumor zone, lesion heterogeneity or morphology, and vascular abnormality. The proposed technique improves the enhancement factor better than the conventional techniques like the Wiener- and wavelet-based procedures. The proposed method can readily enhance the image fusing a unique constructive interaction of noise and signal, and enables improved diagnosis over conventional methods. The approach well illustrates the novel potential of using a small amount of Gaussian noise to improve the image quality. Copyright © 2010 Elsevier Inc. All rights reserved.

  17. EOSTAR: an electro-optical sensor performance model for predicting atmospheric refraction, turbulence, and transmission in the marine surface layer

    NASA Astrophysics Data System (ADS)

    Kunz, Gerard J.; Moerman, Marcel M.; van Eijk, Alexander M. J.; Doss-Hammel, Stephen M.; Tsintikidis, Dimitri

    2004-02-01

    A first version of the integrated model EOSTAR (Electro-Optical Signal Transmission and Ranging) to predict the performance of electro-optical (EO) sensor systems in the marine atmospheric surface layer has been developed. The model allows the user to define camera systems, atmospheric conditions and target characteristics, and it uses standard (shipboard) meteorological data to calculate atmospheric effects such as refraction, turbulence, spectrally resolved transmission, path- and background radiation. Alternatively, the user may specify vertical profiles of meteorological parameters and/or profiles of atmospheric refraction, either interactively or in data files with a flexible format. Atmospheric effects can be presented both numerically and graphically as distorted images of synthetically generated targets with spatially distributed emission properties. EOSTAR is a completely mouse-driven PC Windows program with a user-friendly interface and extended help files. Most calculations are performed in real-time, although spectral transmission and background radiation calculations take up to a few seconds for each new meteorological condition. The program can be used in a wide range of applications, e.g., for operational planning and instruction.

  18. Optical, mechanical, and electro-optical design of an interferometric test station for massive parallel inspection of MEMS and MOEMS

    NASA Astrophysics Data System (ADS)

    Gastinger, Kay; Haugholt, Karl Henrik; Kujawinska, Malgorzata; Jozwik, Michal; Schaeffel, Christoph; Beer, Stephan

    2009-06-01

    The paper presents the optical, mechanical, and electro-optical design of an interferometric inspection system for massive parallel inspection of MicroElectroMechanicalSystems (MEMS) and MicroOptoElectroMechanicalSystems (MOEMS). The basic idea is to adapt a micro-optical probing wafer to the M(O)EMS wafer under test. The probing wafer is exchangeable and contains a micro-optical interferometer array. A low coherent and a laser interferometer array are developed. Two preliminary interferometer designs are presented; a low coherent interferometer array based on a Mirau configuration and a laser interferometer array based on a Twyman-Green configuration. The optical design focuses on the illumination and imaging concept for the interferometer array. The mechanical design concentrates on the scanning system and the integration in a standard test station for micro-fabrication. Models of single channel low coherence and laser interferometers and preliminary measurement results are presented. The smart-pixel approach for massive parallel electro-optical detection and data reduction is discussed.

  19. High throughput full Stokes Fourier transform imaging spectropolarimetry.

    PubMed

    Meng, Xin; Li, Jianxin; Xu, Tingting; Liu, Defang; Zhu, Rihong

    2013-12-30

    A complete full Stokes imaging spectropolarimeter is proposed. Four separate polarized spectra are fed into the Sagnac Fourier transform spectrometer without slit using different angle combinations of the polarized elements. The four polarized spectra are separated without spatial aliasing. And the system has a good performance to resist the instrument noise due to its high light throughput. The mathematical model for the approach is derived and an optimization of the retardance is discussed. For acquiring the four spectra simultaneously, an improved robust polarization modulator using aperture division is outlined. Then the system is discussed in detail including the imaging principle and spectral resolution. Lastly, two proven experiments are carried out and the experimental results in visible light are outlined.

  20. High-speed, Low Voltage, Miniature Electro-optic Modulators Based on Hybrid Photonic-Crystal/Polymer/Sol-Gel Technology

    DTIC Science & Technology

    2012-02-01

    code) 01/02/2012 FINAL 15/11/2008 - 15/11/2011 High-speed, Low Voltage, Miniature Electro - optic Modulators Based on Hybrid Photonic-Crystal/Polymer... optic modulator, silicon photonics, integrated optics, electro - optic polymer, avionics, optical communications, sol-gel, nanotechnology U U U UU 25...2011 Program Manager: Dr. Charles Y-C Lee High-speed, Low Voltage, Miniature Electro - optic Modulators Based on Hybrid Photonic-Crystal/Polymer/Sol

  1. Ultrahigh speed spectral/Fourier domain ophthalmic OCT imaging

    NASA Astrophysics Data System (ADS)

    Potsaid, Benjamin; Gorczynska, Iwona; Srinivasan, Vivek J.; Chen, Yueli; Liu, Jonathan; Jiang, James; Cable, Alex; Duker, Jay S.; Fujimoto, James G.

    2009-02-01

    Ultrahigh speed spectral / Fourier domain optical coherence tomography (OCT) imaging using a CMOS line scan camera with acquisition rates of 70,000 - 312,500 axial scans per second is investigated. Several design configurations are presented to illustrate trade-offs between acquisition speed, sensitivity, resolution and sensitivity roll-off performance. We demonstrate: extended imaging range and improved sensitivity roll-off at 70,000 axial scans per second , high speed and ultrahigh resolution imaging at 106,382 axial scans per second, and ultrahigh speed imaging at 250,000-312,500 axial scans per second. Each configuration is characterized through optical testing and the trade-offs demonstrated with in vivo imaging of the fovea and optic disk in the human retina. OCT fundus images constructed from 3D-OCT data acquired at 250,000 axial scans per second have no noticeable discontinuity of retinal features and show that there are minimal motion artifacts. The fine structures of the lamina cribrosa can be seen. Long cross sectional scans are acquired at 70,000 axial scans per second for imaging large areas of the retina, including the fovea and optic disk. Rapid repeated imaging of a small volume (4D-OCT) enables time resolved visualization of the capillary network surrounding the INL and may show individual red blood cells. The results of this study suggest that high speed CMOS cameras can achieve a significant improvement in performance for ophthalmic imaging. This promises to have a powerful impact in clinical applications by improving early diagnosis, reproducibility of measurements and enabling more sensitive assessment of disease progression or response to therapy.

  2. Mesh-based phase contrast Fourier transform imaging

    NASA Astrophysics Data System (ADS)

    Tahir, Sajjad; Bashir, Sajid; MacDonald, C. A.; Petruccelli, Jonathan C.

    2017-04-01

    Traditional x-ray radiography is limited by low attenuation contrast in materials of low electron density. Phase contrast imaging offers the potential to improve the contrast between such materials, but due to the requirements on the spatial coherence of the x-ray beam, practical implementation of such systems with tabletop (i.e. non-synchrotron) sources has been limited. One phase imaging technique employs multiple fine-pitched gratings. However, the strict manufacturing tolerances and precise alignment requirements have limited the widespread adoption of grating-based techniques. In this work, we have investigated a recently developed technique that utilizes a single grid of much coarser pitch. Our system consisted of a low power 100 μm spot Mo source, a CCD with 22 μm pixel pitch, and either a focused mammography linear grid or a stainless steel woven mesh. Phase is extracted from a single image by windowing and comparing data localized about harmonics of the mesh in the Fourier domain. The effects on the diffraction phase contrast and scattering amplitude images of varying grid types and periods, and of varying the width of the window function used to separate the harmonics were investigated. Using the wire mesh, derivatives of the phase along two orthogonal directions were obtained and combined to form improved phase contrast images.

  3. Non-rigid registration of tomographic images with Fourier transforms

    NASA Astrophysics Data System (ADS)

    Osorio, Ar; Isoardi, Ra; Mato, G.

    2007-11-01

    Spatial image registration of deformable body parts such as thorax and abdomen has important medical applications, but at the same time, it represents an important computational challenge. In this work we propose an automatic algorithm to perform non-rigid registration of tomographic images using a non-rigid model based on Fourier transforms. As a measure of similarity, we use the correlation coefficient, finding that the optimal order of the transformation is n = 3 (36 parameters). We apply this method to a digital phantom and to 7 pairs of patient images corresponding to clinical CT scans. The preliminary results indicate a fairly good agreement according to medical experts, with an average registration error of 2 mm for the case of clinical images. For 2D images (dimensions 512×512), the average running time for the algorithm is 15 seconds using a standard personal computer. Summarizing, we find that intra-modality registration of the abdomen can be achieved with acceptable accuracy for slight deformations and can be extended to 3D with a reasonable execution time.

  4. Numerical Modeling and Analysis of Optical Response of Electro-optic Modulators

    SciTech Connect

    Hussein, Y

    2004-04-14

    This paper presents an analysis of a LiNbO{sub 3} electro-optic modulator using the Finite Difference Time Domain (FDTD) technique, and also a new and efficient multiresolution time-domain technique for fast and accurate modeling of photonic devices. The electromagnetic fields computed by FDTD are coupled to standard electro-optic relations that characterize electro-optic interactions. This novel approach to LiNbO{sub 3} electro-optic modulators using a coupled FDTD technique allows for previously unattainable investigations into device operating bandwidth and data transmission speed. On the other hand, the proposed multiresolution approach presented in this paper solves Maxwell's Equations on nonuniform self-adaptive grids, obtained by applying wavelet transforms followed by hard thresholding. The developed technique is employed to simulate a coplanar waveguide CPW, which represents an electro-optic modulator. Different numerical examples are presented showing more than 75% CPU-time reduction, while maintaining the same degree of accuracy of standard FDTD techniques.

  5. Design and implementation of an electro-optical backplane with pluggable in-plane connectors

    NASA Astrophysics Data System (ADS)

    Pitwon, Richard C. A.; Hopkins, Ken; Wang, Kai; Selviah, David R.; Baghsiahi, Hadi; Offrein, Bert J.; Dangel, Roger; Horst, Folkert; Halter, Markus; Gmür, Max

    2010-02-01

    The design, implementation and characterisation of an electro-optical backplane and an active pluggable optical connector technology are presented. The connection architecture adopted allows line cards to mate and unmate from a passive electro-optical backplane with embedded polymeric waveguides. The active connectors incorporate photonics interfaces operating at 850 nm and a mechanism to passively align the interface to the embedded optical waveguides. A demonstration platform has been constructed to assess the viability of embedded electro-optical backplane technology in dense data storage systems. The electro-optical backplane is comprised of both copper layers and one polymeric optical layer, whereon waveguides have been patterned by a direct laser writing scheme. The optical waveguide design includes arrayed multimode waveguides with a pitch of 250 μm, multiple cascaded waveguide bends, non-orthogonal crossovers and in-plane connector interfaces. In addition, a novel passive alignment method has been employed to simplify high precision assembly of the optical receptacles on the backplane. The in-plane connector interface is based on a two lens free space coupling solution, which reduces susceptibility to contamination. The loss profiles of the complex optical waveguide layout has been characterised and successful transfer of 10.3 Gb/s data along multiple waveguides in the electro-optical backplane demonstrated.

  6. Mesh-Based Fourier Imaging for Biological and Security Applications

    NASA Astrophysics Data System (ADS)

    Hayden, Danielle

    Traditional x-ray imaging provides only low contrast from low atomic number materials, like soft tissue, due to the small attenuation variations producing very small intensity changes. Higher contrast can be achieved through phase information. The phase change is obtained from the x-ray refracting in a sample, or phase object, due to the difference in refractive indexes. This causes a small angular deviation from the original path. Phase contrast imaging has not been realized in everyday practice due to the requirement for large spatial coherence width of the x-ray beam which typically requires sources on the order of 10-50 m, the use of a grating technique or synchrotron sources. The grating-based phase imaging method depends upon multiple fine-pitched, expensive gratings and extremely precise alignment. An alternative procedure based on a technique recently demonstrated by Bennett is mesh-based phase imaging that utilizes a single, inexpensive mesh with a coarse pitch. This considerably eases the small spot size source requirement, allowing the use of a 150 micron, micro-focus, tungsten anode source. The mesh-based phase imaging set up used to study biomedical and security screening applications consisted of a 123x123 m stainless steel mesh and a 1200x1600 CCD detector with a pixel size of 22 microns. This mesh based approach allows for near-real-time phase extraction of the first harmonics in the Fourier domain. With the phase information and absorption information (collected at the zeroth harmonic), edge enhanced images of a mouse's skull were optimized and several potentially dangerous liquids and powders were discriminated from water. The mesh-based phase set up resulted in high contrasts, signal-to-noise ratios and good resolution verifying the potential utility of this technique for future biomedical imaging and airport security screening.

  7. The Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS): noise performance

    NASA Astrophysics Data System (ADS)

    Taylor, Joe K.; Revercomb, Henry E.; Tobin, David C.; Best, Fred A.; Knuteson, Robert O.; Elwell, John D.; Cantwell, Gregory W.; Scott, Deron K.; Bingham, Gail E.; Smith, William L.; Zhou, Daniel K.; Reisse, Robert A.

    2006-12-01

    The NASA New Millennium Program (NMP) Geosynchronous Imaging Fourier Transform Spectrometer (GIFTS) instrument was designed to demonstrate new and emerging technologies and provide immense improvements in satellite based remote sensing of the atmosphere from a geostationary orbit [1]. Combining a Fourier Transform Spectrometer (FTS) and Large Area Focal Plane Arrays, GIFTS measures incident infrared radiance with an extraordinary combination of spectral, temporal, and spatial resolution and coverage. Thermal vacuum testing of the GIFTS Engineering Development Unit (EDU) was performed at the Space Dynamics Laboratory and completed in May 2006 [2,3]. The GIFTS noise performance measured during EDU thermal vacuum testing indicates that threshold performance has been realized, and that goal performance (or better) has been achieved over much of both the Longwave Infrared (LWIR) and Short/Midwave Infrared (SMWIR) detector bands. An organizational structure for the division of the noise sources and effects for the GIFTS instrument is presented. To comprehensively characterize and predict the effects of measurement noise on expected instrument performance, the noise sources are categorically divided and a method of combining the independent effects is defined. Within this architecture, the total noise is principally decomposed into spectrally correlated noise and random (spectrally uncorrelated) noise. The characterization of the spectrally correlated noise sources specified within the structure is presented in detail.

  8. Holographic microscope for measuring displacements of vibrating microbeams using time-averaged, electro-optic holography

    NASA Astrophysics Data System (ADS)

    Brown, Gordon C.; Pryputniewicz, Ryszard J.

    1998-05-01

    An optical microscope, utilizing the principles of time- averaged hologram interferometry, is described for microelectromechanical systems (MEMS) applications. MEMS are devices fabricated via techniques such as microphotolithography to create miniature actuators and sensors. Many of these sensors are currently deployed in automotive applications which rely on, or depend on, the dynamic behavior of the sensor, e.g., airbag sensors, ride monitoring suspensions sensors, etc. Typical dimensions of current MEMS devices are measured in micrometers, a small fraction of the diameter of a human hair, and the current trends is to further decrease the size of MEMS devices to submicrometer dimensions. However, the smaller MEMS become, the more challenging it is to measure with accuracy the dynamic characteristics of these devices. An electro-optic holographic microscope (EOHM) for the purpose of studying the dynamic behavior of MEMS type devices is described. Additionally, by performing phase measurements within an EOHM image, object displacements are determined as illustrated by representative examples. With the EOHM, devices with surface sizes ranging from approximately 35 X 400 to 5 X 18 micrometers are studied while undergoing resonant vibrations at frequencies as high as 2 MHz.

  9. Superior electro-optic response in multiferroic bismuth ferrite nanoparticle doped nematic liquid crystal device

    PubMed Central

    Nayek, Prasenjit; Li, Guoqiang

    2015-01-01

    A superior electro-optic (E-O) response has been achieved when multiferroic bismuth ferrite (BiFeO3/BFO) nanoparticles (NPs) were doped in nematic liquid crystal (NLC) host E7 and the LC device was addressed in the large signal regime by an amplitude modulated square wave signal at the frequency of 100 Hz. The optimized concentration of BFO is 0.15 wt%, and the corresponding total optical response time (rise time + decay time) for a 5 μm-thick cell is 2.5 ms for ~7 Vrms. This might be exploited for the construction of adaptive lenses, modulators, displays, and other E-O devices. The possible reason behind the fast response time could be the visco-elastic constant and restoring force imparted by the locally ordered LCs induced by the multiferroic nanoparticles (MNPs). Polarized optical microscopic textural observation shows that the macroscopic dislocation-free excellent contrast have significant impact on improving the image quality and performance of the devices. PMID:26041701

  10. Continued Development of a Planetary Imaging Fourier Transform Spectrometer (PIFTS)

    NASA Technical Reports Server (NTRS)

    Sromovsky, L. A.

    2002-01-01

    This report describes continued efforts to evaluate a breadboard of a Planetary Imaging Fourier Transform Spectrometer (PIFTS). The PIFTS breadboard was developed under prior PIDDP funding. That effort is described in the final report for NASA Grant NAG5-6248 and in two conference papers (Sromovsky et al. 2000; Revercomb et al. 2000). The PIFTS breadboard was designed for near-IR (1-5.2 micrometer imaging of planetary targets with spectral resolving powers of several hundred to several thousand, using an InSb detector array providing at least 64x64 pixels imaging detail. The major focus of the development effort was to combine existing technologies to produce a small and low power design compatible with a very low mass flyable instrument. The objective of this grant (NAG5-10729) was further characterization of the breadboard performance, including intercomparisons with the highly accurate non-imaging Advanced Emitted Radiance Interferometer (AERI) (Revercomb et al. 1994; Best et al. 1997).

  11. Calibration of the Geostationary Imaging Fourier Transform Spectrometer (GIFTS)

    NASA Technical Reports Server (NTRS)

    Best, F. A.; Revercomb, H. E.; Bingham, G. E.; Knuteson, R. O.; Tobin, D. C.; LaPorte, D. D.; Smith, W. L.

    2001-01-01

    The NASA New Millennium Program's Geostationary Imaging Fourier Transform Spectrometer (GIFTS) requires highly accurate radiometric and spectral calibration in order to carry out its mission to provide water vapor, wind, temperature, and trace gas profiling from geostationary orbit. A calibration concept has been developed for the GIFTS Phase A instrument design. The in-flight calibration is performed using views of two on-board blackbody sources along with cold space. A radiometric calibration uncertainty analysis has been developed and used to show that the expected performance for GIFTS exceeds its top level requirement to measure brightness temperature to better than 1 K. For the Phase A GIFTS design, the spectral calibration is established by the highly stable diode laser used as the reference for interferogram sampling, and verified with comparisons to atmospheric calculations.

  12. Micro-electro-mechanically tunable metamaterial with enhanced electro-optic performance

    SciTech Connect

    Pitchappa, Prakash; Pei Ho, Chong; Lin, Yu-Sheng; Lee, Chengkuo; Kropelnicki, Piotr; Singh, Navab; Huang, Chia-Yi

    2014-04-14

    We experimentally demonstrate a micro-electro-mechanically tunable metamaterial with enhanced electro-optical performance by increasing the number of movable cantilevers in the symmetrical split ring resonator metamaterial unit cell. Simulations were carried out to understand the interaction of the incident terahertz radiation with out-of-plane deforming metamaterial resonator. In order to improve the overall device performance, the number of released cantilever in a unit cell was increased from one to two, and it was seen that the tunable range was doubled and the switching contrast improved by a factor of around five at 0.7 THz. This simple design approach can be adopted for a wide range of high performance electro-optical devices such as continuously tunable filters, modulators, and electro-optic switches to enable future photonic circuit applications.

  13. A magneto-electro-optical effect in a plasmonic nanowire material

    PubMed Central

    Valente, João; Ou, Jun-Yu; Plum, Eric; Youngs, Ian J.; Zheludev, Nikolay I.

    2015-01-01

    Electro- and magneto-optical phenomena play key roles in photonic technology enabling light modulators, optical data storage, sensors and numerous spectroscopic techniques. Optical effects, linear and quadratic in external electric and magnetic field are widely known and comprehensively studied. However, optical phenomena that depend on the simultaneous application of external electric and magnetic fields in conventional media are barely detectable and technologically insignificant. Here we report that a large reciprocal magneto-electro-optical effect can be observed in metamaterials. In an artificial chevron nanowire structure fabricated on an elastic nano-membrane, the Lorentz force drives reversible transmission changes on application of a fraction of a volt when the structure is placed in a fraction-of-tesla magnetic field. We show that magneto-electro-optical modulation can be driven to hundreds of thousands of cycles per second promising applications in magneto-electro-optical modulators and field sensors at nano-tesla levels. PMID:25906761

  14. A magneto-electro-optical effect in a plasmonic nanowire material

    NASA Astrophysics Data System (ADS)

    Valente, João; Ou, Jun-Yu; Plum, Eric; Youngs, Ian J.; Zheludev, Nikolay I.

    2015-04-01

    Electro- and magneto-optical phenomena play key roles in photonic technology enabling light modulators, optical data storage, sensors and numerous spectroscopic techniques. Optical effects, linear and quadratic in external electric and magnetic field are widely known and comprehensively studied. However, optical phenomena that depend on the simultaneous application of external electric and magnetic fields in conventional media are barely detectable and technologically insignificant. Here we report that a large reciprocal magneto-electro-optical effect can be observed in metamaterials. In an artificial chevron nanowire structure fabricated on an elastic nano-membrane, the Lorentz force drives reversible transmission changes on application of a fraction of a volt when the structure is placed in a fraction-of-tesla magnetic field. We show that magneto-electro-optical modulation can be driven to hundreds of thousands of cycles per second promising applications in magneto-electro-optical modulators and field sensors at nano-tesla levels.

  15. Command Electro-Optical Switching of Photoaligned Liquid Crystal on Photopatterned Graphene.

    PubMed

    Varanytsia, Andrii; Chien, Liang-Chy

    2017-09-18

    We report command electro-optical switching on photolithographically-patterned graphene into a high-density electrode pattern for a high-transmission in-plane-switching (IPS) liquid crystal device. A highly-effective liquid crystal photoalignment method is used to maximize the field-driven optical contrast of a prototyped device. A non-contact and low-temperature photoalignment allows delicate surface treatment required for successful processing of graphene layer into an IPS electrode structure. Electro-optic performance of the graphene-based single pixel laboratory IPS prototype demonstrates the application potential of graphene for liquid crystal electro-optic devices with complex and high-definition electrode patterns.

  16. Electro-optic dual-comb interferometry over 40 nm bandwidth

    NASA Astrophysics Data System (ADS)

    Durán, Vicente; Andrekson, Peter A.; Torres-Company, Víctor

    2016-09-01

    Dual-comb interferometry is a measurement technique that uses two laser frequency combs to retrieve complex spectra in a line-by-line basis. This technique can be implemented with electro-optic frequency combs, offering intrinsic mutual coherence, high acquisition speed and flexible repetition-rate operation. A challenge with the operation of this kind of frequency comb in dual-comb interferometry is its limited optical bandwidth. Here, we use coherent spectral broadening and demonstrate electro-optic dual-comb interferometry over the entire telecommunications C band (200 lines covering ~ 40 nm, measured within 10 microseconds at 100 signal-to-noise ratio per spectral line). These results offer new prospects for electro-optic dual-comb interferometry as a suitable technology for high-speed broadband metrology, for example in optical coherence tomography or coherent Raman microscopy.

  17. Electro-optically modulated localized surface plasmon resonance biosensors with gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Wang, Tzyy-Jiann; Lin, Wen-Shao

    2006-10-01

    An integrated-optic biosensor based on electro-optically modulated localized surface plasmon resonance (LSPR) is demonstrated. This biosensor utilizes the electro-optic effect to modulate the wave vector of incident lightwave used to excite localized surface plasmons. Electro-optically modulated LSPR results in the analyte-dependent variation of output intensity with the applied voltage. The linear regression slope of this relation is used to determine the analyte concentration. On the sensing region of LSPR biosensor, human serum albumin is self-assembled on gold nanoparticles in order to sense the beta-blocker concentration. The use of the presented biosensor has the features of no intensity drift problem, no absorption diversity problem in different sample media, and noise reduction by linear regression analysis.

  18. Wavelength dependence of electro-optic effect in paraelectric potassium sodium tantalate niobate single crystal.

    PubMed

    Yao, Bo; Tian, Hao; Hu, Chengpeng; Zhou, Zhongxiang; Liu, Dajun

    2013-12-01

    The refractive indices and quadratic electro-optic effect in terms of the coefficients (R11-R12) in a paraelectric K0.95Na0.05Ta0.58Nb0.42O3 single crystal were measured. The dispersion of the refractive index was described exactly by a single-term Sellmeier equation. We found an obvious dispersion of the electro-optic coefficients (R11-R12), and the coefficients decreased quickly with increasing wavelength above the Curie temperature. Following [J. Appl. Phys.40, 720 (1969)], we obtained a dispersion equation for the electro-optic effect in a paraelectric potassium sodium tantalate niobate single crystal. The experimental results agreed well with the dispersion model.

  19. Non-linear electro-optical effects in the study of the helical smectic liquid crystals

    NASA Astrophysics Data System (ADS)

    Nowicka, K.; Kuczyński, W.

    2016-04-01

    Measurements of the non-linear electro-optical effects for the well-known prototype liquid crystal material (MHPOBC) are presented. The method to identify liquid crystalline phases and to determine temperatures of phase transitions based on the analysis of the second harmonic component of electro-optical response spectra is used. Applying that method, the values of the frequency (?) at which the second harmonic electro-optic response (EOR) possesses an extremum are determined for each smectic phase. We suggest that this characteristic frequency correspond to the phase-type mode processes. Furthermore, we show that the usually neglected results on heating can be useful in discussions of dynamical behaviour of second harmonic EOR in case of smectic phases.

  20. Measurement of Sub-Picosecond Electron Bunches via Electro-Optic Sampling of Coherent Transition Radiation

    SciTech Connect

    Maxwell, Timothy John

    2012-01-01

    Future collider applications as well as present high-gradient laser plasma wakefield accelerators and free-electron lasers operating with picosecond bunch durations place a higher demand on the time resolution of bunch distribution diagnostics. This demand has led to significant advancements in the field of electro-optic sampling over the past ten years. These methods allow the probing of diagnostic light such as coherent transition radiation or the bunch wakefields with sub-picosecond time resolution. We present results on the single-shot electro-optic spectral decoding of coherent transition radiation from bunches generated at the Fermilab A0 photoinjector laboratory. A longitudinal double-pulse modulation of the electron beam is also realized by transverse beam masking followed by a transverse-to-longitudinal phase-space exchange beamline. Live profile tuning is demonstrated by upstream beam focusing in conjunction with downstream monitoring of single-shot electro-optic spectral decoding of the coherent transition radiation.

  1. Space Qualification Issues in Acousto-optic and Electro-optic Devices

    NASA Technical Reports Server (NTRS)

    Prasad, Narasimha S.; Taylor, Edward W.; Trivedi, Sudhir; Kutcher, Sue; Soos, Jolanta

    2007-01-01

    Satellite and space-based applications of photonic devices and systems require operational reliability in the harsh environment of space for extended periods of time. This in turn requires every component of the systems and their packaging to meet space qualifications. Acousto- and electro-optical devices form the major components of many current space based optical systems, which is the focus of this paper. The major space qualification issues are related to: mechanical stability, thermal effects and operation of the devices in the naturally occurring space radiation environment. This paper will discuss acousto- and electro-optic materials and devices with respect to their stability against mechanical vibrations, thermal cycling in operating and non-operating conditions and device responses to space ionizing and displacement radiation effects. Selection of suitable materials and packaging to meet space qualification criteria will also be discussed. Finally, a general roadmap for production and testing of acousto- and electro-optic devices will be discussed.

  2. Electro-optic phase-modulated polarimetry: Instrumentation and signal analysis techniques for the characterization of material properties

    NASA Astrophysics Data System (ADS)

    Mackey, Jeffrey Richard

    Novel compact and robust phase-modulated electro-optic birefringence and material stress measurement instrumentation is needed for the study of anisotropic materials such as non-Newtonian polymers, crystalline structures, biological fluids and many other optically active materials. This instrumentation developed by the research presented in this dissertation utilizes many different modulation approaches in order to incorporate heterodyning signal recovery techniques that improve measurement sensitivity by several orders of magnitude over simple crossed-polarizer methods. Modulation methods include photoelastic techniques, liquid-crystal variable retarder methods, dual-crystal transverse electro-optic modulation and dual lasers sinusoidally intensity-modulated with a pi-phase lag between them. The theoretical framework governing the development of this instrumentation using the Mueller-Stokes polarization matrices and heterodyning signal recovery methods is discussed in detail. Many experiments are performed to compare the measurements obtained by the instrumentation with the results derived theoretically. Results from the experimental material characterization instrumentation agree well with the predicted signal theory. Signal analysis was further refined through the use of wavelet-based denoising techniques. These denoising techniques resulted in improved measurement accuracy and sensitivity. The measurement theory is also adapted to solve several other applications including electro-optic force, pressure and acceleration measurements which use a polymer linkage to infer stresses from the physical system to data that can be analyzed by the material characterization instrumentation. The best commercially available force transducers capable of measuring transient responses have a lower resolution of approximately 10-5 N. Research with the rheology of fluids, transient flows of pharmaceuticals in combinatorial research, biological tissue response, and biomimetic

  3. Unprecedented highest electro-optic coefficient of 226 pm/V for electro-optic polymer/TiO₂ multilayer slot waveguide modulators.

    PubMed

    Jouane, Y; Chang, Y-C; Zhang, D; Luo, J; Jen, A K-Y; Enami, Y

    2014-11-03

    We investigated the electrical properties and optical quality of two layers a titanium dioxide (TiO₂) selective layer and a sol-gel silica cladding layer for use as coating layers for nonlinear optic (NLO) polymers in electro-optic (EO) polymer/TiO₂ multilayer slot waveguide modulators. We used a simple ellipsometric reflective technique developed by Teng and Man to measure the electro-optic (EO) coefficients of poled thin films of an EO polymer in an EO multilayer device. The Pockels coefficient was enhanced up to 226 and 198 pm/V at wavelengths of 1.31 and 1.55 μm, respectively, when optimally poled with TiO₂ and a sol-gel silica cladding.

  4. Electric field and temperature measurement using ultra wide bandwidth pigtailed electro-optic probes.

    PubMed

    Bernier, Maxime; Gaborit, Gwenaël; Duvillaret, Lionel; Paupert, Alain; Lasserre, Jean-Louis

    2008-05-01

    We present pigtailed electro-optic probes that allow a simultaneous measurement of high frequency electric fields and temperature using a unique laser probe beam. This has been achieved by the development of a novel probe design associated with a fully automated servo-controlled optical bench, initially developed to stabilize the electric field sensor response. The developed electro-optic probes present a stable response in outdoors conditions over a time duration exceeding 1 h, a frequency bandwidth from kHz to tens of GHz with a sensitivity of 0.7 Vm(-1)Hz(-(1/2)), and a temperature accuracy of 40 mK.

  5. Kovacs effect enhanced broadband large field of view electro-optic modulators in nanodisordered KTN crystals.

    PubMed

    Chang, Yun-Ching; Wang, Chao; Yin, Shizhuo; Hoffman, Robert C; Mott, Andrew G

    2013-07-29

    The unique physical effect-Kovacs effect is explored to enhance the performance of EO modulators by employing the non-thermal equilibrium state nanodisordered KTN crystals created by super-cooling process, which can have a significant 3.5 fold increase in quadratic electro-optic coefficient. This enables to reduce the switching half wave voltage (almost by half) so that a broadband (~GHz range) and large field of view (+/-30 deg) electro-optic modulator can be realized with much lowered driving power, which can be very useful for a variety of applications: laser Q-switches, laser pulse shaping, high speed optical shutters and modulating retro reflectors.

  6. Electro-optic architecture for servicing sensors and actuators in advanced aircraft propulsion systems

    NASA Technical Reports Server (NTRS)

    Poppel, G. L.; Glasheen, W. M.

    1989-01-01

    A detailed design of a fiber optic propulsion control system, integrating favored sensors and electro-optics architecture is presented. Layouts, schematics, and sensor lists describe an advanced fighter engine system model. Components and attributes of candidate fiber optic sensors are identified, and evaluation criteria are used in a trade study resulting in favored sensors for each measurand. System architectural ground rules were applied to accomplish an electro-optics architecture for the favored sensors. A key result was a considerable reduction in signal conductors. Drawings, schematics, specifications, and printed circuit board layouts describe the detailed system design, including application of a planar optical waveguide interface.

  7. LARGE ANGLE ELECTRO-OPTIC BEAM DEFLECTOR FOR THE INFRARED BASED ON A FERROELECTRIC.

    SciTech Connect

    Gahagan, K. T.; Casson, J. L.; Robinson, J. M.; Scymgeour, D. A.; Gopalan, V.; Libatique, N. J; Tafoya, J.; Jain, R.

    2001-01-01

    An electro-optic beam scanner fabricated on ferroelectric LiTaO{sub 3} is demonstrated which is capable of continuously scanning at wavelengths ranging from 0.4-5 {micro}m. The scanning performance varied from a total deflection angle of 13.38{sup o} at 1558 nm to 16.18{sup o} at 632.8 nm. The dispersion of the r{sub 33} and r{sub 13} electro-optic coefficients of LiTaO{sub 3} with wavelength was also determined.

  8. Spherical Refractive Correction With an Electro-Optical Liquid Lens in a Double-Pass System

    NASA Astrophysics Data System (ADS)

    Sanàbria, F.; Díaz-Doutón, F.; Aldaba, M.; Pujol, J.

    2013-09-01

    In this study we show a novel double-pass configuration to correct the spherical refractive error by means of an electro-optical liquid lens.The proposed method enables spherical correction in the -12 D to +7 D range without movable parts using an electro-optical liquid lens.We have measured the optical performance of the spherical corrector in terms of power, pupil size and optical quality verifying that it fitsthe requirements to be applied to a double-pass system. We have also evaluated the performance of the proposed method in patients bycomparison with a conventional double-pass system using a Badal optometer.

  9. Silicon-integrated thin-film structure for electro-optic applications

    DOEpatents

    McKee, Rodney A.; Walker, Frederick Joseph

    2000-01-01

    A crystalline thin-film structure suited for use in any of an number of electro-optic applications, such as a phase modulator or a component of an interferometer, includes a semiconductor substrate of silicon and a ferroelectric, optically-clear thin film of the perovskite BaTiO.sub.3 overlying the surface of the silicon substrate. The BaTiO.sub.3 thin film is characterized in that substantially all of the dipole moments associated with the ferroelectric film are arranged substantially parallel to the surface of the substrate to enhance the electro-optic qualities of the film.

  10. Applications of electro-optic gratings in integrated optical signal processing devices

    NASA Technical Reports Server (NTRS)

    Verber, C. M.

    1981-01-01

    A variety of applications of electro-optically induced Bragg gratings in integrated optical signal processing and computation devices are shown. The gratings are easy to fabricate, operate efficiently on relatively low voltages and have design principles which are well known and reliable. The component allows a rapid and efficient interaction with an optical wave in a planar electro-optic waveguide. The operation of such gratings and their use as intensity modulators, spatial light modulators, and components in correlators and in a variety of computational units is described.

  11. Switching behavior and electro-optical properties of liquid crystals in nematic gels

    PubMed

    Gautier; Brunet; Grupp; Sauvajol; Anglaret

    2000-11-01

    Anisotropic nematic gels are prepared via in situ polymerization of diacrylate monomers in an orientated nematic liquid crystal (LC) matrix. The switching behavior of the LC molecules under electric field is probed in polarized Raman spectroscopy and straight theta-2straight theta elastic light scattering experiments. The electro-optical characteristics of the gels are directly related to the electric field dependence of the fraction of switched molecules. The electro-optical contrast relates to the coexistence of switched LC domains and LC domains anchored to the polymer network.

  12. Extracting S-parameters of bilateral electro-optic network for lightwave component analyzer calibration

    NASA Astrophysics Data System (ADS)

    Frolov, D.; Levchenko, A.; Korotkov, K.

    2015-11-01

    A new method for extracting E/O and O/E S-parameters of a bilateral electro-optic network (BEON) is theoretically proposed. It is based on measuring reflection coefficients from three optical loads: an absorber and two mirrors. This technique includes two series of reflections measurements: first when loads are connected to optical port of BEON directly and second when loads are connected in series with optical waveguide of fixed length. Using two BEONs and this calibration technique allows to make calibrated lightwave measurements with a standard microwave network analyzer without using additional electro-optical equipment such as lightwave component analyzer or optical heterodyne techniques.

  13. Bubbling effect in the electro-optic delayed feedback oscillator coupled network

    NASA Astrophysics Data System (ADS)

    Liu, Lingfeng; Lin, Jun; Miao, Suoxia

    2017-03-01

    Synchronization in the optical systems coupled network always suffers from bubbling events. In this paper, we numerically investigate the statistical properties of the synchronization characteristics and bubbling effects in the electro-optic delayed feedback oscillator coupled network with different coupling strength, delay time and gain coefficient. Furthermore, we compare our results with the synchronization properties of semiconductor laser (SL) coupled network, which indicates that the electro-optic delayed feedback oscillator can be better to suppress the bubbling effects in the synchronization of coupled network under the same conditions.

  14. Miniaturized photogenerated electro-optic axicon lens Gaussian-to-Bessel beam conversion.

    PubMed

    Di Domenico, G; Parravicini, J; Antonacci, G; Silvestri, S; Agranat, A J; DelRe, E

    2017-04-01

    We experimentally demonstrate an electro-optic Gaussian-to-Bessel beam-converter miniaturized down to a 30×30  μm pixel in a potassium-lithium-tantalate-niobate (KLTN) paraelectric crystal. The converter is based on the electro-optic activation of a photoinduced and reconfigurable volume axicon lens achieved using a prewritten photorefractive funnel space-charge distribution. The transmitted light beam has a tunable depth of field that can be more than twice that of a conventional beam with the added feature of being self-healing.

  15. Coherent electro-optical detection of terahertz radiation from an optical parametric oscillator.

    PubMed

    Meng, F Z; Thomson, M D; Molter, D; Löffler, T; Jonuscheit, J; Beigang, R; Bartschke, J; Bauer, T; Nittmann, M; Roskos, H G

    2010-05-24

    We report the realization of coherent electro-optical detection of nanosecond terahertz (THz) pulses from an optical parametric oscillator, which is pumped by a Q-switched nanosecond Nd:YVO4 laser at 1064 nm and emits at approximately 1.5 THz. The beam profile and wavefront of the THz beam at focus are electro-optically characterized toward the realization of a real-time THz camera. A peak dynamic range of approximately 37 dB/radical Hz is achieved with single-pixel detection.

  16. Method of synthesizing a plurality of reactants and producing thin films of electro-optically active transition metal oxides

    DOEpatents

    Tracy, C. Edwin; Benson, David K.; Ruth, Marta R.

    1987-01-01

    A method of synthesizing electro-optically active reaction products from a plurality of reactants by inducing a reaction by plasma deposition among the reactants. The plasma reaction is effective for consolidating the reactants and producing thin films of electro-optically active transition metal oxides.

  17. Concept of electro-optical sensor module for sniper detection system

    NASA Astrophysics Data System (ADS)

    Trzaskawka, Piotr; Dulski, Rafal; Kastek, Mariusz

    2010-10-01

    The paper presents an initial concept of the electro-optical sensor unit for sniper detection purposes. This unit, comprising of thermal and daylight cameras, can operate as a standalone device but its primary application is a multi-sensor sniper and shot detection system. Being a part of a larger system it should contribute to greater overall system efficiency and lower false alarm rate thanks to data and sensor fusion techniques. Additionally, it is expected to provide some pre-shot detection capabilities. Generally acoustic (or radar) systems used for shot detection offer only "after-the-shot" information and they cannot prevent enemy attack, which in case of a skilled sniper opponent usually means trouble. The passive imaging sensors presented in this paper, together with active systems detecting pointed optics, are capable of detecting specific shooter signatures or at least the presence of suspected objects in the vicinity. The proposed sensor unit use thermal camera as a primary sniper and shot detection tool. The basic camera parameters such as focal plane array size and type, focal length and aperture were chosen on the basis of assumed tactical characteristics of the system (mainly detection range) and current technology level. In order to provide costeffective solution the commercially available daylight camera modules and infrared focal plane arrays were tested, including fast cooled infrared array modules capable of 1000 fps image acquisition rate. The daylight camera operates as a support, providing corresponding visual image, easier to comprehend for a human operator. The initial assumptions concerning sensor operation were verified during laboratory and field test and some example shot recording sequences are presented.

  18. Spurious electro-optic coefficients inferred from modulation ellipsometry measurements in the presence of an air cavity

    NASA Astrophysics Data System (ADS)

    Quilty, J. W.

    2017-04-01

    This paper describes how thin air gaps in multilayer polymer thin film structures can lead to unexpectedly large signals in modulation ellipsometry experiments, which can then be misinterpreted as the electro-optic effect. The contributions from the electro-optic effect and polarisation on reflection from the air cavity are indistinguishable and the reflection contribution can be on the order of 100 times that of the electro-optic effect. Caution must thus be exercised in any attempt to measure electro-optic coefficients with modulation ellipsometry in the presence of air gaps, to avoid spuriously high results. Thin film multilayer structures containing air gaps may be suitable for some of the same applications as electro-optic reflectance modulators.

  19. Spontaneous helix formation in non-chiral bent-core liquid crystals with fast linear electro-optic effect

    NASA Astrophysics Data System (ADS)

    Sreenilayam, Sithara P.; Panarin, Yuri P.; Vij, Jagdish K.; Panov, Vitaly P.; Lehmann, Anne; Poppe, Marco; Prehm, Marko; Tschierske, Carsten

    2016-05-01

    Liquid crystals (LCs) represent one of the foundations of modern communication and photonic technologies. Present display technologies are based mainly on nematic LCs, which suffer from limited response time for use in active colour sequential displays and limited image grey scale. Herein we report the first observation of a spontaneously formed helix in a polar tilted smectic LC phase (SmC phase) of achiral bent-core (BC) molecules with the axis of helix lying parallel to the layer normal and a pitch much shorter than the optical wavelength. This new phase shows fast (~30 μs) grey-scale switching due to the deformation of the helix by the electric field. Even more importantly, defect-free alignment is easily achieved for the first time for a BC mesogen, thus providing potential use in large-scale devices with fast linear and thresholdless electro-optical response.

  20. Error analysis of mast mounted electro-optical stabilized platform based on multi-body kinematics theory

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaoyao; Ma, Dongxi; Fan, Dapeng; Zhang, Zhiyong

    2010-08-01

    Error analysis of target location for Mast Mounted Electro-Optical Stabilized Platform based on multi-body kinematics theory is presented in this paper. Firstly, a typical structure of OMS, which is mounted on the reconnaissance vehicle, is introduced briefly and Multi-body kinematics theory is used to illustrate the topology structure and coordinates relations. Accordingly, target location equations between target and OMS are derived. Secondly, the characteristics and compensation methods are discussed in detail for the error analysis, which influence the system target location accuracy, such as imaging sensors errors, stabilized platform errors and equipments errors. Finally, simulation results based on Monte Carlo and experiment results are presented, showing that axis zero bit, consistency, verticality errors and equipments alignment errors are the primary factors, which influence system target location accuracy. After the compensation, the accuracy has been improved 2 orders and reached 5m/0.060.

  1. Spontaneous helix formation in non-chiral bent-core liquid crystals with fast linear electro-optic effect

    PubMed Central

    Sreenilayam, Sithara P.; Panarin, Yuri P.; Vij, Jagdish K.; Panov, Vitaly P.; Lehmann, Anne; Poppe, Marco; Prehm, Marko; Tschierske, Carsten

    2016-01-01

    Liquid crystals (LCs) represent one of the foundations of modern communication and photonic technologies. Present display technologies are based mainly on nematic LCs, which suffer from limited response time for use in active colour sequential displays and limited image grey scale. Herein we report the first observation of a spontaneously formed helix in a polar tilted smectic LC phase (SmC phase) of achiral bent-core (BC) molecules with the axis of helix lying parallel to the layer normal and a pitch much shorter than the optical wavelength. This new phase shows fast (∼30 μs) grey-scale switching due to the deformation of the helix by the electric field. Even more importantly, defect-free alignment is easily achieved for the first time for a BC mesogen, thus providing potential use in large-scale devices with fast linear and thresholdless electro-optical response. PMID:27156514

  2. Experimental characterization, evaluation, and diagnosis of advanced hybrid infrared focal plane array electro-optical performance

    NASA Astrophysics Data System (ADS)

    Lomheim, Terrence S.; Schumann, Lee W.; Kohn, Stanley E.

    1998-07-01

    High performance scanning time-delay-and-integration and staring hybrid focal plane devices with very large formats, small pixel sizes, formidable frame and line rates, on-chip digital programmability, and high dynamic ranges, are being developed for a myriad of defense, civil, and commercial applications that span the spectral range from shortwave infrared (SWIR) to longwave infrared (LWIR). An essential part in the development of such new advanced hybrid infrared focal planes is empirical validation of their electro-optical (EO) performance. Many high-reliability, high-performance applications demand stringent and near flawless EO performance over a wide variety of operating conditions and environments. Verification of focal plane performance compliance over this wide range of parametric conditions requires the development and use of accurate, flexible, and statistically complete test methods and associated equipment. In this paper we review typical focal plane requirements, the ensuing measurement requirements (quantity, accuracy, repeatability, etc.), test methodologies, test equipment requirements, electronics and computer-based data acquisition requirements, statistical data analysis and display requirements, and associated issues. We also discuss special test requirements for verifying the performance of panchromatic thermal and multispectral imaging focal planes where characterization of dynamic modulation transfer function (MTF), and point-image response and optical overload is generally required. We briefly overview focal plane radiation testing. We conclude with a discussion of the technical challenges of characterizing future advanced hybrid focal plane testing where it is anticipated that analog-to- digital conversion will be included directly on focal plane devices, thus creating the scenario of 'photons-in-to-bits- out' within the focal plane itself.

  3. Embedded Electro-Optic Sensor Network for the On-Site Calibration and Real-Time Performance Monitoring of Large-Scale Phased Arrays

    DTIC Science & Technology

    2005-07-09

    This final report summarizes the progress during the Phase I SBIR project entitled "Embedded Electro - Optic Sensor Network for the On-Site Calibration...sensor network based on an electro - optic field-detection technique (the Electro - optic Sensor Network, or ESN) for the performance evaluation of phased

  4. Heterostructure of ferromagnetic and ferroelectric materials with magneto-optic and electro-optic effects

    NASA Technical Reports Server (NTRS)

    Zou, Yingyin Kevin (Inventor); Jiang, Hua (Inventor); Li, Kewen Kevin (Inventor); Guo, Xiaomei (Inventor)

    2012-01-01

    A heterostructure of multiferroics or magnetoelectrics (ME) was disclosed. The film has both ferromagnetic and ferroelectric properties, as well as magneto-optic (MO) and electro-optic (EO) properties. Oxide buffer layers were employed to allow grown a cracking-free heterostructure a solution coating method.

  5. Liquid-crystals electro-optic modulator based on electrohydrodynamic effects.

    PubMed

    Muriel, M A; Martin-Pereda, J A

    1980-11-01

    A new method of light modulation is reported. This method is based on the electro-optical properties of nematic materials and on the use of a new wedge structure. The advantages of this structure are the possibility of modulating nonpolarized light and the improved signal-to-noise ratio. The highest modulating frequency obtained is 25 kHz.

  6. Electro-optic modulator for infrared laser using gallium arsenide crystal

    NASA Technical Reports Server (NTRS)

    Walsh, T. E.

    1968-01-01

    Gallium arsenide electro-optic modulator used for infrared lasers has a mica quarter-wave plate and two calcite polarizers to amplitude or phase modulate an infrared laser light source in the wavelength range from 1 to 3 microns. The large single crystal has uniformly high resistivities, is strain free, and comparable in quality to good optical glass.

  7. Assessment of Spacecraft Operational Status Using Electro-Optical Predictive Techniques

    DTIC Science & Technology

    2010-09-01

    of natural (solar and earth ) illumination and viewing conditions. Results are generated for comparing baseline, streamlined geometry models with...underlying earth scene are presented for extensive spectral band coverage spanning the electro-optical spectrum from visible wavelengths through...comprehensive scenario range of natural (solar and earth ) illumination and viewing conditions. Results are generated for comparing baseline, streamlined

  8. Development of Articulated Competency-Based Curriculum in Laser/Electro-Optics Technology. Final Report.

    ERIC Educational Resources Information Center

    Luzerne County Community Coll., Nanticoke, PA.

    The project described in this report was conducted at the Community College of Luzerne County (Pennsylvania) to develop, in conjunction with area vocational-technical schools, the second year of a competency-based curriculum in laser/electro-optics technology. During the project, a task force of teachers from the area schools and the college…

  9. Development of Articulated Competency-Based Curriculum in Laser/Electro-Optics Technology. Final Report.

    ERIC Educational Resources Information Center

    Luzerne County Community Coll., Nanticoke, PA.

    A project was conducted at the Community College of Luzerne County (Pennsylvania) to develop, in cooperation with area vocational-technical schools, the first year of a competency-based curriculum in laser/electro-optics technology. Existing programs were reviewed and private sector input was sought in developing the curriculum and identifying…

  10. Development of Generalizable Educational Programs in Laser/Electro-Optics Technology: Final Report.

    ERIC Educational Resources Information Center

    Hull, Daniel M.

    The purpose of the Laser/Electro-Optics Technology (LEOT) Project was to establish a pilot educational program, develop a flexible curriculum, prepare and test instructional materials, transport the curriculum and instructional materials into other educational institutions by establishing relevant LEOT programs wherever they are needed, and to…

  11. Poling and characterization of a novel organic/polymer electro-optic material

    NASA Astrophysics Data System (ADS)

    Liao, Jinkun; Tang, Xianzhong; Lu, Rongguo; Tang, Xionggui; Li, Heping; Zhang, Xiaoxia; Liu, Yongzhi

    2010-10-01

    Electro-optic organic/polymer material is important for the fabrication of polymer integrated optic-electronic devices and organic sensors. Recently, a novel organic high μβ value chromophore FFC have been synthesized by molecular design. The absorption spectrum in 400-4000 cm-1 is measured for the material, and the measurement result shows that the absorption loss is negligibly small. An organic/polymer high electro-optic activity material FFC/PSU is obtained by dissolving guest FFC (wt. 20%) and a host polysulfone (PSU) in a solvent. The resolvability of cyclohexanone for the material is satisfactory by comparison with other solvents experimentally, and the preparation of FFC/PSU thin film is ease relatively. The materiel is poled by electric field-assisted contact poling, and the near optimum poling condition is determined by adjusting poling parameters as pre-curing duration, poling temperature and poling voltage etc. The electro-optic coefficient of the material is measured as high as 130pm/V by using the widely accepted simple reflection technique. The investigation indicates that the FFC/PSU has excellent characteristics, such as high electro-optic coefficient, low absorption loss, good thermal stability and capability for withstanding the subsequent process techniques, suitable for the fabrication of high-performance integrated optic-electronic devices and sensors.

  12. Electro-Optic Modulator Based on Organic Planar Waveguide Integrated with Prism Coupler

    NASA Technical Reports Server (NTRS)

    Sarkisov, Sergey S.

    2002-01-01

    The objectives of the project, as they were formulated in the proposal, are the following: (1) Design and development of novel electro-optic modulator using single crystalline film of highly efficient electro-optic organic material integrated with prism coupler; (2) Experimental characterization of the figures-of-merit of the modulator. It is expected to perform with an extinction ratio of 10 dB at a driving signal of 5 V; (3) Conclusions on feasibility of the modulator as an element of data communication systems of future generations. The accomplishments of the project are the following: (1) The design of the electro-optic modulator based on a single crystalline film of organic material NPP has been explored; (2) The evaluation of the figures-of-merit of the electro-optic modulator has been performed; (3) Based on the results of characterization of the figures-of-merit, the conclusion was made that the modulator based on a thin film of NPP is feasible and has a great potential of being used in optic communication with a modulation bandwidth of up to 100 GHz and a driving voltage of the order of 3 to 5 V.

  13. Organic Polymeric Electro-Optic Materials: Synthesis, Processing and Device Applications

    DTIC Science & Technology

    1993-04-01

    A number of polymeric second and third order nonlinear optical materials were designed and synthesized. The materials were characterized for their...performed.... Electro-Optic Effects, Guided Wave Devices, Organic Polymers, Nonlinear Optical Materials , Langmuir-Blodgett Films, Second Harmonic Generation

  14. High-power electro-optic switch technology based on novel transparent ceramic

    NASA Astrophysics Data System (ADS)

    Xue-Jiao, Zhang; Qing, Ye; Rong-Hui, Qu; Hai-wen, Cai

    2016-03-01

    A novel high-power polarization-independent electro-optic switch technology based on a reciprocal structure Sagnac interferometer and a transparent quadratic electro-optic ceramic is proposed and analyzed theoretically and experimentally. The electro-optic ceramic is used as a phase retarder for the clockwise and counter-clockwise polarized light, and their polarization directions are adjusted to their orthogonal positions by using two half-wave plates. The output light then becomes polarization-independent with respect to the polarization direction of the input light. The switch characteristics, including splitter ratios and polarization states, are theoretically analyzed and simulated in detail by the matrix multiplication method. An experimental setup is built to verify the analysis and experimental results. A new component ceramic is used and a non-polarizing cube beam splitter (NPBS) replaces the beam splitter (BS) to lower the ON/OFF voltage to 305 V and improve the extinction ratio by 2 dB. Finally, the laser-induced damage threshold for the proposed switch is measured and discussed. It is believed that potential applications of this novel polarization-independent electro-optic switch technology will be wide, especially for ultrafast high-power laser systems. Project supported by the National Natural Science Foundation of China (Grant Nos. 61137004, 61405218, and 61535014).

  15. Single-Nanoparticle Plasmonic Electro-optic Modulator Based on MoS2 Monolayers.

    PubMed

    Li, Bowen; Zu, Shuai; Zhou, Jiadong; Jiang, Qiao; Du, Bowen; Shan, Hangyong; Luo, Yang; Liu, Zheng; Zhu, Xing; Fang, Zheyu

    2017-09-07

    The manipulation of light in an integrated circuit is crucial for the development of high-speed electro-optic devices. Recently, molybdenum disulfide (MoS2) monolayers generated broad interest for the optoelectronics because of their huge exciton binding energy, tunable optical emission, direct electronic band-gap structure, etc. Miniaturization and multifunctionality of electro-optic devices further require the manipulation of light-matter interaction at the single-nanoparticle level. The strong exciton-plasmon interaction that is generated between the MoS2 monolayers and metallic nanostructures may be a possible solution for compact electro-optic devices at the nanoscale. Here, we demonstrate a nanoplasmonic modulator in the visible spectral region by combining the MoS2 monolayers with a single Au nanodisk. The narrow MoS2 excitons coupled with broad Au plasmons result in a deep Fano resonance, which can be switched on and off by applying different gate voltages on the MoS2 monolayers. A reversible display device that is based on this single-nanoparticle modulator is demonstrated with a heptamer pattern that is actively controlled by the external gates. Our work provides a potential application for electro-optic modulation on the nanoscale and promotes the development of gate-tunable nanoplasmonic devices in the future.

  16. Fourier-space combination of Planck and Herschel images

    NASA Astrophysics Data System (ADS)

    Abreu-Vicente, J.; Stutz, A.; Henning, Th.; Keto, E.; Ballesteros-Paredes, J.; Robitaille, T.

    2017-08-01

    Context. Herschel has revolutionized our ability to measure column densities (NH) and temperatures (T) of molecular clouds thanks to its far infrared multiwavelength coverage. However, the lack of a well defined background intensity level in the Herschel data limits the accuracy of the NH and T maps. Aims: We aim to provide a method that corrects the missing Herschel background intensity levels using the Planck model for foreground Galactic thermal dust emission. For the Herschel/PACS data, both the constant-offset as well as the spatial dependence of the missing background must be addressed. For the Herschel/SPIRE data, the constant-offset correction has already been applied to the archival data so we are primarily concerned with the spatial dependence, which is most important at 250 μm. Methods: We present a Fourier method that combines the publicly available Planck model on large angular scales with the Herschel images on smaller angular scales. Results: We have applied our method to two regions spanning a range of Galactic environments: Perseus and the Galactic plane region around l = 11deg (HiGal-11). We post-processed the combined dust continuum emission images to generate column density and temperature maps. We compared these to previously adopted constant-offset corrections. We find significant differences (≳20%) over significant ( 15%) areas of the maps, at low column densities (NH ≲ 1022 cm-2) and relatively high temperatures (T ≳ 20 K). We have also applied our method to synthetic observations of a simulated molecular cloud to validate our method. Conclusions: Our method successfully corrects the Herschel images, including both the constant-offset intensity level and the scale-dependent background variations measured by Planck. Our method improves the previous constant-offset corrections, which did not account for variations in the background emission levels. The image FITS files used in this paper are only available at the CDS via anonymous ftp

  17. Extreme nonlinear terahertz electro-optics in diamond for ultrafast pulse switching

    NASA Astrophysics Data System (ADS)

    Shalaby, Mostafa; Vicario, Carlo; Hauri, Christoph P.

    2017-03-01

    Polarization switching of picosecond laser pulses is a fundamental concept in signal processing [C. Chen and G. Liu, Annu. Rev. Mater. Sci. 16, 203 (1986); V. R. Almeida et al., Nature 431, 1081 (2004); and A. A. P. Pohl et al., Photonics Sens. 3, 1 (2013)]. Conventional switching devices rely on the electro-optical Pockels effect and work at radio frequencies. The ensuing gating time of several nanoseconds is a bottleneck for faster switches which is set by the performance of state-of-the-art high-voltage electronics. Here we show that by substituting the electric field of several kV/cm provided by modern electronics by the MV/cm field of a single-cycle THz laser pulse, the electro-optical gating process can be driven orders of magnitude faster, at THz frequencies. In this context, we introduce diamond as an exceptional electro-optical material and demonstrate a pulse gating time as fast as 100 fs using sub-cycle THz-induced Kerr nonlinearity. We show that THz-induced switching in the insulator diamond is fully governed by the THz pulse shape. The presented THz-based electro-optical approach overcomes the bandwidth and switching speed limits of conventional MHz/GHz electronics and establishes the ultrafast electro-optical gating technology for the first time in the THz frequency range. We finally show that the presented THz polarization gating technique is applicable for advanced beam diagnostics. As a first example, we demonstrate tomographic reconstruction of a THz pulse in three dimensions.

  18. Polymer stabilized liquid crystals: Topology-mediated electro-optical behavior and applications

    NASA Astrophysics Data System (ADS)

    Weng, Libo

    There has been a wide range of liquid crystal polymer composites that vary in polymer concentration from as little as 3 wt.% (polymer stabilized liquid crystal) to as high as 60 wt.% (polymer dispersed liquid crystals). In this dissertation, an approach of surface polymerization based on a low reactive monomer concentration about 1 wt.% is studied in various liquid crystal operation modes. The first part of dissertation describes the development of a vertical alignment (VA) mode with surface polymer stabilization, and the effects of structure-performance relationship of reactive monomers (RMs) and polymerization conditions on the electro-optical behaviors of the liquid crystal device has been explored. The polymer topography plays an important role in modifying and enhancing the electro-optical performance of stabilized liquid crystal alignment. The enabling surface-pinned polymer stabilized vertical alignment (PSVA) approach has led to the development of high-performance and fast-switching displays with controllable pretilt angle, increase in surface anchoring energy, high optical contrast and fast response time. The second part of the dissertation explores a PSVA mode with in-plane switching (IPS) and its application for high-efficiency and fast-switching phase gratings. The diffraction patterns and the electro-optical behaviors including diffraction efficiency and response time are characterized. The diffraction grating mechanism and performance have been validated by computer simulation. Finally, the advantages of surface polymerization approach such as good optical contrast and fast response time have been applied to the fringe-field switching (FFS) system. The concentration of reactive monomer on the electro-optical behavior of the FFS cells is optimized. The outstanding electro-optical results and mechanism of increase in surface anchoring strength are corroborated by the director field simulation. The density and topology of nanoscale polymer protrusions

  19. Electro-optic testbed utilizing a dynamic range gated Rayleigh beacon for atmospheric turbulence profiling

    NASA Astrophysics Data System (ADS)

    Zuraski, Steven M.; Fiorino, Steven T.; Beecher, Elizabeth A.; Figlewski, Nathan M.; Schmidt, Jason D.; McCrae, Jack E.

    2016-10-01

    The Photometry Analysis and Optical Tracking and Evaluation System (PANOPTES) Quad Axis Telescope is a unique four axis mount Ritchey-Chretien 24 inch telescope capable of tracking objects through the zenith without axes rotation delay (no Dead Zone). This paper describes enhancement components added to the quad axis mount telescope that will enable measurements supporting novel research and field testing focused on `three-dimensional' characterization of turbulent atmospheres, mitigation techniques, and new sensing modalities. These all support research and operational techniques relating to astronomical imaging and electro-optical propagation though the atmosphere, relative to sub-meter class telescopes in humid, continental environments. This effort will use custom designed and commercial off the shelf hardware; sub-system components discussed will include a wavefront sensor system, a co-aligned beam launch system, and a fiber coupled research laser. The wavefront sensing system has the ability to take measurements from a dynamic altitude adjustable laser beacon scattering spot, a key concept that enables rapid turbulence structure parameter measurements over an altitude varied integrated atmospheric volume. The sub-components are integrated with the overall goal of measuring a height-resolved volumetric profile for the atmospheric turbulence structure parameter at the site, and developing mobile techniques for such measurements. The design concept, part selection optimization, baseline component lab testing, and initial field measurements, will be discussed in the main sections of this paper. This project is a collaborative effort between the Air Force Research Labs Sensors Directorate and the Air Force Institute of Technology Center for Directed Energy.

  20. Optical imaging process based on two-dimensional Fourier transform for synthetic aperture imaging ladar

    NASA Astrophysics Data System (ADS)

    Sun, Zhiwei; Zhi, Ya'nan; Liu, Liren; Sun, Jianfeng; Zhou, Yu; Hou, Peipei

    2013-09-01

    The synthetic aperture imaging ladar (SAIL) systems typically generate large amounts of data difficult to compress with digital method. This paper presents an optical SAIL processor based on compensation of quadratic phase of echo in azimuth direction and two dimensional Fourier transform. The optical processor mainly consists of one phase-only liquid crystal spatial modulator(LCSLM) to load the phase data of target echo and one cylindrical lens to compensate the quadratic phase and one spherical lens to fulfill the task of two dimensional Fourier transform. We show the imaging processing result of practical target echo obtained by a synthetic aperture imaging ladar demonstrator. The optical processor is compact and lightweight and could provide inherent parallel and the speed-of-light computing capability, it has a promising application future especially in onboard and satellite borne SAIL systems.

  1. Optical Fourier techniques for medical image processing and phase contrast imaging

    PubMed Central

    Yelleswarapu, Chandra S.; Kothapalli, Sri-Rajasekhar; Rao, D.V.G.L.N.

    2008-01-01

    This paper briefly reviews the basics of optical Fourier techniques (OFT) and applications for medical image processing as well as phase contrast imaging of live biological specimens. Enhancement of microcalcifications in a mammogram for early diagnosis of breast cancer is the main focus. Various spatial filtering techniques such as conventional 4f filtering using a spatial mask, photoinduced polarization rotation in photosensitive materials, Fourier holography, and nonlinear transmission characteristics of optical materials are discussed for processing mammograms. We also reviewed how the intensity dependent refractive index can be exploited as a phase filter for phase contrast imaging with a coherent source. This novel approach represents a significant advance in phase contrast microscopy. PMID:18458764

  2. Recent results on photonic devices made by laser writing: 3D 3T near IR waveguides, mid-IR spectrometers and electro-optic beam combiners

    NASA Astrophysics Data System (ADS)

    Martin, G.; Vázquez de Aldana, J. R.; Rodenas, A.; d'Amico, C.; Stoian, R.

    2016-07-01

    Direct laser writing is a powerful technique for the development of astrophotonic devices, namely by allowing 3D structuring of waveguides and structures. One of the main interests is the possibility to avoid in-plane crossings of waveguides that can induce losses and crosstalk in future multi-telescope beam combiners. We will present our results in 3D three telescope beam combiners in the near infrared, that allow for phase closure studies. Besides, laser writing can be used to inscribe a grating over long distances along the waveguide direction. This can be used as an on-chip diffraction grating or as a way to sample a stationary wave that can be obtained in the waveguide. Thus, integrated optics spectrometers based on the SWIFTS concept (stationary wave integrated Fourier transform spectrometer) have been realized and characterized in the near and mid infrared using commercial chalcogenide glasses. Finally, we will also present our results on laser writing on electro-optic materials, that allow to obtain waveguides and beam combiners that can be phase-modulated using electrodes. We have focused our work on two well-known materials: Lithium Niobate, that allows for TM waveguides and has a high electro-optical coefficient, and BGO, that has a lower coefficient, but presents the advantage of being isotropic, guiding both TE and TM polarizations identically.

  3. Geostationary Imaging Fourier Transform Spectrometer (GIFTS): science applications

    NASA Astrophysics Data System (ADS)

    Smith, W. L.; Revercomb, H. E.; Zhou, D. K.; Bingham, G. E.; Feltz, W. F.; Huang, H. L.; Knuteson, R. O.; Larar, A. M.; Liu, X.; Reisse, R.; Tobin, D. C.

    2006-12-01

    A revolutionary satellite weather forecasting instrument, called the "GIFTS" which stands for the "Geostationary Imaging Fourier Transform Spectrometer", was recently completed and successfully tested in a space chamber at the Utah State University's Space Dynamics Laboratory. The GIFTS was originally proposed by the NASA Langley Research Center, the University of Wisconsin, and the Utah State University and selected for flight demonstration as NASA's New Millennium Program (NMP) Earth Observing-3 (EO-3) mission, which was unfortunately cancelled in 2004. GIFTS is like a digital 3-d movie camera that, when mounted on a geostationary satellite, would provide from space a revolutionary four-dimensional view of the Earth's atmosphere. GIFTS will measure the distribution, change, and movement of atmospheric moisture, temperature, and certain pollutant gases, such as carbon monoxide and ozone. The observation of the convergence of invisible water vapor, and the change of atmospheric temperature, provides meteorologists with the observations needed to predict where, and when, severe thunderstorms, and possibly tornados, would occur, before they are visible on radar or in satellite cloud imagery. The ability of GIFTS to observe the motion of moisture and clouds at different altitudes enables atmospheric winds to be observed over vast, and otherwise data sparse, oceanic regions of the globe. These wind observations would provide the means to greatly improve the forecast of where tropical storms and hurricanes will move and where and when they will come ashore (i.e., their landfall position and time). GIFTS, if flown into geostationary orbit, would provide about 80,000 vertical profiles per minute, each one like a low vertical resolution (1-2km) weather balloon sounding, but with a spacing of 4 km. GIFTS is a revolutionary atmospheric sensing tool. A glimpse of the science measurement capabilities of GIFTS is provided through airborne measurements with the NPOESS Airborne

  4. Rotational-translational fourier imaging system requiring only one grid pair

    NASA Technical Reports Server (NTRS)

    Campbell, Jonathan W. (Inventor)

    2006-01-01

    The sky contains many active sources that emit X-rays, gamma rays, and neutrons. Unfortunately hard X-rays, gamma rays, and neutrons cannot be imaged by conventional optics. This obstacle led to the development of Fourier imaging systems. In early approaches, multiple grid pairs were necessary in order to create rudimentary Fourier imaging systems. At least one set of grid pairs was required to provide multiple real components of a Fourier derived image, and another set was required to provide multiple imaginary components of the image. It has long been recognized that the expense associated with the physical production of the numerous grid pairs required for Fourier imaging was a drawback. Herein one grid pair (two grids), with accompanying rotation and translation, can be used if one grid has one more slit than the other grid, and if the detector is modified.

  5. Imaging the sun in hard x rays using Fourier telescopes

    NASA Technical Reports Server (NTRS)

    Campbell, J. W.

    1993-01-01

    For several years, solar flares have been observed with a variety of instruments confirming that tremendous amounts of energy are locally stored in the solar magnetic field and then rapidly released during the life of the flare. In concert with observations, theorists have attempted to describe the means by which these energetic events occur and evolve. Two competing theories have emerged and have stood the test of time. One theory describes the flare in terms of nonthermal, electron beam injection into a thick target while the other uses a thermal approach. Both theories provide results which are reasonably consistent with current observations; but to date, none have been able to provide conclusive evidence as to the validity of either model. Imaging on short time scales (1 s) and/or small size scales (1 arc s) should give definitive answers to these questions. In order to test whether a realistic telescope can indeed discriminate between models, we construct model sources based upon the thermal and the nonthermal models and calculate the emission as a function of time and energy in the range from 10 to 100 keV. In addition, we construct model telescopes representing both the spatial modulation collimator (SMC) and the rotating modulation collimator (RMC) techniques of observation using random photon counting statistics. With these two types of telescopes we numerically simulate the instrument response to the above two model flares to see if there are distinct x-ray signatures which may be discernable. We find that theoretical descriptions of the primary models of solar flares do indeed predict different hard x-ray signatures for 1 sec time scales and at 1-5 arc sec spatial resolution. However, these distinguishing signatures can best be observed early in the impulsive phase and from a position perpendicular to the plane of the loop. Furthermore, we find that Fourier telescopes with reasonable and currently attainable design characteristics can image these

  6. Tunable microwave bandpass filter integrated power divider based on the high anisotropy electro-optic nematic liquid crystal.

    PubMed

    Liu, Yupeng; Liu, Yang; Li, Haiyan; Jiang, Di; Cao, Weiping; Chen, Hui; Xia, Lei; Xu, Ruimin

    2016-07-01

    A novel, compact microwave tunable bandpass filter integrated power divider, based on the high anisotropy electro-optic nematic liquid crystal, is proposed in this letter. Liquid crystal, as the electro-optic material, is placed between top inverted microstrip line and the metal plate. The proposed structure can realize continuous tunable bandpass response and miniaturization. The proposed design concept is validated by the good performance of simulation results and experimental results. The electro-optic material has shown great potential for microwave application.

  7. Tunable microwave bandpass filter integrated power divider based on the high anisotropy electro-optic nematic liquid crystal

    NASA Astrophysics Data System (ADS)

    Liu, Yupeng; Liu, Yang; Li, Haiyan; Jiang, Di; Cao, Weiping; Chen, Hui; Xia, Lei; Xu, Ruimin

    2016-07-01

    A novel, compact microwave tunable bandpass filter integrated power divider, based on the high anisotropy electro-optic nematic liquid crystal, is proposed in this letter. Liquid crystal, as the electro-optic material, is placed between top inverted microstrip line and the metal plate. The proposed structure can realize continuous tunable bandpass response and miniaturization. The proposed design concept is validated by the good performance of simulation results and experimental results. The electro-optic material has shown great potential for microwave application.

  8. Applied electro-optics educational and training program with multiple entrance and exit pathways

    NASA Astrophysics Data System (ADS)

    Scott, Patricia; Zhou, Feng; Zilic, Dorothy

    2007-06-01

    This paper presents an innovative hands-on training program designed to create a pipeline of highly-skilled technical workers for today's workforce economy. The 2+2+2 Pennsylvania Integrated Workforce Leadership Program in Electro-Optics prepares students for a career in this new high-tech field. With seamless transition from high school into college, the program offers the versatility of multiple entrance and exit pathways. After completion of each educational level, students can exit the program with various skill levels, including certificates, an associate's degree, or a bachelor's degree. Launched by Indiana University of Pennsylvania (IUP) in partnership with Lenape Vocational School (Lenape), the 2+2+2 educational pathway program was implemented to promote early training of high-school students. During the first level, students in their junior and/or senior year enroll in four Electro-Optics courses at Lenape. Upon completion of these courses and an Advanced Placement Equivalency course with an appropriate exam score, students can earn a certificate from Lenape for the 15+ credits, which also can be articulated into IUP's associate degree program in Electro-Optics. During the second level, students can earn an associate's degree in Electro-Optics, offered only at the IUP Northpointe Campus. After completion of the Associate in Applied Science (A.A.S.), students are prepared to enter the workforce as senior technicians. During the third level, students who have completed the Associate of Science (A.S.) in Electro-Optics have the opportunity to matriculate at IUP's Indiana Campus to earn a Bachelor of Science (B.S.) degree in Applied Physics with a track in Electro-Optics. Hence, the name 2+2+2 refers to getting started in high school, continuing the educational experience with an associate's degree program, and optionally moving on to a bachelor's degree. Consequently, students move from one educational level to the next with advanced credits toward the next

  9. Design of an Electro-Optic Modulator for High Speed Communications

    NASA Astrophysics Data System (ADS)

    Espinoza, David

    The telecommunications and computer technology industries have been requiring higher communications speeds at all levels for devices, components and interconnected systems. Optical devices and optical interconnections are a viable alternative over other traditional technologies such as copper-based interconnections. Latency reductions can be achieved through the use of optical interconnections. Currently, a particular architecture for optical interconnections is being studied at the University of Colorado at Boulder in the EMT/NANO project, called Broadcast Optical Interconnects for Global Communication in Many-Core Chip Multiprocessor. As with most types of networks, including optical networks, one of the most important components are modulators. Therefore adequate design and fabrication techniques for modulators contribute to higher modulation rates which lead to improve the efficiency and reductions in the latency of the optical network. Electro-optical modulators are presented in this study as an alternative to achieve this end. In recent years, nonlinear optical (NLO) materials have been used for the fabrication of high-speed electro-optical modulators. Polymers doped with chromophores are an alternative among NLO materials because they can develop large electro-optic coefficients and low dielectric constants. These two factors are critical for achieving high-speed modulation rates. These polymer-based electro-optical modulators can be fabricated using standard laboratory techniques, such as polymer spin-coating onto substrates, UV bleaching to achieve a refractive index variation and poling techniques to align the chromophores in cured polymers. The design of the electro-optic modulators require the use of the optical parameters of the materials to be used. Therefore the characterization of these materials is a required previous step. This characterization is performed by the fabrication of chromophores-doped polymer samples and conducting transmission and

  10. Adaptive chirp-Fourier transform for chirp estimation with applications in ISAR imaging of maneuvering targets

    NASA Astrophysics Data System (ADS)

    Xia, Xiang-Gen; Wang, Genyuan; Chen, Victor C.

    2001-03-01

    This paper first reviews some basic properties of the discrete chirp-Fourier transform and then present an adaptive chirp- Fourier transform, a generalization of the amplitude and phase estimation of sinusoids (APES) algorithm proposed by Li and Stoica for sinusoidal signals. We finally applied it to the ISAR imaging of maneuvering targets.

  11. Fourier imaging of non-linear structure formation

    NASA Astrophysics Data System (ADS)

    Brandbyge, Jacob; Hannestad, Steen

    2017-04-01

    We perform a Fourier space decomposition of the dynamics of non-linear cosmological structure formation in ΛCDM models. From N-body simulations involving only cold dark matter we calculate 3-dimensional non-linear density, velocity divergence and vorticity Fourier realizations, and use these to calculate the fully non-linear mode coupling integrals in the corresponding fluid equations. Our approach allows for a reconstruction of the amount of mode coupling between any two wavenumbers as a function of redshift. With our Fourier decomposition method we identify the transfer of power from larger to smaller scales, the stable clustering regime, the scale where vorticity becomes important, and the suppression of the non-linear divergence power spectrum as compared to linear theory. Our results can be used to improve and calibrate semi-analytical structure formation models.

  12. Midwave infrared imaging Fourier transform spectrometry of combustion plumes

    NASA Astrophysics Data System (ADS)

    Bradley, Kenneth C.

    A midwave infrared (MWIR) imaging Fourier transform spectrometer (IFTS) was used to successfully capture and analyze hyperspectral imagery of combustion plumes. Jet engine exhaust data from a small turbojet engine burning diesel fuel at a low rate of 300 cm3/min was collected at 1 cm -1 resolution from a side-plume vantage point on a 200x64 pixel window at a range of 11.2 meters. Spectral features of H2O, CO, and CO2 were present, and showed spatial variability within the plume structure. An array of thermocouple probes was positioned within the plume to aid in temperature analysis. A single-temperature plume model was implemented to obtain spatially-varying temperatures and plume concentrations. Model-fitted temperatures of 811 +/- 1.5 K and 543 +/- 1.6 K were obtained from plume regions in close proximity to thermocouple probes measuring temperatures of 719 K and 522 K, respectively. Industrial smokestack plume data from a coal-burning stack collected at 0.25 cm-1 resolution at a range of 600 meters featured strong emission from NO, CO, CO2, SO 2, and HCl in the spectral region 1800-3000 cm-1. A simplified radiative transfer model was employed to derive temperature and concentrations for clustered regions of the 128x64 pixel scene, with corresponding statistical error bounds. The hottest region (closest to stack centerline) was 401 +/- 0.36 K, compared to an in-stack measurement of 406 K, and model-derived concentration values of NO, CO2, and SO2 were 140 +/- 1 ppmV, 110,400 +/- 950 ppmV, and 382 +/- 4 ppmV compared to in-stack measurements of 120 ppmV (NOx), 94,000 ppmV, and 382 ppmV, respectively. In-stack measurements of CO and HCl were not provided by the stack operator, but model-derived values of 19 +/- 0.2 ppmV and 111 +/- 1 ppmV are reported near stack centerline. A deployment to Dugway Proving Grounds, UT to collect hyperspectral imagery of chemical and biological threat agent simulants resulted in weak spectral signatures from several species. Plume

  13. Proposed measurement of spin currents in a GaAs crystal using the electro-optical Pockels effect

    SciTech Connect

    Zhang, Xingchu; Zheng, Yongjun; She, Weilong

    2014-07-14

    A new method for measuring spin currents is proposed, based on the linear electro-optic (Pockels) effect caused by the additional second-order nonlinear electric susceptibility (electro-optic tensor) generated by the spin currents. The non-zero elements of electro-optic tensor induced by spin currents in GaAs crystal are calculated, and the wave coupling theory of linear electro-optic effect is used to analyze the polarization change of a probe beam. The numerical results show that, for a linearly polarized probe beam with a frequency close to the band gap of GaAs crystal, its polarization rotation can be as large as 14 μrad under an applied electric field of about 350 V/mm. This effect should offer an alternative detection method for spintronics.

  14. Active mode-locked lasers and other photonic devices using electro-optic whispering gallery mode resonators

    NASA Technical Reports Server (NTRS)

    Matsko, Andrey B. (Inventor); Ilchenko, Vladimir (Inventor); Savchenkov, Anatoliy (Inventor); Maleki, Lutfollah (Inventor)

    2006-01-01

    Techniques and devices using whispering gallery mode (WGM) optical resonators, where the optical materials of the WGM resonators exhibit an electro-optical effect to perform optical modulation. Examples of actively mode-locked lasers and other devices are described.

  15. Method of synthesizing a plurality of reactants and producing thin films of electro-optically active transition metal oxides

    DOEpatents

    Tracy, C.E.; Benson, D.K.; Ruth, M.R.

    1985-08-16

    A method of synthesizing a plurality of reactants by inducing a reaction by plasma deposition among the reactants. The plasma reaction is effective for consolidating the reactants and producing thin films of electro-optically active transition metal oxides.

  16. Femtosecond fibre laser stabilisation to an optical frequency standard using a KTP electro-optic crystal

    SciTech Connect

    Nyushkov, B N; Pivtsov, V S; Koliada, N A; Kaplun, A B; Meshalkin, A B

    2015-05-31

    A miniature intracavity KTP-based electro-optic phase modulator has been developed which can be used for effective stabilisation of an optical frequency comb of a femtosecond erbiumdoped fibre laser to an optical frequency standard. The use of such an electro-optic modulator (EOM) has made it possible to extend the working frequency band of a phase-locked loop system for laser stabilisation to several hundred kilohertz. We demonstrate that the KTP-based EOM is sufficiently sensitive even at a small optical length, which allows it to be readily integrated into cavities of femtosecond fibre lasers with high mode frequency spacings (over 100 MHz). (extreme light fields and their applications)

  17. Paraxial Theory of Direct Electro-optic Sampling of the Quantum Vacuum.

    PubMed

    Moskalenko, A S; Riek, C; Seletskiy, D V; Burkard, G; Leitenstorfer, A

    2015-12-31

    Direct detection of vacuum fluctuations and analysis of subcycle quantum properties of the electric field are explored by a paraxial quantum theory of ultrafast electro-optic sampling. The feasibility of such experiments is demonstrated by realistic calculations adopting a thin ZnTe electro-optic crystal and stable few-femtosecond laser pulses. We show that nonlinear mixing of a short near-infrared probe pulse with the multiterahertz vacuum field leads to an increase of the signal variance with respect to the shot noise level. The vacuum contribution increases significantly for appropriate length of the nonlinear crystal, short pulse duration, tight focusing, and a sufficiently large number of photons per probe pulse. If the vacuum input is squeezed, the signal variance depends on the probe delay. Temporal positions with a noise level below the pure vacuum may be traced with subcycle resolution.

  18. SiPM electro-optical detection system noise suppression method

    NASA Astrophysics Data System (ADS)

    Bi, Xiangli; Yang, Suhui; Hu, Tao; Song, Yiheng

    2014-11-01

    In this paper, the single photon detection principle of Silicon Photomultipliers (SiPM) device is introduced. The main noise factors that infect the sensitivity of the electro-optical detection system are analyzed, including background light noise, detector dark noise, preamplifier noise and signal light noise etc. The Optical, electrical and thermodynamic methods are used to suppress the SiPM electro-optical detection system noise, which improved the response sensitivity of the detector. Using SiPM optoelectronic detector with a even high sensitivity, together with small field large aperture optical system, high cutoff narrow bandwidth filters, low-noise operational amplifier circuit, the modular design of functional circuit, semiconductor refrigeration technology, greatly improved the sensitivity of optical detection system, reduced system noise and achieved long-range detection of weak laser radiation signal. Theoretical analysis and experimental results show that the proposed methods are reasonable and efficient.

  19. Electro-optic modulation for high-speed characterization of entangled photon pairs

    SciTech Connect

    Lukens, Joseph M.; Odele, Ogaga D.; Leaird, Daniel E.; Weiner, Andrew M.

    2015-11-10

    In this study, we demonstrate a new biphoton manipulation and characterization technique based on electro-optic intensity modulation and time shifting. By applying fast modulation signals with a sharply peaked cross-correlation to each photon from an entangled pair, it is possible to measure temporal correlations with significantly higher precision than that attainable using standard single-photon detection. Low-duty-cycle pulses and maximal-length sequences are considered as modulation functions, reducing the time spread in our correlation measurement by a factor of five compared to our detector jitter. With state-of-the-art electro-optic components, we expect the potential to surpass the speed of any single-photon detectors currently available.

  20. Plasmon electro-optic effect in a subwavelength metallic nanograting with a nematic liquid crystal

    NASA Astrophysics Data System (ADS)

    Palto, S. P.; Barnik, M. I.; Kasyanova, I. V.; Geivandov, A. R.; Shtykov, N. M.; Artemov, V. V.; Gorkunov, M. V.

    2016-01-01

    The electro-optic effect in hybrid structures based on subwavelength metallic nanogratings in contact with a layer of a nematic liquid crystal has been experimentally studied. Metallic gratings are fabricated in the form of interdigitated electrodes, which makes it possible to use them not only as optical elements but also for the production of an electric field in a thin surface region of the layer of the liquid crystal. It has been shown that, owing to the electric-field-induced reorientation of molecules of the liquid crystal near the surface of the grating, it is possible to significantly control the spectral features of the transmission of light, which are caused by the excitation of surface plasmons. The electro-optic effect is superfast for liquid crystal devices because a change in the optical properties of the system requires the reorientation of molecules only in a very thin surface layer of the liquid crystal.

  1. Electro-optic modulation for high-speed characterization of entangled photon pairs

    DOE PAGES

    Lukens, Joseph M.; Odele, Ogaga D.; Leaird, Daniel E.; ...

    2015-11-10

    In this study, we demonstrate a new biphoton manipulation and characterization technique based on electro-optic intensity modulation and time shifting. By applying fast modulation signals with a sharply peaked cross-correlation to each photon from an entangled pair, it is possible to measure temporal correlations with significantly higher precision than that attainable using standard single-photon detection. Low-duty-cycle pulses and maximal-length sequences are considered as modulation functions, reducing the time spread in our correlation measurement by a factor of five compared to our detector jitter. With state-of-the-art electro-optic components, we expect the potential to surpass the speed of any single-photon detectors currentlymore » available.« less

  2. Nanosecond square high voltage pulse generator for electro-optic switch

    NASA Astrophysics Data System (ADS)

    Feng, Xian-wang; Long, Xing-wu; Tan, Zhong-qi

    2011-07-01

    A scalable square high voltage pulse generator, which has the properties of fast rise time, fast fall time, powerful driving capability, and long lifetime, is presented in this paper by utilizing solid state circuitry. A totem-pole topology is designed to supply a powerful driving capability for the electro-optic (EO) crystal which is of capacitive load. Power MOSFETs are configured in series to sustain high voltage, and proper driving circuits are introduced for the specific MOSFETs configurations. A 3000 V pulse generator with ˜49.04 ns rise time and ˜10.40 ns fall time of the output waveform is presented. This kind of generator is desirable for electro-optic switch. However, it is not specific to EO switch and may have broad applications where high voltage fast switching is required.

  3. Growth of Ferro-Electric Tungsten Bronze Epitaxial Thin Films for Electro-Optic Device Applications

    DTIC Science & Technology

    1986-06-01

    b24 = 0 b25 = 0 b26 = %6?l b31 = 0 b32 = 0 b33 = 0 b34 = Q44P1 b25 = Q44P1 b36 = 0 (4.4) 33 C7458A/bje AB 11 = {gn + g2i) pi AB22 = (g11...92l)Pl AB 33 29l3Pl and for the linear electro-optic effect. rll = r22 = 29llPlell ൔ = r21 = 2921Plell r13 = r23 = 29l3Ple 33 r34 = r35...944Ple33 0» Rockwell International Science Center For the quadratic electro-optic effect, SCb340.13FR AB 12 = 965P1 (4.5) r16 = r26 = 944Plell (4.6

  4. Effect of solvents on the electro-optical switching of graphene oxide dispersions

    NASA Astrophysics Data System (ADS)

    Ahmad, Rana Tariq Mehmood; Hong, Seung-Ho; Shen, Tian-Zi; Masud, Aurangzeb Rashid; Song, Jang-Kun

    2016-06-01

    The electrical manipulation of graphene oxide (GO) alignment in aqueous dispersions is a useful technique with various applications. In particular, the electrical switching of GO particles can be used to devise optical birefringent liquid crystal displays. However, the electric switching of aqueous GO dispersions with a high ionic concentration requires driving voltages with high frequencies (˜10 kHz), which is a challenging limitation. We demonstrate that stable electro-optical switching can be achieved at low frequencies (100 Hz) using GO dispersions in organic solvents instead of water. The hydrodynamic flow of the solvent and the electrophoretic drift of the GO particles are hindered in the GO dispersions in organic solvents with lower dielectric constants. Moreover, the electro-optical performance of these GO dispersions is similar to the aqueous GO dispersions, despite the lower magnitude of the ionization ratio for the GO particle functional groups. These results are crucial for developing a liquid crystal display device using GO dispersions.

  5. Polymer electro-optic modulator efficiency enhancement by the high permittivity dielectric strips

    NASA Astrophysics Data System (ADS)

    Tsarev, Andrei; Taziev, Rinat; Heller, Evan; Chalony, Maryvonne

    2017-07-01

    The performance improvement of rib-waveguide electro-optic (EO) polymer modulators resulting from the inclusion of high permittivity dielectric strips is considered. For this study, we take into account the heterogeneous nature of the poling of the electro-optic polymer by the electrode structure, the dispersion of the RF wave due to the material dispersion in the waveguide, and the finite conductivity of the electrodes. It is shown that the insertion of additional insulating strips with high dielectric permittivity (such as MgO) considerably enhances (from 120% to 280%) the efficiency of EO tuning. Furthermore, this efficiency grows with increasing modulation frequency, yielding a 2.0 V half-wave voltage at 100 GHz, when DH-80 EO polymer is used.

  6. High-speed and low-power electro-optical DSP coprocessor.

    PubMed

    Tamir, Dan E; Shaked, Natan T; Wilson, Peter J; Dolev, Shlomi

    2009-08-01

    A fast, power-efficient electro-optical vector-by-matrix multiplier (VMM) architecture is presented. Careful design of an electrical unit supporting high-speed data transfer enables this architecture to overcome bottlenecks encountered by previous VMM architectures. Based on the proposed architecture, we present an electro-optical digital signal processing (DSP) coprocessor that can achieve a significant speedup of 2-3 orders of magnitude over existing DSP technologies and execute more than 16 teraflops. We show that it is feasible to implement the system using off-the-shelf components, analyze the performance of the architecture with respect to primitive DSP operations, and detail the use of the new architecture for several DSP applications.

  7. Adjustable mount for electro-optic transducers in an evacuated cryogenic system

    NASA Technical Reports Server (NTRS)

    Crossley, Edward A., Jr. (Inventor); Haynes, David P. (Inventor); Jones, Howard C. (Inventor); Jones, Irby W. (Inventor)

    1987-01-01

    The invention is an adjustable mount for positioning an electro-optic transducer in an evacuated cryogenic environment. Electro-optic transducers are used in this manner as high sensitivity detectors of gas emission lines of spectroscopic analysis. The mount is made up of an adjusting mechanism and a transducer mount. The adjusting mechanism provided five degrees of freedom, linear adjustments and angular adjustments. The mount allows the use of an internal lens to focus energy on the transducer element thereby improving the efficiency of the detection device. Further, the transducer mount, although attached to the adjusting mechanism, is isolated thermally such that a cryogenic environment can be maintained at the transducer while the adjusting mechanism remains at room temperature. Radiation shields also are incorporated to further reduce heat flow to the transducer location.

  8. Recent Advances in the Design of Electro-Optic Sensors for Minimally Destructive Microwave Field Probing

    PubMed Central

    Lee, Dong-Joon; Kang, No-Weon; Choi, Jun-Ho; Kim, Junyeon; Whitaker, John F.

    2011-01-01

    In this paper we review recent design methodologies for fully dielectric electro-optic sensors that have applications in non-destructive evaluation (NDE) of devices and materials that radiate, guide, or otherwise may be impacted by microwave fields. In many practical NDE situations, fiber-coupled-sensor configurations are preferred due to their advantages over free-space bulk sensors in terms of optical alignment, spatial resolution, and especially, a low degree of field invasiveness. We propose and review five distinct types of fiber-coupled electro-optic sensor probes. The design guidelines for each probe type and their performances in absolute electric-field measurements are compared and summarized. PMID:22346604

  9. Electro-optically tunable, multi-wavelength optical parametric generators in aperiodically poled lithium niobates.

    PubMed

    Chen, Y H; Chung, H P; Chang, W K; Lyu, H T; Chang, J W; Tseng, C H

    2012-12-17

    We report on the design and demonstration of electro-optically tunable, multi-wavelength optical parametric generators (OPGs) based on aperiodically poled lithium niobate (APPLN) crystals. Two methods have been proposed to significantly enhance the electro-optic (EO) tunability of an APPLN OPG constructed by the aperiodic optical superlattice (AOS) technique. This is done by engineering the APPLN domain structure either in the crystal fabrication or in the crystal design process to increase the length or block-number difference of the two opposite-polarity domains used in the structure. Several orders of magnitude enhancement on the EO tuning rate of the APPLN OPGs constructed by the proposed techniques for simultaneous multiple signal wavelength generation over a conventional one has been demonstrated in a near infrared band (1500-1600 nm).

  10. Compact resonant electro-optic modulator using randomness of a photonic crystal waveguide.

    PubMed

    Ooka, Yuta; Daud, Nurul Ashikin Binti; Tetsumoto, Tomohiro; Tanabe, Takasumi

    2016-05-16

    We fabricate and demonstrate an electro-optic modulator that utilizes the randomness in a photonic crystal waveguide. We exploit a way of using random photonic crystals for device application that involves restricting the area influenced by the randomness. Our random photonic crystal waveguide is in a diffusive regime and the confinement of light is observed only for a W0.98 waveguide (98% of the original width) placed between W1.05 photonic crystal waveguides, where we obtained a transmittance spectrum with an ultra-high Q of 2.4 × 105. A numerical investigation revealed that the experimental yield rate of the appearance of the high-Q confined mode is larger than 80%, by properly designing the length of W0.98. Since the confinement location is predictable, we integrate a p-i-n structure and demonstrate a GHz electro-optic modulation.

  11. Properties and applications of polymers in optics and electro-optics

    NASA Astrophysics Data System (ADS)

    Dubois, Jean-Claude; Robin, Philippe; Dentan, Veronique

    1993-12-01

    This paper describes the properties and applications of some recent polymers in the field of electro-optics. We describe the properties of polyacrylates copolymer with a pending group with large hyperpolarizability. These amorphous copolymers show high optical nonlinear coefficients after poling under an electric field. We have used these copolymers for the manufacture of an electro-optic modulator working at 1.3 micrometers at a frequency of 1 GHz. We also look at the nonlinear absorption of the C60 fullerene for applications in the field of optical limiting. Finally, we deal with ferroelectric polymers and their pyroelectric properties. We describe the realization and performance of an IR pyroelectric sensor using copolymers of poly(vinylidene fluoride-ethylene trifluoride).

  12. Paraxial Theory of Direct Electro-optic Sampling of the Quantum Vacuum

    NASA Astrophysics Data System (ADS)

    Moskalenko, A. S.; Riek, C.; Seletskiy, D. V.; Burkard, G.; Leitenstorfer, A.

    2015-12-01

    Direct detection of vacuum fluctuations and analysis of subcycle quantum properties of the electric field are explored by a paraxial quantum theory of ultrafast electro-optic sampling. The feasibility of such experiments is demonstrated by realistic calculations adopting a thin ZnTe electro-optic crystal and stable few-femtosecond laser pulses. We show that nonlinear mixing of a short near-infrared probe pulse with the multiterahertz vacuum field leads to an increase of the signal variance with respect to the shot noise level. The vacuum contribution increases significantly for appropriate length of the nonlinear crystal, short pulse duration, tight focusing, and a sufficiently large number of photons per probe pulse. If the vacuum input is squeezed, the signal variance depends on the probe delay. Temporal positions with a noise level below the pure vacuum may be traced with subcycle resolution.

  13. Measurement of strains at high temperatures by means of electro-optics holography

    NASA Technical Reports Server (NTRS)

    Sciammarella, Cesar A.; Bhat, G.; Vaitekunas, Jeffrey

    1991-01-01

    Electro-optics holographic-moire interferometry is used to measure strains at temperatures up to 1000 C. A description of the instrumentation developed to carry out the measurements is given. The data processing technique is also explained. Main problems encountered in recording patterns at high temperatures are analyzed and possible solutions are outlined. Optical results are compared with strain gage values obtained with instrumented specimens and with theoretical results. Very good agreement is found between optical, strain gage and theoretical results.

  14. Triggerable electro-optic amplitude modulator bias stabilizer for integrated optical devices

    DOEpatents

    Conder, Alan D.; Haigh, Ronald E.; Hugenberg, Keith F.

    1995-01-01

    An improved Mach-Zehnder integrated optical electro-optic modulator is achieved by application and incorporation of a DC bias box containing a laser synchronized trigger circuit, a DC ramp and hold circuit, a modulator transfer function negative peak detector circuit, and an adjustable delay circuit. The DC bias box ramps the DC bias along the transfer function curve to any desired phase or point of operation at which point the RF modulation takes place.

  15. Triggerable electro-optic amplitude modulator bias stabilizer for integrated optical devices

    DOEpatents

    Conder, A.D.; Haigh, R.E.; Hugenberg, K.F.

    1995-09-26

    An improved Mach-Zehnder integrated optical electro-optic modulator is achieved by application and incorporation of a DC bias box containing a laser synchronized trigger circuit, a DC ramp and hold circuit, a modulator transfer function negative peak detector circuit, and an adjustable delay circuit. The DC bias box ramps the DC bias along the transfer function curve to any desired phase or point of operation at which point the RF modulation takes place. 7 figs.

  16. Electro-Optic Segment-Segment Sensors for Radio and Optical Telescopes

    NASA Technical Reports Server (NTRS)

    Abramovici, Alex

    2012-01-01

    A document discusses an electro-optic sensor that consists of a collimator, attached to one segment, and a quad diode, attached to an adjacent segment. Relative segment-segment motion causes the beam from the collimator to move across the quad diode, thus generating a measureable electric signal. This sensor type, which is relatively inexpensive, can be configured as an edge sensor, or as a remote segment-segment motion sensor.

  17. Electro-optic and holographic measurement techniques for the atmospheric sciences. [considering spacecraft simulation applications

    NASA Technical Reports Server (NTRS)

    Moore, W. W., Jr.; Lemons, J. F.; Kurtz, R. L.; Liu, H.-K.

    1977-01-01

    A comprehensive examination is made of recent advanced research directions in the applications of electro-optical and holographic instrumentations and methods to atmospheric sciences problems. In addition, an overview is given of the in-house research program for environmental and atmospheric measurements with emphasis on particulates systems. Special treatment is made of the instrument methods and applications work in the areas of laser scattering spectrometers and pulsed holography sizing systems. Selected engineering tests data on space simulation chamber programs are discussed.

  18. Physics-Based Radiometric Signature Modeling and Detection Algorithms of Landmines Using Electro-Optical Sensors

    DTIC Science & Technology

    2005-07-01

    end to the Office of Management and Budget, Paperwork Reduction Project 10704-If88), Washington, OC 20503. 1 . AGENCY USE ONLY (tLeave blank) 2 . REPORT...Signatures During Darkness ....................... 1 ) 1 4.1.4 Signatures at Dawn and Dusk ..................... 155 4.2 Case 2 : Polarimetric MWIR...234 A.4 Blackbody Radiation ........ .......................... 2 :35 B. Electro-Optic Sensors .................................. 237 B. 1

  19. Ultrasensitive Silicon Photonic-Crystal Nanobeam Electro-Optical Modulator (Preprint)

    DTIC Science & Technology

    2013-10-01

    material is seamlessly and monolithically integrated into the NB. This results in a device that is easier to manufacture and is more CMOS-compatible...nanowire waveguide and resonator are seamlessly integrated via a high-transmission tapered 1D photonic crystal cavity waveguide structure. 15. SUBJECT...insulator (SOI) electro-optical modulator. The nanowire waveguide and resonator are seamlessly integrated via a high-transmission tapered 1D photonic

  20. Electro-optic Michelson Gires Tournois modulator for optical information processing and optical fiber communications.

    PubMed

    Yang, M; Gu, C; Hong, J

    1999-09-01

    We propose and demonstrate an electro-optic modulator based on a Michelson interferometer with a Gires-Tournois etalon (GTE, or asymmetric Fabry-Perot etalon) in one of the two arms. The insertion of a GTE significantly reduces the required interaction length or the operation voltage. Our experimental and theoretical results agree well. An extension of our setup to a waveguide configuration can lead to practical modulators and switches with greater compactness and reduced operation voltage for optical fiber communications.

  1. Single-Grid-Pair Fourier Telescope for Imaging in Hard-X Rays and gamma Rays

    NASA Technical Reports Server (NTRS)

    Campbell, Jonathan

    2008-01-01

    This instrument, a proposed Fourier telescope for imaging in hard-x rays and gamma rays, would contain only one pair of grids made of an appropriate radiation-absorpting/ scattering material, in contradistinction to multiple pairs of such as grids in prior Fourier x- and gamma-ray telescopes. This instrument would also include a relatively coarse gridlike image detector appropriate to the radiant flux to be imaged. Notwithstanding the smaller number of grids and the relative coarseness of the imaging detector, the images produced by the proposed instrument would be of higher quality.

  2. Compact imaging spectrometer combining Fourier transform spectroscopy with a Fabry-Perot interferometer.

    PubMed

    Pisani, Marco; Zucco, Massimo

    2009-05-11

    An imaging spectrometer based on a Fabry-Perot interferometer is presented. The Fabry-Perot interferometer scans the mirror distance up to contact and the intensity modulated light signal is transformed using a Fourier Transform based algorithm, as the Michelson based Fourier Transform Spectrometers does. The resulting instrument has the advantage of a compact, high numerical aperture, high luminosity hyperspectral imaging device. Theory of operation is described along with one experimental realization and preliminary results.

  3. Graphene electro-optic modulator with 30 GHz bandwidth

    NASA Astrophysics Data System (ADS)

    Phare, Christopher T.; Daniel Lee, Yoon-Ho; Cardenas, Jaime; Lipson, Michal

    2015-08-01

    Graphene has generated exceptional interest as an optoelectronic material because its high carrier mobility and broadband absorption promise to make extremely fast and broadband electro-optic devices possible. Electro-optic graphene modulators previously reported, however, have been limited in bandwidth to a few gigahertz because of the large capacitance required to achieve reasonable voltage swings. Here, we demonstrate a graphene electro-optic modulator based on resonator loss modulation at critical coupling that shows drastically increased speed and efficiency. Our device operates with a 30 GHz bandwidth and with a state-of-the-art modulation efficiency of 15 dB per 10 V. We also show the first high-speed large-signal operation in a graphene modulator, paving the way for fast digital communications using this platform. The modulator uniquely uses silicon nitride waveguides, an otherwise completely passive material platform, with promising applications for ultra-low-loss broadband structures and nonlinear optics.

  4. Electrical and electro-optical investigations of liquid crystal cells containing WO3 thin films

    NASA Astrophysics Data System (ADS)

    Strangi, G.; Cazzanelli, E.; Scaramuzza, N.; Versace, C.; Bartolino, R.

    2000-08-01

    An interesting application of the fast ion transport properties of tungsten trioxide is presented, when it is inserted as an electrode in nematic liquid crystal (NLC) cells. In a standard sandwichlike cell the nematic liquid crystal, confined between two transparent plane electrodes of purely electronic conductors [indium tin oxide (ITO)], undergoes a molecular reorientation under the action of an external electric field E. This electrically controlled birefringence (electro-optical switching) is proportional to E2, thus polarity insensitive [L. M. Blinov and V. G. Chigrinov, Electrooptic Effects in Liquid Crystal Materials (Springer-Verlag, New York, 1994)]. When a thin film of tungsten trioxide is deposited by magnetron sputtering onto one of the transparent ITO electrodes, and a NLC cell is assembled with such asymmetry, the electro-optical response becomes polarity sensitive [G. Strangi et al., Appl. Phys. Lett. 74, 534 (1999)]. The analysis of this response suggests the occurrence of a reverse internal electric field, associated with the ionic diffusion process of protons always present in these sputtered WO3 films [E. Cazzanelli et al., Electrochim. Acta 44, 3101 (1999)]. By using an opportune voltage waveform it is possible to evaluate such an internal field. Impedance and cyclic voltammetry measurements were carried out on these cells, comparing ``as-deposited'' and ``annealed'' tungsten trioxide electrodes. These studies confirm that an important ionic diffusion process is involved in the establishment of an internal electric field, which modifies the electro-optical response of the nematic liquid crystal cell.

  5. Electro-optic architecture (EOA) for sensors and actuators in aircraft propulsion systems

    NASA Technical Reports Server (NTRS)

    Glomb, W. L., Jr.

    1989-01-01

    Results of a study to design an optimal architecture for electro-optical sensing and control in advanced aircraft and space systems are described. The propulsion full authority digital Electronic Engine Control (EEC) was the focus for the study. The recommended architecture is an on-engine EEC which contains electro-optic interface circuits for fiber-optic sensors on the engine. Size and weight are reduced by multiplexing arrays of functionally similar sensors on a pair of optical fibers to common electro-optical interfaces. The architecture contains common, multiplex interfaces to seven sensor groups: (1) self luminous sensors; (2) high temperatures; (3) low temperatures; (4) speeds and flows; (5) vibration; (6) pressures; and (7) mechanical positions. Nine distinct fiber-optic sensor types were found to provide these sensing functions: (1) continuous wave (CW) intensity modulators; (2) time division multiplexing (TDM) digital optic codeplates; (3) time division multiplexing (TDM) analog self-referenced sensors; (4) wavelength division multiplexing (WDM) digital optic code plates; (5) wavelength division multiplexing (WDM) analog self-referenced intensity modulators; (6) analog optical spectral shifters; (7) self-luminous bodies; (8) coherent optical interferometers; and (9) remote electrical sensors. The report includes the results of a trade study including engine sensor requirements, environment, the basic sensor types, and relevant evaluation criteria. These figures of merit for the candidate interface types were calculated from the data supplied by leading manufacturers of fiber-optic sensors.

  6. Noninvasive prediction of SAR distributions with an electro-optical E field sensor.

    PubMed

    Wust, P; Meier, T; Seebass, M; Fähling, H; Petermann, K; Felix, R

    1995-01-01

    An integrated electro-optical (eo) E field sensor is developed on the basis of a Ti:LiNbO3 Mach-Zehnder interferometer. A measuring device based on the lock-in principle is introduced to register the E field in phase and amplitude using this E field probe. Segmented electrodes are used to minimize influences from the dielectric surroundings on the base point capacitance of the receiving dipole. The operating point is stabilized against drift phenomena resulting from optical damage and pyroelectric effect. Sensitivity, dynamic range, harmonic distortions and mechanical properties of a prototype of this electro-optical E field sensor are evaluated. A phantom setup in the SIGMA-60 applicator was developed to test this electro-optical sensor for hyperthermia applications. Power deposition patterns of various standard adjustments of the SIGMA ring are visualized in an elliptical lamp phantom. Simultaneously, E field in phase and amplitude is determined on a closed curve in 10 degrees steps around the phantom in a substitute bolus. The numbers are stored and utilized as boundary conditions in a two-dimensional finite elements code which calculates the SAR distribution on an appropriate triangular grid inside the closed curve. An excellent qualitative agreement is obtained between visualized and calculated SAR patterns. This novel measurement method is therefore suitable for noninvasive monitoring of SAR patterns during clinical application of regional radiofrequency hyperthermia.

  7. Externally-Modulated Electro-Optically Coupled Detector Architecture for Nuclear Physics Instrumentation

    SciTech Connect

    Xi, Wenze; McKisson, John E.; Weisenberger, Andrew G.; Zhang, Shukui; Zorn, Carl J.

    2014-06-01

    A new laser-based externally-modulated electro-optically coupled detector (EOCD) architecture is being developed to enable high-density readout for radiation detectors with accurate analog radiation pulse shape and timing preservation. Unlike digital conversion before electro-optical modulation, the EOCD implements complete analog optical signal modulation and multiplexing in its detector front-end. The result is a compact, high performance detector readout that can be both radiation tolerant and immune to magnetic fields. In this work, the feasibility of EOCD was explored by constructing a two-wavelength laser-based externally-modulated EOCD, and testing analog pulse shape preservation and wavelength-division multiplexing (WDM) crosstalk. Comparisons were first made between the corresponding initial pulses and the electro-optically coupled analog pulses. This confirmed an excellent analog pulse preservation over $ sim {hbox {29}}% $ of the modulator’s switching voltage range. Optical spectrum analysis revealed less than $-{hbox {14}}~hbox{dB}$ crosstalk with 1.2 nm WDM wavelength bandgap, and provided insight on experimental conditions that could lead to increased inter-wavelength crosstalk. Further discussions and previous research on the radiation tolerance and magnetic field immunity of the candidate materials were also given, and quantitative device testing is proposed in the future.

  8. High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate

    NASA Astrophysics Data System (ADS)

    Witmer, Jeremy D.; Valery, Joseph A.; Arrangoiz-Arriola, Patricio; Sarabalis, Christopher J.; Hill, Jeff T.; Safavi-Naeini, Amir H.

    2017-04-01

    Future quantum networks, in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality (Q) factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical Q factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices.

  9. High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate

    PubMed Central

    Witmer, Jeremy D.; Valery, Joseph A.; Arrangoiz-Arriola, Patricio; Sarabalis, Christopher J.; Hill, Jeff T.; Safavi-Naeini, Amir H.

    2017-01-01

    Future quantum networks, in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality (Q) factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical Q factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices. PMID:28406177

  10. Midinfrared Electro-optic Modulation in Few-Layer Black Phosphorus.

    PubMed

    Peng, Ruoming; Khaliji, Kaveh; Youngblood, Nathan; Grassi, Roberto; Low, Tony; Li, Mo

    2017-10-11

    Black phosphorus stands out from the family of two-dimensional materials as a semiconductor with a direct, layer-dependent bandgap spanning the visible to mid-infrared (mid-IR) spectral range. It is, therefore, a very promising material for various optoelectronic applications, particularly in the important mid-IR range. While mid-IR technology has been advancing rapidly, both photodetection and electro-optic modulation in the mid-IR rely on narrow-band compound semiconductors, which are difficult and expensive to integrate with the ubiquitous silicon photonics. For mid-IR photodetection, black phosphorus has already been proven to be a viable alternative. Here, we demonstrate electro-optic modulation of mid-IR absorption in few-layer black phosphorus. Our experimental and theoretical results find that, within the doping range obtainable in our samples, the quantum confined Franz-Keldysh effect is the dominant mechanism of electro-optic modulation. A spectroscopic study on samples with varying thicknesses reveals strong layer dependence in the interband transition between specific pairs of sub-bands. Our results show that black phosphorus is a very promising material to realizing efficient mid-IR modulators.

  11. The synthesis of branched TCP chromophores and the research on their electro-optical properties

    NASA Astrophysics Data System (ADS)

    Bo, Shuhui; Chen, Zhuo; Gao, Wu; Zhen, Zhen; Liu, Xinhou

    2012-10-01

    In order to minimize the intermolecular electrostatic interactions and effectively translate high value of chromophore into macroscopic electro-optical (EO) coeffcient (r33), the shape-modification of aniline-pyrroline (TCP) chromophore by combining three kinds of dendritic groups respectively to the N atom of pyrroline acceptor produced three kinds of dendritic chromophores. Their spherical structures can minimize intermolecular electrostatic interactions, and thus the poling efficience was higher than the chromophores without dendritic groups when chromophores as a guest in the host polymer APC. A large electro-optical (EO) coefficient was achieved as high as 75 pm/V at 1315 nm with 9% chromophores loading in APC film. On the basis of the above TCP chromophores, two kinds of novel molecular glasses based on self-assembly dendritic chromophores are also designed and synthesized as second-order nonlinear optical (NLO) materials, which named ETO and ETF. The NLO chromophore glasses ETO and ETF showed excellent filmforming ability by themselves. Their glass transition temperatures (Tg) were determined at 41° and 39°, respectively. The in-situ second harmonic generation (SHG) measurement revealed the resonant electro-optical (EO) coefficient (d33) values of 38 and 32 pm/V for the poled films of ETO and ETF, respectively. The results indicate molecular glasses provide a new possible way different from the conventional polymer approach to prepare second-order NLO materials.

  12. New electro-optic laser scanners for small-sat to ground laser communication links

    NASA Astrophysics Data System (ADS)

    Davis, Scott R.; Johnson, Seth T.; Rommel, Scott D.; Anderson, Michael H.; Chen, Jimmy; Chao, Tien-Hsin

    2013-05-01

    In this paper we present new electro-optic beam steering technology and propose to combine it with optical telecommunication technology, thereby enabling low cost, compact, and rugged free space optical (FSO) communication modules for small-sat applications. Small satellite applications, particularly those characterized as "micro-sats" are often highly constrained by their ability to provide high bandwidth science data to the ground. This will often limit the relevance of even highly capable payloads due to the lack of data availability. FSO modules with unprecedented cost and size, weight, and power (SWaP) advantages will enable multi-access FSO networks to spread across previously inaccessible platforms. An example system would fit within a few cubic inch volume, require less than 1 watt of power and be able to provide ground station tracking (including orbital motion over wide angles and jitter correction) with a 50 to 100 Mbps downlink and no moving parts. This is possible, for the first time, because of emergent and unprecedented electro-optic (EO) laser scanners which will replace expensive, heavy, and power-consuming gimbal mechanisms. In this paper we will describe the design, construction, and performance of these new scanners. Specific examples to be discussed include an all electro-optic beamsteer with a 60 degree by 40 degree field of view. We will also present designs for a cube-sat to ground flight demonstration. This development would provide a significant enhancement in capabilities for future NASA and other Government and industry space projects.

  13. Cavity quantum electro-optics. II. Input-output relations between traveling optical and microwave fields

    NASA Astrophysics Data System (ADS)

    Tsang, Mankei

    2011-10-01

    In a previous paper [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.81.063837 81, 063837 (2010)], I proposed a quantum model of the cavity electro-optic modulator, which can coherently couple an optical cavity mode to a microwave resonator mode and enable quantum operations on the two modes, including laser cooling of the microwave resonator, electro-optic entanglement, and backaction-evading optical measurement of a microwave quadrature. In this sequel, I focus on the quantum input-output relations between traveling optical and microwave fields coupled to the cavity electro-optic modulator. With red-sideband optical pumping, the relations are shown to resemble those of a beam splitter for the traveling fields, so that in the ideal case of zero parasitic loss and critical coupling, microwave photons can be coherently up converted to “flying” optical photons with unit efficiency, and vice versa. With blue-sideband pumping, the modulator acts as a nondegenerate parametric amplifier, which can generate two-mode squeezing and hybrid entangled photon pairs at optical and microwave frequencies. These fundamental operations provide a potential bridge between circuit quantum electrodynamics and quantum optics.

  14. High-Q photonic resonators and electro-optic coupling using silicon-on-lithium-niobate.

    PubMed

    Witmer, Jeremy D; Valery, Joseph A; Arrangoiz-Arriola, Patricio; Sarabalis, Christopher J; Hill, Jeff T; Safavi-Naeini, Amir H

    2017-04-13

    Future quantum networks, in which superconducting quantum processors are connected via optical links, will require microwave-to-optical photon converters that preserve entanglement. A doubly-resonant electro-optic modulator (EOM) is a promising platform to realize this conversion. Here, we present our progress towards building such a modulator by demonstrating the optically-resonant half of the device. We demonstrate high quality (Q) factor ring, disk and photonic crystal resonators using a hybrid silicon-on-lithium-niobate material system. Optical Q factors up to 730,000 are achieved, corresponding to propagation loss of 0.8 dB/cm. We also use the electro-optic effect to modulate the resonance frequency of a photonic crystal cavity, achieving a electro-optic modulation coefficient between 1 and 2 pm/V. In addition to quantum technology, we expect that our results will be useful both in traditional silicon photonics applications and in high-sensitivity acousto-optic devices.

  15. Electro-optic voltage sensor for sensing voltage in an E-field

    DOEpatents

    Woods, Gregory K.; Renak, Todd W.

    1999-01-01

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  16. Electro-optic voltage sensor for sensing voltage in an E-field

    DOEpatents

    Woods, G.K.; Renak, T.W.

    1999-04-06

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages is disclosed. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam`s polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured. 18 figs.

  17. Large electro-optic coefficient in single-crystal film of a novel organic salt, DASMS

    NASA Astrophysics Data System (ADS)

    Tan, Shida; Ahyi, Ayayi; Mishra, Alpana; Thakur, Mrinal

    2001-03-01

    We have synthesized a novel electro-optic material 4'-dimethylamino-4-methylstilbazolium methanesulfonate (DASMS). Large-area ( 60 mm^2), single-crystal films of DASMS with excellent optical quality have been grown for the first time by a modified shear method^1. These films have the noncentrosymmetric hydrated phase, which is electro-optically active^2. Polarized optical microscopy, X-ray diffraction and polarized UV-visible spectroscopic studies have been used to characterize the films. The single-crystal films were observed to be highly dichroic. Using field-induced birefringence measurement, the electro-optic coefficient of DASMS at 632.8 nm has been estimated to be r_11 160 pm/V, which is five times larger than the eletro-optic coefficient of LiNbO_3. For a 1.8 μm thick film, 28% intensity modulation was observed for an electric field of 4 V/μm. 1. M. Thakur and S. Meyler, Macromolecules 18, 2341 (1985); M. Thakur, Y. Shani, G. C. Chi, and K. O'Brien, Synth. Met. 28, D595 (1989). 2. E. P. Boden, P. D. Phelps, C. P. Yakymyshyn, and K. R. Stewart, US patent 5,194,584.

  18. Ultrahigh Q whispering gallery mode electro-optic resonators on a silicon photonic chip.

    PubMed

    Soltani, Mohammad; Ilchenko, Vladimir; Matsko, Andrey; Savchenkov, Anatoliy; Schlafer, John; Ryan, Colm; Maleki, Lute

    2016-09-15

    Crystalline whispering gallery mode (WGM) electro-optic resonators made of LiNbO3 and LiTaO3 are critical for a wide range of applications in nonlinear and quantum optics, as well as RF photonics, due to their remarkably ultrahigh Q(>108) and large electro-optic coefficient. Achieving efficient coupling of these resonators to planar on-chip optical waveguides is essential for any high-yield and robust practical applications. However, it has been very challenging to demonstrate such coupling while preserving the ultrahigh Q properties of the resonators. Here, we show how the silicon photonic platform can overcome this long-standing challenge. Silicon waveguides with appropriate designs enable efficient and strong coupling to these WGM electro-optic resonators. We discuss various integration architectures of these resonators onto a silicon chip and experimentally demonstrate critical coupling of a planar Si waveguide and an ultrahigh QLiTaO3 resonator (Q∼108). Our results show a promising path for widespread and practical applications of these resonators on a silicon photonic platform.

  19. Cavity quantum electro-optics. II. Input-output relations between traveling optical and microwave fields

    SciTech Connect

    Tsang, Mankei

    2011-10-15

    In a previous paper [Phys. Rev. A 81, 063837 (2010)], I proposed a quantum model of the cavity electro-optic modulator, which can coherently couple an optical cavity mode to a microwave resonator mode and enable quantum operations on the two modes, including laser cooling of the microwave resonator, electro-optic entanglement, and backaction-evading optical measurement of a microwave quadrature. In this sequel, I focus on the quantum input-output relations between traveling optical and microwave fields coupled to the cavity electro-optic modulator. With red-sideband optical pumping, the relations are shown to resemble those of a beam splitter for the traveling fields, so that in the ideal case of zero parasitic loss and critical coupling, microwave photons can be coherently up converted to ''flying'' optical photons with unit efficiency, and vice versa. With blue-sideband pumping, the modulator acts as a nondegenerate parametric amplifier, which can generate two-mode squeezing and hybrid entangled photon pairs at optical and microwave frequencies. These fundamental operations provide a potential bridge between circuit quantum electrodynamics and quantum optics.

  20. Optical modulation techniques for analog signal processing and CMOS compatible electro-optic modulation

    NASA Astrophysics Data System (ADS)

    Gill, Douglas M.; Rasras, Mahmoud; Tu, Kun-Yii; Chen, Young-Kai; White, Alice E.; Patel, Sanjay S.; Carothers, Daniel; Pomerene, Andrew; Kamocsai, Robert; Beattie, James; Kopa, Anthony; Apsel, Alyssa; Beals, Mark; Mitchel, Jurgen; Liu, Jifeng; Kimerling, Lionel C.

    2008-02-01

    Integrating electronic and photonic functions onto a single silicon-based chip using techniques compatible with mass-production CMOS electronics will enable new design paradigms for existing system architectures and open new opportunities for electro-optic applications with the potential to dramatically change the management, cost, footprint, weight, and power consumption of today's communication systems. While broadband analog system applications represent a smaller volume market than that for digital data transmission, there are significant deployments of analog electro-optic systems for commercial and military applications. Broadband linear modulation is a critical building block in optical analog signal processing and also could have significant applications in digital communication systems. Recently, broadband electro-optic modulators on a silicon platform have been demonstrated based on the plasma dispersion effect. The use of the plasma dispersion effect within a CMOS compatible waveguide creates new challenges and opportunities for analog signal processing since the index and propagation loss change within the waveguide during modulation. We will review the current status of silicon-based electrooptic modulators and also linearization techniques for optical modulation.

  1. Electro-optical polarimeters for ground-based and space-based observations of the solar K-corona

    NASA Astrophysics Data System (ADS)

    Capobianco, G.; Fineschi, S.; Massone, G.; Balboni, E.; Malvezzi, A. M.; Crescenzio, G.; Zangrilli, L.; Calcidese, P.; Antonucci, E.; Patrini, M.

    2012-09-01

    Polarimeters based on electro-optically tunable liquid crystals (LC) represent a new technology in the field of observational astrophysics. LC-based polarimeters are good candidates for replacing mechanically rotating polarimeters in most ground-based and space-based applications. During the 2006 total solar eclipse, we measured the visible-light polarized brightness (pB) of the solar K-corona with a LC-based polarimeter and imager (E-KPol). In this presentation, we describe the results obtained with the E-KPol, and we evaluate its performances in view of using a similar device for the pB imaging of the K-corona from space-based coronagraphs. Specifically, a broad-band LC polarimeter is planned for the METIS (Multi Element Telescope for Imaging and Spectroscopy) coronagraph for the Solar Orbiter mission to be launched in 2017. The METIS science driver of deriving the coronal electron density from pB images requires an accuracy of better than 1% in the measurement of linear polarization. We present the implications of this requirement on the METIS design to minimize the instrumental polarization of the broad-band visible-light (590-650 nm) polarimeter and of the other optics in the METIS visible-light path. Finally, we report preliminary ellipsometric measurements of the optical components of the METIS visible-light path.

  2. Fourier domain image fusion for differential X-ray phase-contrast breast imaging.

    PubMed

    Coello, Eduardo; Sperl, Jonathan I; Bequé, Dirk; Benz, Tobias; Scherer, Kai; Herzen, Julia; Sztrókay-Gaul, Anikó; Hellerhoff, Karin; Pfeiffer, Franz; Cozzini, Cristina; Grandl, Susanne

    2017-04-01

    X-Ray Phase-Contrast (XPC) imaging is a novel technology with a great potential for applications in clinical practice, with breast imaging being of special interest. This work introduces an intuitive methodology to combine and visualize relevant diagnostic features, present in the X-ray attenuation, phase shift and scattering information retrieved in XPC imaging, using a Fourier domain fusion algorithm. The method allows to present complementary information from the three acquired signals in one single image, minimizing the noise component and maintaining visual similarity to a conventional X-ray image, but with noticeable enhancement in diagnostic features, details and resolution. Radiologists experienced in mammography applied the image fusion method to XPC measurements of mastectomy samples and evaluated the feature content of each input and the fused image. This assessment validated that the combination of all the relevant diagnostic features, contained in the XPC images, was present in the fused image as well. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Multi-modal Color Medical Image Fusion Using Quaternion Discrete Fourier Transform

    NASA Astrophysics Data System (ADS)

    Nawaz, Qamar; Xiao, Bin; Hamid, Isma; Jiao, Du

    2016-12-01

    Multimodal image fusion is a process of combining multiple images, generated by identical or diverse imaging modalities, to get precise inside information about the same body organ. In recent years, various multimodal image fusion algorithms have been proposed to fuse medical image. However, most of them focus on fusing grayscale images. This paper proposes a novel algorithm for the fusion of multimodal color medical images. The proposed algorithm divides source images into blocks, converts each RGB block into quaternion representation and transforms them from special domain to frequency domain by applying quaternion discrete Fourier transform. The fused coefficients are obtained by calculating and comparing contrast values of corresponding coefficients in transformed blocks. The resultant fused image is reconstructed by merging all the blocks after applying inverse quaternion discrete Fourier transform on each block. Experimental evaluation demonstrates that the proposed algorithm qualitatively outperforms many existing state-of-the-art multimodal image fusion algorithms.

  4. A generalized Fourier penalty in prior-image-based reconstruction for cross-platform imaging

    NASA Astrophysics Data System (ADS)

    Pourmorteza, A.; Siewerdsen, J. H.; Stayman, J. W.

    2016-03-01

    Sequential CT studies present an excellent opportunity to apply prior-image-based reconstruction (PIBR) methods that leverage high-fidelity prior imaging studies to improve image quality and/or reduce x-ray exposure in subsequent studies. One major obstacle in using PIBR is that the initial and subsequent studies are often performed on different scanners (e.g. diagnostic CT followed by CBCT for interventional guidance); this results in mismatch in attenuation values due to hardware and software differences. While improved artifact correction techniques can potentially mitigate such differences, the correction is often incomplete. Here, we present an alternate strategy where the PIBR itself is used to mitigate these differences. We define a new penalty for the previously introduced PIBR called Reconstruction of Difference (RoD). RoD differs from many other PIBRs in that it reconstructs only changes in the anatomy (vs. reconstructing the current anatomy). Direct regularization of the difference image in RoD provides an opportunity to selectively penalize spatial frequencies of the difference image (e.g. low frequency differences associated with attenuation offsets and shading artifacts) without interfering with the variations in unchanged background image. We leverage this flexibility and introduce a novel regularization strategy using a generalized Fourier penalty within the RoD framework and develop the modified reconstruction algorithm. We evaluate the performance of the new approach in both simulation studies and in physical CBCT test-bench data. We find that generalized Fourier penalty can be highly effective in reducing low-frequency x-ray artifacts through selective suppression of spatial frequencies in the reconstructed difference image.

  5. Remote ballistic emplacement of an electro-optical and acoustic target detection and localization system

    NASA Astrophysics Data System (ADS)

    West, Aaron; Mellini, Mark

    2015-05-01

    Near real time situational awareness in uncontrolled non line of sight (NLOS) and beyond line of sight (BLOS) environments is critical in the asymmetric battlefield of future conflicts. The ability to detect and accurately locate hostile forces in difficult terrain or urban environments can dramatically increase the survivability and effectiveness of dismounted soldiers, especially when they are limited to the resources available only to the small unit. The Sensor Mortar Network (SMortarNet) is a 60mm Intelligence, Surveillance, and Reconnaissance (ISR) mortar designed to give the Squad near real time situational awareness in uncontrolled NLOS environments. SMortarNet is designed to track targets both acoustically and electro optically and can fuse tracks between, the acoustic, EO, and magnetic modalities on board. The system is linked to other mortar nodes and the user via a masterless frequency hopping spread spectrum ad-hoc mesh radio network. This paper will discuss SMortarNet in the context of a squad level dismounted soldier, its technical capabilities, and its benefit to the small unit Warfighter. The challenges with ballistic remote emplacement of sensitive components and the on board signal processing capabilities of the system will also be covered. The paper will also address how the sensor network can be integrated with existing soldier infrastructure, such as the NettWarrior platform, for rapid transition to soldier systems. Networks of low power sensors can have many forms, but the more practical networks for warfighters are ad hoc radio-based systems that can be rapidly deployed and can leverage a range of assets available at a given time. The low power long life networks typically have limited bandwidth and may have unreliable communication depending on the network health, which makes autonomous sensors a critical component of the network. SMortarNet reduces data to key information features at the sensor itself. The smart sensing approach enables

  6. The Image Registration of Fourier-Mellin Based on the Combination of Projection and Gradient Preprocessing

    NASA Astrophysics Data System (ADS)

    Gao, D.; Zhao, X.; Pan, X.

    2017-09-01

    Image registration is one of the most important applications in the field of image processing. The method of Fourier Merlin transform, which has the advantages of high precision and good robustness to change in light and shade, partial blocking, noise influence and so on, is widely used. However, not only this method can't obtain the unique mutual power pulse function for non-parallel image pairs, even part of image pairs also can't get the mutual power function pulse. In this paper, an image registration method based on Fourier-Mellin transformation in the view of projection-gradient preprocessing is proposed. According to the projection conformational equation, the method calculates the matrix of image projection transformation to correct the tilt image; then, gradient preprocessing and Fourier-Mellin transformation are performed on the corrected image to obtain the registration parameters. Eventually, the experiment results show that the method makes the image registration of Fourier-Mellin transformation not only applicable to the registration of the parallel image pairs, but also to the registration of non-parallel image pairs. What's more, the better registration effect can be obtained

  7. Improving electro-optic window reliability with DIACER coatings

    NASA Astrophysics Data System (ADS)

    Carasso, M. L.; Adair, J. H.; Demkowicz, P. A.; Gilbert, D. G.; Singh, Rajiv K.

    1997-06-01

    Most commercial diamond synthesis processes involve some form of chemical vapor deposition (CVD) which results in heterogeneous nucleation on the surface of window or dome materials. Generally, these processes have relatively long deposition times driven by the slow CVD kinetics. An alternate method called DIACERTM uses an aqueous seed crystal dispersion applied to the window substrates prior to CVD. These seed crystals reduce nucleation times and speed CVD deposition rates. Thicker coatings can be produced by repeating the seeding/CVD cycle until the required thickness is achieved. This paper reviews DIACERTM coating results on silicon substrates. Scanning electron microscopy and atomic force microscopy images of images of the coatings are presented. IR transmission results are presented both before and after sand and rain erosion exposures. The results of this testing will show DICERTM coatings to durable for the protection of silicon substrates after exposure to severe sand environments.

  8. Modeling of woven fabric structures based on fourier image analysis.

    PubMed

    Escofet, J; Millán, M S; Ralló, M

    2001-12-01

    The periodic woven structures of fabrics can be defined on the basis of the convolution theorem. Here an elementary unit with the minimum number of thread crossings and a nonrectangular two-dimensional comb function for the pattern of repetition is used to define woven structures. The expression derived is more compact than the conventional diagram for weaving, and the parameters that one needs to determine a given fabric can easily be extracted from its Fourier transform. Several results with real samples of the most common structures-plain, twill, and satin-are presented.

  9. Emerging electro-optical technologies for defense applications

    NASA Astrophysics Data System (ADS)

    Venkateswarlu, Ronda; Ser, W.; Er, Meng H.; Chan, Philip

    1999-11-01

    Technological breakthroughs in the field of imaging and non- imaging sensor sand the related signal processors helped the military users to achieve 'force multiplication'. Present day 'smart-weapon systems' are being converted to 'brilliant-weapon systems' to bridge the gap until the most potent new 'fourth generation systems' come on line based on nanotechnology. The recent military tactics have evolved to take advantage of ever improving technologies to improve the quality and performance over time. The drive behind these technologies is to get a first-pass-mission-success against the target with negligible collateral damage, protecting property and the lives of non-combatants. These technologies revolve around getting target information, detection, designation, guidance, aim-point selection, and mission accomplishment. The effectiveness of these technologies is amply demonstrated during recent wars. This paper brings out the emerging trends in visible/IR/radar smart-sensors and the related signal processing technologies that lead to brilliant guided weapon systems. The purpose of this paper is to give an overview to the readers about futuristic systems. This paper also addresses various system configurations including sensor-fusion.

  10. Image authentication based on double-image encryption and partial phase decryption in nonseparable fractional Fourier domain

    NASA Astrophysics Data System (ADS)

    Yuan, Lin; Ran, Qiwen; Zhao, Tieyu

    2017-02-01

    In this paper an image authentication scheme is proposed based on double-image encryption and partial phase decryption in nonseparable Fractional Fourier transform domain. Two original images are combined and transformed into the nonseparable fractional Fourier domain. Only part of the phase information of the encrypted result is kept for decryption while the rest part of phase and all the amplitude information are discarded. The two recovered images are hardly recognized by visual inspection but can be authenticated by the nonlinear correlation algorithm. The numerical simulations demonstrate the viability and validity of the proposed image authentication scheme.

  11. Imaging Organ of Corti Vibration Using Fourier-Domain OCT

    NASA Astrophysics Data System (ADS)

    Choudhury, Niloy; Chen, Fangyi; Fridberger, Anders; Zha, Dingjun; Jacques, Steven L.; Wang, Ruikang K.; Nuttall, Alfred L.

    2011-11-01

    Measuring the sound stimulated vibration from various structures in the organ of Corti is important in understanding how the small vibrations are amplified and detected. In this study we examine the feasibility of using phase-sensitive Fourier domain optical coherence tomography (PSFD-OCT) to measure vibration of the cellular structures of the organ of Corti. PSFD-OCT is a low coherence interferrometry system where the interferrogram is detected as a function of wavelength. The phase of the Fourier transformation of the detected spectra contains path deference (between the sample arm and the reference arm) information of the interferometer. In PSFD-OCT this phase is measured as a function of time and thus any time dependent change in the path difference between the sample arm and the reference arm can be detected. In the experiment, we used an in vitro preparation of the guinea pig cochlea and made a surgical opening at the apical end to access the organ of Corti. By applying tones with different frequencies via the intact middle ear, we recorded the structural vibration inside the organ of Corti. Vibration amplitude and phase of different substructures were mapped on a cross-section view of the organ of Corti. Although the measurements were made at the apical turn of the cochlea, it will be possible to make vibration measurement from various turns of the cochlea. The noise floor of the system was 0.3 nm, calibrated using a piezo stack as a calibrator.

  12. The Bulk Density of Meteoroids from Electro-Optical Measurements

    NASA Astrophysics Data System (ADS)

    Kikwaya-Eluo, J.-B.; Brown, P.; Hawkes, R. L.

    2004-11-01

    The mean bulk density of small meteoroids remains a poorly measured quantity. Based on photographic observations of large (gram-sized) meteoroids and the theory of quasi-continuous fragmentation Lebedinets (1987) and Babadzhanov (1994) estimated the average bulk density of meteoroids to be near 3300kg m-3, with values for individual meteoroids ranging from 100 and 8000 kg m-3. These high values are close to the density of solid-iron and stony meteorites and have been shown to contradict some of the assumptions of the quasi-continuous theory (Bellot Rubio et al., 2002). In contrast, application of the competing single body theory (i.e. the heating of the meteoroid occurs without intensive ablation) on 370 meteors with a magnitude range between +2.5 and -5 mag (McCrosky and Posen, 1961) by Bellot et al. (2002) found low values for the density of meteoroids in a similar mass range. For sporadic meteors, Bellot et al. (2002) found an average density of 800 kg m-3, while the density for individual meteoroids ranged from 100 to 4500 kg m-3. Here we report our attempt to measure the bulk density of smaller ( mg) meteoroids using the single body model applied to low-light-level tv (LLLTV) observations. Our data are gathered from two stations (separation 50 km). One station uses a digital, gated image intensifier coupled to a megapixel CCD detector, while the other station uses an image intensifier coupled to a video-rate CCD. The gated sensor permits high temporal snapshots (0.5 ms) of meteors which can then be combined with the LLLTV systems at the second site to define both the trajectory and velocity of the meteoroid to high precision. It is our goal to detect significant deceleration in a sample of both shower and sporadic meteors. Absence of significant wake in the gated images is used as a criterion to select those meteors for which fragmentation is not important and thus application of the single body model is most appropriate.

  13. Performance Modelling of Autonomous Electro-Optical Sensors

    DTIC Science & Technology

    1987-11-01

    results from the 5x5 images in DS4 were ignored. Also a check of the estimated means and variances of 8 between data sets DS1 , DS2, and DS3, and their...upon the significance level. For instance, in data set DS1 we-see that the M-estimate (M) performed better than Normalized residual outlier removal (N...Triples with levels > 0,3 are not shown. DS1 os2 0s3 DS4 s55 M C 0. 140 N C 0.010 M N 0.056 LS M 0037 M N 0.222 M N 0.096 N LS 0.000 M C 0.012 LS N

  14. A lightweight, rugged, solid state laser radar system enabled by non-mechanical electro-optic beam steerers

    NASA Astrophysics Data System (ADS)

    Davis, Scott R.; Rommel, Scott D.; Gann, Derek; Luey, Ben; Gamble, Joseph D.; Ziemkiewicz, Michael; Anderson, Mike

    2016-05-01

    There is currently a good deal of interest in developing laser radar (ladar) for autonomous navigation and collision avoidance in a wide variety of vehicles. In many of these applications, minimizing size, weight and power (SWaP) is of critical importance, particularly onboard aircraft and spacecraft where advanced imaging systems are also needed for location, alignment, and docking. In this paper, we describe the miniaturization of a powerful ladar system based on an electro-optic (EO) beamsteering device in which liquid crystal birefringence is exploited to achieve a 20° x 5° field of view (FOV) with no moving parts. This FOV will be significantly increased in future versions. In addition to scanning, the device is capable of operating in a "point and hold" mode where it locks onto a single moving object. The nonmechanical design leads to exceptionally favorable size and weight values: 1 L and < 1 kg respectively. Furthermore, these EO scanners operate without mechanical resonances or inertial effects. A demonstration was performed with a 50 kHz, 1 microjoule laser with a 2 mm beam diameter to image at a range of 100 m yielding a 2 fps frame rate limited by the pulse laser repetition rate. The fine control provided by the EO steerer results in an angle precision of 6x10-4 degrees. This FOV can be increased with discreet, non-mechanical polarization grating beamsteerers. In this paper, we will present the design, preliminary results, and planned next generation improvements.

  15. Fourier-domain digital holographic optical coherence imaging of living tissue.

    PubMed

    Jeong, Kwan; Turek, John J; Nolte, David D

    2007-08-01

    Digital holographic optical coherence imaging is a full-frame coherence-gated imaging approach that uses a CCD camera to record and reconstruct digital holograms from living tissue. Recording digital holograms at the optical Fourier plane has advantages for diffuse targets compared with Fresnel off-axis digital holography. A digital hologram captured at the Fourier plane requires only a 2D fast Fourier transform for numerical reconstruction. We have applied this technique for the depth-resolved imaging of rat osteogenic tumor multicellular spheroids and acquired cross-section images of the anterior segment and the retinal region of a mouse eye. A penetration depth of 1.4 mm for the tumor spheroids was achieved.

  16. Periodic artifact reduction in Fourier transforms of full field atomic resolution images.

    PubMed

    Hovden, Robert; Jiang, Yi; Xin, Huolin L; Kourkoutis, Lena F

    2015-04-01

    The discrete Fourier transform is among the most routine tools used in high-resolution scanning/transmission electron microscopy (S/TEM). However, when calculating a Fourier transform, periodic boundary conditions are imposed and sharp discontinuities between the edges of an image cause a cross patterned artifact along the reciprocal space axes. This artifact can interfere with the analysis of reciprocal lattice peaks of an atomic resolution image. Here we demonstrate that the recently developed Periodic Plus Smooth Decomposition technique provides a simple, efficient method for reliable removal of artifacts caused by edge discontinuities. In this method, edge artifacts are reduced by subtracting a smooth background that solves Poisson's equation with boundary conditions set by the image's edges. Unlike the traditional windowed Fourier transforms, Periodic Plus Smooth Decomposition maintains sharp reciprocal lattice peaks from the image's entire field of view.

  17. Electro-optical property of extremely stretched skinned muscle fibers.

    PubMed Central

    Umazume, Y; Fujime, S

    1975-01-01

    Skinned fibers of frog semitendinosus muscle could easily be stretched up to 8 mum or more in sarcomere length. Such extremely stretched fibers gave quite sharp optical diffraction patterns. The intensities of all observable diffraction lines were found to increase on application of electric field (10 similar to 100 V/cm) parallel to the fiber axis, provided that there was no overlap between thin and thick filaments. By use of a polarizing microscope, it was concluded that I-bands were mainly responsible for this intensity increase. By application of square pulses, the time course of the intensity increase and decay was followed. The analysis based on a simple model suggests: (a) Each thin filament has a permanent dipole movement and the movement directs from Z-bands to the free end of the thin filament. (b) The flexural rigidity of thin filaments is estimated to be similar to 3 with 10-17 dyn with cm-2. The present fibers will provide various applications in physiochemical studies of in vivo thin and thick filaments. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 8 FIGURE 9 FIGURE 10 PMID:1078630

  18. Creating an extended focus image of a tilted object in Fourier digital holography.

    PubMed

    Paturzo, Melania; Ferraro, Pietro

    2009-10-26

    We present a new method to numerically reconstruct images on a tilted plane by digital holography in Fourier configuration. The proposed technique is based on a quadratic deformation of spatial coordinates of the digital hologram. By this approach we demonstrate that it is possible to recover the extended focus image (EFI) of a tilted object in a single reconstruction step from the deformed hologram.

  19. Commissioning SITELLE: an imaging Fourier transform spectrometer for the Canada France Hawaii Telescope

    NASA Astrophysics Data System (ADS)

    Baril, Marc R.; Grandmont, Frédéric J.; Mandar, Julie; Drissen, Laurent; Martin, Thomas; Rousseau-Nepton, Laurie; Thibault, Simon; Brousseau, Denis; Levesque, Steve R.; Thomas, Jim; Malo, Lison; Morrison, Glenn; le Gal, Maëlle; Jones, Windell; Barrick, Gregory; Benedict, Tom; Salmon, Derrick; Prunet, Simon; Devost, Daniel

    2016-08-01

    The SITELLE Imaging Fourier Transform Spectrometer was successfully commissioned at the Canada France Hawaii Telescope starting in July 2015. Here we discuss the commissioning process, the outcome of the early tests on-sky as well as the ensuing work to optimize the modulation efficiency at large optical path difference and the image quality of the instrument.

  20. Fourier Power Spectrum Characteristics of Face Photographs: Attractiveness Perception Depends on Low-Level Image Properties

    PubMed Central

    Langner, Oliver; Wiese, Holger; Redies, Christoph

    2015-01-01

    We investigated whether low-level processed image properties that are shared by natural scenes and artworks – but not veridical face photographs – affect the perception of facial attractiveness and age. Specifically, we considered the slope of the radially averaged Fourier power spectrum in a log-log plot. This slope is a measure of the distribution of special frequency power in an image. Images of natural scenes and artworks possess – compared to face images – a relatively shallow slope (i.e., increased high spatial frequency power). Since aesthetic perception might be based on the efficient processing of images with natural scene statistics, we assumed that the perception of facial attractiveness might also be affected by these properties. We calculated Fourier slope and other beauty-associated measurements in face images and correlated them with ratings of attractiveness and age of the depicted persons (Study 1). We found that Fourier slope – in contrast to the other tested image properties – did not predict attractiveness ratings when we controlled for age. In Study 2A, we overlaid face images with random-phase patterns with different statistics. Patterns with a slope similar to those in natural scenes and artworks resulted in lower attractiveness and higher age ratings. In Studies 2B and 2C, we directly manipulated the Fourier slope of face images and found that images with shallower slopes were rated as more attractive. Additionally, attractiveness of unaltered faces was affected by the Fourier slope of a random-phase background (Study 3). Faces in front of backgrounds with statistics similar to natural scenes and faces were rated as more attractive. We conclude that facial attractiveness ratings are affected by specific image properties. An explanation might be the efficient coding hypothesis. PMID:25835539