Science.gov

Sample records for active optical systems

  1. Active optical zoom system

    DOEpatents

    Wick, David V.

    2005-12-20

    An active optical zoom system changes the magnification (or effective focal length) of an optical imaging system by utilizing two or more active optics in a conventional optical system. The system can create relatively large changes in system magnification with very small changes in the focal lengths of individual active elements by leveraging the optical power of the conventional optical elements (e.g., passive lenses and mirrors) surrounding the active optics. The active optics serve primarily as variable focal-length lenses or mirrors, although adding other aberrations enables increased utility. The active optics can either be LC SLMs, used in a transmissive optical zoom system, or DMs, used in a reflective optical zoom system. By appropriately designing the optical system, the variable focal-length lenses or mirrors can provide the flexibility necessary to change the overall system focal length (i.e., effective focal length), and therefore magnification, that is normally accomplished with mechanical motion in conventional zoom lenses. The active optics can provide additional flexibility by allowing magnification to occur anywhere within the FOV of the system, not just on-axis as in a conventional system.

  2. Experiment system of LAMOST active optics

    NASA Astrophysics Data System (ADS)

    Cui, Xiangqun; Su, Ding; Li, Guoping; Yao, Zhengqiu; Zhang, Zhengcao; Li, Yeping; Zhang, Yong; Wang, You; Xu, Xinqi; Wang, Hai

    2004-10-01

    Active optics is the most difficult part in LAMOST project. Especially for the segmented reflecting Schmidt plate Ma, in which both segmented mirror active optics and thin mirror (or deformable mirror) active optics are applied. To test and optimize the thin mirror active optics of Ma, and to approach the reality of operating environment of the telescope, an outdoor experiment system has been established. This experiment system is also a `small LAMOST" with one sub-mirror of the primary mirror Mb and one sub-mirror of the Schmidt plate Ma, and with full scale in spacing (40 meters) between Ma and Mb. many parts of LAMOST were tested in the experiment system except segmented mirror active optics. Especially for force actuators, thin mirror support system, friction driving of the alt-azimuth mounting and its control system, wave front test along such a long optical path. This paper presents the experiment system, research and developments, and some experiment results.

  3. LDEF active optical system components experiment

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1992-01-01

    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. Thermal, mechanical, and structural considerations leading to the design of the tray hardware are discussed. In general, changes in the retested component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials, multilayer optical interference filters, and extreme-infrared reflectivity of black paints show unexpected changes.

  4. LDEF active optical system components experiment

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1991-01-01

    A preliminary report on the Active Optical System Components Experiment is presented. This experiment contained 136 components in a six-inch deep tray including lasers, infrared detectors and arrays, ultraviolet light detectors, light-emitting diodes, a light modulator, flash lamps, optical filters, glasses, and samples of surface finishes. The experimental results for those component characteristics appear as much related to the passage of time as to the effects of the space environment, but organic materials and extreme-infrared reflectivity of black paints show unexpected changes.

  5. Optically Active Porphyrin and Phthalocyanine Systems.

    PubMed

    Lu, Hua; Kobayashi, Nagao

    2016-05-25

    This review highlights and summarizes various optically active porphyrin and phthalocyanine molecules prepared using a wide range of structural modification methods to improve the design of novel structures and their applications. The induced chirality of some illustrative achiral bis-porphyrins with a chiral guest molecule is introduced because these systems are ideal for the identification and separation of chiral biologically active substrates. In addition, the relationship between CD signal and the absolute configuration of the molecule is analyzed through an analysis of the results of molecular modeling calculations. Possible future research directions are also discussed. PMID:27186902

  6. Active polarimeter optical system laser hazard analysis.

    SciTech Connect

    Augustoni, Arnold L.

    2005-07-01

    A laser hazard analysis was performed for the SNL Active Polarimeter Optical System based on the ANSI Standard Z136.1-2000, American National Standard for Safe Use of Lasers and the ANSI Standard Z136.6-2000, American National Standard for Safe Use of Lasers Outdoors. The Active Polarimeter Optical System (APOS) uses a pulsed, near-infrared, chromium doped lithium strontium aluminum fluoride (Cr:LiSAF) crystal laser in conjunction with a holographic diffuser and lens to illuminate a scene of interest. The APOS is intended for outdoor operations. The system is mounted on a height adjustable platform (6 feet to 40 feet) and sits atop a tripod that points the beam downward. The beam can be pointed from nadir to as much as 60 degrees off of nadir producing an illuminating spot geometry that can vary from circular (at nadir) to elliptical in shape (off of nadir). The JP Innovations crystal Cr:LiSAF laser parameters are presented in section II. The illuminating laser spot size is variable and can be adjusted by adjusting the separation distance between the lens and the holographic diffuser. The system is adjusted while platform is at the lowest level. The laser spot is adjusted for a particular spot size at a particular distance (elevation) from the laser by adjusting the separation distance (d{sub diffuser}) to predetermined values. The downward pointing angle is also adjusted before the platform is raised to the selected operation elevation.

  7. Fault analysis and detection in large active optical systems

    NASA Astrophysics Data System (ADS)

    Cox, Charles D.; Furber, Mark E.; Jordan, David C.; Blaszak, David D.

    1995-05-01

    Active optical systems are complex systems that may be expected to operate in hostile environments such as space. The ability of such a system either to tolerate failures of components or to reconfigure to accommodate failed components could significantly increase the useful lifetime of the system. Active optical systems often contain hundreds of actuators and sensor channels but have an inherent redundancy, i.e., more actuators or sensor channels than the minimum needed to achieve the required performance. A failure detection and isolation system can be used to find and accommodate failures. One type of failure is the failure of an actuator. The effect of actuator failure on the ability of a deformable mirror to correct aberrations is analyzed using a finite-element model of the deformable mirror, and a general analytical procedure for determining the effect of actuator failures on system performance is given. The application of model-based failure detection, isolation and identification algorithms to active optical systems is outlined.

  8. Active phase compensation system for fiber optic holography

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.; Beheim, Glenn

    1989-01-01

    Fiber optic delivery systems promise to extend the application of holography to severe environments by simplifying test configurations and permitting the laser to be remotely placed in a more benign location. However, the introduction of optical fiber leads to phase stability problems. Environmental effects cause the pathlengths of the fibers to change randomly, preventing the formation of stationary interference patterns which are required for holography. An active phase control system has been designed and used with an all-fiber optical system to stabilize the phase difference between light emitted from two fibers, and to step the phase difference by 90 deg without applying any constraints on the placement of the fibers. The accuracy of the phase steps is shown to be better than 0.02 deg., and a stable phase difference can be maintained for 30 min. This system can be applied to both conventional and electro-optic holography, as well as to any system where the maintenance of an accurate phase difference between two coherent beams is required.

  9. Active phase compensation system for fiber optic holography

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.; Beheim, Glenn

    1988-01-01

    Fiber optic delivery systems promise to extend the application of holography to severe environments by simplifying test configurations and permitting the laser to be remotely placed in a more benign location. However, the introduction of optical fiber leads to phase stability problems. Environmental effects cause the pathlengths of the fibers to change randomly, preventing the formation of stationary interference patterns which are required for holography. An active phase control system has been designed and used with an all-fiber optical system to stabilize the phase difference between light emitted from two fibers, and to step the phase difference by 90 deg without applying any constraints on the placement of the fibers. The accuracy of the phase steps is shown to be better than 0.02 deg., and a stable phase difference can be maintained for 30 min. This system can be applied to both conventional and electro-optic holography, as well as to any system where the maintenance of an accurate phase difference between two coherent beams is required.

  10. Optical ordnance system for use in explosive ordnance disposal activities

    NASA Technical Reports Server (NTRS)

    Merson, J. A.; Salas, F. J.; Helsel, F.M.

    1994-01-01

    A portable hand-held solid state rod laser system and an optically-ignited detonator have been developed for use in explosive ordnance disposal (EOD) activities. Laser prototypes from Whittaker Ordnance and Universal Propulsion have been tested and evaluated. The optical detonator contains 2-(5 cyanotetrazolato) pentaamine cobalt(III) perchlorate (CP) as the DDT column and the explosive Octahydro- 1,3,5,7 - tetrazocine (HMX) as the output charge. The laser is designed to have an output of 150 mJ in a 500 microsecond pulse. This output allows firing through 2000 meters of optical fiber. The detonator can also be ignited with a portable laser diode source through a shorter length of fiber.

  11. Optical ordance system for use in explosive ordnance disposal activities

    SciTech Connect

    Merson, J.A.; Salas, F.J.; Helsel, F.M.

    1994-01-01

    A portable hand-held solid state rod laser system and an optically-ignited detonator have been developed for use in explosive ordnance disposal (EOD) activities. Laser prototypes from Whittaker Ordnance and Universal Propulsion have been tested and evaluated. The optical detonator contains 2-(5 cyanotetrazolato) pentaamine cobalt III perchlorate (CP) as the DDT column and the explosive Octahydro 1, 3, 5, 7 -- tetranitro -- 1, 3, 5, 7 -- tetrazocine (HMX) as the output charge. The laser is designed to have an output of 150 mJ in a 500 microsecond pulse. This output allows firing through 2000 meters of optical fiber. The detonator can also be ignited with a portable laser diode source through a shorter length of fiber.

  12. Active optics system of the VLT Survey Telescope.

    PubMed

    Schipani, Pietro; Noethe, Lothar; Magrin, Demetrio; Kuijken, Konrad; Arcidiacono, Carmelo; Argomedo, Javier; Capaccioli, Massimo; Dall'Ora, Massimo; D'Orsi, Sergio; Farinato, Jacopo; Fierro, Davide; Holzlöhner, Ronald; Marty, Laurent; Molfese, Cesare; Perrotta, Francesco; Ragazzoni, Roberto; Savarese, Salvatore; Rakich, Andrew; Umbriaco, Gabriele

    2016-03-01

    This paper describes the active optics system of the VLT Survey Telescope, the 2.6-m survey telescope designed for visible wavelengths of the European Southern Observatory at Cerro Paranal, in the Atacama desert. The telescope is characterized by a wide field of view (1.42 deg diameter), leading to tighter active optics than in conventional telescopes, in particular for the alignment requirements. We discuss the effects of typical error sources on the image quality and present the specific solutions adopted for wavefront sensing and correction of the aberrations, which are based on the shaping of a monolithic primary mirror and the positioning of the secondary in five degrees of freedom. PMID:26974616

  13. Low-power MOEMS components for active optical systems

    NASA Astrophysics Data System (ADS)

    Castracane, James; Yan, Dong; Madison, Seth; Xu, Bai

    2004-01-01

    The eventual, widespread insertion of Micro-Opto-Electro-Mechanical Systems (MOEMS) into the marketplace rests fundamentally on the ability to produce viable components that maximize optical performance while minimizing power consumption and size. In addition, the incorporation of optical reconfigurability into custom MOEMS devices offers an extra degree of freedom not possible with conventional components. Active control of surface topology allows for one component to perform multiple functions thus reducing cost and complexity. This paper will focus on the current status of the MOEMS research program at the University at Albany Institute for Materials" (UAIM) NanoFab 200 with several examples described to illustrate component and system development. In particular, among the MOEMS research portfolio at UAIM, the development of selected MOEMS-based, active optics will be discussed. This active control of diffraction and reflection forms the basis for the utility of such devices. Leveraging the extensive research expertise on the patented MEMS Compound Grating (MCG), emphasis will be placed on the extension of the approach to novel designs, materials and fabrication methods to yield low power, high performance prototypes. The main focus of this paper is on the development of a polymer version (including sacrificial layer, in some designs) of the MCG which allows for ease of fabrication and a reduced electrostatic actuation voltage. Following a system design effort, several generations of the component were fabricated to optimize the process flow. Component metrology, electromechanical characterization and initial results of optical tests will be reported. A second example presented is the design and prototype fabrication of a spring micrograting using a customized SOI process. This highly flexible component builds on the MCG concept and yields an order of magnitude reduction in actuation voltage. These examples will be presented against a backdrop of the broad UAIM

  14. Optically powered active sensing system for Internet Of Things

    NASA Astrophysics Data System (ADS)

    Gao, Chen; Wang, Jin; Yin, Long; Yang, Jing; Jiang, Jian; Wan, Hongdan

    2014-10-01

    Internet Of Things (IOT) drives a significant increase in the extent and type of sensing technology and equipment. Sensors, instrumentation, control electronics, data logging and transmission units comprising such sensing systems will all require to be powered. Conventionally, electrical powering is supplied by batteries or/and electric power cables. The power supply by batteries usually has a limited lifetime, while the electric power cables are susceptible to electromagnetic interference. In fact, the electromagnetic interference is the key issue limiting the power supply in the strong electromagnetic radiation area and other extreme environments. The novel alternative method of power supply is power over fiber (PoF) technique. As fibers are used as power supply lines instead, the delivery of the power is inherently immune to electromagnetic radiation, and avoids cumbersome shielding of power lines. Such a safer power supply mode would be a promising candidate for applications in IOT. In this work, we built up optically powered active sensing system, supplying uninterrupted power for the remote active sensors and communication modules. Also, we proposed a novel maximum power point tracking technique for photovoltaic power convertors. In our system, the actual output efficiency greater than 40% within 1W laser power. After 1km fiber transmission and opto-electric power conversion, a stable electric power of 210mW was obtained, which is sufficient for operating an active sensing system.

  15. Novel implementations of optical switch control module and 3D-CSP for 10 Gbps active optical access system

    NASA Astrophysics Data System (ADS)

    Wakayama, Koji; Okuno, Michitaka; Matsuoka, Yasunobu; Hosomi, Kazuhiko; Sagawa, Misuzu; Sugawara, Toshiki

    2009-11-01

    We propose an optical switch control procedure for high-performance and cost-effective 10 Gbps Active Optical Access System (AOAS) in which optical switches are used instead of optical splitters in PON (Passive Optical Network). We demonstrate the implemented optical switch control module on Optical Switching Unit (OSW) with logic circuits works effectively. We also propose a compact optical 3D-CSP (Chip Scale Package) to achieve the high performance of AOAS without losing cost advantage of PON. We demonstrate the implemented 3D-CSP works effectively.

  16. Control system of a dispersed fringe type sensing system of active optics

    NASA Astrophysics Data System (ADS)

    Zhang, Yajun; Zhang, Zhenchao; Zhang, Yong

    2010-07-01

    Active optics plays an important part in segmented mirrors of astronomy telescopes. A dispersed fringe sensor(DFS) using a broadband point source is an efficient method for cophasing and is also highly automated and robust. DFS can estimate the piston between segments only through the spectrum formed by the transmissive grating's dispersion and therefore can replace the edge sensors. So we build an system in our lab to experiment the DFS method. The whole control system of DFS is put forward, including control of displacement actuators and control of shifting the optical fiber. Control of displacement actuators consists in industry computer, HY-6120 I/O card, six stepper motor and other parts. Some theoretical analysis and experiment tests reveal that the actuator could be controlled to 5nm and without backlash by this control strategy. The optical fiber could be shifted out of optical path or shifted in part or whole of optical path so that the spectrum formed by the transmissive grating's dispersion could alter. When six actuators are moving, the piston is changing, and the spectrum is also moving and altering. And the whole control of DFS system is constructed now and seems well. Further test and experiment will be carry out.

  17. An electrically-activated dynamic tissue-equivalent phantom for assessment of diffuse optical imaging systems.

    PubMed

    Hebden, Jeremy C; Brunker, Joanna; Correia, Teresa; Price, Ben D; Gibson, Adam P; Everdell, N L

    2008-01-21

    A novel design of solid dynamic phantom with tissue-like optical properties is presented, which contains variable regions of contrast which are activated electrically. Reversible changes in absorption are produced by localized heating of targets impregnated with thermochromic pigment. A portable, battery-operated prototype has been constructed, and its optical and temporal characteristics have been investigated. The phantom has been developed as a means of assessing the performance of diffuse optical imaging systems, such as those used to monitor haemodynamic changes in the brain and other tissues. Images of the phantom have been reconstructed using data acquired with a continuous wave optical topography system. PMID:18184989

  18. An electrically-activated dynamic tissue-equivalent phantom for assessment of diffuse optical imaging systems

    NASA Astrophysics Data System (ADS)

    Hebden, Jeremy C.; Brunker, Joanna; Correia, Teresa; Price, Ben D.; Gibson, Adam P.; Everdell, N. L.

    2008-01-01

    A novel design of solid dynamic phantom with tissue-like optical properties is presented, which contains variable regions of contrast which are activated electrically. Reversible changes in absorption are produced by localized heating of targets impregnated with thermochromic pigment. A portable, battery-operated prototype has been constructed, and its optical and temporal characteristics have been investigated. The phantom has been developed as a means of assessing the performance of diffuse optical imaging systems, such as those used to monitor haemodynamic changes in the brain and other tissues. Images of the phantom have been reconstructed using data acquired with a continuous wave optical topography system.

  19. Active alignment and vibration control system for a large airborne optical system

    NASA Astrophysics Data System (ADS)

    Kienholz, David A.

    2000-04-01

    Airborne optical or electro-optical systems may be too large for all elements to be mounted on a single integrating structure, other than the aircraft fuselage itself. An active system must then be used to maintain the required alignment between elements. However the various smaller integrating structures (benches) must still be isolated from high- frequency airframe disturbances that could excite resonances outside the bandwidth of the alignment control system. The combined active alignment and vibration isolation functions must be performed by flight-weight components, which may have to operate in vacuum. A testbed system developed for the Air Force Airborne Laser program is described. The payload, a full-scale 1650-lb simulated bench, is mounted in six degrees- of-freedom to a vibrating platform by a set of isolator- actuators. The mounts utilize a combination of pneumatics and magnetics to perform the dual functions of low-frequency alignment and high-frequency isolation. Test results are given and future directions for development are described.

  20. Parallel robots in a ground-based telescope active optics system: theory and experiments

    NASA Astrophysics Data System (ADS)

    Schipani, P.; Ferragina, L.; Marty, L.; Grado, A.; Di Fiore, L.; De Rosa, R.; La Rana, A.; Busatta, A.

    2007-10-01

    This work deals with the application of parallel robots for the correction of defocus and coma optical aberrations in the case study of the VST (VLT Survey Telescope) telescope, to be installed at the ESO observatory of Cerro Paranal (Chile). The parallel robots are used to change position and orientation of the secondary mirror. The secondary mirror positioning capability is a fundamental part in an active optics system, i.e. a closed loop control system for the minimization of the telescope optical aberrations, where the outer optical feedback coming from the wavefront sensor is used to generate references for the inner motion control loop of the secondary mirror positioning robots. Two devices are presented: a 6-6 Stewart platform where both fixed and mobile platforms are regular and similar hexagons whose vertexes belong to the same plane and are on a circle, and a two stages device composed by a XY table plus a tilt platform. The basic theory of active optics corrections is presented. The kinematics of both devices is solved in connection with the active optics application; first test data are presented.

  1. Strain gauge ambiguity sensor for segmented mirror active optical system

    NASA Technical Reports Server (NTRS)

    Wyman, C. L.; Howe, T. L. (Inventor)

    1974-01-01

    A system is described to measure alignment between interfacing edges of mirror segments positioned to form a segmented mirror surface. It serves as a gauge having a bending beam with four piezoresistive elements coupled across the interfaces of the edges of adjacent mirror segments. The bending beam has a first position corresponding to alignment of the edges of adjacent mirror segments, and it is bendable from the first position in a direction and to a degree dependent upon the relative misalignment between the edges of adjacent mirror segments to correspondingly vary the resistance of the strain guage. A source of power and an amplifier are connected in circuit with the strain gauge whereby the output of the amplifier varies according to the misalignment of the edges of adjacent mirror segments.

  2. Antenna gain of actively compensated free-space optical communication systems under strong turbulence conditions.

    PubMed

    Juarez, Juan C; Brown, David M; Young, David W

    2014-05-19

    Current Strehl ratio models for actively compensated free-space optical communications terminals do not accurately predict system performance under strong turbulence conditions as they are based on weak turbulence theory. For evaluation of compensated systems, we present an approach for simulating the Strehl ratio with both low-order (tip/tilt) and higher-order (adaptive optics) correction. Our simulation results are then compared to the published models and their range of turbulence validity is assessed. Finally, we propose a new Strehl ratio model and antenna gain equation that are valid for general turbulence conditions independent of the degree of compensation. PMID:24921373

  3. Active disturbance rejection controller of fine tracking system for free space optical communication

    NASA Astrophysics Data System (ADS)

    Cui, Ning; Liu, Yang; Chen, Xinglin; Wang, Yan

    2013-08-01

    Free space optical communication is one of the best approaches in future communications. Laser beam's acquisition, pointing and tracking are crucial technologies of free space optical communication. Fine tracking system is important component of APT (acquisition, pointing and tracking) system. It cooperates with the coarse pointing system in executing the APT mission. Satellite platform vibration and disturbance, which reduce received optical power, increase bit error rate and affect seriously the natural performance of laser communication. For the characteristic of satellite platform, an active disturbance rejection controller was designed to reduce the vibration and disturbance. There are three major contributions in the paper. Firstly, the effects of vibration on the inter satellite optical communications were analyzed, and the reasons and characters of vibration of the satellite platform were summarized. The amplitude-frequency response of a filter was designed according to the power spectral density of platform vibration of SILEX (Semiconductor Inter-satellite Laser Experiment), and then the signals of platform vibration were generated by filtering white Gaussian noise using the filter. Secondly, the fast steering mirror is a key component of the fine tracking system for optical communication. The mechanical design and model analysis was made to the tip/tilt mirror driven by the piezoelectric actuator and transmitted by the flexure hinge. The transfer function of the fast steering mirror, camera, D/A data acquisition card was established, and the theory model of transfer function of this system was further obtained. Finally, an active disturbance rejection control method is developed, multiple parallel extended state observers were designed for estimation of unknown dynamics and external disturbance, and the estimated states were used for nonlinear feedback control and compensation to improve system performance. The simulation results show that the designed

  4. Design of secondary optics for IRED in active night vision systems.

    PubMed

    Xin, Di; Liu, Hua; Jing, Lei; Wang, Yao; Xu, Wenbin; Lu, Zhenwu

    2013-01-14

    An effective optical design method is proposed to solve the problem of adjustable view angle for infrared illuminator in active night vision systems. A novel total internal reflection (TIR) lens with three segments of the side surface is designed as the secondary optics of infrared emitting diode (IRED). It can provide three modes with different view angles to achieve a complete coverage of the monitored area. As an example, a novel TIR lens is designed for SONY FCB-EX 480CP camera. Optical performance of the novel TIR lens is investigated by both numerical simulation and experiments. The results demonstrate that it can meet the requirements of different irradiation distances quit well with view angles of 7.5°, 22° and 50°. The mean optical efficiency is improved from 62% to 75% and the mean irradiance uniformity is improved from 65% to 85% compared with the traditional structure. PMID:23389004

  5. Active optics: variable curvature mirrors for ELT laser guide star refocusing systems

    NASA Astrophysics Data System (ADS)

    Challita, Zalpha; Hugot, Emmanuel; Madec, Fabrice; Ferrari, Marc; Le Mignant, David; Vivès, Sébastien; Cuby, Jean-Gabriel

    2011-10-01

    The future generation of Extremely Large Telescopes will require a complex combination of technologies for adaptive optics (AO) systems assisted by laser guide stars (LGS). In this context, the distance from the LGS spot to the telescope pupil ranges from about 80 to 200 km, depending on the Sodium layer altitude and the elevation of the telescope. This variation leads to a defocusing effect on the LGS wave-front sensor which needs to be compensated. We propose an active mirror able to compensate for this variation, based on an original optical design including this active optics component. This LGS Variable Curvature Mirror (LGS-VCM) is a 120 mm spherical active mirror able to achieve 820 μm deflection sag with an optical quality better than 150 nm RMS, allowing the radius of curvature variation from F/12 to F/2. Based on elasticity theory, the deformation of the metallic mirror is provided by an air pressure applied on a thin meniscus with a variable thickness distribution. In this article, we detail the analytical development leading to the specific geometry of the active component, the results of finite element analysis and the expected performances in terms of surface error versus the range of refocalisation. Three prototypes have been manufactured to compare the real behavior of the mirror and the simulations data. Results obtained on the prototypes are detailed, showing that the deformation of the VCM is very close to the simulation, and leads to a realistic active concept.

  6. Active optics system of the ASTRI SST-2M prototype for the Cherenkov Telescope Array

    NASA Astrophysics Data System (ADS)

    Gardiol, Daniele; Capobianco, Gerardo; Fantinel, Daniela; Giro, Enrico; Lessio, Luigi; Loreggia, Davide; Rodeghiero, Gabriele; Russo, Federico; Volpicelli, Antonio C.

    2014-07-01

    ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) SST-2M is an end-to-end prototype of Small Size class of Telescope for the Cherenkov Telescope Array. It will apply a dual mirror configuration to Imaging Atmospheric Cherenkov Telescopes. The 18 segments composing the primary mirror (diameter 4.3 m) are equipped with an active optics system enabling optical re-alignment during telescope slew. The secondary mirror (diameter 1.8 m) can be moved along three degrees of freedom to perform focus and tilt corrections. We describe the kinematic model used to predict the system performance as well as the hardware and software design solution that will be implemented for optics control.

  7. Development and performance of the EAGLE active optics LGS WFS refocusing system

    NASA Astrophysics Data System (ADS)

    Madec, Fabrice; Le Mignant, David; Chardin, Elodie; Hugot, Emmanuel; Mazzanti, Silvio; Gimenez, Jean-Luc; Ferrari, Marc; Moreaux, Gabriel; Vives, Sébastien; Cuby, Jean-Gabriel

    2010-07-01

    We designed, developed, and tested a Variable Curvature Mirror (VCM) as an active refocusing system for the Laser Guide Star (LGS) Wave Front Sensor (WFS) of the E-ELT EAGLE instrument [1]. This paper is the second of two from our team on this R&D activity: Hugot et al. this conf. [2] presented the mirror design and performance simulations. Here, we report on the fabrication integration, testing and performance of the VCM system. During this activity, we developed all necessary parts for the VCM system: a metallic mirror, its housing and mounts, a computer-controlled pressure system, an internal metrology, a testbench etc. The functional testing of the VCM system is successful: we can control the internal pressure to less than 1 mBar, and measure the mirror displacement with a 100 nm accuracy. The mirror displacement is a near-linear and well-simulated function of internal pressure for the desired range of focus. The intrinsic optical quality of the mirror meniscus is well within the specifications. Once mounted in its housing, we observe additional mechanical constraints for the current design that generate optical aberrations. We measured the amplitude of the Zernike modes, and we showed that the axisymetric terms display a variation trend very similar to simulations, with amplitude close to simulations. All these results are very promising for a design of focus compensation without any moving part.

  8. Parallel guidance endoscopic optical coherence tomography system for internal diagnosis through active cannulas

    NASA Astrophysics Data System (ADS)

    Gim, Suhyeon; Moon, Hyowon; Shin, Hyun-Joon; Lee, Deukhee; Kang, Sungchul; Kim, Keri

    2014-08-01

    A parallel guidance endoscopic optical coherence tomography (OCT) system is proposed for minimally invasive internal inspection of inner organs or complex structures for diagnosis. The system is maneuvered to access the target using an active cannulas' steerable structures. The integration of a specially designed linkage device with the developed system allows the OCT endoscope to scan with enhanced signal-collective performance, while maintaining its tip at a constant distance from the target, as well as expanding the scanning range. The proposed system is integrated with flexible active cannulas, and this prototype is used for testing. The test results show that the device reliably performs for biological samples. Thus, it could be implemented for various types of noninvasive diagnoses in situations involving small entrances or crooked passage to a target.

  9. MULTIWAVELENGTH OPTICAL OBSERVATIONS OF TWO CHROMOSPHERICALLY ACTIVE BINARY SYSTEMS: V789 MON AND GZ LEO

    SciTech Connect

    Galvez, M. C.; Montes, D.; Fernandez-Figueroa, M. J.; De Castro, E.; Cornide, M.

    2009-04-15

    This paper describes a multiwavelength optical study of chromospheres in two X-ray/EUV-selected active binary stars with strong H{alpha} emission, V789 Mon (2RE J0725 - 002) and GZ Leo (2RE J1101+223). The goal of the study is to determine radial velocities and fundamental stellar parameters in chromospherically active binary systems in order to include them in the activity-rotation and activity-age relations. We carried out high-resolution echelle spectroscopic observations and applied spectral-subtraction technique in order to measure emission excesses due to chromosphere. The detailed study of activity indicators allowed us to characterize the presence of different chromospheric features in these systems and enabled to include them in a larger activity-rotation survey. We computed radial velocities of the systems using cross-correlation with the radial velocity standards. The double-line spectral binarity was confirmed and the orbital solutions improved for both systems. In addition, other stellar parameters such as spectral types, projected rotational velocities (vsin i) and the equivalent width of the lithium Li I {lambda}6707.8 A absorption line were determined.

  10. Active thermal lensing elements for mode matching optimization in optical systems

    NASA Astrophysics Data System (ADS)

    Fulda, Paul

    2014-03-01

    In interferometric gravitational wave detectors of the advanced era and beyond, the high laser powers used lead to the generation of thermal lenses in the optics. This can lead to a reduction in the coupling between the various optical cavities comprising the detector, thus reducing its overall sensitivity. We present here an active device which can be used to compensate for such thermal effects, as well as static mismatches between cavities. The device uses a 4 segmented heater to heat a transmissive optic, generating a spherical or astigmatic lens which can be used to compensate other thermal lenses within an optical system. We report on in-vacuum tests of the device, including an interferometric measurement of the wavefront distortions induced by the device, and measurements of the dynamic range and response time. The device was shown to have no observable detrimental effect on wavefront distortion, a focal power dynamic range of 0 to -40 mD, and a response time of the order 1000 s. Supported by NSF grant PHY-1205512.

  11. MAGNETIC LIQUID DEFORMABLE MIRRORS FOR ASTRONOMICAL APPLICATIONS: ACTIVE CORRECTION OF OPTICAL ABERRATIONS FROM LOWER-GRADE OPTICS AND SUPPORT SYSTEM

    SciTech Connect

    Borra, E. F.

    2012-08-01

    Deformable mirrors are increasingly used in astronomy. However, they still are limited in stroke for active correction of high-amplitude optical aberrations. Magnetic liquid deformable mirrors (MLDMs) are a new technology that has the advantages of high-amplitude deformations and low costs. In this paper, we demonstrate extremely high strokes and interactuator strokes achievable by MLDMs which can be used in astronomical instrumentation. In particular, we consider the use of such a mirror to suggest an interesting application for the next generation of large telescopes. We present a prototype 91 actuator deformable mirror made of a magnetic liquid (ferrofluid). This mirror uses a technique that linearizes the response of such mirrors by superimposing a large and uniform magnetic field on the magnetic field produced by an array of small coils. We discuss experimental results that illustrate the performance of MLDMs. A most interesting application of MLDMs comes from the fact they could be used to correct the aberrations of large and lower optical quality primary mirrors held by simple support systems. We estimate basic parameters of the needed MLDMs, obtaining reasonable values.

  12. An Optical Actuation System and Curvature Sensor for a MR-compatible Active Needle

    PubMed Central

    Ryu, Seok Chang; Quek, Zhan Fan; Renaud, Pierre; Black, Richard J.; Daniel, Bruce L.; Cutkosky, Mark R.

    2015-01-01

    A side optical actuation method is presented for a slender MR-compatible active needle. The needle includes an active region with a shape memory alloy (SMA) wire actuator, where the wire generates a contraction force when optically heated by a laser delivered though optical fibers, producing needle tip bending. A prototype, with multiple side heating spots, demonstrates twice as fast an initial response compared to fiber tip heating when 0.8 W of optical power is applied. A single-ended optical sensor with a gold reflector is also presented to measure the curvature as a function of optical transmission loss. Preliminary tests with the sensor prototype demonstrate approximately linear response and a repeatable signal, independent of the bending history. PMID:26509099

  13. Multiwavelength Optical Observations of Two Chromospherically Active Binary Systems: V789 Mon and GZ Leo

    NASA Astrophysics Data System (ADS)

    Gálvez, M. C.; Montes, D.; Fernández-Figueroa, M. J.; De Castro, E.; Cornide, M.

    2009-04-01

    This paper describes a multiwavelength optical study of chromospheres in two X-ray/EUV-selected active binary stars with strong Hα emission, V789 Mon (2RE J0725 - 002) and GZ Leo (2RE J1101+223). The goal of the study is to determine radial velocities and fundamental stellar parameters in chromospherically active binary systems in order to include them in the activity-rotation and activity-age relations. We carried out high-resolution echelle spectroscopic observations and applied spectral-subtraction technique in order to measure emission excesses due to chromosphere. The detailed study of activity indicators allowed us to characterize the presence of different chromospheric features in these systems and enabled to include them in a larger activity-rotation survey. We computed radial velocities of the systems using cross-correlation with the radial velocity standards. The double-line spectral binarity was confirmed and the orbital solutions improved for both systems. In addition, other stellar parameters such as spectral types, projected rotational velocities (vsin i) and the equivalent width of the lithium Li I λ6707.8 Å absorption line were determined. Based on observations collected with the 2.2 m telescope at the Centro Astronómico Hispano Alemán (CAHA) at Calar Alto (Almería, Spain), operated jointly by the Max-Planck Institut für Astronomie and the Instituto de Astrofísica de Andalucía (CSIC) and with the 2.1 m Otto Struve Telescope at McDonald Observatory of the University of Texas at Austin (USA).

  14. Synthesis and Antifeedant Activity of Racemic and Optically Active Hydroxy Lactones with the p-Menthane System.

    PubMed

    Grudniewska, Aleksandra; Kłobucki, Marek; Dancewicz, Katarzyna; Szczepanik, Maryla; Gabryś, Beata; Wawrzeńczyk, Czesław

    2015-01-01

    Two racemic and two enantiomeric pairs of new δ-hydroxy-γ-lactones based on the p-menthane system were prepared from racemic and optically active cis- and trans-piperitols. The Johnson-Claisen rearrangement of the piperitols, epoxidation of the γδ-unsaturated esters, and acidic lactonization of the epoxy esters were described. The structures of the compounds were confirmed spectroscopically. The antifeedant activities of the hydroxy lactones and racemic piperitone were evaluated against three insect pests: lesser mealworm, Alphitobius diaperinus (Panzer); Colorado potato beetle, Leptinotarsa decemlineata (Say); and peach-potato aphid, Myzus persicae (Sulz.). The chemical transformation of piperitone by the introduction of a lactone moiety and a hydroxy group changed its antifeedant properties. Behavioral bioassays showed that the feeding deterrent activity depended on the insect species and the structure of the compounds. All hydroxy lactones deterred the settling of M. persicae. Among chewing insects, the highest sensitivity showed A. diaperinus adults. PMID:26132506

  15. Synthesis and Antifeedant Activity of Racemic and Optically Active Hydroxy Lactones with the p-Menthane System

    PubMed Central

    Grudniewska, Aleksandra; Kłobucki, Marek; Dancewicz, Katarzyna; Szczepanik, Maryla; Gabryś, Beata; Wawrzeńczyk, Czesław

    2015-01-01

    Two racemic and two enantiomeric pairs of new δ-hydroxy-γ-lactones based on the p-menthane system were prepared from racemic and optically active cis- and trans-piperitols. The Johnson-Claisen rearrangement of the piperitols, epoxidation of the γδ-unsaturated esters, and acidic lactonization of the epoxy esters were described. The structures of the compounds were confirmed spectroscopically. The antifeedant activities of the hydroxy lactones and racemic piperitone were evaluated against three insect pests: lesser mealworm, Alphitobius diaperinus (Panzer); Colorado potato beetle, Leptinotarsa decemlineata (Say); and peach-potato aphid, Myzus persicae (Sulz.). The chemical transformation of piperitone by the introduction of a lactone moiety and a hydroxy group changed its antifeedant properties. Behavioral bioassays showed that the feeding deterrent activity depended on the insect species and the structure of the compounds. All hydroxy lactones deterred the settling of M. persicae. Among chewing insects, the highest sensitivity showed A. diaperinus adults. PMID:26132506

  16. Active infrared hyperspectral imaging system using a broadly tunable optical parametric oscillator

    NASA Astrophysics Data System (ADS)

    Malcolm, G. P. A.; Maker, G. T.; Robertson, G.; Dunn, M. H.; Stothard, D. J. M.

    2009-09-01

    The in situ identification and spatial location of gases, discrete liquid droplets and residues on surfaces is a technically challenging problem. Active Infrared (IR) hyperspectral imaging is a powerful technique that combines real-time imaging and optical spectroscopy for "standoff" detection of suspected chemical substances, including chemical warfare agents, toxic industrial chemicals, explosives and narcotics. An active IR hyperspectral imaging system requires a coherent, broadly tunable IR light source of high spectral purity, in order to detect a broad range of target substances. In this paper we outline a compact and power-efficient IR illumination source with high stability, efficiency, tuning range and spectral purity based upon an optical parametric oscillator (OPO). The fusion of established OPO technology with novel diode-pumped laser technology and electro-mechanical scanning has enabled a broadly applicable imaging system. This system is capable of hyperspectral imaging at both Near-IR (1.3 - 1.9 μm) and Mid-IR (2.3 - 4.6 μm) wavelengths simultaneously with a line width of < 3 cm-1. System size and complexity are minimised by using a dual InGaAs/InSb single element detector, and images are acquired by raster scanning the coaxial signal and idler beams simultaneously, at ranges up to 20 m. Reflection, absorption and scatter of incident radiation by chemical targets and their surroundings provide a method for spatial location, and characteristic spectra obtained from each sample can be used to identify targets uniquely. To date, we have recognized liquids in sample sizes as small 20 μl-and gases with sensitivity as high as 10ppm.m-at detection standoff distances > 10 m.

  17. Design of active disturbance rejection controller for space optical communication coarse tracking system

    NASA Astrophysics Data System (ADS)

    Gu, Jian; Ai, Yong

    2015-10-01

    In order to improve the dynamic tracking performance of coarse tracking system in space optical communication, a new control method based on active disturbance rejection controller (ADRC) is proposed. Firstly, based on the structure analysis of coarse tracking system, the simplified system model was obtained, and then the extended state observer was designed to calculate state variables and spot disturbance from the input and output signals. Finally, the ADRC controller of coarse tracking system is realized with the combination of nonlinear PID controller. The simulation experimental results show that compared with the PID method, this method can significantly reduce the step response overshoot and settling time. When the target angular velocity is120mrad/s, tracking error with ADRC method is 30μrad, which decreases 85% compared with the PID method. Meanwhile the disturbance rejection bandwidth is increased by 3 times with ADRC. This method can effectively improve the dynamic tracking performance of coarse tracking and disturbance rejection degree, with no need of hardware upgrade, and is of certain reference value to the wide range and high dynamic precision photoelectric tracking system.

  18. Optical absorption measurement system

    DOEpatents

    Draggoo, Vaughn G.; Morton, Richard G.; Sawicki, Richard H.; Bissinger, Horst D.

    1989-01-01

    The system of the present invention contemplates a non-intrusive method for measuring the temperature rise of optical elements under high laser power optical loading to determine the absorption coefficient. The method comprises irradiating the optical element with a high average power laser beam, viewing the optical element with an infrared camera to determine the temperature across the optical element and calculating the absorption of the optical element from the temperature.

  19. Active microdisk resonators in an optical code division multiple access system

    NASA Astrophysics Data System (ADS)

    Akhavan, Hooman

    2013-02-01

    An optical code division multiple access design consisting of a set of active microdisks coupled to a waveguide bus for both encoder and decoder is presented. This integrated design is beneficial for secure transmission of data through an optical fiber channel. Device optimization and performance analysis shows dependence of the output signal quality on number of users and necessity of proper adjustment of quality factor of the resonators considering intended transmitted data rate.

  20. Building blocks for actively-aligned micro-optical systems in rapid prototyping and small series production

    NASA Astrophysics Data System (ADS)

    Böttger, Gunnar; Queisser, Marco; Arndt-Staufenbiel, Norbert; Schröder, Henning; Lang, K.-D.

    2015-03-01

    In recent years there has been considerable progress in utilizing fully automated machines for the assembly of microoptical systems. Such systems integrate laser sources, optical elements and detectors into tight packages, and efficiently couple light to free space beams, waveguides in optical backplanes, or optical fibers for longer reach transmission. The required electrical-optical and optical components are placed and aligned actively in more than one respect. For one, all active components are actually operated in the alignment process, and, more importantly, the placing of all components is controlled actively by camera systems and power detectors with live feedback for an optimal coupling efficiency. The total number of optical components typically is in the range of 5 to 50, whereas the number of actors with gripping tools for the actual handling and aligning is limited, with little flexibility in the gripping width. The assembly process therefore is strictly sequential and, given that an automated tool changing has not been established in this class of machines yet, there are either limitations in the geometries of components that may be used, or time-consuming interaction by human operators is needed. As a solution we propose and present lasered glass building blocks with standardized gripping geometries that enclose optical elements of various shapes and functionalities. These are cut as free form geometries with green short pulse and CO2 lasers. What seems to add cost at first rather increases freedom of design and adds an economical flexibility to create very hybrid assemblies of various micro-optical assemblies also in small numbers.

  1. Investigation of the effects of long duration space exposure on active optical system components

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1994-01-01

    This experiment was exposed to the space environment for 6 years on the Long Duration Exposure Facility (LDEF). It investigated quantitatively the effects of the long-duration space exposure on the relevant performance parameters of a representative set of electron-optic system components, including lasers, radiation detectors, filters, modulators, windows, and other related components. It evaluated the results and implications of the measurements indicating real or suspected degradation mechanisms. This information will be used to establish guidelines for the selection and use of components for space-based, electro-optic systems.

  2. Development of wearable optical topography system for mapping the prefrontal cortex activation

    NASA Astrophysics Data System (ADS)

    Atsumori, Hirokazu; Kiguchi, Masashi; Obata, Akiko; Sato, Hiroki; Katura, Takusige; Funane, Tsukasa; Maki, Atsushi

    2009-04-01

    Optical topography (OT) based on near infrared spectroscopy is effective for measuring changes in the concentrations of oxygenated hemoglobin (oxy-Hb) and deoxygenated hemoglobin (deoxy-Hb) in the brain. It can be used to investigate brain functions of subjects of all ages because it is noninvasive and less constraining for subjects. Conventional OT systems use optical fibers to irradiate the scalp and detect light transmitted through the tissue in the human head, but optical fibers limit the subject's head position, so some small systems have been developed without using optical fibers. These systems, however, have a small number of measurement channels. We developed a prototype of a small, light, and wearable OT system that covers the entire forehead. We measured changes in the concentrations of oxy-Hb and deoxy-Hb in the prefrontal cortex while a subject performed a word fluency task. The results show typical changes in oxy-Hb and deoxy-Hb during the task and suggest that the prototype of our system can be used to investigate functions in the prefrontal cortex.

  3. Reflective optical imaging system

    DOEpatents

    Shafer, David R.

    2000-01-01

    An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four reflective elements for projecting a mask image onto a substrate. The four optical elements are characterized in order from object to image as convex, concave, convex and concave mirrors. The optical system is particularly suited for step and scan lithography methods. The invention increases the slit dimensions associated with ringfield scanning optics, improves wafer throughput and allows higher semiconductor device density.

  4. Removing static aberrations from the active optics system of a wide-field telescope.

    PubMed

    Schipani, Pietro; Noethe, Lothar; Arcidiacono, Carmelo; Argomedo, Javier; Dall'Ora, Massimo; D'Orsi, Sergio; Farinato, Jacopo; Magrin, Demetrio; Marty, Laurent; Ragazzoni, Roberto; Umbriaco, Gabriele

    2012-07-01

    The wavefront sensor in active and adaptive telescopes is usually not in the optical path toward the scientific detector. It may generate additional wavefront aberrations, which have to be separated from the errors due to the telescope optics. The aberrations that are not rotationally symmetric can be disentangled from the telescope aberrations by a series of measurements taken in the center of the field, with the wavefront sensor at different orientation angles with respect to the focal plane. This method has been applied at the VLT Survey Telescope on the ESO Paranal observatory. PMID:22751401

  5. Optically controlled welding system

    NASA Technical Reports Server (NTRS)

    Gordon, Stephen S. (Inventor)

    1989-01-01

    An optically controlled welding system (10) wherein a welding torch (12) having through-the-torch viewing capabilities is provided with an optical beam splitter (56) to create a transmitted view and a reflective view of a welding operation. These views are converted to digital signals which are then processed and utilized by a computerized robotic welder (15) to make the welding torch responsive thereto. Other features includes an actively cooled electrode holder (26) which minimizes a blocked portion of the view by virtue of being constructed of a single spoke or arm (28) and a weld pool contour detector (14) comprising a laser beam directed onto the weld pool with the position of specular radiation reflected therefrom being characteristic of a penetrated or unpenetrated condition of the weld pool.

  6. Optically controlled welding system

    NASA Technical Reports Server (NTRS)

    Gordon, Stephen S. (Inventor)

    1988-01-01

    An optically controlled welding system wherein a welding torch having through-the-torch viewing capabilities is provided with an optical beam splitter to create a transmitted view and a reflective view of a welding operation. These views are converted to digital signals which are then processed and utilized by a computerized robotic welder to make the welding torch responsive thereto. Other features include an actively cooled electrode holder which minimizes a blocked portion of the view by virtue of being constructed of a single spoke or arm, and a weld pool contour detector comprising a laser beam directed onto the weld pool with the position of specular radiation reflected therefrom, being characteristic of a penetrated or unpenetrated condition of the weld pool.

  7. Modular Optical PDV System

    SciTech Connect

    Araceli Rutkowski, David Esquibel

    2008-12-11

    A modular optical photon Doppler velocimetry (PDV) detector system has been developed by using readily available optical components with a 20-GHz Miteq optical detector into eight channels of single-wide modules integrated into a 3U rack unit (1U = 1.75 inches) with a common power supply. Optical fibers were precisely trimmed, welded, and timed within each unit. This system has been used to collect dynamic velocity data on various physics experiments. An optical power meter displays the laser input power to the module and optical power at the detector. An adjustable micro-electromechanical system (MEMS) optical attenuator is used to adjust the amount of unshifted light entering the detector. Front panel LEDs show the presence of power to the module. A fully loaded chassis with eight channels consumes 45 watts of power. Each chassis requires 1U spacing above and below for heat management. Modules can be easily replaced.

  8. Intelligent Optical Systems Using Adaptive Optics

    NASA Technical Reports Server (NTRS)

    Clark, Natalie

    2012-01-01

    Until recently, the phrase adaptive optics generally conjured images of large deformable mirrors being integrated into telescopes to compensate for atmospheric turbulence. However, the development of smaller, cheaper devices has sparked interest for other aerospace and commercial applications. Variable focal length lenses, liquid crystal spatial light modulators, tunable filters, phase compensators, polarization compensation, and deformable mirrors are becoming increasingly useful for other imaging applications including guidance navigation and control (GNC), coronagraphs, foveated imaging, situational awareness, autonomous rendezvous and docking, non-mechanical zoom, phase diversity, and enhanced multi-spectral imaging. The active components presented here allow flexibility in the optical design, increasing performance. In addition, the intelligent optical systems presented offer advantages in size and weight and radiation tolerance.

  9. APE: the Active Phasing Experiment to test new control system and phasing technology for a European Extremely Large Optical Telescope

    NASA Astrophysics Data System (ADS)

    Gonte, F.; Yaitskova, N.; Derie, F.; Constanza, A.; Brast, R.; Buzzoni, B.; Delabre, B.; Dierickx, P.; Dupuy, C.; Esteves, R.; Frank, C.; Guisard, S.; Karban, R.; Koenig, E.; Kolb, J.; Nylund, M.; Noethe, L.; Surdej, I.; Courteville, A.; Wilhelm, R.; Montoya, L.; Reyes, M.; Esposito, S.; Pinna, E.; Dohlen, K.; Ferrari, M.; Langlois, M.

    2005-08-01

    The future European Extremely Large Telescope will be composed of one or two giant segmented mirrors (up to 100 m of diameter) and of several large monolithic mirrors (up to 8 m in diameter). To limit the aberrations due to misalignments and defective surface quality it is necessary to have a proper active optics system. This active optics system must include a phasing system to limit the degradation of the PSF due to misphasing of the segmented mirrors. We will present the lastest design and development of the Active Phasing Experiment that will be tested in laboratory and on-sky connected to a VLT at Paranal in Chile. It includes an active segmented mirror, a static piston plate to simulate a secondary segmented mirror and of four phasing wavefront sensors to measure the piston, tip and tilt of the segments and the aberrations of the VLT. The four phasing sensors are the Diffraction Image Phase Sensing Instrument developed by Instituto de Astrofisica de Canarias, the Pyramid Phasing Sensor developed by Arcetri Astrophysical Observatory, the Shack-Hartmann Phasing Sensor developed by the European Southern Observatory and the Zernike Unit for Segment phasing developed by Laboratoire d'Astrophysique de Marseille. A reference measurement of the segmented mirror is made by an internal metrology developed by Fogale Nanotech. The control system of Active Phasing Experiment will perform the phasing of the segments, the guiding of the VLT and the active optics of the VLT. These activities are included in the Framework Programme 6 of the European Union.

  10. Optically active quantum dots

    NASA Astrophysics Data System (ADS)

    Gerard, Valerie; Govan, Joseph; Loudon, Alexander; Baranov, Alexander V.; Fedorov, Anatoly V.; Gun'ko, Yurii K.

    2015-10-01

    The main goal of our research is to develop new types of technologically important optically active quantum dot (QD) based materials, study their properties and explore their biological applications. For the first time chiral II-VI QDs have been prepared by us using microwave induced heating with the racemic (Rac), D- and L-enantiomeric forms of penicillamine as stabilisers. Circular dichroism (CD) studies of these QDs have shown that D- and L-penicillamine stabilised particles produced mirror image CD spectra, while the particles prepared with a Rac mixture showed only a weak signal. It was also demonstrated that these QDs show very broad emission bands between 400 and 700 nm due to defects or trap states on the surfaces of the nanocrystals. These QDs have demonstrated highly specific chiral recognition of various biological species including aminoacids. The utilisation of chiral stabilisers also allowed the preparation of new water soluble white emitting CdS nano-tetrapods, which demonstrated circular dichroism in the band-edge region of the spectrum. Biological testing of chiral CdS nanotetrapods displayed a chiral bias for an uptake of the D- penicillamine stabilised nano-tetrapods by cancer cells. It is expected that this research will open new horizons in the chemistry of chiral nanomaterials and their application in nanobiotechnology, medicine and optical chemo- and bio-sensing.

  11. Atmospheric optical calibration system

    DOEpatents

    Hulstrom, Roland L.; Cannon, Theodore W.

    1988-01-01

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions.

  12. Atmospheric optical calibration system

    DOEpatents

    Hulstrom, R.L.; Cannon, T.W.

    1988-10-25

    An atmospheric optical calibration system is provided to compare actual atmospheric optical conditions to standard atmospheric optical conditions on the basis of aerosol optical depth, relative air mass, and diffuse horizontal skylight to global horizontal photon flux ratio. An indicator can show the extent to which the actual conditions vary from standard conditions. Aerosol scattering and absorption properties, diffuse horizontal skylight to global horizontal photon flux ratio, and precipitable water vapor determined on a real-time basis for optical and pressure measurements are also used to generate a computer spectral model and for correcting actual performance response of a photovoltaic device to standard atmospheric optical condition response on a real-time basis as the device is being tested in actual outdoor conditions. 7 figs.

  13. Optical Disk Testing System

    NASA Astrophysics Data System (ADS)

    Manns, Basil H.

    1987-01-01

    This paper describes the development of the basics of an optical disk testing system used to test 12 inch, write once, Alcatel Thomson Gigadisk (ATG) media that are used at the Library of Congress in a pilot document storage and retrieval system. Since very little is known regarding the longevity of optical disk media and the fact that disk manufacturers are still refining processing techniques, any conclusions regarding error patterns, failure modes, or longevity may be superceded by a new "batch" of disks. Therefore, this paper focuses on the development of procedures for testing disks that can be used as the write once optical disk technology continues to advance.

  14. Imaging performance of elliptical-boundary varifocal mirrors in active optical systems

    NASA Astrophysics Data System (ADS)

    Lukes, Sarah Jane

    Micro-electro-mechanical systems deformable-membrane mirrors provide a means of focus control and attendant spherical aberration correction for miniaturized imaging systems. The technology has greatly advanced in the last decade, thereby extending their focal range capabilities. This dissertation describes a novel SU-8 2002 silicon-on-insulator wafer deformable mirror. A 4.000 mm x 5.657 mm mirror for 45o incident light rays achieves 22 mum stroke or 65 diopters, limited by snapdown. The mirrors show excellent optical quality while flat. Most have peak-to-valley difference of less than 150 nm and root-mean-square less than 25 nm. The process proves simple, only requiring a silicon-on-insulator wafer, SU-8 2002, and a metal layer. Xenon difluoride etches the silicon to release the mirrors. Greater than 90% of the devices survive fabrication and release. While current literature includes several aberration analyses on static mirrors, analyses that incorporate the dynamic nature of these mirrors do not exist. Optical designers may have a choice between deformable mirrors and other types of varifocal mirrors or lenses. Furthermore, a dynamic mirror at an incidence angle other than normal may be desired due to space limitations or for higher throughput (normal incidence requires a beam splitter). This dissertation presents an analysis based on the characteristic function of the system. It provides 2nd and 3rd order aberration coefficients in terms of dynamic focus range and base ray incidence angle. These afford an understanding of the significance of different types of aberrations. Root-mean-square and Strehl calculations provide insight into overall imaging performance for various conditions. I present general guidelines for maximum incidence angle and field of fiew that provide near diffraction-limited performance. Experimental verification of the MEMS mirrors at 5o and 45o incidence angles validates the analytical results. A Blu-ray optical pick-up imaging

  15. Noninvasive imaging of prefrontal activation during attention-demanding tasks performed while walking using a wearable optical topography system

    NASA Astrophysics Data System (ADS)

    Atsumori, Hirokazu; Kiguchi, Masashi; Katura, Takusige; Funane, Tsukasa; Obata, Akiko; Sato, Hiroki; Manaka, Takaaki; Iwamoto, Mitsumasa; Maki, Atsushi; Koizumi, Hideaki; Kubota, Kisou

    2010-07-01

    Optical topography (OT) based on near-infrared spectroscopy is a noninvasive technique for mapping the relative concentration changes in oxygenated and deoxygenated hemoglobin (oxy- and deoxy-Hb, respectively) in the human cerebral cortex. In our previous study, we developed a small and light wearable optical topography (WOT) system that covers the entire forehead for monitoring prefrontal activation. In the present study, we examine whether the WOT system is applicable to OT measurement while walking, which has been difficult with conventional OT systems. We conduct OT measurements while subjects perform an attention-demanding (AD) task of balancing a ping-pong ball on a small card while walking. The measured time course and power spectra of the relative concentration changes in oxy- and deoxy-Hb show that the step-related changes in the oxy- and deoxy-Hb signals are negligible compared to the task-related changes. Statistical assessment of the task-related changes in the oxy-Hb signals show that the dorsolateral prefrontal cortex and rostral prefrontal area are significantly activated during the AD task. These results suggest that our functional imaging technique with the WOT system is applicable to OT measurement while walking, and will be a powerful tool for evaluating brain activation in a natural environment.

  16. Active control of adaptive optics system in a large segmented mirror telescope

    NASA Astrophysics Data System (ADS)

    Nagashima, M.; Agrawal, B. N.

    2014-02-01

    For a large adaptive optics system such as a large segmented mirror telescope (SMT), it is often difficult, although not impossible, to directly apply common multi-input multi-output (MIMO) controller design methods due to the computational burden imposed by the large dimension of the system model. In this article, a practical controller design method is proposed which significantly reduces the system dimension for a system where the dimension required to represent the dynamics of the plant is much smaller than the dimension of the full plant model. The proposed method decouples the dynamic and static parts of the plant model by a modal decomposition technique to separately design a controller for each part. Two controllers are then combined using the so-called sensitivity decoupling method so that the resulting feedback loop becomes the superposition of the two individual feedback loops of the dynamic and static parts. A MIMO controller was designed by the proposed method using the H ∞ loop-shaping technique for an SMT model to be compared with other controllers proposed in the literature. Frequency-domain analysis and time-domain simulation results show the superior performance of the proposed controller.

  17. Stereoscopic optical viewing system

    DOEpatents

    Tallman, C.S.

    1986-05-02

    An improved optical system which provides the operator with a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

  18. Stereoscopic optical viewing system

    DOEpatents

    Tallman, Clifford S.

    1987-01-01

    An improved optical system which provides the operator a stereoscopic viewing field and depth of vision, particularly suitable for use in various machines such as electron or laser beam welding and drilling machines. The system features two separate but independently controlled optical viewing assemblies from the eyepiece to a spot directly above the working surface. Each optical assembly comprises a combination of eye pieces, turning prisms, telephoto lenses for providing magnification, achromatic imaging relay lenses and final stage pentagonal turning prisms. Adjustment for variations in distance from the turning prisms to the workpiece, necessitated by varying part sizes and configurations and by the operator's visual accuity, is provided separately for each optical assembly by means of separate manual controls at the operator console or within easy reach of the operator.

  19. Modular optical detector system

    DOEpatents

    Horn, Brent A.; Renzi, Ronald F.

    2006-02-14

    A modular optical detector system. The detector system is designed to detect the presence of molecules or molecular species by inducing fluorescence with exciting radiation and detecting the emitted fluorescence. Because the system is capable of accurately detecting and measuring picomolar concentrations it is ideally suited for use with microchemical analysis systems generally and capillary chromatographic systems in particular. By employing a modular design, the detector system provides both the ability to replace various elements of the detector system without requiring extensive realignment or recalibration of the components as well as minimal user interaction with the system. In addition, the modular concept provides for the use and addition of a wide variety of components, including optical elements (lenses and filters), light sources, and detection means, to fit particular needs.

  20. Optical parallel selectionist systems

    NASA Astrophysics Data System (ADS)

    Caulfield, H. John

    1993-01-01

    There are at least two major classes of computers in nature and technology: connectionist and selectionist. A subset of connectionist systems (Turing Machines) dominates modern computing, although another subset (Neural Networks) is growing rapidly. Selectionist machines have unique capabilities which should allow them to do truly creative operations. It is possible to make a parallel optical selectionist system using methods describes in this paper.

  1. An optical telemetry system for underwater recording of electromyogram and neuronal activity from non-tethered crayfish.

    PubMed

    Tsuchida, Yoshikazu; Hama, Noriyuki; Takahata, Masakazu

    2004-08-15

    We have developed an optical telemetry system for recording electrical signals associated with muscle and neuronal activities from freely walking crayfish under water. The device was made from conventional electronic parts which are commercially available, utilizing infrared light (880 nm) for signal transmission. Two or four channels of biological signals were multiplexed, the voltage of each data point modulated to the duration of subcarrier pulses and further to the interval of narrower carrier pulses that directly drove the infrared light emission diode (IRLED) under water. The light-pulse modulated signals were received by photodiodes and demodulated to restore the original two or four channel signals. Electrical recordings using wired electrodes and conventional amplifiers revealed that the optically transmitted signals were consistent with the wire-transmitted ones. In order to test the performance of this system, we recorded electromyograms (EMGs) from the second and third walking legs on each side of crayfish together with the neuronal activity in the ventral nerve cord. The results confirmed our previous observation in tethered crayfish that the background tonus of leg muscles showed an increase preceding their rhythmic activation. PMID:15196832

  2. Optics activity for hospitalized children

    NASA Astrophysics Data System (ADS)

    Gargallo, Ana; Gómez-Varela, Ana I.; González-Nuñez, Hector; Delgado, Tamara; Almaguer, Citlalli; Cambronero, Ferran; Garcia-Sanchez, Angel; Flores-Arias, Maria T.

    2014-08-01

    USC-OSA is a student chapter whose objective is to bring Optics knowledge closer to the non-optics community. The activity developed at the Hospital school was one of the most important last year. It was consisted in a few Optics experiments and workshops with hospitalized children of different ages and pathologies. The experiments had to be adapted to their physical conditions with the aim of everyone could participate. We think this activity has several benefits including spreading Optics through children meanwhile they have fun and forget their illness for a while.

  3. Optics Supply Planning System

    SciTech Connect

    Gaylord, J

    2009-04-30

    The purpose of this study is to specify the design for an initial optics supply planning system for NIF, and to present quality assurance and test plans for the construction of the system as specified. The National Ignition Facility (NIF) is a large laser facility that is just starting operations. Thousands of specialized optics are required to operate the laser, and must be exchanged over time based on the laser shot plan and predictions of damage. Careful planning and tracking of optic exchanges is necessary because of the tight inventory of spare optics, and the long lead times for optics procurements and production changes. Automated inventory forecasting and production planning tools are required to replace existing manual processes. The optics groups members who are expected to use the supply planning system are the stakeholders for this project, and are divided into three groups. Each of these groups participated in a requirements specification that was used to develop this design. (1) Optics Management--These are the top level stakeholdersk, and the final decision makers. This group is the interface to shot operations, is ultimately responsible for optics supply, and decides which exchanges will be made. (2) Work Center Managers--This group manages the on site optics processing work centers. They schedule the daily work center operations, and are responsible for developing long term processing, equipment, and staffing plans. (3) Component Engineers--This group manages the vendor contracts for the manufacture of new optics and the off site rework of existing optics. They are responsible for sourcing vendors, negotiating contracts, and managing vendor processes. The scope of this analysis is to describe the structure and design details of a system that will meet all requirements that were described by stakeholders and documented in the analysis model for this project. The design specifies the architecture, components, interfaces, and data stores of the system

  4. Active Faraday optical frequency standard.

    PubMed

    Zhuang, Wei; Chen, Jingbiao

    2014-11-01

    We propose the mechanism of an active Faraday optical clock, and experimentally demonstrate an active Faraday optical frequency standard based on narrow bandwidth Faraday atomic filter by the method of velocity-selective optical pumping of cesium vapor. The center frequency of the active Faraday optical frequency standard is determined by the cesium 6 (2)S(1/2) F=4 to 6 (2)P(3/2) F'=4 and 5 crossover transition line. The optical heterodyne beat between two similar independent setups shows that the frequency linewidth reaches 281(23) Hz, which is 1.9×10(4) times smaller than the natural linewidth of the cesium 852-nm transition line. The maximum emitted light power reaches 75 μW. The active Faraday optical frequency standard reported here has advantages of narrow linewidth and reduced cavity pulling, which can readily be extended to other atomic transition lines of alkali and alkaline-earth metal atoms trapped in optical lattices at magic wavelengths, making it useful for new generation of optical atomic clocks. PMID:25361349

  5. Optical key system

    DOEpatents

    Hagans, Karla G.; Clough, Robert E.

    2000-01-01

    An optical key system comprises a battery-operated optical key and an isolated lock that derives both its operating power and unlock signals from the correct optical key. A light emitting diode or laser diode is included within the optical key and is connected to transmit a bit-serial password. The key user physically enters either the code-to-transmit directly, or an index to a pseudorandom number code, in the key. Such person identification numbers can be retained permanently, or ephemeral. When a send button is pressed, the key transmits a beam of light modulated with the password information. The modulated beam of light is received by a corresponding optical lock with a photovoltaic cell that produces enough power from the beam of light to operate a password-screen digital logic. In one application, an acceptable password allows a two watt power laser diode to pump ignition and timing information over a fiberoptic cable into a sealed engine compartment. The receipt of a good password allows the fuel pump, spark, and starter systems to each operate. Therefore, bypassing the lock mechanism as is now routine with automobile thieves is pointless because the engine is so thoroughly disabled.

  6. Optical key system

    SciTech Connect

    Hagans, K.G.; Clough, R.E.

    2000-04-25

    An optical key system comprises a battery-operated optical key and an isolated lock that derives both its operating power and unlock signals from the correct optical key. A light emitting diode or laser diode is included within the optical key and is connected to transmit a bit-serial password. The key user physically enters either the code-to-transmit directly, or an index to a pseudorandom number code, in the key. Such person identification numbers can be retained permanently, or ephemeral. When a send button is pressed, the key transmits a beam of light modulated with the password information. The modulated beam of light is received by a corresponding optical lock with a photovoltaic cell that produces enough power from the beam of light to operate a password-screen digital logic. In one application, an acceptable password allows a two watt power laser diode to pump ignition and timing information over a fiberoptic cable into a sealed engine compartment. The receipt of a good password allows the fuel pump, spark, and starter systems to each operate. Therefore, bypassing the lock mechanism as is now routine with automobile thieves is pointless because the engine is so thoroughly disabled.

  7. Optical Imaging of Neuronal Activity and Visualization of Fine Neural Structures in Non-Desheathed Nervous Systems

    PubMed Central

    Stein, Wolfgang

    2014-01-01

    Locating circuit neurons and recording from them with single-cell resolution is a prerequisite for studying neural circuits. Determining neuron location can be challenging even in small nervous systems because neurons are densely packed, found in different layers, and are often covered by ganglion and nerve sheaths that impede access for recording electrodes and neuronal markers. We revisited the voltage-sensitive dye RH795 for its ability to stain and record neurons through the ganglion sheath. Bath-application of RH795 stained neuronal membranes in cricket, earthworm and crab ganglia without removing the ganglion sheath, revealing neuron cell body locations in different ganglion layers. Using the pyloric and gastric mill central pattern generating neurons in the stomatogastric ganglion (STG) of the crab, Cancer borealis, we found that RH795 permeated the ganglion without major residue in the sheath and brightly stained somatic, axonal and dendritic membranes. Visibility improved significantly in comparison to unstained ganglia, allowing the identification of somata location and number of most STG neurons. RH795 also stained axons and varicosities in non-desheathed nerves, and it revealed the location of sensory cell bodies in peripheral nerves. Importantly, the spike activity of the sensory neuron AGR, which influences the STG motor patterns, remained unaffected by RH795, while desheathing caused significant changes in AGR activity. With respect to recording neural activity, RH795 allowed us to optically record membrane potential changes of sub-sheath neuronal membranes without impairing sensory activity. The signal-to-noise ratio was comparable with that previously observed in desheathed preparations and sufficiently high to identify neurons in single-sweep recordings and synaptic events after spike-triggered averaging. In conclusion, RH795 enabled staining and optical recording of neurons through the ganglion sheath and is therefore both a good anatomical

  8. Self-referencing Mach-Zehnder interferometer as a laser system diagnostic: Active and adaptive optical systems

    SciTech Connect

    Feldman, M.; Mockler, D.J.; English, R.E. Jr.; Byrd, J.L.; Salmon, J.T.

    1991-02-01

    We are incorporating a novel self-referencing Mach-Zehnder interferometer into a large scale laser system as a real time, interactive diagnostic tool for wavefront measurement. The instrument is capable of absolute wavefront measurements accurate to better than {lambda}/10 pv over a wavelength range > 300 nm without readjustment of the optical components. This performance is achieved through the design of both refractive optics and catadioptric collimator to achromatize the Mach-Zehnder reference arm. Other features include polarization insensitivity through the use of low angles of incidence on all beamsplitters as well as an equal path length configuration that allows measurement of either broad-band or closely spaced laser-line sources. Instrument accuracy is periodically monitored in place by means of a thermally and mechanically stable wavefront reference source that is calibrated off-line with a phase conjugate interferometer. Video interferograms are analyzed using Fourier transform techniques on a computer that includes dedicated array processor. Computer and video networks maintain distributed interferometers under the control of a single analysis computer with multiple user access. 7 refs., 11 figs.

  9. OPTOGELs: optically active xerogels

    NASA Astrophysics Data System (ADS)

    Canva, Michael; Georges, Patrick M.; Brun, Alain; Chaput, Frederic; Devreux, Francois; Boilot, Jean-Pierre

    1992-12-01

    Using the sol-gel process, we synthesized zirconia/silica matrices doped with different organic dyes (rhodamine 640, ...). These samples were used to perform optical Kerr effect experiments with sequences of ultrashort light pulses (100 fs, 620 nm, 1 (mu) J focused on 50 micrometers diameter) to induce refractive index changes. A permanent birefringence around 7 X 10-5 was obtained. By changing the direction of the polarization of the excitation pulses, we were able to locally control the directions of the neutral axes. We thus demonstrated the possibility of using this media as an all optical memory matrix and such doped xerogels will subsequently be referred to as OPTOGELS. We interpret our results as the possibility of locally controlling the orientation of the doping molecules encaged in the solid host matrix. The memory effect is probably due to links of hydrogen bond type between the organic molecules and the pore surface which prevent thermal reorientation. The electric field of the optical excitation pulses exerts a torque on the molecules. If this torque is greater than the energy linking the molecules to the pore surface, the molecules are temporarily released and aligned in the direction of the pulse polarization. Based on this interpretation, we have developed a model to explain the evolution of the birefringence as a function of the number of excitation pulses.

  10. Binary optics at Hughes Danbury Optical Systems

    NASA Technical Reports Server (NTRS)

    Logue, James; Power, Michael

    1993-01-01

    An overview of binary optics development at Hughes Danbury Optical Systems is presented. Design software used for mask design is presented. A brief discussion of fabrication follows. Two examples of actual projects are used to highlight the discussion: (1) a large aspheric lens; and (2) a set of grating and lenslet arrays.

  11. Entangling unstable optically active matter qubits

    SciTech Connect

    Matsuzaki, Yuichiro; Fitzsimons, Joseph; Benjamin, Simon C.

    2011-06-15

    In distributed quantum computation, small devices composed of a single or a few qubits are networked together to achieve a scalable machine. Typically, there is an optically active matter qubit at each node, so that photons are exploited to achieve remote entanglement. However, in many systems the optically active states are unstable or poorly defined. We report a scheme to perform a high-fidelity entanglement operation even given severe instability. The protocol exploits the existence of optically excited states for phase acquisition without actually exciting those states; it functions with or without cavities and does not require number-resolving detectors.

  12. Optical systems integrated modeling

    NASA Technical Reports Server (NTRS)

    Shannon, Robert R.; Laskin, Robert A.; Brewer, SI; Burrows, Chris; Epps, Harlan; Illingworth, Garth; Korsch, Dietrich; Levine, B. Martin; Mahajan, Vini; Rimmer, Chuck

    1992-01-01

    An integrated modeling capability that provides the tools by which entire optical systems and instruments can be simulated and optimized is a key technology development, applicable to all mission classes, especially astrophysics. Many of the future missions require optical systems that are physically much larger than anything flown before and yet must retain the characteristic sub-micron diffraction limited wavefront accuracy of their smaller precursors. It is no longer feasible to follow the path of 'cut and test' development; the sheer scale of these systems precludes many of the older techniques that rely upon ground evaluation of full size engineering units. The ability to accurately model (by computer) and optimize the entire flight system's integrated structural, thermal, and dynamic characteristics is essential. Two distinct integrated modeling capabilities are required. These are an initial design capability and a detailed design and optimization system. The content of an initial design package is shown. It would be a modular, workstation based code which allows preliminary integrated system analysis and trade studies to be carried out quickly by a single engineer or a small design team. A simple concept for a detailed design and optimization system is shown. This is a linkage of interface architecture that allows efficient interchange of information between existing large specialized optical, control, thermal, and structural design codes. The computing environment would be a network of large mainframe machines and its users would be project level design teams. More advanced concepts for detailed design systems would support interaction between modules and automated optimization of the entire system. Technology assessment and development plans for integrated package for initial design, interface development for detailed optimization, validation, and modeling research are presented.

  13. Compressive optical imaging systems

    NASA Astrophysics Data System (ADS)

    Wu, Yuehao

    Compared to the classic Nyquist sampling theorem, Compressed Sensing or Compressive Sampling (CS) was proposed as a more efficient alternative for sampling sparse signals. In this dissertation, we discuss the implementation of the CS theory in building a variety of optical imaging systems. CS-based Imaging Systems (CSISs) exploit the sparsity of optical images in their transformed domains by imposing incoherent CS measurement patterns on them. The amplitudes and locations of sparse frequency components of optical images in their transformed domains can be reconstructed from the CS measurement results by solving an l1-regularized minimization problem. In this work, we review the theoretical background of the CS theory and present two hardware implementation schemes for CSISs, including a single pixel detector based scheme and an array detector based scheme. The first implementation scheme is suitable for acquiring Two-Dimensional (2D) spatial information of the imaging scene. We demonstrate the feasibility of this implementation scheme by developing a single pixel camera, a multispectral imaging system, and an optical sectioning microscope for fluorescence microscopy. The array detector based scheme is suitable for hyperspectral imaging applications, wherein both the spatial and spectral information of the imaging scene are of interest. We demonstrate the feasibility of this scheme by developing a Digital Micromirror Device-based Snapshot Spectral Imaging (DMD-SSI) system, which implements CS measurement processes on the Three-Dimensional (3D) spatial/spectral information of the imaging scene. Tens of spectral images can be reconstructed from the DMD-SSI system simultaneously without any mechanical or temporal scanning processes.

  14. An Efficient Correction Algorithm for Eliminating Image Misalignment Effects on Co-Phasing Measurement Accuracy for Segmented Active Optics Systems

    PubMed Central

    Yue, Dan; Xu, Shuyan; Nie, Haitao; Wang, Zongyang

    2016-01-01

    The misalignment between recorded in-focus and out-of-focus images using the Phase Diversity (PD) algorithm leads to a dramatic decline in wavefront detection accuracy and image recovery quality for segmented active optics systems. This paper demonstrates the theoretical relationship between the image misalignment and tip-tilt terms in Zernike polynomials of the wavefront phase for the first time, and an efficient two-step alignment correction algorithm is proposed to eliminate these misalignment effects. This algorithm processes a spatial 2-D cross-correlation of the misaligned images, revising the offset to 1 or 2 pixels and narrowing the search range for alignment. Then, it eliminates the need for subpixel fine alignment to achieve adaptive correction by adding additional tip-tilt terms to the Optical Transfer Function (OTF) of the out-of-focus channel. The experimental results demonstrate the feasibility and validity of the proposed correction algorithm to improve the measurement accuracy during the co-phasing of segmented mirrors. With this alignment correction, the reconstructed wavefront is more accurate, and the recovered image is of higher quality. PMID:26934045

  15. Optical gyroscope system

    NASA Technical Reports Server (NTRS)

    Goss, W. C.; Goldstein, R. (Inventor)

    1981-01-01

    Light beams pass in opposite directions through a single mode fiber optic wave guide that extends in a circle or coil in an optical gyroscope system which measures the rotation rate of the coil by measuring the relative phase shifts of the beams by interferometric techniques. Beam splitting and phase shifting of the light are facilitated by utilizing brief pulses of light and by using light-controlling devices which are operated for a brief time only when the light pulse passes in one direction through the device but not at a different time when the pulse is passing in the opposite direction through the device. High accuracy in rotation measurement is achieved at both very slow and very fast rotation rates, by alternately operating the system so that at zero rotation the interfering waves are alternately 90 out of phase and in phase. Linear polarization of the light beams is maintained by coiling the full length of the optic fiber in a single plane.

  16. Optical fiber inspection system

    DOEpatents

    Moore, F.W.

    1985-04-05

    A remote optical inspection system including an inspection head. The inspection head has a passageway through which pellets or other objects are passed. A window is provided along the passageway through which light is beamed against the objects being inspected. A plurality of lens assemblies are arranged about the window so that reflected light can be gathered and transferred to a plurality of coherent optical fiber light guides. The light guides transfer the light images to a television or other image transducer which converts the optical images into a representative electronic signal. The electronic signal can then be displayed on a signal viewer such as a television monitor for inspection by a person. A staging means can be used to support the objects for viewing through the window. Routing means can be used to direct inspected objects into appropriate exit passages for accepted or rejected objects. The inspected objects are advantageously fed in a singular manner to the staging means and routing means. The inspection system is advantageously used in an enclosure when toxic or hazardous materials are being inspected. 10 figs.

  17. Optical fiber inspection system

    DOEpatents

    Moore, Francis W.

    1987-01-01

    A remote optical inspection system including an inspection head. The inspection head has a passageway through which pellets or other objects are passed. A window is provided along the passageway through which light is beamed against the objects being inspected. A plurality of lens assemblies are arranged about the window so that reflected light can be gathered and transferred to a plurality of coherent optical fiber light guides. The light guides transfer the light images to a television or other image transducer which converts the optical images into a representative electronic signal. The electronic signal can then be displayed on a signal viewer such as a television monitor for inspection by a person. A staging means can be used to support the objects for viewing through the window. Routing means can be used to direct inspected objects into appropriate exit passages for accepted or rejected objects. The inspected objects are advantageously fed in a singular manner to the staging means and routing means. The inspection system is advantageously used in an enclosure when toxic or hazardous materials are being inspected.

  18. CP symmetry in optical systems

    NASA Astrophysics Data System (ADS)

    Dana, Brenda; Bahabad, Alon; Malomed, Boris A.

    2015-04-01

    We introduce a model of a dual-core optical waveguide with opposite signs of the group-velocity dispersion in the two cores, and a phase-velocity mismatch between them. The coupler is embedded into an active host medium, which provides for the linear coupling of a gain-loss type between the two cores. The same system can be derived, without phenomenological assumptions, by considering the three-wave propagation in a medium with the quadratic nonlinearity, provided that the depletion of the second-harmonic pump is negligible. This linear system offers an optical realization of the charge-parity symmetry, while the addition of the intracore cubic nonlinearity breaks the symmetry. By means of direct simulations and analytical approximations, it is demonstrated that the linear system generates expanding Gaussian states, while the nonlinear one gives rise to broad oscillating solitons, as well as a general family of stable stationary gap solitons.

  19. Multispectral scanner optical system

    NASA Technical Reports Server (NTRS)

    Stokes, R. C.; Koch, N. G. (Inventor)

    1980-01-01

    An optical system for use in a multispectral scanner of the type used in video imaging devices is disclosed. Electromagnetic radiation reflected by a rotating scan mirror is focused by a concave primary telescope mirror and collimated by a second concave mirror. The collimated beam is split by a dichroic filter which transmits radiant energy in the infrared spectrum and reflects visible and near infrared energy. The long wavelength beam is filtered and focused on an infrared detector positioned in a cryogenic environment. The short wavelength beam is dispersed by a pair of prisms, then projected on an array of detectors also mounted in a cryogenic environment and oriented at an angle relative to the optical path of the dispersed short wavelength beam.

  20. Flow system for optical activity detection of vegetable extracts employing molecular exclusion continuous chromatographic detection

    NASA Astrophysics Data System (ADS)

    Fajer, V.; Rodríguez, C.; Naranjo, S.; Mesa, G.; Mora, W.; Arista, E.; Cepero, T.; Fernández, H.

    2006-02-01

    The combination of molecular exclusion chromatography and laser polarimetric detection has turned into a carbohydrate separation and quantification system for plant fluids of industrial value, making it possible the evaluation of the quality of sugarcane juices, agave juices and many other plant extracts. Some previous papers described a system where liquid chromatography separation and polarimetric detection using a LASERPOL 101M polarimeter with He-Ne light source allowed the collection and quantification of discrete samples for analytical purposes. In this paper, the authors are introducing a new improved system which accomplishes polarimetric measurements in a continuous flux. Chromatograms of several carbohydrates standard solutions were obtained as useful references to study juice quality of several sugarcane varieties under different physiological conditions. Results by either discrete or continuous flux systems were compared in order to test the validation of the new system. An application of the system to the diagnostics of scalded foliar is described. A computer program allowing the output of the chromatograms to a display on line and the possibility of digital storing, maxima detections, zone integration, and some other possibilities make this system very competitive and self-convincing.

  1. Optical detector calibrator system

    NASA Technical Reports Server (NTRS)

    Strobel, James P. (Inventor); Moerk, John S. (Inventor); Youngquist, Robert C. (Inventor)

    1996-01-01

    An optical detector calibrator system simulates a source of optical radiation to which a detector to be calibrated is responsive. A light source selected to emit radiation in a range of wavelengths corresponding to the spectral signature of the source is disposed within a housing containing a microprocessor for controlling the light source and other system elements. An adjustable iris and a multiple aperture filter wheel are provided for controlling the intensity of radiation emitted from the housing by the light source to adjust the simulated distance between the light source and the detector to be calibrated. The geared iris has an aperture whose size is adjustable by means of a first stepper motor controlled by the microprocessor. The multiple aperture filter wheel contains neutral density filters of different attenuation levels which are selectively positioned in the path of the emitted radiation by a second stepper motor that is also controlled by the microprocessor. An operator can select a number of detector tests including range, maximum and minimum sensitivity, and basic functionality. During the range test, the geared iris and filter wheel are repeatedly adjusted by the microprocessor as necessary to simulate an incrementally increasing simulated source distance. A light source calibration subsystem is incorporated in the system which insures that the intensity of the light source is maintained at a constant level over time.

  2. Teaching Optics and Systems Engineering With Adaptive Optics Workbenches

    NASA Astrophysics Data System (ADS)

    Harrington, D. M.; Ammons, M.; Hunter, L.; Max, C.; Hoffmann, M.; Pitts, M.; Armstrong, J. D.

    2010-12-01

    Adaptive optics workbenches are fully functional optical systems that can be used to illustrate and teach a variety of concepts and cognitive processes. Four systems have been funded, designed and constructed by various institutions and people as part of education programs associated with the Center for Adaptive Optics, the Professional Development Program and the Institute for Scientist & Engineer Educators. Activities can range from first-year undergraduate explorations to professional level training. These workbenches have been used in many venues including the Center for Adaptive Optics AO Summer School, the Maui Community College-hosted Akamai Maui Short Course, classrooms, training of new staff in laboratories and other venues. The activity content has focused on various elements of systems thinking, characterization, feedback and system control, basic optics and optical alignment as well as advanced topics such as phase conjugation, wave-front sensing and correction concepts, and system design. The workbenches have slightly different designs and performance capabilities. We describe here outlines for several activities utilizing these different designs and some examples of common student learner outcomes and experiences.

  3. Optical system defect propagation in ABCD systems.

    PubMed

    McKinley, W G; Yura, H T; Hanson, S G

    1988-05-01

    We describe how optical system defects (tilt/jitter, decenter, and despace) propagate through an arbitrary paraxial optical system that can be described by an ABCD ray transfer matrix. A pedagogical example is given that demonstrates the effect of alignment errors on a typical optical system. PMID:19745889

  4. Active figure maintenance control using an optical truss laser metrology system for a space-based far-IR segmented telescope

    NASA Technical Reports Server (NTRS)

    Lau, Kenneth; Breckenridge, Bill; Nerheim, Noble; Redding, David

    1992-01-01

    A two-stage active control approach was developed addressing the figure control problem for a spaceborne FIR telescope, the Precision Segmented Reflectors Focus Moderate Mission Telescope (FMMT). The first active control stage aligns the optical segments based on images; attention is here given to the second stage, active figure maintenance control system, which maintains the alignment of the optical elements between initializations to hold the mirror figure steady while obtaining data and fixes translational and rotational changes of the optical segments induced by long-term thermal drifts of the support structure. Errors are expected to be 10-100 microns at the nodes of the primary backup structure over the course of an orbit. An rms performance of 0.8 microns of wavefront error can be expected during the maintenance function based on specified nominal sensor noises, actuator accuracies, and system environments. A performance of less than 0.3 microns rms can be expected, based on advanced components.

  5. The Adaptive Optics Summer School Laboratory Activities

    NASA Astrophysics Data System (ADS)

    Ammons, S. M.; Severson, S.; Armstrong, J. D.; Crossfield, I.; Do, T.; Fitzgerald, M.; Harrington, D.; Hickenbotham, A.; Hunter, J.; Johnson, J.; Johnson, L.; Li, K.; Lu, J.; Maness, H.; Morzinski, K.; Norton, A.; Putnam, N.; Roorda, A.; Rossi, E.; Yelda, S.

    2010-12-01

    Adaptive Optics (AO) is a new and rapidly expanding field of instrumentation, yet astronomers, vision scientists, and general AO practitioners are largely unfamiliar with the root technologies crucial to AO systems. The AO Summer School (AOSS), sponsored by the Center for Adaptive Optics, is a week-long course for training graduate students and postdoctoral researchers in the underlying theory, design, and use of AO systems. AOSS participants include astronomers who expect to utilize AO data, vision scientists who will use AO instruments to conduct research, opticians and engineers who design AO systems, and users of high-bandwidth laser communication systems. In this article we describe new AOSS laboratory sessions implemented in 2006-2009 for nearly 250 students. The activity goals include boosting familiarity with AO technologies, reinforcing knowledge of optical alignment techniques and the design of optical systems, and encouraging inquiry into critical scientific questions in vision science using AO systems as a research tool. The activities are divided into three stations: Vision Science, Fourier Optics, and the AO Demonstrator. We briefly overview these activities, which are described fully in other articles in these conference proceedings (Putnam et al., Do et al., and Harrington et al., respectively). We devote attention to the unique challenges encountered in the design of these activities, including the marriage of inquiry-like investigation techniques with complex content and the need to tune depth to a graduate- and PhD-level audience. According to before-after surveys conducted in 2008, the vast majority of participants found that all activities were valuable to their careers, although direct experience with integrated, functional AO systems was particularly beneficial.

  6. Optical activity of BL Lacertae

    NASA Astrophysics Data System (ADS)

    Larionov, V.; Blinov, D.; Konstantinova, T.

    2012-04-01

    We perform optical photometric and R-band polarimetric monitoring of BL Lac using 70-cm AZT-8 (CrAO, Ukraine) and 0.4-m LX-200 (St.Petersburg, Russia) telescopes, as a part of GASP project. As reported in Atel#4028, this blazar was found by Fermi LAT in active state on 2012 April 9. Our data show that a sharp optical maximum was reached on the date 2012-04-08UT02:20, R=13.10, while on 2012-04-11UT01:30 R=13.40.

  7. Fiber optic control system integration

    NASA Technical Reports Server (NTRS)

    Poppel, G. L.; Glasheen, W. M.; Russell, J. C.

    1987-01-01

    A total fiber optic, integrated propulsion/flight control system concept for advanced fighter aircraft is presented. Fiber optic technology pertaining to this system is identified and evaluated for application readiness. A fiber optic sensor vendor survey was completed, and the results are reported. The advantages of centralized/direct architecture are reviewed, and the concept of the protocol branch is explained. Preliminary protocol branch selections are made based on the F-18/F404 application. Concepts for new optical tools are described. Development plans for the optical technology and the described system are included.

  8. Optical Studies of Active Comets

    NASA Technical Reports Server (NTRS)

    Jewitt, David

    1998-01-01

    This grant was to support optical studies of comets close enough to the sun to be outgassing. The main focus of the observations was drawn to the two extraordinarily bright comets Hyakutake and Hale-Bopp, but other active comets were also studied in detail during the period of funding. Major findings (all fully published) under this grant include: (1) Combined optical and submillimeter observations of the comet/Centaur P/Schwassmann-Wachmann 1 were used to study the nature of mass loss from this object. The submillimeter observations show directly that the optically prominent dust coma is ejected by the sublimation of carbon monoxide. Simultaneous optical-submillimeter observations allowed us to test earlier determinations of the dust mass loss rate. (2) We modelled the rotation of cometary nuclei using time-resolved images of dust jets as the primary constraint. (3) We obtained broad-band optical images of several comets for which we subsequently attempted submillimeter observations, in order to test and update the cometary ephemerides. (4) Broad-band continuum images of a set of weakly active comets and, apparently, inactive asteroids were obtained in BVRI using the University of Hawaii 2.2-m telescope. These images were taken in support of a program to test the paradigm that many near-Earth asteroids might be dead or dormant comets. We measured coma vs. nucleus colors in active comets (finding that coma particle scattering is different from, and cannot be simply related to, nucleus color). We obtained spectroscopic observations of weakly active comets and other small bodies using the HIRES spectrograph on the Keck 10-m telescope. These observation place sensitive limits to outgassing from these bodies, aided by the high (40,000) spectral resolution of HIRES.

  9. Development of a portable active long-path differential optical absorption spectroscopy system for volcanic gas measurements

    USGS Publications Warehouse

    Vita, Fabio; Kern, Christoph; Inguaggiato, Salvatore

    2014-01-01

    Active long-path differential optical absorption spectroscopy (LP-DOAS) has been an effective tool for measuring atmospheric trace gases for several decades. However, instruments were large, heavy and power-inefficient, making their application to remote environments extremely challenging. Recent developments in fibre-coupling telescope technology and the availability of ultraviolet light emitting diodes (UV-LEDS) have now allowed us to design and construct a lightweight, portable, low-power LP-DOAS instrument for use at remote locations and specifically for measuring degassing from active volcanic systems. The LP-DOAS was used to measure sulfur dioxide (SO2) emissions from La Fossa crater, Vulcano, Italy, where column densities of up to 1.2 × 1018 molec cm−2 (~ 500 ppmm) were detected along open paths of up to 400 m in total length. The instrument's SO2 detection limit was determined to be 2 × 1016 molec cm−2 (~ 8 ppmm), thereby making quantitative detection of even trace amounts of SO2 possible. The instrument is capable of measuring other volcanic volatile species as well. Though the spectral evaluation of the recorded data showed that chlorine monoxide (ClO) and carbon disulfide (CS2) were both below the instrument's detection limits during the experiment, the upper limits for the X / SO2 ratio (X = ClO, CS2) could be derived, and yielded 2 × 10−3 and 0.1, respectively. The robust design and versatility of the instrument make it a promising tool for monitoring of volcanic degassing and understanding processes in a range of volcanic systems.

  10. Compact color schlieren optical system

    NASA Technical Reports Server (NTRS)

    Buchele, Donald R.; Griffin, Devon W.

    1993-01-01

    A compact optical system for use with rainbow schlieren deflectometry is described. Both halves of the optical system consist of well-corrected telescopes whose refractive elements are all from manufacturer's stock catalogs, with the reflective primary being a spherical surface. As a result, the system is relatively easy to construct and meets the requirement of long focal length for quantitative rainbow schlieren measurements.

  11. Optical system for multispectral scanner

    NASA Technical Reports Server (NTRS)

    Stokes, R. C.; Koch, N. G.

    1979-01-01

    Optical system designed for scanning eight spectra bands simultaneously from aircraft at variety of speeds and altitudes is compact, easy to align, and reliable. System efficiently and effectively circumvents many problems associated with previous systems.

  12. Benchmarking of optical dimerizer systems.

    PubMed

    Pathak, Gopal P; Strickland, Devin; Vrana, Justin D; Tucker, Chandra L

    2014-11-21

    Optical dimerizers are a powerful new class of optogenetic tools that allow light-inducible control of protein-protein interactions. Such tools have been useful for regulating cellular pathways and processes with high spatiotemporal resolution in live cells, and a growing number of dimerizer systems are available. As these systems have been characterized by different groups using different methods, it has been difficult for users to compare their properties. Here, we set about to systematically benchmark the properties of four optical dimerizer systems, CRY2/CIB1, TULIPs, phyB/PIF3, and phyB/PIF6. Using a yeast transcriptional assay, we find significant differences in light sensitivity and fold-activation levels between the red light regulated systems but similar responses between the CRY2/CIB and TULIP systems. Further comparison of the ability of the CRY2/CIB1 and TULIP systems to regulate a yeast MAPK signaling pathway also showed similar responses, with slightly less background activity in the dark observed with CRY2/CIB. In the process of developing this work, we also generated an improved blue-light-regulated transcriptional system using CRY2/CIB in yeast. In addition, we demonstrate successful application of the CRY2/CIB dimerizers using a membrane-tethered CRY2, which may allow for better local control of protein interactions. Taken together, this work allows for a better understanding of the capacities of these different dimerization systems and demonstrates new uses of these dimerizers to control signaling and transcription in yeast. PMID:25350266

  13. Different ways to active optical frequency standards

    NASA Astrophysics Data System (ADS)

    Pan, Duo; Xue, Xiaobo; Zhang, Xiaogang; Chen, Jingbiao

    2016-06-01

    Active optical frequency standard, or active optical clock, is a new concept of optical frequency standard, where a weak feedback with phase coherence information in optical bad-cavity limitation is formed, and the continuous self-sustained coherent stimulated emission between two atomic transition levels with population inversion is realized. Through ten years of both theoretical and experimental exploration, the narrow linewidth and suppression of cavity pulling effect of active optical frequency standard have been initially proved. In this paper, after a simple review, we will mainly present the most recent experimental progresses of active optical frequency standards in Peking University, including 4-level cesium active optical frequency standards and active Faraday optical frequency standards. The future development of active optical frequency standards is also discussed.

  14. Optical positions of active galaxies

    NASA Astrophysics Data System (ADS)

    Meurs, E. J. A.

    1984-04-01

    Optical positions are calculated for 26 active galaxies (mainly Markarian dn Arakelian objects), using the plate-measuring apparatus at Leiden Observatory on the O plates of the Palomar Sky Survey and applying AGK-3 data in the reductions. The results are presented in a table and have accuracy 0.5 arcsec; a comparison with the positions determined by Clements (1981, 1983) for 19 objects reveals a possible offset of -0.28 arcsec in the right-ascension determinations.

  15. Optical control of antibacterial activity

    NASA Astrophysics Data System (ADS)

    Velema, Willem A.; van der Berg, Jan Pieter; Hansen, Mickel J.; Szymanski, Wiktor; Driessen, Arnold J. M.; Feringa, Ben L.

    2013-11-01

    Bacterial resistance is a major problem in the modern world, stemming in part from the build-up of antibiotics in the environment. Novel molecular approaches that enable an externally triggered increase in antibiotic activity with high spatiotemporal resolution and auto-inactivation are highly desirable. Here we report a responsive, broad-spectrum, antibacterial agent that can be temporally activated with light, whereupon it auto-inactivates on the scale of hours. The use of such a ‘smart’ antibiotic might prevent the build-up of active antimicrobial material in the environment. Reversible optical control over active drug concentration enables us to obtain pharmacodynamic information. Precisely localized control of activity is achieved, allowing the growth of bacteria to be confined to defined patterns, which has potential for the development of treatments that avoid interference with the endogenous microbial population in other parts of the organism.

  16. Synthesis and optical properties of a crosslinkable polymer system containing TCF and TCP chromophores with excellent electro-optic activity and thermal stability

    NASA Astrophysics Data System (ADS)

    Chen, Zhuo; Bo, Shuhui; Zhen, Zhen; Liu, Xinhou

    2012-10-01

    Crosslinkable polymer with side-chain system was investigated to increase the content of NLO chromophores and improve the stability of oriented chromophores. In this work, a series of crosslinkable copolymers which beared different concentrations of chromophores with the tricyanofurane (TCF) acceptor and a kind of crosslinkable copolymers beared chromophores with dendritic tricyanopyrroline (TCP) acceptor were successfully synthesized and characterized. The crosslinked EO polymers which beared chromophores with the tricyanofurane (TCF) acceptor revealed the highest EO coefficient (r33) of 47.0 pm/V at 1310 nm, which was similar with the r33 of uncrosslinked systems. Compared to the uncrosslinked EO polymer systems, the crosslinked ones exhibited significantly enhanced temporal stability. Keywords: Nonlinear optics; Crosslinkable system; Chromophore-containing copolymers; Side-chain; Crosslinking reaction; Thermally stable polymer

  17. Optical modulator system

    NASA Technical Reports Server (NTRS)

    Brand, J.

    1972-01-01

    The fabrication, test, and delivery of an optical modulator system which will operate with a mode-locked Nd:YAG laser indicating at either 1.06 or 0.53 micrometers is discussed. The delivered hardware operates at data rates up to 400 Mbps and includes a 0.53 micrometer electrooptic modulator, a 1.06 micrometer electrooptic modulator with power supply and signal processing electronics with power supply. The modulators contain solid state drivers which accept digital signals with MECL logic levels, temperature controllers to maintain a stable thermal environment for the modulator crystals, and automatic electronic compensation to maximize the extinction ratio. The modulators use two lithium tantalate crystals cascaded in a double pass configuration. The signal processing electronics include encoding electronics which are capable of digitizing analog signals between the limit of + or - 0.75 volts at a maximum rate of 80 megasamples per second with 5 bit resolution. The digital samples are serialized and made available as a 400 Mbps serial NRZ data source for the modulators. A pseudorandom (PN) generator is also included in the signal processing electronics. This data source generates PN sequences with lengths between 31 bits and 32,767 bits in a serial NRZ format at rates up to 400 Mbps.

  18. Optical power distribution system

    SciTech Connect

    Lalmond, R.G.

    1987-09-08

    This patent describes an apparatus for supplying electrical power to electrical components mounted on a circuit board. It consists of: a printed circuit board; electrical components mounted on the printed circuit board; electrically powered sources of optical energy; photovoltaic cell arrays; each photovoltaic cell array being mounted on a corresponding one of the electrical components to provide electrical power to the electrical component on which it is mounted; and means for coupling the optical energy from the electrically powered sources of optical energy to the photovoltaic cell arrays.

  19. Technology reviews: Daylighting optical systems

    SciTech Connect

    Schuman, J.; Rubinstein, F.; Papamichael, K.; Beltran, L.; Lee, E.S.; Selkowitz, S.

    1992-09-01

    We present a representative review of existing, emerging, and future technology options in each of five hardware and systems areas in envelope and lighting technologies: lighting systems, glazing systems, shading systems, daylighting optical systems, and dynamic curtain wall systems. The term technology is used here to describe any design choice for energy efficiency, ranging from individual components to more complex systems to general design strategies. The purpose of this task is to characterize the state of the art in envelope and lighting technologies in order to identify those with promise for advanced integrated systems, with an emphasis on California commercial buildings. For each technology category, the following activities have been attempted to the extent possible: Identify key performance characteristics and criteria for each technology. Determine the performance range of available technologies. Identify the most promising technologies and promising trends in technology advances. Examine market forces and market trends.Develop a continuously growing in-house database to be used throughout the project. A variety of information sources have been used in these technology characterizations, including miscellaneous periodicals, manufacturer catalogs and cut sheets, other research documents, and data from previous computer simulations. We include these different sources in order to best show the type and variety of data available, however publication here does not imply our guarantee of these data. Within each category, several broad classes are identified, and within each class we examine the generic individual technologies that fall into that class.

  20. Optical design and active optics methods in astronomy

    NASA Astrophysics Data System (ADS)

    Lemaitre, Gerard R.

    2013-03-01

    Optical designs for astronomy involve implementation of active optics and adaptive optics from X-ray to the infrared. Developments and results of active optics methods for telescopes, spectrographs and coronagraph planet finders are presented. The high accuracy and remarkable smoothness of surfaces generated by active optics methods also allow elaborating new optical design types with high aspheric and/or non-axisymmetric surfaces. Depending on the goal and performance requested for a deformable optical surface analytical investigations are carried out with one of the various facets of elasticity theory: small deformation thin plate theory, large deformation thin plate theory, shallow spherical shell theory, weakly conical shell theory. The resulting thickness distribution and associated bending force boundaries can be refined further with finite element analysis.

  1. Multiwavelength optical observations of chromospherically active binary systems. V. FF UMa (2RE J0933+624): a system with orbital period variation

    NASA Astrophysics Data System (ADS)

    Gálvez, M. C.; Montes, D.; Fernández-Figueroa, M. J.; de Castro, E.; Cornide, M.

    2007-09-01

    Context: This is the fifth paper in a series aimed at studying the chromospheres of active binary systems using several optical spectroscopic indicators to obtain or improve orbital solution and fundamental stellar parameters. Aims: We present here the study of FF UMa (2RE J0933+624), a recently discovered, X-ray/EUV selected, active binary with strong Hα emission. The objectives of this work are, to find orbital solutions and define stellar parameters from precise radial velocities and carry out an extensive study of the optical indicators of chromospheric activity. Methods: We obtained high resolution echelle spectroscopic observations during five observing runs from 1998 to 2004. We found radial velocities by cross correlation with radial velocity standard stars to achieve the best orbital solution. We also measured rotational velocity by cross-correlation techniques and have studied the kinematic by galactic space-velocity components (U, V, W) and Eggen criteria. Finally, we have determined the chromospheric contribution in optical spectroscopic indicators, from Ca ii H & K to Ca ii IRT lines, using the spectral subtraction technique. Results: We have found that this system presents an orbital period variation, higher than previously detected in other RS CVn systems. We determined an improved orbital solution, finding a circular orbit with a period of 3.274 days. We derived the stellar parameters, confirming the subgiant nature of the primary component (MP = 1.67 M⊙ and R sin{i}_P=2.17 R⊙) and obtained rotational velocities (v sin{i}), of 33.57 ± 0.45 km s-1 and 32.38 ± 0.75 km s-1 for the primary and secondary components respectively. From our kinematic study, we can deduce its membership to the Castor moving group. Finally, the activity study has given us a better understanding of the possible mechanisms that produce the orbital period variation. Based on observations collected with the 2.2 m telescope at the Centro Astronómico Hispano Alemán (CAHA

  2. System for testing optical fibers

    DOEpatents

    Golob, J.E.; Looney, L.D.; Lyons, P.B.; Nelson, M.A.; Davies, T.J.

    1980-07-15

    A system for measuring a combination of optical transmission properties of fiber optic waveguides. A polarized light pulse probe is injected into one end of the optical fiber. Reflections from discontinuities within the fiber are unpolarized whereas reflections of the probe pulse incident to its injection remain polarized. The polarized reflections are prevented from reaching a light detector whereas reflections from the discontinuities reaches the detector. 2 figs.

  3. System for testing optical fibers

    DOEpatents

    Golob, John E. [Olathe, KS; Looney, Larry D. [Los Alamos, NM; Lyons, Peter B. [Los Alamos, NM; Nelson, Melvin A. [Santa Barbara, CA; Davies, Terence J. [Santa Barbara, CA

    1980-07-15

    A system for measuring a combination of optical transmission properties of fiber optic waveguides. A polarized light pulse probe is injected into one end of the optical fiber. Reflections from discontinuities within the fiber are unpolarized whereas reflections of the probe pulse incident to its injection remain polarized. The polarized reflections are prevented from reaching a light detector whereas reflections from the discontinuities reaches the detector.

  4. Compact color schlieren optical system.

    PubMed

    Buchele, D R; Griffin, D W

    1993-08-01

    A compact optical system for use with rainbow schlieren deflectometry is described. Both halves of the optical system consist of well-corrected telescopes whose refractive elements are all from manufacturer's stock catalogs, with the reflective primary being a spherical surface. As a result, the system is relatively easy to construct and meets the requirement of long focal length for quantitative rainbow schlieren measurements. PMID:20830072

  5. Active optics with a minimum number of actuators

    NASA Astrophysics Data System (ADS)

    Lemaitre, Gerard R.

    2014-06-01

    Optics for astronomy implies powerful developments of active and adaptive optics methods applied to instrumentation from X-rays to the near infrared for the design of telescopes, spectrographs, and coronagraph planet finders. This presentation particularly emphasizes the development of active optics methods. Highly accurate and remarkably smooth surfaces from active optics methods allow new optical systems that use highly aspheric and non-axisymmetric - freeform - surfaces. Depending on the goal and performance required for a deformable optical surface, elasticity theory analysis is carried out either with small deformation thin plate theory, large deformation thin plate theory, shallow spherical shell theory, or the weakly conical shell theory. A mirror thickness distribution is then determined as a function of associated bending actuators and boundary conditions. For a given optical shape to generate, one searches for optical solutions with a minimum number of actuators.

  6. Nonimaging optical illumination system

    DOEpatents

    Winston, R.; Ries, H.

    1998-10-06

    A nonimaging illumination optical device for producing a selected far field illuminance over an angular range. The optical device includes a light source a light reflecting surface, and a family of light edge rays defined along a reference line with the reflecting surface defined in terms of the reference lines a parametric function R(t) where t is a scalar parameter position and R(t)=k(t)+Du(t) where k(t) is a parameterization of the reference line, and D is a distance from a point on the reference line to the reflection surface along the desired edge ray through the point. 35 figs.

  7. Nonimaging optical illumination system

    DOEpatents

    Winston, R.; Ries, H.

    1996-12-17

    A nonimaging illumination optical device for producing a selected far field illuminance over an angular range. The optical device includes a light source, a light reflecting surface, and a family of light edge rays defined along a reference line with the reflecting surface defined in terms of the reference line as a parametric function R(t) where t is a scalar parameter position and R(t)=k(t)+Du(t) where k(t) is a parameterization of the reference line, and D is a distance from a point on the reference line to the reflection surface along the desired edge ray through the point. 35 figs.

  8. All optical OFDM transmission systems

    NASA Astrophysics Data System (ADS)

    Rhee, June-Koo K.; Lim, Seong-Jin; Kserawi, Malaz

    2011-12-01

    All-optical OFDM data transmission opens up a new realm of advanced optical transmission at extreme data rates, as subcarriers are multiplexed and demultiplexed by all optical discrete Fourier transforms (DFT). This paper reviews the principles of all optical OFDM transmission and its system application techniques, providing the generic ideas and the practical implementation issues to achieve 100Gbps or higher data rates with a spectral efficiency of 1 bps/Hz or better. This paper also include discussions on all-optical OFDM implementation variants such as an AWG-based OFDM multiplexer and demultiplexer, a receiver design without optical sampling, a transmitter design with frequency-locked cw lasers, an OFDM cyclic prefix designs, and a chromatic dispersion mitigation technique.

  9. Improved optical lens system

    NASA Technical Reports Server (NTRS)

    Schmidt, L. F.

    1970-01-01

    Objective lens produces a backwardly curving image of a star field that matches the similarly curved surface of the photocathode of an image dissector tube. Lens eliminates the need for a fiber-optics translation between the flat plane image and curved photocathode.

  10. Compact Color Schlieren Optical System

    NASA Technical Reports Server (NTRS)

    Buchele, Donald R.; Griffin, Devon W.

    1996-01-01

    Compact, rugged optical system developed for use in rainbow schlieren deflectometry. Features unobscured telescope with focal-length/aperture-width ratio of 30. Made of carefully selected but relatively inexpensive parts. All of lenses stock items. By-product of design is optical system with loose tolerances on interlens spacing. One of resulting advantages, insensitivity to errors in fabrication of optomechanical mounts. Another advantage is ability to compensate for some of unit-to-unit variations inherent in stock lenses.

  11. Target for optically activated seekers and trackers

    NASA Astrophysics Data System (ADS)

    Lakin, C. T.; Willett, N. F.

    1984-05-01

    This abstract discloses a target for optically activated seekers and trackers (TOAST) which provides for calibrated and variable target characteristics such as size, intensity, spatial position, color and interfering background. The TOAST has a first ilumination system providing a target light beam through an adjustable iris which controls image size. The target beam passes through a collimator lens which focuses the light at infinity. With the target beam focused at infinity, the motion of an elevation plate lengthens or shortens the distance from the collimator lens to a one motion mirror. The target beam is attenuated by a variable filter driven by a servo-motor, and a color selection process is provided by passing the beam through spectral filters. A background light beam with background imagery is provided to the beamsplitter mirror and mixed with the target image so as to simulate the target environment encountered by an operating optically activated seeker and tracker.

  12. Nonimaging optical illumination system

    DOEpatents

    Winston, Roland; Ries, Harald

    2000-01-01

    A nonimaging illumination optical device for producing a selected far field illuminance over an angular range. The optical device includes a light source 102, a light reflecting surface 108, and a family of light edge rays defined along a reference line 104 with the reflecting surface 108 defined in terms of the reference line 104 as a parametric function R(t) where t is a scalar parameter position and R(t)=k(t)+Du(t) where k(t) is a parameterization of the reference line 104, and D is a distance from a point on the reference line 104 to the reflection surface 108 along the desired edge ray through the point.

  13. Nonimaging optical illumination system

    DOEpatents

    Winston, Roland; Ries, Harald

    1998-01-01

    A nonimaging illumination optical device for producing a selected far field illuminance over an angular range. The optical device includes a light source 102, a light reflecting surface 108, and a family of light edge rays defined along a reference line 104 with the reflecting surface 108 defined in terms of the reference line 104 as a parametric function R(t) where t is a scalar parameter position and R(t)=k(t)+Du(t) where k(t) is a parameterization of the reference line 104, and D is a distance from a point on the reference line 104 to the reflection surface 108 along the desired edge ray through the point.

  14. Nonimaging optical illumination system

    DOEpatents

    Winston, Roland; Ries, Harald

    1996-01-01

    A nonimaging illumination optical device for producing a selected far field illuminance over an angular range. The optical device includes a light source 102, a light reflecting surface 108, and a family of light edge rays defined along a reference line 104 with the reflecting surface 108 defined in terms of the reference line 104 as a parametric function R(t) where t is a scalar parameter position and R(t)=k(t)+Du(t) where k(t) is a parameterization of the reference line 104, and D is a distance from a point on the reference line 104 to the reflection surface 108 along the desired edge ray through the point.

  15. Nonimaging Optical Illumination System

    DOEpatents

    Winston, Roland

    1994-02-22

    A nonimaging illumination or concentration optical device. An optical device is provided having a light source, a light reflecting surface with an opening and positioned partially around the light source which is opposite the opening of the light reflecting surface. The light reflecting surface is disposed to produce a substantially uniform intensity output with the reflecting surface defined in terms of a radius vector R.sub.i in conjunction with an angle .phi..sub.i between R.sub.i, a direction from the source and an angle .theta..sub.i between direct forward illumination and the light ray reflected once from the reflecting surface. R.sub.i varies as the exponential of tan (.phi..sub.i -.theta..sub.i)/2 integrated over .phi..sub.i.

  16. Nonimaging Optical Illumination System

    DOEpatents

    Winston, Roland

    1994-08-02

    A nonimaging illumination optical device for producing selected intensity output over an angular range. The device includes a light reflecting surface (24, 26) around a light source (22) which is disposed opposite the aperture opening of the light reflecting surface (24, 26). The light source (22) has a characteristic dimension which is small relative to one or more of the distance from the light source (22) to the light reflecting surface (24, 26) or the angle subtended by the light source (22) at the light reflecting surface (24, 26).

  17. Actively controlled thin-shell space optics

    NASA Astrophysics Data System (ADS)

    Denoyer, Keith K.; Flint, Eric M.; Main, John A.; Lindler, Jason E.

    2003-08-01

    Increasingly, scientific and military missions require the use of space-based optical systems. For example, new capabilities are required for imaging terrestrial like planets, for surveillance, and for directed energy applications. Given the difficulties in producing and launching large optics, it is doubtful that refinements of conventional technology will meet future needs, particularly in a cost-effective manner. To meet this need, recent research has been investigating the feasibility of a new class of ultra-lightweight think-skin optical elements that combine recent advances in lightweight thermally formed materials, active materials, and novel sensing and control architectures. If successful, the approach may lead to an order of magnitude reduction in space optics areal density, improved large scale manufacturing capability, and dramatic reductions in manufacturing and launch costs. In a recent effort, a one meter thin-film mirror like structure was fabricated. This paper provides an overview of tools used to model and simulate this structure as well as results from structural dynamic testing. In addition, progress in the area of non-contact global shape control using smart materials is presented.

  18. Roadmap on quantum optical systems

    NASA Astrophysics Data System (ADS)

    Dumke, Rainer; Lu, Zehuang; Close, John; Robins, Nick; Weis, Antoine; Mukherjee, Manas; Birkl, Gerhard; Hufnagel, Christoph; Amico, Luigi; Boshier, Malcolm G.; Dieckmann, Kai; Li, Wenhui; Killian, Thomas C.

    2016-09-01

    This roadmap bundles fast developing topics in experimental optical quantum sciences, addressing current challenges as well as potential advances in future research. We have focused on three main areas: quantum assisted high precision measurements, quantum information/simulation, and quantum gases. Quantum assisted high precision measurements are discussed in the first three sections, which review optical clocks, atom interferometry, and optical magnetometry. These fields are already successfully utilized in various applied areas. We will discuss approaches to extend this impact even further. In the quantum information/simulation section, we start with the traditionally successful employed systems based on neutral atoms and ions. In addition the marvelous demonstrations of systems suitable for quantum information is not progressing, unsolved challenges remain and will be discussed. We will also review, as an alternative approach, the utilization of hybrid quantum systems based on superconducting quantum devices and ultracold atoms. Novel developments in atomtronics promise unique access in exploring solid-state systems with ultracold gases and are investigated in depth. The sections discussing the continuously fast-developing quantum gases include a review on dipolar heteronuclear diatomic gases, Rydberg gases, and ultracold plasma. Overall, we have accomplished a roadmap of selected areas undergoing rapid progress in quantum optics, highlighting current advances and future challenges. These exciting developments and vast advances will shape the field of quantum optics in the future.

  19. Measurement of optical activity of honey bee

    NASA Astrophysics Data System (ADS)

    Ortiz-Gutiérrez, Mauricio; Olivares-Pérez, Arturo; Salgado-Verduzco, Marco Antonio; Ibarra-Torres, Juan Carlos

    2016-03-01

    Optical activity of some substances, such as chiral molecules, often exhibits circular birefringence. Circular birefringence causes rotation of the vibration plane of the plane polarized light as it passes through the substance. In this work we present optical characterization of honey as function of the optical activity when it is placed in a polariscope that consists of a light source and properly arranged polarizing elements.

  20. Freeform mirror based optical systems for FAME

    NASA Astrophysics Data System (ADS)

    Agócs, Tibor; Kroes, Gabby; Venema, Lars; Hugot, Emmanuel; Schnetler, Hermine; Jaskó, Attila

    2014-07-01

    In this paper we present the design of freeform mirror based optical systems that have the potential to be used in future astronomical instrumentation in the era of extremely large ground based telescopes. Firstly we describe the optical requirements followed by a summary of the optimization methodology used to design the freeform surface. The intention is to create optical architectures, which not only have the numerous advantages of freeform based systems (increased optical performance and/or reduction of mass and volume), but also can be manufactured and tested with today's manufacturing techniques and technologies. The team plans to build a demonstrator based on one of the optical design examples presented in this paper. The demonstrator will be built and tested as part of the OPTICON FP7 Freeform Active Mirror Experiment (FAME) project. A hydroforming technique developed as part of the previous OPTICON FP7 project will be used to produce an accurate, compact and stable freeform mirror. The manufacturing issues normally experienced in the production of freeform mirrors are solved through the hydroforming of thin polished substrates, which then will be supported with an active array structure. The active array will be used to compensate for residual manufacturing errors, thermo-elastic deformation and gravity-induced errors.

  1. Two improved coherent optical feedback systems for optical information processing

    NASA Technical Reports Server (NTRS)

    Lee, S. H.; Bartholomew, B.; Cederquist, J.

    1976-01-01

    Coherent optical feedback systems are Fabry-Perot interferometers modified to perform optical information processing. Two new systems based on plane parallel and confocal Fabry-Perot interferometers are introduced. The plane parallel system can be used for contrast control, intensity level selection, and image thresholding. The confocal system can be used for image restoration and solving partial differential equations. These devices are simpler and less expensive than previous systems. Experimental results are presented to demonstrate their potential for optical information processing.

  2. Laser beam modeling in optical storage systems

    NASA Technical Reports Server (NTRS)

    Treptau, J. P.; Milster, T. D.; Flagello, D. G.

    1991-01-01

    A computer model has been developed that simulates light propagating through an optical data storage system. A model of a laser beam that originates at a laser diode, propagates through an optical system, interacts with a optical disk, reflects back from the optical disk into the system, and propagates to data and servo detectors is discussed.

  3. Fiber optic data systems

    NASA Astrophysics Data System (ADS)

    Hartenstein, R.

    1985-08-01

    An overview is given of a continuing data system architecture development effort. Accomplishments and states of Office of Aeronautics and Space Technology, NASA efforts are discussed, and possible future directions are briefly commented upon. Some performance data is presented on the access protocol utilized in the Bus Interface Unit (BIU) design effort, and it is compared with other access protocols. The status of the qualification effort is presented showing the successful qualification testing of cables, connectors, light emitting diodes and PIN diodes. Information is given in the form of charts and diagrams.

  4. Fiber optic data systems

    NASA Technical Reports Server (NTRS)

    Hartenstein, R.

    1985-01-01

    An overview is given of a continuing data system architecture development effort. Accomplishments and states of Office of Aeronautics and Space Technology, NASA efforts are discussed, and possible future directions are briefly commented upon. Some performance data is presented on the access protocol utilized in the Bus Interface Unit (BIU) design effort, and it is compared with other access protocols. The status of the qualification effort is presented showing the successful qualification testing of cables, connectors, light emitting diodes and PIN diodes. Information is given in the form of charts and diagrams.

  5. Optical magnetism and optical activity in nonchiral planar plasmonic metamaterials.

    PubMed

    Li, Guozhou; Li, Qiang; Yang, Lizhen; Wu, Lijun

    2016-07-01

    We investigate optical magnetism and optical activity in a simple planar metamolecule composed of double U-shaped metal split ring resonators (SRRs) twisted by 90° with respect to one another. Compared to a single SRR, the resonant energy levels are split and strong magnetic response can be observed due to inductive and conductive coupling. More interestingly, the nonchiral structures exhibit strong optical gyrotropy (1100°/λ) under oblique incidence, benefiting from the strong electromagnetic coupling. A chiral molecule model is proposed to shed light on the physical origin of optical activity. These artificial chiral metamaterials could be utilized to control the polarization of light and promise applications in enantiomer sensing-based medicine, biology, and drug development. PMID:27367063

  6. System for testing optical fibers

    DOEpatents

    Davies, Terence J.; Franks, Larry A.; Nelson, Melvin A.

    1981-01-01

    A system for nondestructively determining the attenuation coefficient, .alpha.(.lambda.), of low-loss optical fiber wave guides. Cerenkov light pulses are generated at a plurality of locations in the fiber by a beam of charged particles. The transit times of selected spectral components and their intensities are utilized to unfold the .alpha.(.lambda.) values over the measured spectrum.

  7. VCSEL arrays for optical wireless systems

    NASA Astrophysics Data System (ADS)

    Tada, Katsuhisa; Nitatori, Koichi; Iwamoto, Takashi; Miura, Takamitsu; Sakai, Masahisa

    2001-05-01

    Now we have studied the development of the optical devices used in optical wireless communication systems. For optical wireless systems, the emitted light should have an intensity distribution in the shape of a pill-box. Use of VCSEL array was believed to allow the emitted light to have pill-box distribution and we performed the study concerning the optimum VCSEL array for optical wireless systems. This article describes the development of the VCSEL array for optical wireless systems.

  8. Use Of A Digital Optical Storage System

    NASA Astrophysics Data System (ADS)

    Collins, M. W.

    1983-01-01

    The Common File System (CFS) is a file management and file storage system for the Los Alamos National Laboratory's computer network. The CFS is organized as a hierarchical storage system: active files are stored on fast-access storage devices, larger, less active files are stored on slower, less expensive devices, and archival files are stored offline. Files are automatically moved between the various classes of storage by a file migration program that analyzes file activity, file size, and storage device capabilities. This has resulted in a cost-effective system that provides both fast access and large data storage capability (over 9 trillion bits currently stored). A large capacity (1014 bits), reliable Digital Optical Storage System would replace the offline storage as the archival part of the CFS and might also be used for active storage if it had a reasonable file access time.

  9. Optical system storage design with diffractive optical elements

    NASA Technical Reports Server (NTRS)

    Kostuk, Raymond K.; Haggans, Charles W.

    1993-01-01

    Optical data storage systems are gaining widespread acceptance due to their high areal density and the ability to remove the high capacity hard disk from the system. In magneto-optical read-write systems, a small rotation of the polarization state in the return signal from the MO media is the signal which must be sensed. A typical arrangement used for detecting these signals and correcting for errors in tracking and focusing on the disk is illustrated. The components required to achieve these functions are listed. The assembly and alignment of this complex system has a direct impact on cost, and also affects the size, weight, and corresponding data access rates. As a result, integrating these optical components and improving packaging techniques is an active area of research and development. Most designs of binary optic elements have been concerned with optimizing grating efficiency. However, rigorous coupled wave models for vector field diffraction from grating surfaces can be extended to determine the phase and polarization state of the diffracted field, and the design of polarization components. A typical grating geometry and the phase and polarization angles associated with the incident and diffracted fields are shown. In our current stage of work, we are examining system configurations which cascade several polarization functions on a single substrate. In this design, the beam returning from the MO disk illuminates a cascaded grating element which first couples light into the substrate, then introduces a quarter wave retardation, then a polarization rotation, and finally separates s- and p-polarized fields through a polarization beam splitter. The input coupler and polarization beam splitter are formed in volume gratings, and the two intermediate elements are zero-order elements.

  10. Multiwavelength optical observations of chromospherically active binary systems. III. High resolution echelle spectra from Ca II H & K to Ca II IRT

    NASA Astrophysics Data System (ADS)

    Montes, D.; Fernández-Figueroa, M. J.; De Castro, E.; Cornide, M.; Latorre, A.; Sanz-Forcada, J.

    2000-10-01

    This is the third paper of a series aimed at studying the chromosphere of active binary systems using the information provided for several optical spectroscopic features. High resolution echelle spectra including all the optical chromospheric activity indicators from the Ca II H & K to Ca II IRT lines are analysed here for 16 systems. The chromospheric contribution in these lines has been determined using the spectral subtraction technique. Very broad wings have been found in the subtracted Hα profile of the very active star HU Vir. These profiles are well matched using a two-component Gaussian fit (narrow and broad) and the broad component can be interpreted as arising from microflaring. Red-shifted absorption features in the Hα line have been detected in several systems and excess emission in the blue wing of FG UMa was also detected. These features indicate that several dynamical processes, or a combination of them, may be involved. Using the E_Hα /E_Hβ ratio as a diagnostic we have detected prominence-like extended material viewed off the limb in many stars of the sample, and prominences viewed against the disk at some orbital phases in the dwarfs OU Gem and BF Lyn. The He i D3 line has been detected as an absorption feature in mainly all the giants of the sample. Total filling-in of the He i D3, probably due to microflaring activity, is observed in HU Vir. Self-absorption with red asymmetry is detected in the Ca II H & K lines of the giants 12 Cam, FG UMa and BM CVn. All the stars analysed show clear filled-in Ca II IRT lines or even notable emission reversal. The small values of the E_8542/E_8498 ratio we have found indicate Ca II IRT emission arises from plage-like regions. Orbital phase modulation of the chromospheric emission has been detected in some systems, in the case of HU Vir evidence of an active longitude area has been found. Based on observations made with the Isaac Newton Telescope (INT) operated on the island of La Palma by the Isaac Newton

  11. Advanced rotorcraft helmet display sighting system optics

    NASA Astrophysics Data System (ADS)

    Raynal, Francois; Chen, Muh-Fa

    2002-08-01

    Kaiser Electronics' Advanced Rotorcraft Helmet Display Sighting System is a Biocular Helmet Mounted Display (HMD) for Rotary Wing Aviators. Advanced Rotorcraft HMDs requires low head supported weight, low center of mass offsets, low peripheral obstructions of the visual field, large exit pupils, large eye relief, wide field of view (FOV), high resolution, low luning, sun light readability with high contrast and low prismatic deviations. Compliance with these safety, user acceptance and optical performance requirements is challenging. The optical design presented in this paper provides an excellent balance of these different and conflicting requirements. The Advanced Rotorcraft HMD optical design is a pupil forming off axis catadioptric system that incorporates a transmissive SXGA Active Matrix liquid Crystal Display (AMLCD), an LED array backlight and a diopter adjustment mechanism.

  12. The Rochester Optical Streak System

    NASA Astrophysics Data System (ADS)

    Jaanimagi, P. A.; Boni, R.; Keck, R. L.; Donaldson, W. R.; Meyerhofer, D. D.

    2004-11-01

    A modern, self-calibrating, remotely controlled streak camera platform capable of accepting a variety of different streak tubes has been developed. Our current systems include P510, P820, and PJX streak tubes with both S-1 and S-20 photocathodes. The input may be either fiber delivery or free-space propagation and is relayed to the photocathode with an achromatic Offner triplet. Calibration functions include autofocus of the input and electron optics, geometric distortion and flat-field correction, system gain, and linearity. The four remotely selectable sweep speeds are calibrated with an on-board optical comb generator. The recording system is a fiber-coupled back-illuminated CCD camera. We will present data illustrating the many features of the ROSS camera as applied to laser and plasma diagnostics. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-92SF19460.

  13. Describing functions for nonlinear optical systems.

    PubMed

    Ghosh, A K

    1997-10-10

    The concept of describing functions is useful for analyzing and designing nonlinear systems. A proposal for using the idea of describing functions for studying the behavior of a nonlinear optical processing system is given. The describing function can be used in the same way that a coherent transfer function or optical transfer function is used to characterize linear, shift-invariant optical processors. Two coherent optical systems for measuring the magnitude of the describing function of nonlinear optical processors are suggested. PMID:18264243

  14. Integrated optical devices using bacteriorhodopsin as active nonlinear optical material

    NASA Astrophysics Data System (ADS)

    Dér, András; Fábián, László; Valkai, Sándor; Wolff, Elmar; Ramsden, Jeremy; Ormos, Pál

    2006-08-01

    Coupling of optical data-processing devices with microelectronics, telecocommunication and sensory functions, is among the biggest challenges in molecular electronics. Intensive research is going on to find suitable nonlinear optical materials that could meet the demanding requirements of optoelectronic applications, especially regarding high sensitivity and stability. In addition to inorganic and organic crystals, biological molecules have also been considered for use in integrated optics, among which the bacterial chromoprotein, bacteriorhodopsin (bR) generated the most interest. bR undergoes enormous absorption and concomitant refractive index changes upon initiation of a cyclic series of photoreactions by a burst of actinic light. This effect can be exploited to create highly versatile all-optical logical elements. We demonstrate the potential of this approach by investigating the static and dynamic response of several basic elements of integrated optical devices. Our results show that, due to its relatively high refractive index changes, bR can be used as an active nonlinear optical material to produce a variety of integrated optical switching and modulation effects.

  15. Optical devices for proximity operations study and test report. [intensifying images for visual observation during space transportation system activities

    NASA Technical Reports Server (NTRS)

    Smith, R. A.

    1979-01-01

    Operational and physical requirements were investigated for a low-light-level viewing device to be used as a window-mounted optical sight for crew use in the pointing, navigating, stationkeeping, and docking of space vehicles to support space station operations and the assembly of large structures in space. A suitable prototype, obtained from a commercial vendor, was subjected to limited tests to determine the potential effectiveness of a proximity optical device in spacecraft operations. The constructional features of the device are discussed as well as concepts for its use. Tests results show that a proximity optical device is capable of performing low-light-level viewing services and will enhance manned spacecraft operations.

  16. Gregorian optical system with non-linear optical technology for protection against intense optical transients

    DOEpatents

    Ackermann, Mark R.; Diels, Jean-Claude M.

    2007-06-26

    An optical system comprising a concave primary mirror reflects light through an intermediate focus to a secondary mirror. The secondary mirror re-focuses the image to a final image plane. Optical limiter material is placed near the intermediate focus to optically limit the intensity of light so that downstream components of the optical system are protected from intense optical transients. Additional lenses before and/or after the intermediate focus correct optical aberrations.

  17. A simplified adaptive optics system

    NASA Astrophysics Data System (ADS)

    Ivanescu, Liviu; Racine, René; Nadeau, Daniel

    2003-02-01

    Affordable adaptive optics on small telescopes allow to introduce the technology to a large community and provide opportunities to train new specialists in the field. We have developed a low order, low cost adaptive optics system for the 1.6m telescope of the Mont Megantic Observatory. The system corrects tip-tilt, focus, astigmatisms and one trefoil term. It explores a number of new approaches. The sensor receives a single out-of-focus image of the reference star. The central obstruction of the telescope can free the focus detection from the effect of seeing and allows a very small defocus. The deformable mirror is profiled so as to preserve a parabolic shape under pressure from actuators located at its edge. A separate piezoelectric platform drives the tilt mirror.

  18. Constant magnification optical tracking system

    NASA Technical Reports Server (NTRS)

    Frazer, R. E. (Inventor)

    1982-01-01

    A constant magnification optical tracking system for continuously tracking of a moving object is described. In the tracking system, a traveling objective lens maintains a fixed relationship with an object to be optically tracked. The objective lens was chosen to provide a collimated light beam oriented in the direction of travel of the moving object. A reflective surface is attached to the traveling objective lens for reflecting an image of the moving object. The object to be tracked is a free-falling object which is located at the focal point of the objective lens for at least a portion of its free-fall path. A motor and control means is provided for mantaining the traveling objective lens in a fixed relationship relative to the free-falling object, thereby keeping the free-falling object at the focal point and centered on the axis of the traveling objective lens throughout its entire free-fall path.

  19. Potential for integrated optical circuits in advanced aircraft with fiber optic control and monitoring systems

    NASA Technical Reports Server (NTRS)

    Baumbick, Robert

    1991-01-01

    The current Fiber Optic Control System Integration (FOCSI) program is reviewed and the potential role of IOCs in FOCSI applications is described. The program is intended for building, environmentally testing, and demonstrating operation in piggyback flight tests (no active control with optical sensors) of a representative sensor system for propulsion and flight control. The optical sensor systems are to be designed to fit alongside the bill-of-materials sensors for comparison. The sensors are to be connected to electrooptic architecture cards which will contain the optical sources and detectors to recover and process the modulated optical signals. The FOCSI program is to collect data on the behavior of passive optical sensor systems in a flight environment and provide valuable information on installation amd maintenance problems for this technology, as well as component survivability (light sources, connectors, optical fibers, etc.).

  20. Fiber optic hydrogen detection system

    NASA Astrophysics Data System (ADS)

    Kazemi, Alex A.; Larson, David B.; Wuestling, Mark D.

    1999-12-01

    Commercial and military launch vehicles are designed to use hydrogen as the main propellant, which is very volatile, extremely flammable, and highly explosive. Current detection systems uses Teflon transfer tubes at a large number of vehicle locations through which gas samples are drawn and the stream analyzed by a mass spectrometer. A concern with this approach is the high cost of the system. Also, the current system does not provide leak location and is not in real-time. This system is very complex and cumbersome for production and ground support measurement personnel. The fiber optic micromirror sensor under development for cryogenic environment relies on a reversible chemical interaction causing a change in reflectivity of a thin film of coated Palladium. The magnitude of the reflectivity change is correlated to hydrogen concentration. The sensor uses only a tiny light beam, with no electricity whatsoever at the sensor, leading to devices that is intrinsically safe from explosive ignition. The sensor, extremely small in size and weight detects, hydrogen concentration using a passive element consisting of chemically reactive microcoatings deposited on the surface of a glass microlens, which is then bonded to an optical fiber. The system uses a multiplexing technique with a fiber optic driver-receiver consisting of a modulated LED source that is launched into the sensor, and a photodiode detector that synchronously measures the reflected signal. The system incorporates a microprocessor (or PC) to perform the data analysis and storage, as well as trending and set alarm function. As it is a low cost system with a fast response, many more detection sensors can be used that will be extremely helpful in determining leak location for safety of crew and vehicles during launch operations.

  1. Optical fiber data transfer system

    NASA Technical Reports Server (NTRS)

    Mcmillan, S. H.

    1988-01-01

    This Phase 2 effort applies the results of Phase 1 to design and fabricate an optical slip ring system for a helicopter rotor blade/wind tunnel application. In this application, there are two assemblies: one on the rotating portion of the mechanical system, one on the stationary portion. The assembly on the rotating portion digitizes and encodes 128 transducer signals from various parts of the blade, and optically transfers data across the noncontacting coupling. Two complete identical independent channels are provided. On the stationary side, the signals are decoded and one channel is transmitted in digital form to a computer for recording and analysis. The second channel reconstructs the analog transducer signals for real time observation. In the opposite direction, eight signal channels enable control signals to be passed from the stationary to the rotating part of the system. Power to the rotor mounted electronics is supplied via power slip rings. The advantages of the optical over the traditional electro-mechanical slip ring method of data transfer across a rotating joint are long life, low-maintenance, immunity to crosstalk, and wider bandwidth. Successful completion of this effort demonstrated that this method is practical and reliable, and can be implemented under difficult conditions of available space, power, environment, and stringent performance and equipment life requirements.

  2. Optical Strain Measurement System Development

    NASA Technical Reports Server (NTRS)

    Lant, C. T.

    1985-01-01

    Investigations of physical phenomena affecting the durability of SSME components require measurement systems operational in hostile environments. The need for such instrumentation caused the definition and operation of an optical strain measurement system. This optical strain measurement system based on the speckle shift method is being developed. This is a noncontact, automatic method of measuring surface strain in one dimension that corrects for error due to rigid body motion. It provides a gauge length of 1 to 2 mm and allows the region of interest on the test specimen to be mapped point by point. The output is a graphics map of the points inspected on the specimen; data points is stored in quasi-real time. This is the first phase of a multiphase effort in optical strain measurement. The speckle pattern created by the test specimen is interpreted as high order interference fringes resulting from a random diffraction grating, being the natural surface roughness of the specimen. Strain induced on the specimen causes a change in spacing of the surface roughness, which in turn shifts the position of the interference pattern (speckles).

  3. Active Correction of Aberrations of Low-Quality Telescope Optics

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid; Chen, Yijian

    2007-01-01

    A system of active optics that includes a wavefront sensor and a deformable mirror has been demonstrated to be an effective means of partly correcting wavefront aberrations introduced by fixed optics (lenses and mirrors) in telescopes. It is envisioned that after further development, active optics would be used to reduce wavefront aberrations of about one wave or less in telescopes having aperture diameters of the order of meters or tens of meters. Although this remaining amount of aberration would be considered excessive in scientific applications in which diffraction-limited performance is required, it would be acceptable for free-space optical- communication applications at wavelengths of the order of 1 m. To prevent misunderstanding, it is important to state the following: The technological discipline of active optics, in which the primary or secondary mirror of a telescope is directly and dynamically tilted, distorted, and/or otherwise varied to reduce wavefront aberrations, has existed for decades. The term active optics does not necessarily mean the same thing as does adaptive optics, even though active optics and adaptive optics are related. The term "adaptive optics" is often used to refer to wavefront correction at speeds characterized by frequencies ranging up to between hundreds of hertz and several kilohertz high enough to enable mitigation of adverse effects of fluctuations in atmospheric refraction upon propagation of light beams. The term active optics usually appears in reference to wavefront correction at significantly lower speeds, characterized by times ranging from about 1 second to as long as minutes. Hence, the novelty of the present development lies, not in the basic concept of active or adaptive optics, but in the envisioned application of active optics in conjunction with a deformable mirror to achieve acceptably small wavefront errors in free-space optical communication systems that include multi-meter-diameter telescope mirrors that are

  4. Knowledge-based optical system design

    NASA Astrophysics Data System (ADS)

    Nouri, Taoufik

    1992-03-01

    This work is a new approach for the design of start optical systems and represents a new contribution of artificial intelligence techniques in the optical design field. A knowledge-based optical-systems design (KBOSD), based on artificial intelligence algorithms, first order logic, knowledge representation, rules, and heuristics on lens design, is realized. This KBOSD is equipped with optical knowledge in the domain of centered dioptrical optical systems used at low aperture and small field angles. It generates centered dioptrical, on-axis and low-aperture optical systems, which are used as start systems for the subsequent optimization by existing lens design programs. This KBOSD produces monochromatic or polychromatic optical systems, such as singlet lens, doublet lens, triplet lens, reversed singlet lens, reversed doublet lens, reversed triplet lens, and telescopes. In the design of optical systems, the KBOSD takes into account many user constraints such as cost, resistance of the optical material (glass) to chemical, thermal, and mechanical effects, as well as the optical quality such as minimal aberrations and chromatic aberrations corrections. This KBOSD is developed in the programming language Prolog and has knowledge on optical design principles and optical properties. It is composed of more than 3000 clauses. Inference engine and interconnections in the cognitive world of optical systems are described. The system uses neither a lens library nor a lens data base; it is completely based on optical design knowledge.

  5. Optical Energy Transfer and Conversion System

    NASA Technical Reports Server (NTRS)

    Stone, William C. (Inventor); Hogan, Bartholomew P. (Inventor)

    2015-01-01

    An optical power transfer system comprising a fiber spooler, a fiber optic rotary joint mechanically connected to the fiber spooler, and an electrical power extraction subsystem connected to the fiber optic rotary joint with an optical waveguide. Optical energy is generated at and transferred from a base station through fiber wrapped around the spooler, through the rotary joint, and ultimately to the power extraction system at a remote mobility platform for conversion to another form of energy.

  6. Reflective optical imaging system with balanced distortion

    DOEpatents

    Chapman, Henry N.; Hudyma, Russell M.; Shafer, David R.; Sweeney, Donald W.

    1999-01-01

    An optical system compatible with short wavelength (extreme ultraviolet) An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four reflective elements for projecting a mask image onto a substrate. The four optical elements comprise, in order from object to image, convex, concave, convex and concave mirrors. The optical system is particularly suited for step and scan lithography methods. The invention enables the use of larger slit dimensions associated with ring field scanning optics, improves wafer throughput and allows higher semiconductor device density. The inventive optical system is characterized by reduced dynamic distortion because the static distortion is balanced across the slit width.

  7. Chiral THz metamaterial with tunable optical activity

    SciTech Connect

    Zhou, Jiangfeng; Taylor, Antoinette; O' Hara, John; Chowdhury, Roy; Zhao, Rongkuo; Soukoullis, Costas M

    2010-01-01

    Optical activity in chiral metamaterials is demonstrated in simulation and shows actively tunable giant polarization rotation at THz frequencies. Electric current distributions show that pure chirality is achieved by our bi-Iayer chiral metamaterial design. The chirality can be optically controlled by illumination with near-infrared light. Optical activity, occurring in chiral materials such as DNA, sugar and many other bio-molecules, is a phenomenon of great importance to many areas of science including molecular biology, analytical chemistry, optoelectronics and display applications. This phenomenon is well understood at an effective medium level as a magnetic/electric moment excited by the electric/magnetic field of the incident electromagnetic (EM) wave. Usually, natural chiral materials exhibit very weak optical activity e.g. a gyrotropic quartz crystal. The optical activity of chiral metamaterials, however, can be five orders of magnitude stronger. Chiral metamaterials are made of sub-wavelength resonators lacking symmetry planes. The asymmetry allows magnetic moments to be excited by the electric field of the incident EM wave and vice versa. Recently, chiral metamaterials have been demonstrated and lead to prospects in giant optical activity, circular dichroism, negative refraction and reversing the Casmir force. These fascinating optical properties require strong chirality, which may be designed through the microscopic structure of chiral metamaterials. However, these metamaterials have a fixed response function, defined by the geometric structuring, which limits their ability to manipulate EM waves. Active metamaterials realize dynamic control of response functions and have produced many influential applications such as ultra-fast switching devices, frequency and phase modulation and memory devices. Introducing active designs to chiral metamaterials will give additional freedom in controlling the optical activity, and therefore enable dynamic manipulation

  8. 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.

  9. Optical theorem detectors for active scatterers

    NASA Astrophysics Data System (ADS)

    Marengo, Edwin A.; Tu, Jing

    2015-10-01

    We develop a new theory of the optical theorem for scalar fields in nonhomogeneous media which can be bounded or unbounded. It applies to arbitrary lossless backgrounds and quite general probing fields. The derived formulation holds for arbitrary passive scatterers, which can be dissipative, as well as for the more general class of active scatterers which are composed of a (passive) scatterer component and an active, radiating (antenna) component. The generalization of the optical theorem to active scatterers is relevant to many applications such as surveillance of active targets including certain cloaks and invisible scatterers and wireless communications. The derived theoretical framework includes the familiar real power optical theorem describing power extinction due to both dissipation and scattering as well as a novel reactive optical theorem related to the reactive power changes. The developed approach naturally leads to three optical theorem indicators or statistics which can be used to detect changes or targets in unknown complex media. The paper includes numerical simulation results that illustrate the application of the derived optical theorem results to change detection in complex and random media.

  10. Fiber optic in vivo imaging in the mammalian nervous system

    PubMed Central

    Mehta, Amit D; Jung, Juergen C; Flusberg, Benjamin A; Schnitzer, Mark J

    2010-01-01

    The compact size, mechanical flexibility, and growing functionality of optical fiber and fiber optic devices are enabling several new modalities for imaging the mammalian nervous system in vivo. Fluorescence microendoscopy is a minimally invasive fiber modality that provides cellular resolution in deep brain areas. Diffuse optical tomography is a non-invasive modality that uses assemblies of fiber optic emitters and detectors on the cranium for volumetric imaging of brain activation. Optical coherence tomography is a sensitive interferometric imaging technique that can be implemented in a variety of fiber based formats and that might allow intrinsic optical detection of brain activity at a high resolution. Miniaturized fiber optic microscopy permits cellular level imaging in the brains of behaving animals. Together, these modalities will enable new uses of imaging in the intact nervous system for both research and clinical applications. PMID:15464896

  11. Stem cell tracking with optically active nanoparticles

    PubMed Central

    Gao, Yu; Cui, Yan; Chan, Jerry KY; Xu, Chenjie

    2013-01-01

    Stem-cell-based therapies hold promise and potential to address many unmet clinical needs. Cell tracking with modern imaging modalities offers insight into the underlying biological process of the stem-cell-based therapies, with the goal to reveal cell survival, migration, homing, engraftment, differentiation, and functions. Adaptability, sensitivity, resolution, and non-invasiveness have contributed to the longstanding use of optical imaging for stem cell tracking and analysis. To identify transplanted stem cells from the host tissue, optically active probes are usually used to label stem cells before the administration. In comparison to the traditional fluorescent probes like fluorescent proteins and dyes, nanoparticle-based probes are advantageous in terms of the photo-stabilities and minimal changes to the cell phenotype. The main focus here is to overview the recent development of optically active nanoparticles for stem cells tracking. The related optical imaging modalities include fluorescence imaging, photoacoustic imaging, Raman and surface enhanced Raman spectroscopy imaging. PMID:23638335

  12. An experimental indoor phasing system based on active optics using dispersed Hartmann sensing technology in the visible waveband

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Liu, Gen-Rong; Wang, Yue-Fei; Li, Ye-Ping; Zhang, Ya-Jun; Zhang, Liang; Zeng, Yi-Zhong; Zhang, Jie

    2011-09-01

    A telescope with a larger primary mirror can collect much more light and resolve objects much better than one with a smaller mirror, and so the larger version is always pursued by astronomers and astronomical technicians. Instead of using a monolithic primary mirror, more and more large telescopes, which are currently being planned or in construction, have adopted a segmented primary mirror design. Therefore, how to sense and phase such a primary mirror is a key issue for the future of extremely large optical/infrared telescopes. The Dispersed Fringe Sensor (DFS), or Dispersed Hartmann Sensor (DHS), is a non-contact method using broadband point light sources and it can estimate the piston by the two-directional spectrum formed by the transmissive grating's dispersion and lenslet array. Thus it can implement the combination of co-focusing by Shack-Hartmann technology and phasing by dispersed fringe sensing technologies such as the template-mapping method and the Hartmann method. We introduce the successful design, construction and alignment of our dispersed Hartmann sensor together with its design principles and simulations. We also conduct many successful real phasing tests and phasing corrections in the visible waveband using our existing indoor segmented mirror optics platform. Finally, some conclusions are reached based on the test and correction of experimental results.

  13. Photovoltaic concentrator assembly with optically active cover

    DOEpatents

    Plesniak, Adam P

    2014-01-21

    A photovoltaic concentrator assembly that includes a housing that defines an internal volume and includes a rim, wherein the rim defines an opening into the internal volume, a photovoltaic cell positioned in the internal volume, and an optical element that includes an optically active body and a flange extending outward from the body, wherein the flange is sealingly engaged with the rim of the housing to enclose the internal volume.

  14. Recent optical activity of Mrk 421

    NASA Astrophysics Data System (ADS)

    Semkov, E.; Bachev, R.; Strigachev, A.; Ibryamov, S.; Peneva, S.; Gupta, A. C.

    2013-04-01

    Our BVRI optical observations of Mrk 421 were performed within the multiwavelength international campaign (December 2012-June 2013), with the participation of GASP-WEBT, Swift, MAGIC, VLBA, NuSTAR, Fermi, VERITAS, F-GAMMA and other collaborations. Following the reports of enhanced X-ray and gamma activity of Mrk 421 (ATel #4978, ATel #4977, ATel #4976, ATel #4974, ATel #4918), we observed this blazar with the optical telescopes of the National Astronomical Observatory Rozhen and the Astronomical Observatory Belogradchik, Bulgaria.

  15. The ANTARES optical beacon system

    NASA Astrophysics Data System (ADS)

    Ageron, M.; Aguilar, J. A.; Albert, A.; Ameli, F.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardellier-Desages, F.; Aslanides, E.; Aubert, J.-J.; Auer, R.; Barbarito, E.; Basa, S.; Battaglieri, M.; Becherini, Y.; Beltramelli, J.; Bertin, V.; Bigi, A.; Billault, M.; Blaes, R.; de Botton, N.; Bouwhuis, M. C.; Bradbury, S. M.; Bruijn, R.; Brunner, J.; Burgio, G. F.; Busto, J.; Cafagna, F.; Caillat, L.; Calzas, A.; Capone, A.; Caponetto, L.; Carmona, E.; Carr, J.; Cartwright, S. L.; Castel, D.; Castorina, E.; Cavasinni, V.; Cecchini, S.; Ceres, A.; Charvis, P.; Chauchot, P.; Chiarusi, T.; Circella, M.; Colnard, C.; Compère, C.; Coniglione, R.; Cottini, N.; Coyle, P.; Cuneo, S.; Cussatlegras, A.-S.; Damy, G.; van Dantzig, R.; de Bonis, G.; de Marzo, C.; de Vita, R.; Dekeyser, I.; Delagnes, E.; Denans, D.; Deschamps, A.; Destelle, J.-J.; Dinkespieler, B.; Distefano, C.; Donzaud, C.; Drogou, J.-F.; Druillole, F.; Durand, D.; Ernenwein, J.-P.; Escoffier, S.; Falchini, E.; Favard, S.; Fehr, F.; Feinstein, F.; Ferry, S.; Fiorello, C.; Flaminio, V.; Fratini, K.; Fuda, J.-L.; Galeotti, S.; Gallone, J.-M.; Giacomelli, G.; Girard, N.; Gojak, C.; Goret, Ph.; Graf, K.; Hallewell, G.; Harakeh, M. N.; Hartmann, B.; Heijboer, A.; Heine, E.; Hello, Y.; Hernández-Rey, J. J.; Hößl, J.; Hoffman, C.; Hogenbirk, J.; Hubbard, J. R.; Jaquet, M.; Jaspers, M.; de Jong, M.; Jouvenot, F.; Kalantar-Nayestanaki, N.; Kappes, A.; Karg, T.; Katz, U.; Keller, P.; Kok, E.; Kok, H.; Kooijman, P.; Kopper, C.; Korolkova, E. V.; Kouchner, A.; Kretschmer, W.; Kruijer, A.; Kuch, S.; Kudryavstev, V. A.; Lagier, P.; Lahmann, R.; Lamanna, G.; Lamare, P.; Lambard, G.; Languillat, J.-C.; Laschinsky, H.; Lavalle, J.; Le Guen, Y.; Le Provost, H.; Le van Suu, A.; Lefèvre, D.; Legou, T.; Lelaizant, G.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Louis, F.; Lucarelli, F.; Lyashuk, V.; Marcelin, M.; Margiotta, A.; Masullo, R.; Mazéas, F.; Mazure, A.; McMillan, J. E.; Megna, R.; Melissas, M.; Migneco, E.; Milovanovic, A.; Mongelli, M.; Montaruli, T.; Morganti, M.; Moscoso, L.; Musumeci, M.; Naumann-Godo, M.; Naumann, C.; Niess, V.; Noble, T.; Olivetto, C.; Ostasch, R.; Palanque-Delabrouille, N.; Payre, P.; Peek, H.; Perez, A.; Petta, C.; Piattelli, P.; Pillet, R.; Pineau, J.-P.; Poinsignon, J.; Popa, V.; Pradier, T.; Racca, C.; Randazzo, N.; van Randwijk, J.; Real, D.; van Rens, B.; Réthoré, F.; Rewiersma, P.; Riccobene, G.; Rigaud, V.; Ripani, M.; Roca, V.; Roda, C.; Rolin, J. F.; Rose, H. J.; Rostovtsev, A.; Roux, J.; Ruppi, M.; Russo, G. V.; Rusydi, G.; Salesa, F.; Salomon, K.; Sapienza, P.; Schmitt, F.; Schuller, J.-P.; Shanidze, R.; Sokalski, I.; Spona, T.; Spurio, M.; van der Steenhoven, G.; Stolarczyk, T.; Streeb, K.; Sulak, L.; Taiuti, M.; Tamburini, C.; Tao, C.; Terreni, G.; Thompson, L. F.; Urbano, F.; Valdy, P.; Valente, V.; Vallage, B.; Vaudaine, G.; Venekamp, G.; Verlaat, B.; Vernin, P.; de Vries-Uiterweerd, G.; van Wijk, R.; Wijnker, G.; de Witt Huberts, P.; Wobbe, G.; de Wolf, E.; Yao, A.-F.; Zaborov, D.; Zaccone, H.; Zornoza, J. D.; Zúñiga, J.

    2007-08-01

    ANTARES is a neutrino telescope being deployed in the Mediterranean Sea. It consists of a three-dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. High angular resolution can be achieved, in particular, when a muon is produced, provided that the Cherenkov photons are detected with sufficient timing precision. Considerations of the intrinsic time uncertainties stemming from the transit time spread in the photomultiplier tubes and the mechanism of transmission of light in sea water lead to the conclusion that a relative time accuracy of the order of 0.5 ns is desirable. Accordingly, different time calibration systems have been developed for the ANTARES telescope. In this article, a system based on Optical Beacons, a set of external and well-controlled pulsed light sources located throughout the detector, is described. This calibration system takes into account the optical properties of sea water, which is used as the detection volume of the ANTARES telescope. The design, tests, construction and first results of the two types of beacons, LED and laser-based, are presented.

  16. Design of Optical Systems with Extended Depth of Field: An Educational Approach to Wavefront Coding Techniques

    ERIC Educational Resources Information Center

    Ferran, C.; Bosch, S.; Carnicer, A.

    2012-01-01

    A practical activity designed to introduce wavefront coding techniques as a method to extend the depth of field in optical systems is presented. The activity is suitable for advanced undergraduate students since it combines different topics in optical engineering such as optical system design, aberration theory, Fourier optics, and digital image…

  17. Evolution Of Map Display Optical Systems

    NASA Astrophysics Data System (ADS)

    Boot, Alan

    1983-06-01

    It is now over 20 years since Ferranti plc introduced optically projected map displays into operational aircraft navigation systems. Then, as now, it was the function of the display to present an image of a topographical map to a pilot or navigator with his present position clearly identified. Then, as now, the map image was projected from a reduced image stored on colour micro film. Then, as now, the fundamental design problems are the same.In the exposed environment of an aircraft cockpit where brightness levels may vary from those associated with direct sunlight on the one hand, to starlight on the other, how does one design an optical system with sufficient luminance, contrast and resolution where in the daytime sunlight may fall on the display or in the pilot's eyes, and at night time the display luminance must not detract from the pilot's ability to pick up external clues? This paper traces the development of Ferranti plc optically projected map displays from the early V Bomber and the ill-fated TSR2 displays to the Harrier and Concorde displays. It then goes on to the development of combined map and electronic displays (COMED), showing how an earlier design, as fitted to Tornado, has been developed into the current COMED design which is fitted to the F-18 and Jaguar aircraft. In each of the above display systems particular features of optical design interest are identified and their impact on the design as a whole are discussed. The use of prisms both for optical rotation and translation, techniques for the maximisation of luminance, the problems associated with contrast enhancement, particularly with polarising filters in the presence of optically active materials, the use of aerial image combining systems and the impact of the pilot interface on the system parameter are all included.Perhaps the most interesting result in considering the evolution of map displays has not been so much the designer's solutions in overcoming the various design problems but

  18. Active stabilization of a fiber-optic two-photon interferometer using continuous optical length control.

    PubMed

    Cho, Seok-Beom; Kim, Heonoh

    2016-05-16

    The practical realization of long-distance entanglement-based quantum communication systems strongly rely on the observation of highly stable quantum interference between correlated single photons. This task must accompany active stabilization of the optical path lengths within the single-photon coherence length. Here, we provide two-step interferometer stabilization methods employing continuous optical length control and experimentally demonstrate two-photon quantum interference using an actively stabilized 6-km-long fiber-optic Hong-Ou-Mandel interferometer. The two-step active control techniques are applied for measuring highly stable two-photon interference fringes by scanning the optical path-length difference. The obtained two-photon interference visibilities with and without accidental subtraction are found to be approximately 90.7% and 65.4%, respectively. PMID:27409920

  19. Advanced optical manufacturing digital integrated system

    NASA Astrophysics Data System (ADS)

    Tao, Yizheng; Li, Xinglan; Li, Wei; Tang, Dingyong

    2012-10-01

    It is necessarily to adapt development of advanced optical manufacturing technology with modern science technology development. To solved these problems which low of ration, ratio of finished product, repetition, consistent in big size and high precision in advanced optical component manufacturing. Applied business driven and method of Rational Unified Process, this paper has researched advanced optical manufacturing process flow, requirement of Advanced Optical Manufacturing integrated System, and put forward architecture and key technology of it. Designed Optical component core and Manufacturing process driven of Advanced Optical Manufacturing Digital Integrated System. the result displayed effective well, realized dynamic planning Manufacturing process, information integration improved ratio of production manufactory.

  20. High pressure fiber optic sensor system

    DOEpatents

    Guida, Renato; Xia, Hua; Lee, Boon K; Dekate, Sachin N

    2013-11-26

    The present application provides a fiber optic sensor system. The fiber optic sensor system may include a small diameter bellows, a large diameter bellows, and a fiber optic pressure sensor attached to the small diameter bellows. Contraction of the large diameter bellows under an applied pressure may cause the small diameter bellows to expand such that the fiber optic pressure sensor may measure the applied pressure.

  1. Optical CDMA system using bacteriorhodopsin for optical data storage

    PubMed

    Bae; Yang; Jin; Lee; Park

    1999-11-01

    An optical CDMA (code division multiple access) system for the optical data storage using bacteriorhodopsin (BR) is reported as an application of the BR materials. The desired signal of multiple input can be recorded and reconstructed by use of orthogonal codes. An experimental setup is proposed and demonstrated. PMID:10585180

  2. Label-free optical activation of astrocyte in vivo

    NASA Astrophysics Data System (ADS)

    Choi, Myunghwan; Yoon, Jonghee; Ku, Taeyun; Choi, Kyungsun; Choi, Chulhee

    2011-07-01

    As the most abundant cell type in the central nervous system, astrocyte has been one of main research topics in neuroscience. Although various tools have been developed, at present, there is no tool that allows noninvasive activation of astrocyte in vivo without genetic or pharmacological perturbation. Here we report a noninvasive label-free optical method for physiological astrocyte activation in vivo using a femtosecond pulsed laser. We showed the laser stimulation robustly induced astrocytic calcium activation in vivo and further verified physiological relevance of the calcium increase by demonstrating astrocyte mediated vasodilation in the brain. This novel optical method will facilitate noninvasive physiological study on astrocyte function.

  3. A single optical fiber telephone system

    NASA Astrophysics Data System (ADS)

    Feldman, N. W.

    1984-09-01

    A hybrid telephone system comprising a plurality of optical telephones and a plurality of electrical telephones all connected to a conventional central office is discussed. The optical telephones are all provided with opto-electrical interface units co-located with the central office, for converting optical signals received from the optical telephones to electrical telephone signals, and for converting electrical telephone signals from said central office to optical signals for transmission to the optical telephones. The optical telephones are connected to the interface units by means of a single optical fiber which carries both directions of traffic as well as supervisory signals at one of two wavelengths. The optical telephone include means for separating these two wavelengths as well as opto-acoustic and acousto-optic converters.

  4. Manifestation of optical activity in different materials

    NASA Astrophysics Data System (ADS)

    Konstantinova, A. F.; Golovina, T. G.; Konstantinov, K. K.

    2014-07-01

    Various manifestations of optical activity (OA) in crystals and organic materials are considered. Examples of optically active enantiomorphic and nonenantiomorphic crystals of 18 symmetry classes are presented. The OA of enantiomorphic organic materials as components of living nature (amino acids, sugars, and proteins) is analyzed. Questions related to the origin of life on earth are considered. Examples of differences in the enantiomers of drugs are shown. The consequences of replacing conventional left-handed amino acids with additionally right-handed amino acids for living organisms are indicated.

  5. Wide field strip-imaging optical system

    NASA Technical Reports Server (NTRS)

    Vaughan, Arthur H. (Inventor)

    1994-01-01

    A strip imaging wide angle optical system is provided. The optical system is provided with a 'virtual' material stop to avoid aberrational effects inherent in wide angle optical systems. The optical system includes a spherical mirror section for receiving light from a 180-degree strip or arc of a target image. Light received by the spherical mirror section is reflected to a frusto-conical mirror section for subsequent rereflection to a row of optical fibers. Each optical fiber transmits a portion of the received light to a detector. The optical system exploits the narrow cone of acceptance associated with optical fibers to substantially eliminate vignetting effects inherent in wide-angle systems. Further, the optical system exploits the narrow cone of acceptance of the optical fibers to substantially limit spherical aberration. The optical system is ideally suited for any application wherein a 180-degree strip image need be detected, and is particularly well adapted for use in hostile environments such as in planetary exploration.

  6. Magneto-Optical Activity in High Index Dielectric Nanoantennas.

    PubMed

    de Sousa, N; Froufe-Pérez, L S; Sáenz, J J; García-Martín, A

    2016-01-01

    The magneto-optical activity, namely the polarization conversion capabilities of high-index, non-absorbing, core-shell dielectric nanospheres is theoretically analyzed. We show that, in analogy with their plasmonic counterparts, the polarization conversion in resonant dielectric particles is linked to the amount of electromagnetic field probing the magneto-optical material in the system. However, in strong contrast with plasmon nanoparticles, due to the peculiar distribution of the internal fields in resonant dielectric spheres, the magneto-optical response is fully governed by the magnetic (dipolar and quadrupolar) resonances with little effect of the electric ones. PMID:27488903

  7. Magneto-Optical Activity in High Index Dielectric Nanoantennas

    NASA Astrophysics Data System (ADS)

    de Sousa, N.; Froufe-Pérez, L. S.; Sáenz, J. J.; García-Martín, A.

    2016-08-01

    The magneto-optical activity, namely the polarization conversion capabilities of high-index, non-absorbing, core-shell dielectric nanospheres is theoretically analyzed. We show that, in analogy with their plasmonic counterparts, the polarization conversion in resonant dielectric particles is linked to the amount of electromagnetic field probing the magneto-optical material in the system. However, in strong contrast with plasmon nanoparticles, due to the peculiar distribution of the internal fields in resonant dielectric spheres, the magneto-optical response is fully governed by the magnetic (dipolar and quadrupolar) resonances with little effect of the electric ones.

  8. Magneto-Optical Activity in High Index Dielectric Nanoantennas

    PubMed Central

    de Sousa, N.; Froufe-Pérez, L. S.; Sáenz, J. J.; García-Martín, A.

    2016-01-01

    The magneto-optical activity, namely the polarization conversion capabilities of high-index, non-absorbing, core-shell dielectric nanospheres is theoretically analyzed. We show that, in analogy with their plasmonic counterparts, the polarization conversion in resonant dielectric particles is linked to the amount of electromagnetic field probing the magneto-optical material in the system. However, in strong contrast with plasmon nanoparticles, due to the peculiar distribution of the internal fields in resonant dielectric spheres, the magneto-optical response is fully governed by the magnetic (dipolar and quadrupolar) resonances with little effect of the electric ones. PMID:27488903

  9. Membrane optical activity: some facts and fallacies.

    PubMed

    Wallach, D F; Low, D A; Bertland, A V

    1973-11-01

    The circular dichroism of hypothetical, water-filled, spherical shells, 75-3500 nm in radius, with walls 7.5 nm thick, composed of poly(L-lysine) in various conformational proportions, and suspended in water, were computed from the known optical properties of this polypeptide by classical general light-scattering theory (Mie theory). Comparison of the computed curves of circular dichroism spectra with those of diverse membranes reveals large discrepancies below 215 nm and shows that light scattering does not adequately account for the optical activity of membranes containing appreciable proportions of nonhelical conformation. However, turbidity effects can explain the anomalies of membrane optical rotatory dispersion near 233 nm, if not uniquely so. We conclude that the optical activity of neither most soluble proteins nor membrane proteins can provide accurate conformational information when synthetic polypeptides are used as standards and list the reasons for this argument. We also show that present techniques to "correct" membrane optical activity are likely to produce additional artifact. PMID:4522300

  10. Reflective optical imaging system with balanced distortion

    SciTech Connect

    Chapman, H.N.; Hudyma, R.M.; Shafer, D.R.; Sweeney, D.W.

    1999-10-26

    An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four reflective elements for projecting a mask image onto a substrate is disclosed. The four optical elements comprise, in order from object to image, convex, concave, convex and concave mirrors. The optical system is particularly suited for step and scan lithography methods. The invention enables the use of larger slit dimensions associated with ring field scanning optics, improves wafer throughput and allows higher semiconductor device density. The inventive optical system is characterized by reduced dynamic distortion because the static distortion is balanced across the slit width.

  11. Reflective optical imaging systems with balanced distortion

    DOEpatents

    Hudyma, Russell M.

    2001-01-01

    Optical systems compatible with extreme ultraviolet radiation comprising four reflective elements for projecting a mask image onto a substrate are described. The four optical elements comprise, in order from object to image, convex, concave, convex and concave mirrors. The optical systems are particularly suited for step and scan lithography methods. The invention enables the use of larger slit dimensions associated with ring field scanning optics, improves wafer throughput, and allows higher semiconductor device density. The inventive optical systems are characterized by reduced dynamic distortion because the static distortion is balanced across the slit width.

  12. ERIS adaptive optics system design

    NASA Astrophysics Data System (ADS)

    Marchetti, Enrico; Le Louarn, Miska; Soenke, Christian; Fedrigo, Enrico; Madec, Pierre-Yves; Hubin, Norbert

    2012-07-01

    The Enhanced Resolution Imager and Spectrograph (ERIS) is the next-generation instrument planned for the Very Large Telescope (VLT) and the Adaptive Optics facility (AOF). It is an AO assisted instrument that will make use of the Deformable Secondary Mirror and the new Laser Guide Star Facility (4LGSF), and it is planned for the Cassegrain focus of the telescope UT4. The project is currently in its Phase A awaiting for approval to continue to the next phases. The Adaptive Optics system of ERIS will include two wavefront sensors (WFS) to maximize the coverage of the proposed sciences cases. The first is a high order 40x40 Pyramid WFS (PWFS) for on axis Natural Guide Star (NGS) observations. The second is a high order 40x40 Shack-Hartmann WFS for single Laser Guide Stars (LGS) observations. The PWFS, with appropriate sub-aperture binning, will serve also as low order NGS WFS in support to the LGS mode with a field of view patrolling capability of 2 arcmin diameter. Both WFSs will be equipped with the very low read-out noise CCD220 based camera developed for the AOF. The real-time reconstruction and control is provided by a SPARTA real-time platform adapted to support both WFS modes. In this paper we will present the ERIS AO system in all its main aspects: opto-mechanical design, real-time computer design, control and calibrations strategy. Particular emphasis will be given to the system performance obtained via dedicated numerical simulations.

  13. The ERIS adaptive optics system

    NASA Astrophysics Data System (ADS)

    Marchetti, Enrico; Fedrigo, Enrico; Le Louarn, Miska; Madec, Pierre-Yves; Soenke, Christian; Brast, Roland; Conzelmann, Ralf; Delabre, Bernard; Duchateau, Michel; Frank, Christoph; Klein, Barbara; Amico, Paola; Hubin, Norbert; Esposito, Simone; Antichi, Jacopo; Carbonaro, Luca; Puglisi, Alfio; Quirós-Pacheco, Fernando; Riccardi, Armando; Xompero, Marco

    2014-07-01

    The Enhanced Resolution Imager and Spectrograph (ERIS) is the new Adaptive Optics based instrument for ESO's VLT aiming at replacing NACO and SINFONI to form a single compact facility with AO fed imaging and integral field unit spectroscopic scientific channels. ERIS completes the instrument suite at the VLT adaptive telescope. In particular it is equipped with a versatile AO system that delivers up to 95% Strehl correction in K band for science observations up to 5 micron It comprises high order NGS and LGS correction enabling the observation from exoplanets to distant galaxies with a large sky coverage thanks to the coupling of the LGS WFS with the high sensitivity of its visible WFS and the capability to observe in dust embedded environment thanks to its IR low order WFS. ERIS will be installed at the Cassegrain focus of the VLT unit hosting the Adaptive Optics Facility (AOF). The wavefront correction is provided by the AOF deformable secondary mirror while the Laser Guide Star is provided by one of the four launch units of the 4 Laser Guide Star Facility for the AOF. The overall layout of the ERIS AO system is extremely compact and highly optimized: the SPIFFI spectrograph is fed directly by the Cassegrain focus and both the NIX's (IR imager) and SPIFFI's entrance windows work as visible/infrared dichroics. In this paper we describe the concept of the ERIS AO system in detail, starting from the requirements and going through the estimated performance, the opto-mechanical design and the Real-Time Computer design.

  14. CAD/CAM-Interface For Optical Systems And Optical Drawings

    NASA Astrophysics Data System (ADS)

    Wieder, Eckart

    1989-04-01

    It is explained why a general interface for optical data between CAD/CAM-Systems is necessary. The requirements for the interface are discussed. The philosophy of a solution is demonstrated and it is shown how to proceed.

  15. GridOPTICS Software System

    SciTech Connect

    Akyol, Bora A; Ciraci, PNNL Selim; Gibson, PNNL Tara; Rice, PNNL Mark; Sharma, PNNL Poorva; Yin, PNNL Jian; Allwardt, PNNL Craig; PNNL,

    2014-02-24

    GridOPTICS Software System (GOSS) is a middleware that facilitates creation of new, modular and flexible operational and planning platforms that can meet the challenges of the next generation power grid. GOSS enables Department of Energy, power system utilities, and vendors to build better tools faster. GOSS makes it possible to integrate Future Power Grid Initiative software products/prototypes into existing power grid software systems, including the PNNL PowerNet and EIOC environments. GOSS is designed to allow power grid applications developed for different underlying software platforms installed in different utilities to communicate with ease. This can be done in compliance with existing security and data sharing policies between the utilities. GOSS not only supports one-to-one data transfer between applications, but also publisher/subscriber scheme. To support interoperability requirements of future EMS, GOSS is designed for CIM compliance. In addition to this, it supports authentication and authorization capabilities to protect the system from cyber threats. In summary, the contributions of the GOSS middleware are as follows: • A platform to support future EMS development. • A middleware that promotes interoperability between power grid applications. • A distributed architecture that separates data sources from power grid applications. • Support for data exchange with either one-to-one or publisher/subscriber interfaces. • An authentication and authorization scheme for limiting the access to data between utilities.

  16. GridOPTICS Software System

    2014-02-24

    GridOPTICS Software System (GOSS) is a middleware that facilitates creation of new, modular and flexible operational and planning platforms that can meet the challenges of the next generation power grid. GOSS enables Department of Energy, power system utilities, and vendors to build better tools faster. GOSS makes it possible to integrate Future Power Grid Initiative software products/prototypes into existing power grid software systems, including the PNNL PowerNet and EIOC environments. GOSS is designed to allowmore » power grid applications developed for different underlying software platforms installed in different utilities to communicate with ease. This can be done in compliance with existing security and data sharing policies between the utilities. GOSS not only supports one-to-one data transfer between applications, but also publisher/subscriber scheme. To support interoperability requirements of future EMS, GOSS is designed for CIM compliance. In addition to this, it supports authentication and authorization capabilities to protect the system from cyber threats. In summary, the contributions of the GOSS middleware are as follows: • A platform to support future EMS development. • A middleware that promotes interoperability between power grid applications. • A distributed architecture that separates data sources from power grid applications. • Support for data exchange with either one-to-one or publisher/subscriber interfaces. • An authentication and authorization scheme for limiting the access to data between utilities.« less

  17. Specular optical activity of achiral metasurfaces

    NASA Astrophysics Data System (ADS)

    Plum, Eric; Fedotov, Vassili A.; Zheludev, Nikolay I.

    2016-04-01

    Optical activity in 3D-chiral media in the form of circular dichroism and birefringence is a fundamental phenomenon that serves as evidence of life forms and is widely used in spectroscopy. Even in 3D-chiral media exhibiting strong transmission optical activity, the reflective effect is weak and sometimes undetectable. Here, we report that specular optical activity at structured interfaces can be very strong. Resonant polarization rotation reaching 25 ° and reflectivity contrast exceeding 50% for oppositely circularly polarized waves are observed for microwaves reflected by a metasurface with structural elements lacking two-fold rotational symmetry. The effect arises at oblique incidence from a 3D-chiral arrangement of the wave's direction and the metasurface's structure that itself does not possess chiral elements. Specular optical activity of such magnitude is unprecedented. It is fundamentally different from the polarization effects occurring upon scattering, reflection, and transmission from surfaces with 2D-chiral patterns. The scale of the effect allows applications in polarization sensitive devices and surface spectroscopies.

  18. An Overhead Projection Demonstration of Optical Activity

    ERIC Educational Resources Information Center

    Hill, John W.

    1973-01-01

    Describes the use of two polarizing lenses, a yellow filter, an oatmeal bos, a piece of cardboard, a 1,000 ml beaker, and an overhead projector to demonstrate compound optical activity to large classes. Indicates the presence of an accuracy within 1-2 degrees of usually acceptable data. (CC)

  19. A portable free space optical system

    NASA Astrophysics Data System (ADS)

    Ai, Yong; Lu, Xingguang; Yang, Jinglin; Chen, Jing; Hao, Zhonggang

    2005-08-01

    A portable protocol independent free space optical communication terminal was developed, which enables customer to quickly deploy optical bandwidth services for applications such as fiber extension, wild field point to point communication and wireless backhaul while avoiding costly and time-consuming fiber installation. By using specially designed optical components and optical-mechanical structure, the system is very compact and effective, can establish optical link within a few minutes, with total weight 4kg, size 160 x 360 x 155 mm, effective transmitting/receiving aperture 40mm, data rate 100Mbps, maximum communication distance 1500m. The system and experiments are presented in the paper.

  20. Small scale adaptive optics experiment systems engineering

    NASA Technical Reports Server (NTRS)

    Boykin, William H.

    1993-01-01

    Assessment of the current technology relating to the laser power beaming system which in full scale is called the Beam Transmission Optical System (BTOS). Evaluation of system integration efforts are being conducted by the various government agencies and industry. Concepts are being developed for prototypes of adaptive optics for a BTOS.

  1. Optical fiber sensor having an active core

    NASA Technical Reports Server (NTRS)

    Egalon, Claudio Oliveira (Inventor); Rogowski, Robert S. (Inventor)

    1993-01-01

    An optical fiber is provided. The fiber is comprised of an active fiber core which produces waves of light upon excitation. A factor ka is identified and increased until a desired improvement in power efficiency is obtained. The variable a is the radius of the active fiber core and k is defined as 2 pi/lambda wherein lambda is the wavelength of the light produced by the active fiber core. In one embodiment, the factor ka is increased until the power efficiency stabilizes. In addition to a bare fiber core embodiment, a two-stage fluorescent fiber is provided wherein an active cladding surrounds a portion of the active fiber core having an improved ka factor. The power efficiency of the embodiment is further improved by increasing a difference between the respective indices of refraction of the active cladding and the active fiber core.

  2. 3D optical measuring technologies and systems

    NASA Astrophysics Data System (ADS)

    Chugui, Yuri V.

    2005-02-01

    The results of the R & D activity of TDI SIE SB RAS in the field of the 3D optical measuring technologies and systems for noncontact 3D optical dimensional inspection applied to atomic and railway industry safety problems are presented. This activity includes investigations of diffraction phenomena on some 3D objects, using the original constructive calculation method. The efficient algorithms for precise determining the transverse and longitudinal sizes of 3D objects of constant thickness by diffraction method, peculiarities on formation of the shadow and images of the typical elements of the extended objects were suggested. Ensuring the safety of nuclear reactors and running trains as well as their high exploitation reliability requires a 100% noncontact precise inspection of geometrical parameters of their components. To solve this problem we have developed methods and produced the technical vision measuring systems LMM, CONTROL, PROFIL, and technologies for noncontact 3D dimensional inspection of grid spacers and fuel elements for the nuclear reactor VVER-1000 and VVER-440, as well as automatic laser diagnostic COMPLEX for noncontact inspection of geometric parameters of running freight car wheel pairs. The performances of these systems and the results of industrial testing are presented and discussed. The created devices are in pilot operation at Atomic and Railway Companies.

  3. Optical axis jitter rejection for double overlapped adaptive optics systems

    NASA Astrophysics Data System (ADS)

    Luo, Qi; Luo, Xi; Li, Xinyang

    2016-04-01

    Optical axis jitters, or vibrations, which arise from wind shaking and structural oscillations of optical platforms, etc., cause a deleterious impact on the performance of adaptive optics systems. When conventional integrators are utilized to reject such high frequency and narrow-band disturbance, the benefits are quite small despite their acceptable capabilities to reject atmospheric turbulence. In our case, two suits of complete adaptive optics systems called double overlapped adaptive optics systems (DOAOS) are used to counteract both optical jitters and atmospheric turbulence. A novel algorithm aiming to remove vibrations is proposed by resorting to combine the Smith predictor and notch filer. With the help of loop shaping method, the algorithm will lead to an effective and stable controller, which makes the characteristics of error transfer function close to notch filters. On the basis of the spectral analysis of observed data, the peak frequency and bandwidth of vibrations can be identified in advance. Afterwards, the number of notch filters and their parameters will be determined using coordination descending method. The relationship between controller parameters and filtering features is discussed, and the robustness of the controller against varying parameters of the control object is investigated. Preliminary experiments are carried out to validate the proposed algorithms. The overall control performance of DOAOS is simulated. Results show that time delays are a limit of the performance, but the algorithm can be successfully implemented on our systems, which indicate that it has a great potential to reject jitters.

  4. Optical Potential Field Mapping System

    NASA Technical Reports Server (NTRS)

    Reid, Max B. (Inventor)

    1996-01-01

    The present invention relates to an optical system for creating a potential field map of a bounded two dimensional region containing a goal location and an arbitrary number of obstacles. The potential field mapping system has an imaging device and a processor. Two image writing modes are used by the imaging device, electron deposition and electron depletion. Patterns written in electron deposition mode appear black and expand. Patterns written in electron depletion mode are sharp and appear white. The generated image represents a robot's workspace. The imaging device under processor control then writes a goal location in the work-space using the electron deposition mode. The black image of the goal expands in the workspace. The processor stores the generated images, and uses them to generate a feedback pattern. The feedback pattern is written in the workspace by the imaging device in the electron deposition mode to enhance the expansion of the original goal pattern. After the feedback pattern is written, an obstacle pattern is written by the imaging device in the electron depletion mode to represent the obstacles in the robot's workspace. The processor compares a stored image to a previously stored image to determine a change therebetween. When no change occurs, the processor averages the stored images to produce the potential field map.

  5. Capillary Electrophoresis - Optical Detection Systems

    SciTech Connect

    Sepaniak, M. J.

    2001-08-06

    Molecular recognition systems are developed via molecular modeling and synthesis to enhance separation performance in capillary electrophoresis and optical detection methods for capillary electrophoresis. The underpinning theme of our work is the rational design and development of molecular recognition systems in chemical separations and analysis. There have been, however, some subtle and exciting shifts in our research paradigm during this period. Specifically, we have moved from mostly separations research to a good balance between separations and spectroscopic detection for separations. This shift is based on our perception that the pressing research challenges and needs in capillary electrophoresis and electrokinetic chromatography relate to the persistent detection and flow rate reproducibility limitations of these techniques (see page 1 of the accompanying Renewal Application for further discussion). In most of our work molecular recognition reagents are employed to provide selectivity and enhance performance. Also, an emerging trend is the use of these reagents with specially-prepared nano-scale materials. Although not part of our DOE BES-supported work, the modeling and synthesis of new receptors has indirectly supported the development of novel microcantilevers-based MEMS for the sensing of vapor and liquid phase analytes. This fortuitous overlap is briefly covered in this report. Several of the more significant publications that have resulted from our work are appended. To facilitate brevity we refer to these publications liberally in this progress report. Reference is also made to very recent work in the Background and Preliminary Studies Section of the Renewal Application.

  6. Optical Power Transfer System for Powering a Remote Mobility System for Multiple Missions

    NASA Technical Reports Server (NTRS)

    Stone, William C. (Inventor); Hogan, Bartholomew P. (Inventor)

    2016-01-01

    An optical power transfer system for powering a remote mobility system for multiple missions comprising a high power source and a chilling station connected to a laser source. The laser source transmits a high optical energy to a beam switch assembly via an optical fiber. The beam switch assembly is optically connected to actively cooled fiber spoolers. Docking stations are adapted for securing the fiber spoolers until alternatively ready for use by a remote mobility system. The remote mobility system is optically connected to the fiber spoolers and has a receiving port adapted for securing the fiber spoolers thereon. The fiber spooler transmits the optical energy to a power conversion system which converts the optical energy received to another usable form of energy. More than one power source may be used where the remote mobility system transfers from one source to another while maintaining an operational radius to each source.

  7. Accuracy of optical navigation systems for automatic head surgery: optical tracking versus optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Díaz Díaz, Jesús; Riva, Mauro H.; Majdani, Omid; Ortmaier, Tobias

    2014-03-01

    The choice of a navigation system highly depends on the medical intervention and its accuracy demands. The most commonly used systems for image guided surgery (IGS) are based on optical and magnetic tracking systems. This paper compares two optical systems in terms of accuracy: state of the art triangulation-based optical tracking (OT) and optical coherence tomography (OCT). We use an experimental setup with a combined OCT and cutting laser, and an external OT. We simulate a robotic assisted surgical intervention, including planning, navigation, and processing, and compare the accuracies reached at a specific target with each navigation system.

  8. Active Optics Modernization of the AEOS Telescope

    NASA Astrophysics Data System (ADS)

    Greenwald, D.

    2012-09-01

    Since first light in 1997, the Advanced Electro-Optical System (AEOS) telescope at the Maui Space Surveillance Site has used an active system for figure control that applies forces on the primary mirror and positions the secondary mirror to minimize wavefront aberrations. Periodically a wavefront optimization loop is closed with a Shack-Hartmann WaveFront Sensor (WFS), 84 primary mirror force actuators and three secondary mirror translation actuators. This optimization loop is used with a series of stellar targets to find coefficients for each force or position in a sine and cosine of elevation model. During normal telescope operation when the WFS is not in use, this elevation angle dependant model is used to control the primary mirror forces and secondary mirror positions. Recently the system was upgraded with new computers, electronics and algorithms. The primary goal of the upgrade was to replace obsolete and no longer maintainable hardware with secondary goals of reducing the effort required to update the wavefront model, and improving the final operational wavefront performance. This paper discusses the algorithms implemented to achieve the secondary goals and initial performance results. In order to eliminate erroneous data from the WFS, the processing algorithms were modified to dynamically assign pixels on the WFS camera to lenslets, and closed loop tracking of the gimbal was implemented using a camera that shares the focal plane with the WFS. These changes permit the elimination of human operator review from the wavefront optimization loop. The original system collected data for either a single star or a series of stars and then replaced either the constant or the complete model at the end of a data collection session. In the revised system, each wavefront measurement is used for a Kalman update to the model. Operationally, the Kalman updates allow data to be collected intermittently as time is available between other telescope tasks. By combining the

  9. Micro-optical-mechanical system photoacoustic spectrometer

    DOEpatents

    Kotovsky, Jack; Benett, William J.; Tooker, Angela C.; Alameda, Jennifer B.

    2013-01-01

    All-optical photoacoustic spectrometer sensing systems (PASS system) and methods include all the hardware needed to analyze the presence of a large variety of materials (solid, liquid and gas). Some of the all-optical PASS systems require only two optical-fibers to communicate with the opto-electronic power and readout systems that exist outside of the material environment. Methods for improving the signal-to-noise are provided and enable mirco-scale systems and methods for operating such systems.

  10. Prototype Optical Correlator For Robotic Vision System

    NASA Technical Reports Server (NTRS)

    Scholl, Marija S.

    1993-01-01

    Known and unknown images fed in electronically at high speed. Optical correlator and associated electronic circuitry developed for vision system of robotic vehicle. System recognizes features of landscape by optical correlation between input image of scene viewed by video camera on robot and stored reference image. Optical configuration is Vander Lugt correlator, in which Fourier transform of scene formed in coherent light and spatially modulated by hologram of reference image to obtain correlation.

  11. Silicon retina for optical tracking systems

    NASA Technical Reports Server (NTRS)

    Strohbehn, K.; Jenkins, R. E.; Sun, X.; Andreou, A. G.

    1993-01-01

    There are a host of position sensors, such as quadcells and CCD's, which are candidates for detecting optical position errors and providing error signals for a mirror positioning loop. We are developing a novel, very high bandwidth, biologically inspired position sensor for optical position tracking systems. We present recent test results and design issues for the use of biologically inspired silicon retinas for spaceborne optical position tracking systems.

  12. Optics Toolbox: An Intelligent Relational Database System For Optical Designers

    NASA Astrophysics Data System (ADS)

    Weller, Scott W.; Hopkins, Robert E.

    1986-12-01

    Optical designers were among the first to use the computer as an engineering tool. Powerful programs have been written to do ray-trace analysis, third-order layout, and optimization. However, newer computing techniques such as database management and expert systems have not been adopted by the optical design community. For the purpose of this discussion we will define a relational database system as a database which allows the user to specify his requirements using logical relations. For example, to search for all lenses in a lens database with a F/number less than two, and a half field of view near 28 degrees, you might enter the following: FNO < 2.0 and FOV of 28 degrees ± 5% Again for the purpose of this discussion, we will define an expert system as a program which contains expert knowledge, can ask intelligent questions, and can form conclusions based on the answers given and the knowledge which it contains. Most expert systems store this knowledge in the form of rules-of-thumb, which are written in an English-like language, and which are easily modified by the user. An example rule is: IF require microscope objective in air and require NA > 0.9 THEN suggest the use of an oil immersion objective The heart of the expert system is the rule interpreter, sometimes called an inference engine, which reads the rules and forms conclusions based on them. The use of a relational database system containing lens prototypes seems to be a viable prospect. However, it is not clear that expert systems have a place in optical design. In domains such as medical diagnosis and petrology, expert systems are flourishing. These domains are quite different from optical design, however, because optical design is a creative process, and the rules are difficult to write down. We do think that an expert system is feasible in the area of first order layout, which is sufficiently diagnostic in nature to permit useful rules to be written. This first-order expert would emulate an expert

  13. Small diameter, deep bore optical inspection system

    DOEpatents

    Lord, David E.; Petrini, Richard R.; Carter, Gary W.

    1981-01-01

    An improved rod optic system for inspecting small diameter, deep bores. The system consists of a rod optic system utilizing a curved mirror at the end of the rod lens such that the optical path through the system is bent 90.degree. to minimize optical distortion in examining the sides of a curved bore. The system is particularly useful in the examination of small bores for corrosion, and is capable of examining 1/16 inch diameter and up to 4 inch deep drill holes, for example. The positioning of the curved mirror allows simultaneous viewing from shallow and right angle points of observation of the same artifact (such as corrosion) in the bore hole. The improved rod optic system may be used for direct eye sighting, or in combination with a still camera or a low-light television monitor; particularly low-light color television.

  14. Small diameter, deep bore optical inspection system

    DOEpatents

    Lord, D.E.; Petrini, R.R.; Carter, G.W.

    An improved rod optic system for inspecting small diameter, deep bores is described. The system consists of a rod optic system utilizing a curved mirror at the end of the rod lens such that the optical path through the system is bent 90/sup 0/ to minimize optical distortion in examing the sides of a curved bore. The system is particularly useful in the examination of small bores for corrosion, and is capable if examing 1/16 inch diameter and up to 4-inch deep drill holes, for example. The positioning of the curved mirror allows simultaneous viewing from shallow and righ angle points of observation of the same artifact (such as corrosion) in the bore hole. The improved rod optic system may be used for direct eye sighting, or in combination with a still camera or a low-light television monitor; particularly low-light color television.

  15. Smart and precise alignment of optical systems

    NASA Astrophysics Data System (ADS)

    Langehanenberg, Patrik; Heinisch, Josef; Stickler, Daniel

    2013-09-01

    For the assembly of any kind of optical systems the precise centration of every single element is of particular importance. Classically the precise alignment of optical components is based on the precise centering of all components to an external axis (usually a high-precision rotary spindle axis). Main drawback of this timeconsuming process is that it is significantly sensitive to misalignments of the reference (e.g. the housing) axis. In order to facilitate process in this contribution we present a novel alignment strategy for the TRIOPTICS OptiCentric® instrument family that directly aligns two elements with respect to each other by measuring the first element's axis and using this axis as alignment reference without the detour of considering an external reference. According to the optical design any axis in the system can be chosen as target axis. In case of the alignment to a barrel this axis is measured by using a distance sensor (e.g., the classically used dial indicator). Instead of fine alignment the obtained data is used for the calculation of its orientation within the setup. Alternatively, the axis of an optical element (single lens or group of lenses) whose orientation is measured with the standard OptiCentric MultiLens concept can be used as a reference. In the instrument's software the decentering of the adjusting element to the calculated axis is displayed in realtime and indicated by a target mark that can be used for the manual alignment. In addition, the obtained information can also be applied for active and fully automated alignment of lens assemblies with the help of motorized actuators.

  16. Optically active particles of chiral polymers.

    PubMed

    Song, Ci; Liu, Xuan; Liu, Dong; Ren, Chonglei; Yang, Wantai; Deng, Jianping

    2013-09-01

    Particles constructed by chiral polymers (defined as PCPs) have emerged as a rapidly expanding research field in recent years because of their potentially wide-ranging applications in asymmetric catalysis, enantioselective crystallization, enantioselective release, amongst many others. The particles show considerable optical activity, due to the chirality of the corresponding polymers from which the particles are derived. This review article presents an overview on PCPs with emphasis on our group's recent achievements in the preparation of PCPs derived from optically active helical polymers and their applications. PCPs can be prepared via emulsion polymerization, precipitation polymerization, and suspension polymerization by starting from monomers. Emulsification of preformed chiral polymers and self-assembly approaches also can lead to PCPs. Chiral polymer-based core/shell particles, hollow particles, and magnetic particles are also covered because of their remarkable properties and significant potential applications. PMID:24030962

  17. Optical activity of chirally distorted nanocrystals

    NASA Astrophysics Data System (ADS)

    Tepliakov, Nikita V.; Baimuratov, Anvar S.; Baranov, Alexander V.; Fedorov, Anatoly V.; Rukhlenko, Ivan D.

    2016-05-01

    We develop a general theory of optical activity of semiconductor nanocrystals whose chirality is induced by a small perturbation of their otherwise achiral electronic subsystems. The optical activity is described using the quantum-mechanical expressions for the rotatory strengths and dissymmetry factors introduced by Rosenfeld. We show that the rotatory strengths of optically active transitions are decomposed on electric dipole and magnetic dipole contributions, which correspond to the electric dipole and magnetic dipole transitions between the unperturbed quantum states. Remarkably, while the two kinds of rotatory strengths are of the same order of magnitude, the corresponding dissymmetry factors can differ by a factor of 105. By maximizing the dissymmetry of magnetic dipole absorption one can significantly enhance the enantioselectivity in the interaction of semiconductor nanocrystals with circularly polarized light. This feature may advance chiral and analytical methods, which will benefit biophysics, chemistry, and pharmaceutical science. The developed theory is illustrated by an example of intraband transitions inside a semiconductor nanocuboid, whose rotatory strengths and dissymmetry factors are calculated analytically.

  18. Power system applications of fiber optics

    NASA Technical Reports Server (NTRS)

    Kirkham, H.; Johnston, A.; Lutes, G.; Daud, T.; Hyland, S.

    1984-01-01

    Power system applications of optical systems, primarily using fiber optics, are reviewed. The first section reviews fibers as components of communication systems. The second section deals with fiber sensors for power systems, reviewing the many ways light sources and fibers can be combined to make measurements. Methods of measuring electric field gradient are discussed. Optical data processing is the subject of the third section, which begins by reviewing some widely different examples and concludes by outlining some potential applications in power systems: fault location in transformers, optical switching for light fired thyristors and fault detection based on the inherent symmetry of most power apparatus. The fourth and final section is concerned with using optical fibers to transmit power to electric equipment in a high voltage situation, potentially replacing expensive high voltage low power transformers. JPL has designed small photodiodes specifically for this purpose, and fabricated and tested several samples. This work is described.

  19. Fiber Optic Network Design Expert System

    NASA Astrophysics Data System (ADS)

    Artz, Timothy J.; Wnek, Roy M.

    1987-05-01

    The Fiber Optic Network Design Expert System (FONDES) is an engineering tool for the specification, design, and evaluation of fiber optic transmission systems. FONDES encompasses a design rule base and a data base of specifications of system components. This package applies to fiber optic design work in two ways, as a design-to-specification tool and a system performance prediction model. The FONDES rule base embodies the logic of design engineering. It can be used to produce a system design given a requirement specification or it can be used to predict system performance given a system design. The periodically updated FONDES data base contains performance specifications, price, and availability data for current fiber optic system components. FONDES is implemented in an artificial intelligence language, TURBO-PROLOG, and runs on an IBM-PC.

  20. Influence of optical activity on rogue waves propagating in chiral optical fibers

    NASA Astrophysics Data System (ADS)

    Temgoua, D. D. Estelle; Kofane, T. C.

    2016-06-01

    We derive the nonlinear Schrödinger (NLS) equation in chiral optical fiber with right- and left-hand nonlinear polarization. We use the similarity transformation to reduce the generalized chiral NLS equation to the higher-order integrable Hirota equation. We present the first- and second-order rational solutions of the chiral NLS equation with variable and constant coefficients, based on the modified Darboux transformation method. For some specific set of parameters, the features of chiral optical rogue waves are analyzed from analytical results, showing the influence of optical activity on waves. We also generate the exact solutions of the two-component coupled nonlinear Schrödinger equations, which describe optical activity effects on the propagation of rogue waves, and their properties in linear and nonlinear coupling cases are investigated. The condition of modulation instability of the background reveals the existence of vector rogue waves and the number of stable and unstable branches. Controllability of chiral optical rogue waves is examined by numerical simulations and may bring potential applications in optical fibers and in many other physical systems.

  1. Optical multicast system for data center networks.

    PubMed

    Samadi, Payman; Gupta, Varun; Xu, Junjie; Wang, Howard; Zussman, Gil; Bergman, Keren

    2015-08-24

    We present the design and experimental evaluation of an Optical Multicast System for Data Center Networks, a hardware-software system architecture that uniquely integrates passive optical splitters in a hybrid network architecture for faster and simpler delivery of multicast traffic flows. An application-driven control plane manages the integrated optical and electronic switched traffic routing in the data plane layer. The control plane includes a resource allocation algorithm to optimally assign optical splitters to the flows. The hardware architecture is built on a hybrid network with both Electronic Packet Switching (EPS) and Optical Circuit Switching (OCS) networks to aggregate Top-of-Rack switches. The OCS is also the connectivity substrate of splitters to the optical network. The optical multicast system implementation requires only commodity optical components. We built a prototype and developed a simulation environment to evaluate the performance of the system for bulk multicasting. Experimental and numerical results show simultaneous delivery of multicast flows to all receivers with steady throughput. Compared to IP multicast that is the electronic counterpart, optical multicast performs with less protocol complexity and reduced energy consumption. Compared to peer-to-peer multicast methods, it achieves at minimum an order of magnitude higher throughput for flows under 250 MB with significantly less connection overheads. Furthermore, for delivering 20 TB of data containing only 15% multicast flows, it reduces the total delivery energy consumption by 50% and improves latency by 55% compared to a data center with a sole non-blocking EPS network. PMID:26368190

  2. Adaptive optical system for astronomical applications

    NASA Astrophysics Data System (ADS)

    Merkle, F.; Bille, J.; Freischlad, K.; Frieben, M.; Jahn, G.; Reischmann, H.-L.

    The active optical system being developed for use with the 0.75-m RC telescope at the Landessternwarte in Heidelberg, FRG, is discussed. A 5-cm electrostatically deformable aluminum-coated polymer mirror (sensitivity 0.05 microns/V, maximum local tilt 3 microns/5 mm) is mounted in a gimbal with piezoelectric-actuator tilt control. The mirror control systems being tested are a modified shearing interferometer with crosstalk-compensated feedback and Fourier-modulus wavefront computation, both using a 32 x 32 diode array as detector. Modal phase compensation is achieved using Zernike polynomials and Karhunen-Loeve functions; the correction for the tilt terms of the series expansion is left to the overall-tilt compensation unit, for which preliminary test results are shown.

  3. Knowledge-based optical system design: some optical systems generated by the KBOSD

    NASA Astrophysics Data System (ADS)

    Nouri, Taoufik; Erard, Pierre-Jean

    1993-04-01

    This work is a new approach for the design of start optical systems and represents a new contribution of artificial intelligence techniques in the optical design field. A knowledge-based optical-systems design (KBOSD), based on artificial intelligence algorithms, first order logic, knowledge representation, rules, and heuristics on lens design, is realized. This KBOSD is equipped with optical knowledge in the domain of centered dioptrical optical systems used at low aperture and small field angles. This KBOSD generates centered dioptrical, on-axis and low-aperture optical-systems, which are used as start systems for the subsequent optimization by existing lens design programs. This KBOSD produces monochromatic or polychromatic optical systems, such as singlet lens, doublet lens, triplet lens, reversed singlet lens, reversed doublet lens, reversed triplet lens, and telescopes. In the design of optical systems, the KBOSD takes into account many user constraints such as cost, resistance of the optical material (glass) to chemical, thermal, and mechanical effects, as well as the optical quality such as minimal aberrations and chromatic aberrations corrections. This KBOSD is developed in the programming language Prolog and has knowledge on optical design principles and optical properties and uses neither a lens library nor a lens data base, it is completely based on optical design knowledge.

  4. Optical system components for navigation grade fiber optic gyroscopes

    NASA Astrophysics Data System (ADS)

    Heimann, Marcus; Liesegang, Maximilian; Arndt-Staufenbiel, Norbert; Schröder, Henning; Lang, Klaus-Dieter

    2013-10-01

    Interferometric fiber optic gyroscopes belong to the class of inertial sensors. Due to their high accuracy they are used for absolute position and rotation measurement in manned/unmanned vehicles, e.g. submarines, ground vehicles, aircraft or satellites. The important system components are the light source, the electro optical phase modulator, the optical fiber coil and the photodetector. This paper is focused on approaches to realize a stable light source and fiber coil. Superluminescent diode and erbium doped fiber laser were studied to realize an accurate and stable light source. Therefor the influence of the polarization grade of the source and the effects due to back reflections to the source were studied. During operation thermal working conditions severely affect accuracy and stability of the optical fiber coil, which is the sensor element. Thermal gradients that are applied to the fiber coil have large negative effects on the achievable system accuracy of the optic gyroscope. Therefore a way of calculating and compensating the rotation rate error of a fiber coil due to thermal change is introduced. A simplified 3 dimensional FEM of a quadrupole wound fiber coil is used to determine the build-up of thermal fields in the polarization maintaining fiber due to outside heating sources. The rotation rate error due to these sources is then calculated and compared to measurement data. A simple regression model is used to compensate the rotation rate error with temperature measurement at the outside of the fiber coil. To realize a compact and robust optical package for some of the relevant optical system components an approach based on ion exchanged waveguides in thin glass was developed. This waveguides are used to realize 1x2 and 1x4 splitter with fiber coupling interface or direct photodiode coupling.

  5. Optical pumping of generalized laser active materials.

    PubMed

    Fry, F H

    1967-11-01

    Results are presented of a computer-based study on the rate of excitation in the active cores of two types of optically pumped lasers as a function of a number of parameters of the active core. The absorption bands of the active materials are generated by Lorentzian and Gaussian functions. The excitation rate of the active core is proportional to the width of the absorption band at all depths of penetration. The plots of excitation rate as a function of frequency show curves similar to line reversal spectra and emphasize the importance of excitation some distance from the center of the absorption band in the slab model. In the cylindrical model, this wing pumping is even more important due to focusing. The effect of refractive index on the excitation rate is also described. PMID:20062337

  6. Optically pumped isotopic ammonia laser system

    DOEpatents

    Buchwald, Melvin I.; Jones, Claude R.; Nelson, Leonard Y.

    1982-01-01

    An optically pumped isotopic ammonia laser system which is capable of producing a plurality of frequencies in the middle infrared spectral region. Two optical pumping mechanisms are disclosed, i.e., pumping on R(J) and lasing on P(J) in response to enhancement of rotational cascade lasing including stimulated Raman effects, and, pumping on R(J) and lasing on P(J+2). The disclosed apparatus for optical pumping include a hole coupled cavity and a grating coupled cavity.

  7. Strong optical activity from twisted-cross photonic metamaterials.

    PubMed

    Decker, M; Ruther, M; Kriegler, C E; Zhou, J; Soukoulis, C M; Linden, S; Wegener, M

    2009-08-15

    Following a recent theoretical suggestion and microwave experiments, we fabricate photonic metamaterials composed of pairs of twisted gold crosses using two successive electron-beam-lithography steps and intermediate planarization via a spin-on dielectric. The resulting two effective resonances of the coupled system lie in the 1-2 microm wavelength regime and exhibit pronounced circular dichroism, while the circular polarization conversion is very small. In between the two resonances, we find a fairly broad spectral regime with strong optical activity, i.e., with a pure rotation of incident linear polarization. The measured optical transmittance spectra agree well with theory. PMID:19684829

  8. Plasmonic Biofoam: A Versatile Optically Active Material.

    PubMed

    Tian, Limei; Luan, Jingyi; Liu, Keng-Ku; Jiang, Qisheng; Tadepalli, Sirimuvva; Gupta, Maneesh K; Naik, Rajesh R; Singamaneni, Srikanth

    2016-01-13

    Owing to their ability to confine and manipulate light at the nanoscale, plasmonic nanostructures are highly attractive for a broad range of applications. While tremendous progress has been made in the synthesis of size- and shape-controlled plasmonic nanostructures, their integration with other materials and application in solid-state is primarily through their assembly on rigid two-dimensional (2D) substrates, which limits the plasmonically active space to a few nanometers above the substrate. In this work, we demonstrate a simple method to create plasmonically active three-dimensional biofoams by integrating plasmonic nanostructures with highly porous biomaterial aerogels. We demonstrate that plasmonic biofoam is a versatile optically active platform that can be harnessed for numerous applications including (i) ultrasensitive chemical detection using surface-enhanced Raman scattering; (ii) highly efficient energy harvesting and steam generation through plasmonic photothermal heating; and (iii) optical control of enzymatic activity by triggered release of biomolecules encapsulated within the aerogel. Our results demonstrate that 3D plasmonic biofoam exhibits significantly higher sensing, photothermal, and loading efficiency compared to conventional 2D counterparts. The design principles and processing methodology of plasmonic aerogels demonstrated here can be broadly applied in the fabrication of other functional foams. PMID:26630376

  9. Optical panel system including stackable waveguides

    DOEpatents

    DeSanto, Leonard; Veligdan, James T.

    2007-11-20

    An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, wherein each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.

  10. Optical panel system including stackable waveguides

    DOEpatents

    DeSanto, Leonard; Veligdan, James T.

    2007-03-06

    An optical panel system including stackable waveguides is provided. The optical panel system displays a projected light image and comprises a plurality of planar optical waveguides in a stacked state. The optical panel system further comprises a support system that aligns and supports the waveguides in the stacked state. In one embodiment, the support system comprises at least one rod, wherein each waveguide contains at least one hole, and wherein each rod is positioned through a corresponding hole in each waveguide. In another embodiment, the support system comprises at least two opposing edge structures having the waveguides positioned therebetween, wherein each opposing edge structure contains a mating surface, wherein opposite edges of each waveguide contain mating surfaces which are complementary to the mating surfaces of the opposing edge structures, and wherein each mating surface of the opposing edge structures engages a corresponding complementary mating surface of the opposite edges of each waveguide.

  11. Optical system for trapping particles in air.

    PubMed

    Kampmann, R; Chall, A K; Kleindienst, R; Sinzinger, S

    2014-02-01

    An innovative optical system for trapping particles in air is presented. We demonstrate an optical system specifically optimized for high precision positioning of objects with a size of several micrometers within a nanopositioning and nanomeasuring machine (NPMM). Based on a specification sheet, an initial system design was calculated and optimized in an iterative design process. By combining optical design software with optical force simulation tools, a highly efficient optical system was developed. Both components of the system, which include a refractive double axicon and a parabolic ring mirror, were fabricated by ultra-precision turning. The characterization of the optical elements and the whole system, especially the force simulations based on caustic measurements, represent an important interim result for the subsequently performed trapping experiments. The caustic of the trapping beam produced by the system was visualized with the help of image processing techniques. Finally, we demonstrated the unique efficiency of the configuration by reproducibly trapping fused silica spheres with a diameter of 10 μm at a distance of 2.05 mm from the final optical surface. PMID:24514197

  12. Optical components damage parameters database system

    NASA Astrophysics Data System (ADS)

    Tao, Yizheng; Li, Xinglan; Jin, Yuquan; Xie, Dongmei; Tang, Dingyong

    2012-10-01

    Optical component is the key to large-scale laser device developed by one of its load capacity is directly related to the device output capacity indicators, load capacity depends on many factors. Through the optical components will damage parameters database load capacity factors of various digital, information technology, for the load capacity of optical components to provide a scientific basis for data support; use of business processes and model-driven approach, the establishment of component damage parameter information model and database systems, system application results that meet the injury test optical components business processes and data management requirements of damage parameters, component parameters of flexible, configurable system is simple, easy to use, improve the efficiency of the optical component damage test.

  13. Micro electro mechanical system optical switching

    SciTech Connect

    Thorson, Kevin J; Stevens, Rick C; Kryzak, Charles J; Leininger, Brian S; Kornrumpf, William P; Forman, Glenn A; Iannotti, Joseph A; Spahn, Olga B; Cowan, William D; Dagel, Daryl J

    2013-12-17

    The present disclosure includes apparatus, system, and method embodiments that provide micro electo mechanical system optical switching and methods of manufacturing switches. For example, one optical switch embodiment includes at least one micro electro mechanical system type pivot mirror structure disposed along a path of an optical signal, the structure having a mirror and an actuator, and the mirror having a pivot axis along a first edge and having a second edge rotatable with respect to the pivot axis, the mirror being capable of and arranged to be actuated to pivot betweeen a position parallel to a plane of an optical signal and a position substantially normal to the plane of the optical signal.

  14. Doppler and range determination for deep space vehicles using active optical transponders

    NASA Technical Reports Server (NTRS)

    Kinman, Peter W.; Gagliardi, Robert M.

    1988-01-01

    This paper describes and analyzes two types of laser system employing active transponders that could accurately determine Doppler and range to deep space vehicles from earth-orbiting satellites. The first is a noncoherent optical system in which the Doppler effect on an intensity-modulating subcarrier is measured. The second is a coherent optical system in which the Doppler effect of the optical carrier itself is measured. Doppler and range measurement errors are mathematically modeled and, for three example systems, numerically evaluated.

  15. Integrated optical biosensor system (IOBS)

    DOEpatents

    Grace, Karen M.; Sweet, Martin R.; Goeller, Roy M.; Morrison, Leland Jean; Grace, Wynne Kevin; Kolar, Jerome D.

    2007-10-30

    An optical biosensor has a first enclosure with a pathogen recognition surface, including a planar optical waveguide and grating located in the first enclosure. An aperture is in the first enclosure for insertion of sample to be investigated to a position in close proximity to the pathogen recognition surface. A laser in the first enclosure includes means for aligning and means for modulating the laser, the laser having its light output directed toward said grating. Detection means are located in the first enclosure and in optical communication with the pathogen recognition surface for detecting pathogens after interrogation by the laser light and outputting the detection. Electronic means is located in the first enclosure and receives the detection for processing the detection and outputting information on the detection, and an electrical power supply is located in the first enclosure for supplying power to the laser, the detection means and the electronic means.

  16. Squeezing spectra for nonlinear optical systems

    NASA Technical Reports Server (NTRS)

    Collett, M. J.; Walls, D. F.

    1985-01-01

    The squeezing spectra for the output fields of several intracavity nonlinear optical systems are obtained. It is shown that at critical points, e.g., the turning points for optical bistability, the threshold for parametric oscillation, and the self-pulsing instability in second-harmonic generation, perfect squeezing in the output field is, in principle, possible.

  17. Optical simulations for Ambilight TV systems

    NASA Astrophysics Data System (ADS)

    Bruyneel, Filip; Lanoye, Lieve

    2012-06-01

    Ambilight is a unique Philips feature, where RGB LEDs are used to create a dynamic light halo around the television. This extends the screen and hence increases the viewing experience, as it draws the viewer more into the action on the screen. The feature receives very positive consumer feedback. However, implementing Ambilight in the increasingly stringent design boundary conditions of a slim and thin TV set is a challenging task. Optical simulations play a vital role in each step of the Ambilight development. Ranging from prototype to final product, we use simulations, next to prototyping, to aid the choice of LEDs, optical materials and optical systems during different phases of the design process. Each step the impact of the optical system on the mechanical design and TV set dimensions needs to be taken into account. Moreover, optical simulations are essential to guarantee the required optical performance given a big spread in LED performance, mechanical tolerances and material properties. Next to performance, optical efficiency is also an important parameter to evaluate an optical design, as it establishes the required number of LEDs and the total LED power. As such optical efficiency defines the thermal power which needs to be dissipated by the LED system. The innovation roadmap does not stop here. For future systems we see a miniaturization trend, where smaller LED packages and smaller dies are used. This evolution makes the impact of mechanical tolerances on the optical design more severe. Consequentially, this approach poses a whole new challenge to the way we use optical simulations in our design process.

  18. Optical concept for an active headlamp with a DMD array

    NASA Astrophysics Data System (ADS)

    Günther, A.

    2008-04-01

    Present car-headlamps can adapt their light distribution to the traffic situation only in a predefined way. The next generation of headlamps will offer a more flexible adaptation of their light distribution like an adaptive Cut-Off-Line in "Advanced Frontlighting Systems" (AFS). Addressable light sources in future active headlamps enable functions like glare free high beam or marking light. There are several possibilities to design such an addressable light source. In this contribution one solution using a digital micro mirror device (DMD) is presented. With this device an adaptive light distribution can be generated by modulating every pixel of the DMD individually. For the design of an optical system for a DMD headlamp a DMD-Projector was analyzed. The procedure of generating a light distribution can be divided into two processes: a.) illumination of DMD b.) projecting the image of the DMD on the street. In a DMD projector the illumination of a DMD is a very complex optical system with many optical elements. Some of these optical elements are not necessary for a car headlamp because of different requirements for car headlamps and DMD projectors. The illumination system can be simplified if these elements are eliminated. Also the aspect ratio of the imaging system for the DMD has to change 4:3 (DMD) to 7:2 (light distribution on the street).

  19. Steamy Optics: A System for Demonstrating Geometric and Physical Optics

    NASA Astrophysics Data System (ADS)

    Craig, Matthew; Johnson, Ryan; Schultz, Sara

    2007-04-01

    A simple apparatus consisting of a plastic box with transparent sides filled with fog from an ultrasonic humidifier is very effective for demonstrating the passage of light through optical elements. There are several other methods for making the light passing through an optical system visible, including an apparatus that generates fog using liquid nitrogen. Logiurato et al.2 have described a setup that employs a mist maker available from scientific supply companies to produce the fog. The demonstration described here is useful because the initial equipment costs are low, and the necessary items may all be easily obtained locally. The vapor is generated using only tap water.

  20. All-optical active switching in individual semiconductor nanowires

    NASA Astrophysics Data System (ADS)

    Piccione, Brian; Cho, Chang-Hee; van Vugt, Lambert K.; Agarwal, Ritesh

    2012-10-01

    The imminent limitations of electronic integrated circuits are stimulating intense activity in the area of nanophotonics for the development of on-chip optical components, and solutions incorporating direct-bandgap semiconductors are important in achieving this end. Optical processing of data at the nanometre scale is promising for circumventing these limitations, but requires the development of a toolbox of components including emitters, detectors, modulators, waveguides and switches. In comparison to components fabricated using top-down methods, semiconductor nanowires offer superior surface properties and stronger optical confinement. They are therefore ideal candidates for nanoscale optical network components, as well as model systems for understanding optical confinement. Here, we demonstrate all-optical switching in individual CdS nanowire cavities with subwavelength dimensions through stimulated polariton scattering, as well as a functional NAND gate built from multiple switches. The device design exploits the strong light-matter coupling present in these nanowires, leading to footprints that are a fraction of those of comparable silicon-based dielectric contrast and photonic crystal devices.

  1. Optical Activity of Anisotropic Achiral Surfaces

    SciTech Connect

    Verbiest, T.; Kauranen, M.; Van Rompaey, Y.; Persoons, A. |

    1996-08-01

    Anisotropic achiral surfaces respond differently to left- and right-hand circularly polarized light. This occurs when the orientation of the surface with respect to an otherwise achiral experimental setup makes the total geometry chiral. Such optical activity is demonstrated in second-harmonic generation from an anisotropic thin molecular film. The circular-difference response reverses sign as the handedness of the geometry is reversed and vanishes when the setup possesses a mirror plane. The results are explained within the electric-dipole-allowed second-order surface nonlinearity. {copyright} {ital 1996 The American Physical Society.}

  2. Advanced optical blade tip clearance measurement system

    NASA Technical Reports Server (NTRS)

    Ford, M. J.; Honeycutt, R. E.; Nordlund, R. E.; Robinson, W. W.

    1978-01-01

    An advanced electro-optical system was developed to measure single blade tip clearances and average blade tip clearances between a rotor and its gas path seal in an operating gas turbine engine. This system is applicable to fan, compressor, and turbine blade tip clearance measurement requirements, and the system probe is particularly suitable for operation in the extreme turbine environment. A study of optical properties of blade tips was conducted to establish measurement system application limitations. A series of laboratory tests was conducted to determine the measurement system's operational performance characteristics and to demonstrate system capability under simulated operating gas turbine environmental conditions. Operational and environmental performance test data are presented.

  3. Fiber optics for propulsion control systems

    NASA Technical Reports Server (NTRS)

    Baumbick, R. J.

    1985-01-01

    In aircraft systems with digital controls, fiberoptics has advantages over wire systems because of its inherent immunity to electromagnetic noise (EMI) and electromagnetic pulses (EMP). It also offers a weight benefit when metallic conductors are replaced by optical fibers. To take full advantage of the benefits of optical waveguides, passive optical sensors are also being developed to eliminate the need for electrical power to the sensor. Fiberoptics may also be used for controlling actuators on engine and airframe. In this application, the optical fibers, connectors, etc. will be subjected to high temperature and vibrations. This paper discussed the use of fiberoptics in aircraft propulsion systems together with the optical sensors and optically controlled actuators being developed to take full advantage of the benefits which fiberoptics offers. The requirements for sensors and actuators in advanced propulsion systems are identified. The benefits of using fiberoptics in place of conventional wire systems are discussed as well as the environmental conditions under which the optical components must operate.

  4. Active Optics for a Segmented Primary Mirror on a Deep-Space Optical Receiver Antenna (DSORA)

    NASA Technical Reports Server (NTRS)

    Clymer, B. D.

    1990-01-01

    This article investigates the active optical control of segments in the primary mirror to correct for wavefront errors in the Deep-Space Optical Receiver Antenna (DSORA). Although an exact assessment of improvement in signal blur radius cannot be made until a more detailed preliminary structural design is completed, analytical tools are identified for a time when such designs become available. A brief survey of appropriate sensing approaches is given. Since the choice of control algorithm and architecture depends on the particular sensing system used, typical control systems, estimated complexities, and the type of equipment required are discussed. Once specific sensor and actuator systems are chosen, the overall control system can be optimized using methods identified in the literature.

  5. Hemodynamic responses to functional activation accessed by optical imaging

    NASA Astrophysics Data System (ADS)

    Ni, Songlin; Li, Pengcheng; Yang, Yuanyuan; Lv, Xiaohua; Luo, Qingming

    2006-01-01

    A multi-wavelength light-emitting diode (LED) and laser diode (LD) based optical imaging system was developed to visualize the changes in cerebral blood flow, oxygenation following functional activation simultaneously in rodent cortex. The 2-D blood flow image was accessed by laser speckle contrast imaging, and the spectroscopic imaging of intrinsic signal was used for the calculation of oxyhemoglobin (HbO), deoxyhemoglobin (Hb) and total hemoglobin (HbT) concentration. The combination of spectroscopic imaging and laser speckle contrast imaging provides the capability to simultaneously investigate the spatial and temporal blood flow and hemoglobin concentration changes with high resolution, which may lead to a better understanding of the coupling between neuronal activation and vascular responses. The optical imaging system been built is compact and convenient to investigators. And it is reliable to acquire raw data. In present study, the hemodynamic responses to cortical spreading depression (CSD) in parietal cortex of ~-chloralose/urethan anesthetized rats were demonstrated.

  6. Optical spring effect in nanoelectromechanical systems

    SciTech Connect

    Tian, Feng; Zhou, Guangya Du, Yu; Chau, Fook Siong; Deng, Jie

    2014-08-11

    In this Letter, we report a hybrid system consisting of nano-optical and nano-mechanical springs, in which the optical spring effect works to adjust the mechanical frequency of a nanoelectromechanical systems resonator. Nano-scale folded beams are fabricated as the mechanical springs and double-coupled one-dimensional photonic crystal cavities are used to pump the “optical spring.” The dynamic characteristics of this hybrid system are measured and analyzed at both low and high input optical powers. This study leads the physical phenomenon of optomechanics in complex nano-opto-electro-mechanical systems (NOEMS) and could benefit the future applications of NOEMS in chip-level communication and sensing.

  7. Nonlinear Mixing in Optical Multicarrier Systems

    NASA Astrophysics Data System (ADS)

    Hameed, Mahmood Abdul

    Although optical fiber has a vast spectral bandwidth, efficient use of this bandwidth is still important in order to meet the ever increased capacity demand of optical networks. In addition to wavelength division multiplexing, it is possible to partition multiple low-rate subcarriers into each high speed wavelength channel. Multicarrier systems not only ensure efficient use of optical and electrical components, but also tolerate transmission impairments. The purpose of this research is to understand the impact of mixing among subcarriers in Radio-Over-Fiber (RoF) and high speed optical transmission systems, and experimentally demonstrate techniques to minimize this impact. We also analyze impact of clipping and quantization on multicarrier signals and compare bandwidth efficiency of two popular multiplexing techniques, namely, orthogonal frequency division multiplexing (OFDM) and Nyquist modulation. For an OFDM-RoF system, we present a novel technique that minimizes the RF domain signal-signal beat interference (SSBI), relaxes the phase noise limit on the RF carrier, realizes the full potential of optical heterodyne-based RF carrier generation, and increases the performance-to-cost ratio of RoF systems. We demonstrate a RoF network that shares the same RF carrier for both downlink and uplink, avoiding the need of an additional RF oscillator in the customer unit. For multi-carrier optical transmission, we first experimentally compare performance degradations of coherent optical OFDM and single-carrier Nyquist pulse modulated systems in a nonlinear environment. We then experimentally evaluate SSBI compensation techniques in the presence of semiconductor optical amplifier (SOA) induced nonlinearities for a multicarrier optical system with direct detection. We show that SSBI contamination can be significantly reduced from the data signal when the carrier-to-signal power ratio is sufficiently low.

  8. Study on test metrology of large aperture optical system wavefront

    NASA Astrophysics Data System (ADS)

    Liu, Zhiying; Fu, Yuegang; Gao, Tianyuan; Wang, Zhijian

    2009-05-01

    Large aperture optical system test has been a key problem for a long time. It could be solved by sub-aperture stitching method after the sub-apertures are tested. Sub-aperture stitching technology is a feasible method for testing large diameter optical system with small diameter interferometer sub-aperture stitching. Auto-collimating component will be needed with interferometer stitching method. Auto-collimating component is defined that the image could be kept stable when the optical component rotates about any axis in space. And the beam could be back along original optical path. By this means, auto collimation could be realized. The auto-collimating component is smaller than the test system. The whole wavefront of large aperture system could be tested through the method that the auto-collimating component moves along the guide rail and rotates about optical axis. A right angle roof prism is chosen as the auto-collimating component due to its character of easier manufacture. The active matrix, characteristic orientation and extreme axial is deduced with dynamic optics. The sub-aperture stitching testing process is simulated by ZEMAX in detail. The test result by stitching method is compared with that by directive test method for large aperture optical system. It is shown that the relative test error is less than 4.3λ 0/00. The sub -aperture stitching test method is verified.

  9. Integral optical system design of injection molded optics

    NASA Astrophysics Data System (ADS)

    Baumer, Stefan M.; Shulepova, Lena; Willemse, Jan; Renkema, Kor

    2003-11-01

    Injection molded optics are frequently applied in many high volume applications. Bar code scanners, CD / DVD systems, CMOS cameras are a few examples. In all of these applications cost effective and fast design cycles are essential. At Philips High Tech Plastics we developed a design system that touches on all different aspects of the system design. Starting with traditional lens design (sequential ray tracing) and tolernacing we transport the initial design into mechanical solid modeling. During mechanical modeling, tolerances, injection molding design rules and integration of mechanical features, reference marks, etc. are incorporated as well. Here the full advantage of injection molding can be utilized. After the opto - mechanical modeling the system is ported back to non - sequential ray tracing for ghost - and stray light analysis. Finally extended tolerancing is performed in order to come to a robust high volume product. If necessary all or several steps in this design process are repeated in order to arrive at the final design. As an additional requirement the metrology possibilities for the design are checked in at an early stage. This integral system approach to optical design, including optical modeling (sequential and non-sequential) combined with mechanical solid modeling is presented using some recent examples.

  10. Talbot effect in Gaussian optical systems

    SciTech Connect

    Kandidov, V P; Kondrat'ev, Andrei V

    2001-11-30

    It is shown that the diffraction reproduction of a periodically modulated wave field takes place when light propagates through Gaussian optical systems. Generally, such a reproduction is accompanied by image scaling. Equations are derived that relate the reproducton distance and scaling factor to the ABCD matrix elements of the optical system. The Talbot effect in a convergent (divergent) wave is considered. (laser applications and other topics in quantum electronics)

  11. Optics and multilayer coatings for EUVL systems

    SciTech Connect

    Soufli, R; Bajt, S; Hudyma, R M; Taylor, J S

    2008-03-21

    EUV lithography (EUVL) employs illumination wavelengths around 13.5 nm, and in many aspects it is considered an extension of optical lithography, which is used for the high-volume manufacturing (HVM) of today's microprocessors. The EUV wavelength of illumination dictates the use of reflective optical elements (mirrors) as opposed to the refractive lenses used in conventional lithographic systems. Thus, EUVL tools are based on all-reflective concepts: they use multilayer (ML) coated optics for their illumination and projection systems, and they have a ML-coated reflective mask.

  12. Neutron Activation of NIF Final Optics Assemblies

    SciTech Connect

    Sitaraman, S; Dauffy, L; Khater, H; Brereton, S

    2009-09-29

    Analyses were performed to characterize the radiation field in the vicinity of the Final Optics Assemblies (FOAs) at the National Ignition Facility (NIF) due to neutron activation following Deuterium-Deuterium (DD), Tritium-Hydrogen-Deuterium (THD), and Deuterium-Tritium (DT) shots associated with different phases of the NIF operations. The activation of the structural components of the FOAs produces one of the larger sources of gamma radiation and is a key factor in determining the stay out time between shots to ensure worker protection. This study provides estimates of effective dose rates in the vicinity of a single FOA and concludes that the DD and THD targets produce acceptable dose rates within 10 minutes following a shot while about 6-days of stay out time is suggested following DT shots. Studies are ongoing to determine the combined effects of multiple FOAs and other components present in the Target Bay on stay-out time and worker dose.

  13. Optical Design for Extremely Large Telescope Adaptive Optics Systems

    SciTech Connect

    Bauman, B J

    2003-11-26

    Designing an adaptive optics (AO) system for extremely large telescopes (ELT's) will present new optical engineering challenges. Several of these challenges are addressed in this work, including first-order design of multi-conjugate adaptive optics (MCAO) systems, pyramid wavefront sensors (PWFS's), and laser guide star (LGS) spot elongation. MCAO systems need to be designed in consideration of various constraints, including deformable mirror size and correction height. The y,{bar y} method of first-order optical design is a graphical technique that uses a plot with marginal and chief ray heights as coordinates; the optical system is represented as a segmented line. This method is shown to be a powerful tool in designing MCAO systems. From these analyses, important conclusions about configurations are derived. PWFS's, which offer an alternative to Shack-Hartmann (SH) wavefront sensors (WFS's), are envisioned as the workhorse of layer-oriented adaptive optics. Current approaches use a 4-faceted glass pyramid to create a WFS analogous to a quad-cell SH WFS. PWFS's and SH WFS's are compared and some newly-considered similarities and PWFS advantages are presented. Techniques to extend PWFS's are offered: First, PWFS's can be extended to more pixels in the image by tiling pyramids contiguously. Second, pyramids, which are difficult to manufacture, can be replaced by less expensive lenslet arrays. An approach is outlined to convert existing SH WFS's to PWFS's for easy evaluation of PWFS's. Also, a demonstration of PWFS's in sensing varying amounts of an aberration is presented. For ELT's, the finite altitude and finite thickness of LGS's means that the LGS will appear elongated from the viewpoint of subapertures not directly under the telescope. Two techniques for dealing with LGS spot elongation in SH WFS's are presented. One method assumes that the laser will be pulsed and uses a segmented micro-electromechanical system (MEMS) to track the LGS light subaperture by

  14. Optical correlators: systems and domains of applications

    NASA Astrophysics Data System (ADS)

    Dragulinescu, Andrei; Cojoc, Dan

    2005-08-01

    The paper presents the basic concepts of the optical correlators. In our knowledge, it is the first systematic presentation of the applications of optical correlators. The main three types of optical correlators: the optical correlator in incoherent light, the optical correlator in coherent light (VanderLugt) and the joint transform correlator are presented. The optical correlators are very powerll systems used for image recognition, that perform a correlation between a bidimensional function which represents a Scene that must be analyzed and another bidimensional function that contains information about the reference function. This correlation is optically realized by a Fourier transform between the two functions. The optical Correlators have found a lot of applications for image recognition and target detection in various fields, such as the military field, robotics, medical field, industry a.s.o. Among the various applications of the optical correlators we can mention: digital fingerprints identification, credit card security, antique scripts recognition, determination of the cosmic ships and satellites behavior, amelioration of cancer tests precision, quality control etc.

  15. Optical activity in planar chiral metamaterials: Theoretical study

    SciTech Connect

    Bai, Benfeng; Svirko, Yuri; Turunen, Jari; Vallius, Tuomas

    2007-08-15

    A thorough theoretical study of the optical activity in planar chiral metamaterial (PCM) structures, made of both dielectric and metallic media, is conducted by the analysis of gammadion-shaped nanoparticle arrays. The general polarization properties are first analyzed from an effective-medium perspective, by analogy with natural optical activity, and then verified by rigorous numerical simulation, some of which are corroborated by previous experimental results. The numerical analysis suggests that giant polarization rotation (tens of degrees) may be achieved in the PCM structures with a thickness of only hundreds of nanometers. The artificial optical activity arises from circular birefringence induced by the structural chirality and is enhanced by the guided-mode or surface-plasmon resonances taking place in the structures. There are two polarization conversion types in the dielectric PCMs, whereas only one type in the metallic ones. Many intriguing features of the polarization property of PCMs are also revealed and explained: the polarization effect is reciprocal and vanishes in the symmetrically layered structures; the effect occurs only in the transmitted field, but not in the reflected field; and the polarization spectra of two enantiomeric PCM structures are mirror symmetric to each other. These remarkable properties pave the way for the PCMs to be used as polarization elements in new-generation integrated optical systems.

  16. Detecting eavesdropping activity in fiber optic networks

    NASA Astrophysics Data System (ADS)

    MacDonald, Gregory G.

    The secure transmission of data is critical to governments, military organizations, financial institutions, health care providers and other enterprises. The primary method of securing in-transit data is though data encryption. A number of encryption methods exist but the fundamental approach is to assume an eavesdropper has access to the encrypted message but does not have the computing capability to decrypt the message in a timely fashion. Essentially, the strength of security depends on the complexity of the encryption method and the resources available to the eavesdropper. The development of future technologies, most notably quantum computers and quantum computing, is often cited as a direct threat to traditional encryption schemes. It seems reasonable that additional effort should be placed on prohibiting the eavesdropper from coming into possession of the encrypted message in the first place. One strategy for denying possession of the encrypted message is to secure the physical layer of the communications path. Because the majority of transmitted information is over fiber-optic networks, it seems appropriate to consider ways of enhancing the integrity and security of the fiber-based physical layer. The purpose of this research is to investigate the properties of light, as they are manifested in single mode fiber, as a means of insuring the integrity and security of the physical layer of a fiber-optic based communication link. Specifically, the approach focuses on the behavior of polarization in single mode fiber, as it is shown to be especially sensitive to fiber geometry. Fiber geometry is necessarily modified during the placement of optical taps. The problem of detecting activity associated with the placement of an optical tap is herein approached as a supervised machine learning anomaly identification task. The inputs include raw polarization measurements along with additional features derived from various visualizations of the raw data (the inputs are

  17. High Density Read/Write Optical System

    NASA Astrophysics Data System (ADS)

    Chen, Philip L.

    1982-05-01

    Xerox Electro-Optical Systems is developing an information storage and retrieval system for the Library of Congress to store a data base consisting of seven million library cards. The library card image will be digitized, stored, and retrieved by a computer system and printed out on a Xerox 9700 high speed laser printer.

  18. Brain activation during immediate and delayed reaching in optic ataxia.

    PubMed

    Himmelbach, Marc; Nau, Marion; Zündorf, Ida; Erb, Michael; Perenin, Marie-Therese; Karnath, Hans-Otto

    2009-05-01

    Patients with optic ataxia after lesions of the occipito-parietal cortex demonstrate gross deviations of movements to visual targets in their peripheral visual field. When the same patients point to remembered target locations their accuracy improves considerably. Taking into account opposite findings in a single patient suffering from visual form agnosia due to bilateral occipito-temporal lesions (D.F.), this paradoxical improvement was attributed to brain structures outside the dorsal stream, and supposed to be specifically associated with delayed movement execution. This conclusion was based on the still unverified assumption that the dorsal system is almost completely lacking any localization function in patients with optic ataxia who demonstrate the paradoxical delay effect. We thus investigated brain activity associated with immediately executed and delayed movements in a patient with optic ataxia due to extensive bilateral lesions (I.G.) and in 16 healthy subjects using functional magnetic resonance imaging. Our analysis revealed robust and indistinguishable activation of intact dorsal occipital and parietal areas adjacent to the patient's lesions for both types of movements. In healthy subjects, we found the same visuomotor network activated during immediate and delayed movements as well as additionally higher signal increases for movements to visible targets than for delayed movements in bilateral occipito-parietal and occipito-temporal areas. Our results suggest that in healthy subjects as well as in the optic ataxia patient I.G. dorsal areas are not only involved in immediate but also in delayed reaching. This observation questions the hypothesis that residual visuospatial abilities in patients with optic ataxia could only be mediated by a system outside of the dorsal stream. PMID:19428407

  19. Optical seismic sensor systems and methods

    DOEpatents

    Beal, A. Craig; Cummings, Malcolm E.; Zavriyev, Anton; Christensen, Caleb A.; Lee, Keun

    2015-12-08

    Disclosed is an optical seismic sensor system for measuring seismic events in a geological formation, including a surface unit for generating and processing an optical signal, and a sensor device optically connected to the surface unit for receiving the optical signal over an optical conduit. The sensor device includes at least one sensor head for sensing a seismic disturbance from at least one direction during a deployment of the sensor device within a borehole of the geological formation. The sensor head includes a frame and a reference mass attached to the frame via at least one flexure, such that movement of the reference mass relative to the frame is constrained to a single predetermined path.

  20. Axle Shaft Optical Inspection System

    NASA Astrophysics Data System (ADS)

    Freese, Fritz; Geise, Philip; George, Eugene; Singh, Tom

    1980-11-01

    An electro-optical instrument to gauge automotive rear axle shafts is described. A high contrast image of the axle lug flange is projected via a high quality photographic lens on two self-scanning linear photodiode arrays. In one three-second rotation, a dedicated digital processor measures bolt circle location, hole diameter and separation. The unit automatically: compares each measurement with preset tolerances, computes the average bolt circle diameter, computes the bolt circle runout, makes a pass/fail decision, provides a digital readout, marks the axle shaft with colored ink and provides the operator a pass/fail light.

  1. Optical switching system and method

    DOEpatents

    Ranganathan, Radha; Gal, Michael; Taylor, P. Craig

    1992-01-01

    An optically bistable device is disclosed. The device includes a uniformly thick layer of amorphous silicon to constitute a Fabry-Perot chamber positioned to provide a target area for a probe beam. The probe beam has a maximum energy less than the energy band gap of the amorphous semiconductor. In a preferred embodiment, a multilayer dielectric mirror is positioned on the Fabry-Perot chamber to increase the finesse of switching of the device. The index of refraction of the amorphous material is thermally altered to alter the transmission of the probe beam.

  2. Multilayer Active Control For Structural Damping And Optical-Path Regulation

    NASA Technical Reports Server (NTRS)

    Rahman, Zahidul H.; Spanos, John T.; Fanson, James L.

    1995-01-01

    Two active-control concepts incorporated into system for suppression of vibrations in truss structure and regulation of length of optical path on structure to nanometer level. Optical-path-length-control subsystem contains two feedback control loops to obtain active damping in wide amplitude-and-frequency range. Concept described in more detail in number of previous articles, including "Stabilizing Optical-Path Length on a Vibrating Structure" (NPO-19040), "Controllable Optical Delay Line for Stellar Interferometry" (NPO-18686), "Test Bed for Control of Optical-Path Lengths" (NPO-18487).

  3. Optical disk uses in criminal identification systems

    NASA Astrophysics Data System (ADS)

    Sypherd, Allen D.

    1990-08-01

    A significant advancement in law enforcement tools has been made possible by the rapid and innovative development of electronic imaging for criminal identification systems. In particular, development of optical disks capable of high-capacity and random-access storage has provided a unique marriage of application and technology. Fast random access to any record, non-destructive reading of stored images, electronic sorting and transmission of images and an accepted legal basis for evidence are a few of the advantages derived from optical disk technology. This paper discusses the application of optical disk technology to both Automated Fingerprint Identification Systems (AFIS) and Automated Mugshot Retrieval Systems (AMRS). The following topics are addressed in light of AFIS and AMRS user requirements and system capabilities: Write once vs. rewritable, gray level and storage requirements, multi-volume library systems, data organization and capacity trends.

  4. Fiber optic coherent laser radar 3d vision system

    SciTech Connect

    Sebastian, R.L.; Clark, R.B.; Simonson, D.L.

    1994-12-31

    Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic of coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  5. Status of optical model activities at Los Alamos National Laboratory

    SciTech Connect

    Young, P.G.

    1995-12-01

    An update will be given of activities at Los Alamos National Laboratory aimed at developing optical model potentials for applied calculations. Recent work on a coupled-channels potential for neutron reactions on {sup 241,243}Am and spherical neutron potential updates for {sup 56}Fe and {sup 59}Co will be presented, together with examples of their application in nuclear reaction calculations with the GNASH code system. New potentials utilized in evaluations at Livermore for {sup 12}C, {sup 14}N and {sup 16}O are described and additional potentials from earlier analyses at Los Alamos of Ti, V, and Ni data are made available for possible inclusion in the Reference Input Parameter Library (RIPL) for nuclear model calculations of nuclear data. Specific activities directed at development of the optical potential segment of the RIPL will be summarized.

  6. A System Architect's View Of Optical Storage

    NASA Astrophysics Data System (ADS)

    McIntosh, John W.; Harness, Kent; Parham, Frederick

    1983-11-01

    The design and the development of optical storage creates a significant impact on system architecture. Some of the highlights of optical storage include the following: both direct and sequential access are supported, large units of data are divided into bands that act as the unit of physical and logical data addressahility, and the user deals with logical records that can be of variable length, up to two megabytes. Ease of use is enhanced by the simplicity of data manipulation and access. Future consideratons will allow rapid retrieval of a platter from a library for subsequent automatic insertion of the cartridge into an optical storage unit.

  7. Full-duplex optical communication system

    NASA Technical Reports Server (NTRS)

    Shay, Thomas M. (Inventor); Hazzard, David A. (Inventor); Horan, Stephen (Inventor); Payne, Jason A. (Inventor)

    2004-01-01

    A method of full-duplex electromagnetic communication wherein a pair of data modulation formats are selected for the forward and return data links respectively such that the forward data electro-magnetic beam serves as a carrier for the return data. A method of encoding optical information is used wherein right-hand and left-hand circular polarizations are assigned to optical information to represent binary states. An application for an earth to low earth orbit optical communications system is presented which implements the full-duplex communication and circular polarization keying modulation format.

  8. Characterization of Fiber Optic CMM Probe System

    SciTech Connect

    K.W.Swallow

    2007-05-15

    This report documents a study completed on the fiber optic probe system that is a part of the Werth optical CMM. This study was necessary due to a lack of documentation from the vendor for the proper use and calibration of the fiber probe, and was performed in support of the Lithographie Galvanoformung Abformung (LIGA) development program at the FM&T. As a result of this study, a better understanding of the fiber optic probe has been developed, including guidelines for its proper use and calibration.

  9. Novel pH control strategy for efficient production of optically active l-lactic acid from kitchen refuse using a mixed culture system.

    PubMed

    Tashiro, Yukihiro; Inokuchi, Shota; Poudel, Pramod; Okugawa, Yuki; Miyamoto, Hirokuni; Miayamoto, Hisashi; Sakai, Kenji

    2016-09-01

    Uninvestigated control factors of meta-fermentation, the fermentative production of pure chemicals and fuels in a mixed culture system, were examined for production of optically pure l-lactic acid (LA) from food waste. In meta-fermentations by pH swing control, l-LA production with 100% optical purity (OPl-LA) was achieved even using unsterilized model kitchen refuse medium with preferential proliferation of l-LA-producing Bacillus coagulans, a minor member in the seed, whereas agitation decreased OPl-LA drastically. pH constant control shortened the fermentation time but decreased OPl-LA and LA selectivity (SLA) by stimulating growth of heterofermentative Bacillus thermoamylovorans. Deliberately switching from pH swing control to constant control exhibited the best performance for l-LA production: maximum accumulation, 39.2gL(-1); OPl-LA, 100%; SLA, 96.6%; productivity, 1.09gL(-1)h(-1). These results present a novel pH control strategy for efficient l-LA production in meta-fermentation based on a concept different from that of pure culture systems. PMID:27233097

  10. Active Optical Control of Quasi-Static Aberrations for ATST

    NASA Astrophysics Data System (ADS)

    Johnson, L. C.; Upton, R.; Rimmele, T. R.; Hubbard, R.; Barden, S. C.

    2012-12-01

    The Advanced Technology Solar Telescope (ATST) requires active control of quasi-static telescope aberrations in order to achieve the image quality set by its science requirements. Four active mirrors will be used to compensate for optical misalignments induced by changing gravitational forces and thermal gradients. These misalignments manifest themselves primarily as low-order wavefront aberrations that will be measured by a Shack-Hartmann wavefront sensor. When operating in closed-loop with the wavefront sensor, the active optics control algorithm uses a linear least-squares reconstructor incorporating force constraints to limit force applied to the primary mirror while also incorporating a neutral-point constraint on the secondary mirror to limit pointing errors. The resulting system compensates for astigmatism and defocus with rigid-body motion of the secondary mirror and higher-order aberrations with primary mirror bending modes. We demonstrate this reconstruction method and present simulation results that apply the active optics correction to aberrations generated by finite-element modeling of thermal and gravitational effects over a typical day of ATST operation. Quasi-static wavefront errors are corrected to within limits set by wavefront sensor noise in all cases with very little force applied to the primary mirror surface and minimal pointing correction needed.

  11. Diffuse optical imaging of brain activation to joint attention experience.

    PubMed

    Zhu, Banghe; Yadav, Nitin; Rey, Gustavo; Godavarty, Anuradha

    2009-08-24

    In the early development of social cognition and language, infants tend to participate in face-to-face interactions engaging in joint attention exchanges. Joint attention is vital to social competence at all ages, lacking which is a primary feature to distinguish autistic from non-autistic population. In this study, diffuse optical imaging is used for the first time to investigate the joint attention experience in normal adults. Imaging studies were performed in the frontal regions of the brain (BA9 and BA10) in order to study the differences in the brain activation in response to video clips corresponding to joint attention based skills. The frontal regions of the brain were non-invasively imaged using a novel optical cap coupled to a frequency-domain optical imaging system. The statistical analysis from 11 normal adult subjects, with three repetitions from each subject, indicated that the averaged changes in the cerebral blood oxygenation levels were different under the joint and non-joint attention based stimulus. The preliminary studies demonstrate the feasibility of implementing diffuse optical imaging towards autism-related research to study the brain activation in response to socio-communication skills. PMID:19447278

  12. Efficient optical pulse stacker system

    DOEpatents

    Seppala, Lynn G.; Haas, Roger A.

    1982-01-01

    Method and apparatus for spreading and angle-encoding each pulse of a multiplicity of small area, short pulses into several temporally staggered pulses by use of appropriate beam splitters, with the optical elements being arranged so that each staggered pulse is contiguous with one or two other such pulses, and the entire sequence of stacked pulses comprising a single, continuous long pulse. The single long pulse is expanded in area, and then doubly passed through a nonstorage laser amplifier such as KrF. After amplification, the physically separated, angle-encoded and temporally staggered pulses are recombined into a single pulse of short duration. This high intensity output beam is well collimated and may be propagated over long distance, or used for irradiating inertial confinement fusion targets.

  13. A Concept for Zero-Alignment Micro Optical Systems

    SciTech Connect

    DESCOUR, MICHAEL R.; KOLOLUOMA,TERHO; LEVEY,RAVIV; RANTALA,JUHA T.; SHUL,RANDY J.; WARREN,MIAL E.; WILLISON,CHRISTI LEE

    1999-09-16

    We are developing a method of constructing compact, three-dimensional photonics systems consisting of optical elements, e.g., lenses and mirrors, photo-detectors, and light sources, e.g., VCSELS or circular-grating lasers. These optical components, both active and passive, are mounted on a lithographically prepared silicon substrate. We refer to the substrate as a micro-optical table (MOT) in analogy with the macroscopic version routinely used in optics laboratories. The MOT is a zero-alignment, microscopic optical-system concept. The position of each optical element relative to other optical elements on the MOT is determined in the layout of the MOT photomask. Each optical element fits into a slot etched in the silicon MOT. The slots are etched using a high-aspect-ratio silicon etching (HARSE) process. Additional positioning features in each slot's cross-section and complementary features on each optical element permit accurate placement of that element's aperture relative to the MOT substrate. In this paper we present the results of the first fabrication and micro-assembly experiments of a silicon-wafer based MOT. Based on these experiments, estimates of position accuracy are reported. We also report on progress in fabrication of lens elements in a hybrid sol-gel material (HSGM). Diffractive optical elements have been patterned in a 13-micron thick HSGM layer on a 150-micron thick soda-lime glass substrate. The measured ms surface roughness was 20 nm. Finally, we describe modeling of MOT systems using non-sequential ray tracing (NSRT).

  14. Lightweight, Active Optics for Space and Near Space

    NASA Astrophysics Data System (ADS)

    Wick, D.; Bagwell, B.; Martinez, T.; Payne, D.; Restaino, S.; Romeo, R.

    Size, weight, and a lack of adaptability currently hinder the effectiveness of conventional imaging sensors in a number of military applications, including space-based space situational awareness (SSA), intelligence, surveillance, and reconnaissance (ISR), and missile tracking. The development of sensors that are smaller, lighter weight, adaptive, and use less power is critical for the success of future military initiatives. Threat detection systems need the flexibility of a wide FOV for surveillance and situational awareness while simultaneously maintaining high-resolution for target identification and precision tracking from a single, nonmechanical imaging system. Sandia National Laboratories, the Naval Research Laboratory, Narrascape, Inc., and Composite Mirror Applications, Inc. are at the forefront of active optics research, leading the development of active systems for foveated imaging, nonmechanical zoom, phase diversity, and actively enhanced multi-spectral imaging. Increasing the field-of-view, spatial resolution, spectral capability and system magnification have all been demonstrated with active optics. Adding active components to existing systems should significantly enhance capability in a number of military applications, including night vision, remote sensing and surveillance, chemical/biological detection, and large aperture, space-based systems. Deployment costs of large aperture systems in space or near-space are directly related to the weight of the system. In order to minimize the weight of conventional primary mirrors and simultaneously achieve an agile system that is capable of true optical zoom without macroscopic moving parts, we are proposing a revolutionary alternative to conventional telescopes where moving lenses/mirrors and gimbals are replaced with lightweight carbon fiber reinforced polymer (CFRP) variable radius-of-curvature mirrors (VRMs) and MEMS deformable mirrors (DMs). CFRP and MEMS DMs can provide a variable effective focal

  15. Seamless Transmission between Single-Mode Optical Fibers Using Free Space Optics System

    NASA Astrophysics Data System (ADS)

    Yoshida, Koichi; Tsujimura, Takeshi

    This paper presents a free space optics system installed between two single-mode optical fibers (SMFs). The result looks as if the two SMFs were seamlessly connected without the need for any photoelectric devices. Misalignments between the two SMFs caused by disturbances are actively compensated for by introducing a laser beam controller that incorporates an opto-mechatronic mechanism with four degrees of freedom. Experiments using a prototype are conducted to verify the effectiveness of the proposed FSO system for initial beam acquisition and beam tracking when there is a vibration disturbance.

  16. Fiber optic gyroscopes for vehicle navigation systems

    NASA Astrophysics Data System (ADS)

    Kumagai, Tatsuya; Soekawa, Hirokazu; Yuhara, Toshiya; Kajioka, Hiroshi; Oho, Shigeru; Sonobe, Hisao

    1994-03-01

    Fiber optic gyroscopes (FOGs) have been developed for vehicle navigation systems and are used in Toyota Motor Corporation models Mark II, Chaser and Cresta in Japan. Use of FOGs in these systems requires high reliability under a wide range of conditions, especially in a temperature range between -40 and 85 degree(s)C. In addition, a high cost-performance ratio is needed. We have developed optical and electrical systems that are inexpensive and can perform well. They are ready to be mass-produced. FOGs have already been installed in luxury automobiles, and will soon be included in more basic vehicles. We have developed more inexpensive FOGs for this purpose.

  17. Multistate transitions and quantum oscillations of optical activity

    NASA Astrophysics Data System (ADS)

    Blanco, Celia; Hochberg, David

    2012-02-01

    We consider the effects of multistate transitions on the tunneling racemization of chiral molecules. This requires going beyond simple two-state models of enantiomers and to include transitions within a multiple-level quantum-mechanical system. We derive an effective two-level description which accounts for transitions from the enantiomers to an arbitrary number of excited states as an application of the Weisskopf-Wigner approximation scheme. Modifications to the optical activity from these additional states are considered in general terms under the assumption of CPT invariance and then under T invariance. Some formal dynamical analogies between enantiomers and the neutral K-meson system are discussed.

  18. Testing of electro-optical imaging systems

    NASA Astrophysics Data System (ADS)

    Chrzanowski, Krzysztof; Barela, Jaroslaw; Firmanty, Krzysztof

    2004-08-01

    Humans cannot objectively judge electro-optical imaging systems looking on an image of typical scenery. Quality of the image can be bad for some people but good for others and therefore objective test methods and advanced equipment are needed to evaluate these imaging systems. Test methods and measuring systems that enable reliable testing and evaluation of modern thermal cameras, color and monochrome TV cameras, LLLTV cameras and image intensifier systems are presented in this paper.

  19. Application of Optical Biosensors in Small-Molecule Screening Activities

    PubMed Central

    Geschwindner, Stefan; Carlsson, Johan F.; Knecht, Wolfgang

    2012-01-01

    The last two decades have seen remarkable progress and improvements in optical biosensor systems such that those are currently seen as an important and value-adding component of modern drug screening activities. In particular the introduction of microplate-based biosensor systems holds the promise to match the required throughput without compromising on data quality thus representing a sought-after complement to traditional fluidic systems. This article aims to highlight the application of the two most prominent optical biosensor technologies, namely surface plasmon resonance (SPR) and optical waveguide grating (OWG), in small-molecule screening and will present, review and discuss the advantages and disadvantages of different assay formats on these platforms. A particular focus will be on the specific advantages of the inhibition in solution assay (ISA) format in contrast to traditional direct binding assays (DBA). Furthermore we will discuss different application areas for both fluidic as well as plate-based biosensor systems by considering the individual strength of the platforms. PMID:22666031

  20. The Discovery Channel Telescope optical coating system

    NASA Astrophysics Data System (ADS)

    Marshall, Heather K.; Ash, Gary S.; Parsley, William F.

    2010-07-01

    The Discovery Channel Telescope (DCT) is a project of Lowell Observatory, undertaken with support from Discovery Communications, Inc., to design and construct a 4-meter class telescope and support facility on a site approximately 40 miles southeast of Flagstaff, AZ. Lowell Observatory contracted with Dynavac of Hingham, MA to design and build an optical coating system for the DCT optics. The DCT Optical Coating System includes a mechanical roughing pump, two high-vacuum cryogenic pumps, a Meissner trap, evaporative filament aluminum deposition system, LabView software and PLC-based control system, and all ancillary support equipment. The system was installed at the site and acceptance testing was completed in October 2009. The Optical Coating System achieved near perfect reflectivity performance, thickness uniformity of 1000 angstroms +/-10%, and adhesion conforming to MIL-F-48616, Section 4.6.8.1. This paper discusses the design and analysis of the coating system, the process of transportation and assembly as well as testing results.

  1. Extrinsic chirality: Tunable optically active reflectors and perfect absorbers

    NASA Astrophysics Data System (ADS)

    Plum, Eric

    2016-06-01

    Conventional three-dimensional (3D) chiral media can exhibit optical activity for transmitted waves, but optical activity for reflected waves is negligible. This work shows that mirror asymmetry of the experimental arrangement—extrinsic 3D chirality—leads to giant optical activity for reflected waves with fundamentally different characteristics. It is demonstrated experimentally that extrinsically 3D-chiral illumination of a lossy metasurface backed by a mirror enables tunable circular dichroism and circular birefringence as well as perfect absorption of circularly polarized waves. In contrast, such polarization phenomena vanish for conventional optically active media backed by a mirror.

  2. Analysis of advanced optical glass and systems

    NASA Technical Reports Server (NTRS)

    Johnson, R. Barry; Feng, Chen

    1991-01-01

    Optical lens systems performance utilizing optical materials comprising reluctant glass forming compositions was studied. Such special glasses are being explored by NASA/Marshall Space Flight Center (MSFC) researchers utilizing techniques such as containerless processing in space on the MSFC Acoustic Levitation Furnace and on the High Temperature Acoustic Levitation Furnace in the conceptual design phase for the United States Microgravity Laboratory (USML) series of shuttle flights. The application of high refractive index and low dispersive power glasses in optical lens design was investigated. The potential benefits and the impacts to the optical lens design performance were evaluated. The results of the studies revealed that the use of these extraordinary glasses can result in significant optical performance improvements. Recommendations of proposed optical properties for potential new glasses were also made. Applications of these new glasses are discussed, including the impact of high refractive index and low dispersive power, improvements of the system performance by using glasses which are located outside of traditional glass map, and considerations in establishing glass properties beyond conventional glass map limits.

  3. Gregorian all-reflective optical system

    NASA Technical Reports Server (NTRS)

    King, W. L. (Inventor)

    1977-01-01

    An optical heterodyne receiver comprises a system of reflectors forming a folded Gregorian configuration for collecting a signal beam, and an optical detector located at the focus of the system. A paraboloidal primary reflector and an elipsoidal secondary reflector face each other on an optical axis with the focus of the secondary reflector coinciding with the focus of the primary reflector. An auxiliary laser generates a local oscillator beam that is combined with the signal beam after the signal beam emerges from the exit pupil (which is also the aperture stop) of the system, and the resultant is impinged on the detector. A pair of image motion compensators is located as close to the exit pupil as possible for aligning off-axis inputs to the detector.

  4. Ultrasonic temperature measurements with fiber optic system

    NASA Astrophysics Data System (ADS)

    Bi, Siwen; Wu, Nan; Zhou, Jingcheng; Ma, Tong; Liu, Yuqian; Cao, Chengyu; Wang, Xingwei

    2016-04-01

    Ultrasonic temperature measurements have been developed and widely applied in non-contact temperature tests in many industries. However, using optical fibers to build ultrasound generators are novel. This paper reports this new fiber optic ultrasonic system based on the generator of gold nanoparticles/polydimethylsiloxane (PDMS) composites. The optical acoustic system was designed to test the change of temperature on the aluminum plate and the temperature of the torch in the air. This paper explores the relationship between the ultrasonic transmission and the change of temperature. From the experimental results, the trend of ultrasonic speed was different in the aluminum plate and air with the change of temperature. Since the system can measure the average temperature of the transmission path, it will have significant influence on simulating the temperature distribution.

  5. Fiber optical parametric amplifiers in optical communication systems

    PubMed Central

    Marhic (†), Michel E; Andrekson, Peter A; Petropoulos, Periklis; Radic, Stojan; Peucheret, Christophe; Jazayerifar, Mahmoud

    2015-01-01

    The prospects for using fiber optical parametric amplifiers (OPAs) in optical communication systems are reviewed. Phase-insensitive amplifiers (PIAs) and phase-sensitive amplifiers (PSAs) are considered. Low-penalty amplification at/or near 1 Tb/s has been achieved, for both wavelength- and time-division multiplexed formats. High-quality mid-span spectral inversion has been demonstrated at 0.64 Tb/s, avoiding electronic dispersion compensation. All-optical amplitude regeneration of amplitude-modulated signals has been performed, while PSAs have been used to demonstrate phase regeneration of phase-modulated signals. A PSA with 1.1-dB noise figure has been demonstrated, and preliminary wavelength-division multiplexing experiments have been performed with PSAs. 512 Gb/s have been transmitted over 6,000 km by periodic phase conjugation. Simulations indicate that PIAs could reach data rate x reach products in excess of 14,000 Tb/s × km in realistic wavelength-division multiplexed long-haul networks. Technical challenges remaining to be addressed in order for fiber OPAs to become useful for long-haul communication networks are discussed. PMID:25866588

  6. Ultrafast optical pulse interactions in active disordered condensed matter

    NASA Astrophysics Data System (ADS)

    Siddique, Masood

    2005-07-01

    The goal of this research is to better understand the basic physics that governs the behavior of short-pulsed light propagating in scattering media where either the host medium or the scattering particles exhibit emission or absorption interact with the incident light in form of absorption or stimulated emission. The temporal and spectral dynamics from the interactions of optically active disordered-media with ultrashort optical pulses is the focus of the research performed in this thesis. The interaction processes studied are optical gain, spectral narrowing, fluorescence and pulse lifetime reduction and transport of ultrashort optical pulses in disordered media containing optically active discrete scattering particles. Linear and nonlinear effects are presented where the propagation of picosecond and femtosecond laser pulses in active disordered media is measured experimentally and compared with the theories of Boltzmann radiative transport and diffusive propagation of radiation in disordered media. Active media can be involved in optical processes in disordered media where either the propagation of optical radiation can result in gain or absorption upon optical excitation. A study of optical scattering in non-discrete media such as the biological heterogeneously-continuous scattering tissues is carried out as well. Lasing in random media is one of the outcomes of these results. The optical gain of optically excited active media is divided into clear subdivisions of Amplified Spontaneous Emission, Stimulated Emission and Laser Emission by characterizing them by their temporal and spectral emission.

  7. Testing methodologies and systems for semiconductor optical amplifiers

    NASA Astrophysics Data System (ADS)

    Wieckowski, Michael

    Semiconductor optical amplifiers (SOA's) are gaining increased prominence in both optical communication systems and high-speed optical processing systems, due primarily to their unique nonlinear characteristics. This in turn, has raised questions regarding their lifetime performance reliability and has generated a demand for effective testing techniques. This is especially critical for industries utilizing SOA's as components for system-in-package products. It is important to note that very little research to date has been conducted in this area, even though production volume and market demand has continued to increase. In this thesis, the reliability of dilute-mode InP semiconductor optical amplifiers is studied experimentally and theoretically. The aging characteristics of the production level devices are demonstrated and the necessary techniques to accurately characterize them are presented. In addition, this work proposes a new methodology for characterizing the optical performance of these devices using measurements in the electrical domain. It is shown that optical performance degradation, specifically with respect to gain, can be directly qualified through measurements of electrical subthreshold differential resistance. This metric exhibits a linear proportionality to the defect concentration in the active region, and as such, can be used for prescreening devices before employing traditional optical testing methods. A complete theoretical analysis is developed in this work to explain this relationship based upon the device's current-voltage curve and its associated leakage and recombination currents. These results are then extended to realize new techniques for testing semiconductor optical amplifiers and other similarly structured devices. These techniques can be employed after fabrication and during packaged operation through the use of a proposed stand-alone testing system, or using a proposed integrated CMOS self-testing circuit. Both methods are capable

  8. Optical design of laser transmission system

    NASA Astrophysics Data System (ADS)

    Zhang, Yulan; Feng, Jinliang; Li, Yongliang; Yang, Jiandong

    1998-08-01

    This paper discusses a design of optical transfer system used in carbon-dioxide laser therapeutic machine. The design of this system is according to the requirement of the therapeutic machine. The therapeutic machine requires the movement of laser transfer system is similar to the movement of human beings arms, which possesses 7 rotating hinges. We use optical hinges, which is composed of 45 degree mirrors. Because the carbon-dioxide laser mode is not good, light beam diameter at focus and divergence angle dissemination are big, we use a collecting lens at the transfer system output part in order to make the light beam diameter at focus in 0.2 to approximately 0.3 mm. For whole system the focus off-axis error is less than 0.5 mm, the transfer power consumption is smaller than 10%. The system can move in three dimension space freely and satisfies the therapeutic machine requirement.

  9. Active imaging system with Faraday filter

    DOEpatents

    Snyder, J.J.

    1993-04-13

    An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.

  10. Active imaging system with Faraday filter

    DOEpatents

    Snyder, James J.

    1993-01-01

    An active imaging system has a low to medium powered laser transmitter and receiver wherein the receiver includes a Faraday filter with an ultranarrow optical bandpass and a bare (nonintensified) CCD camera. The laser is locked in the vicinity of the passband of the Faraday filter. The system has high sensitivity to the laser illumination while eliminating solar background.

  11. Laser fiber optics ordnance initiation system

    NASA Technical Reports Server (NTRS)

    Yang, L. C.

    1976-01-01

    Recent progress on system development in the laser initiation of explosive devices is summarized. The topics included are: development of compact free-running mode and Q-switched lasers, development of low-loss fiber optic bundles and connectors, study of nuclear radiation effects on the system, characterization of laser initiation sensitivities of insensitive high explosives, and the design methods used to achieve attractive system weight and cost savings. Direction for future work is discussed.

  12. Active Stand-off Detection of Gas Leaks Using a Short Range Hard-target Backscatter Differential Optical Absorption System Based on a Quantum Cascade Laser Transmitter

    NASA Astrophysics Data System (ADS)

    Diaz, Adrian; Thomas, Benjamin; Castillo, Paulo; Gross, Barry; Moshary, Fred

    2016-06-01

    Fugitive gas emissions from agricultural or industrial plants and gas pipelines are an important environmental concern as they can contribute to the global increase of greenhouse gas concentration. Moreover, they are also a security and safety concern because of possible risk of fire/explosion or toxicity. This study presents gas concentration measurements using a quantum cascade laser open path system (QCLOPS). The system retrieves the pathaveraged concentration of N2O and CH4 by collecting the backscattered light from a scattering target. The gas concentration measurements have a high temporal resolution (68 ms) and are achieved at sufficient range (up to 40 m, ~ 130 feet) with a detection limit of 2.6 ppm CH4 and 0.4 ppm for N2O. Given these characteristics, this system is promising for mobile/multidirectional remote detection and evaluation of gas leaks. The instrument is monostatic with a tunable QCL emitting at ~ 7.7 μm wavelength range. The backscattered radiation is collected by a Newtonian telescope and focused on an infrared light detector. Puffs of N2O and CH4 are released along the optical path to simulate a gas leak. The measured absorption spectrum is obtained using the thermal intra-pulse frequency chirped DFB QCL and is analyzed to obtain path averaged gas concentrations.

  13. Developing system for delivery of optical radiation in medicobiological researches

    NASA Astrophysics Data System (ADS)

    Loschenov, Victor B.; Taraz, Majid

    2004-06-01

    Methods of optical diagnostics and methods of photodynamic therapy are actively used in medico-biological researches. The system for delivery of optical radiation is one of the key methods in these researches. Usually these systems use flexible optical fibers with diameters from 200 to 1000 micron. Two types of systems for delivery are subdivided, first for diagnostic researches, second for therapeutic procedures. Existing diagnostic catheters, which have most widely applied in medicine, have bifurcated with diameter of the tip equal 1.8 mm. These devices, which are called fiber-optical catheters, satisfy the majority endoscopes researches. However, till now the problem of optical-diagnostics inside tissue is not soled. Especially it is important at diagnostics of a mammary gland, livers, thyroid glands tumor, tumor of a brain and some other studies connected with punctures. In these cases, it is necessary that diameter of fiber-optical catheters be less than one millimeter. This work is devoted to the development of these catheters. Also in clinical procedures such as photodynamic therapy (PDT) and interstitial laser photocoagulation (ILP), cylindrical light diffusing tips are rapidly becoming a popular device for the administration of the desired light dose for the illumination of hollow organs, such as bronchus, trachea and oesophagus. This work is devoted to the development of these catheters.

  14. Reflective optics system for uniform spherical illumination.

    PubMed

    Phipps, C R; Bodner, S E; Shearer, J W

    1975-04-01

    A reflective optical system is described that permits nearly uniform illumination of a small sphere with one or two laser beams. The primary application of this device is to studies of laser-driven implosion of small targets. Other applications include the production of plasma by optical breakdown of gases for spectroscopic studies and for optimum light collection in intensity-limited plasma diagnostics. Simple calculations show that the intensity mapping properties of this system are not excessively sensitive to variations in the radial intensity distribution nor to departures from diffraction-limited propagation in the input beams. Optical damage and the illuminated solid angle required at the focus determine the size of the device. PMID:20135009

  15. Multiple channel optical data acquisition system

    DOEpatents

    Fasching, G.E.; Goff, D.R.

    1985-02-22

    A multiple channel optical data acquisition system is provided in which a plurality of remote sensors monitoring specific process variable are interrogated by means of a single optical fiber connecting the remote station/sensors to a base station. The remote station/sensors derive all power from light transmitted through the fiber from the base station. Each station/sensor is individually accessed by means of a light modulated address code sent over the fiber. The remote station/sensors use a single light emitting diode to both send and receive light signals to communicate with the base station and provide power for the remote station. The system described can power at least 100 remote station/sensors over an optical fiber one mile in length.

  16. The JEM-EUSO optics system

    SciTech Connect

    Takizawa, Yoshiyuki; Marchi, Alessandor Zuccaro; Takahashi, Yoshiyuki

    2011-09-22

    The Extreme Universe Space Observatory onboard the Japanese Experiment Module is an international mission devoted to the detection of ultra high-energy cosmic particles with energies E>7x10{sup 19} eV. They are revealed through emission in the atmosphere of Cherenkov and fluorescence light in the near-UV region, by using an optical system with 60 deg. field of view and a 2.3 m entrance pupil. One of the challenges consists in developing an unusual combination of large and lightweight refractive optics: two double-sided curved Fresnel lenses and a central curved Fresnel+diffractive lens, whose maximum dimensions are 2.65 m. This paper describes the development of such a optical system and its performances of the latest configurations.

  17. Demonstration of portable solar adaptive optics system

    NASA Astrophysics Data System (ADS)

    Ren, Deqing; Dong, Bing

    2012-10-01

    Solar-adaptive optics (AO) are more challenging than night-time AO, in some aspects. A portable solar adaptive optics (PSAO) system featuring compact physical size, low cost, and good performance has been proposed and developed. PSAO can serve as a visiting instrument for any existing ground-based solar telescope to improve solar image quality by replacing just a few optical components. High-level programming language, LabVIEW, is used to develop the wavefront sensing and control software, and general purpose computers are used to drive the whole system. During October 2011, the feasibility and good performance of PSAO was demonstrated with the 61-cm solar telescope at San Fernando Observatory. The image contrast and resolution are noticeably improved after AO correction.

  18. Manufacturing implications of fibre optic systems

    NASA Astrophysics Data System (ADS)

    Roy, S. D.; Gardiner, P. T.

    1982-08-01

    It is pointed out that fiber optic data transmission offers powerful advantages over conventional copper based links. These advantages are related to increased bandwidth, smaller diameter, lower weight, elimination of crosstalk, and complete immunity to electromagnetic interference. A major difficulty concerning the introduction of fiber optic systems has been related to the lack of properly developed manufacturing and repair techniques to produce systems which have an adequate performance compatible with operation in the airborne environment. An experimental manufacturing program was, therefore, initiated to assess the performance of operation, tooling systems, and airborne system performance. On the basis of the results of the investigations, it is concluded that a complete set of components exist, albeit in the prototype state to enable a range of applications. The system performance obtainable is adequate for many interconnection applications.

  19. Nonlinear Optics in Novel Polymer Systems.

    NASA Astrophysics Data System (ADS)

    Li, Lian

    Polymeric nonlinear optical (NLO) materials have recently attracted considerable attention and been the subject of intensive investigations. Polymeric NLO materials possessing large second and third order NLO properties, ultrafast response times, high optical damage threshold, transparency over a broad wavelength range, and capability to be easily processed into good optical quality thin films, offer significant advantages over the traditional inorganic materials for applications in fabricating integrated optical devices, such as waveguide electro-optic (EO) modulators and optical frequency doublers, and optical signal processing devices. This dissertation presents the experimental investigations on novel NLO polymers synthesized in the Laboratory of Electronic and Photonic Materials at University of Massachusetts Lowell. Progress made for the past few years on polymeric NLO materials is reviewed, especially with regard to the second order NLO properties of the polymeric materials. Two novel stable second order NLO polymer systems, an interpenetrating polymer network (IPN) formed via thermal crosslinking and a sol-gel process, and a photocrosslinkable conducting polymer, upon poling and crosslinking, exhibited large and stable second order NLO properties measured for these polymers by using the second harmonic generation (SHG) technique. For the IPN system, the SHG measurements as a function of time at several elevated temperatures indicate the superb stability of the second order NLO properties. For the conducting NLO polymer, the NLO property of the poled and photocrosslinked polymer film is stable at room temperature. The wavelength shifting of a Q-switched Nd:YAG laser by stimulated Raman scattering is also described. Measurements were made on the third order NLO properties of a dye doped photocrosslinkable guest-host polymer system at different dye concentrations with a modified Michelson interferometer. By functionalizing the dye to make it more compatible to

  20. Natural optical design concepts for highly miniaturized camera systems

    NASA Astrophysics Data System (ADS)

    Voelkel, Reinhard

    1999-08-01

    Microcameras for computers, mobile phones, watches, security system and credit cards is a very promising future market. Semiconductor industry is now able to integrate light reception, signal amplification and processing in a low- power-consuming microchip of a few mm2 size. Active pixel sensors supply each pixel in an image sensor with an individually programmable functionality. Beside the electronic receptor chip, a highly miniaturized lens system is required. Compared to the progress in microelectronics, optics has not yet made a significant step. Today's microcamera lenses are usually a downscaled version of a classical lens system and rarely smaller than 3 mm X 3 mm X 3 mm. This lagging of optics is quite surprising. Biologists have systematically studied all types of natural eye sensors since the 18th Century. Mother Nature provides a variety of highly effective examples for miniaturized imaging system. Single-aperture systems are the appropriate solution if the size is a free design parameter. If the budget is tight and optics limited to size, nature prefers multiple-aperture systems, the so-called compound eyes. As compound eyes are limited in resolution and night view, a cluster of single-aperture eyes, as jumping spiders use, is probably a better solution. The recent development in micro- optics offers the chance to imitate such natural design concepts. We have investigated miniaturized imaging systems based on microlens array and natural optical design concepts. Practical limitations for system design, packaging and assembling are given. Examples for micro-optical components and imaging systems are presented.

  1. Tbit/s Optical Transmission Systems

    NASA Astrophysics Data System (ADS)

    Gunning, Fatima C. G.; Ellis, Andrew D.; Cuenot, Benjamin; Healy, Tadhg; McCarthy, Mary

    2005-10-01

    We discuss our Science Foundation Ireland-funded work to design of a highly spectral efficient Tbit/s optical transmission system for long-haul communications. Such systems are comprised of several wavelength division multiplexing (WDM) channels (or frequency channels), closely spaced (<100 GHz), and modulated at high bit rates (40 Gbit/s). The highest efficiencies have been achieved using combinations of techniques, by increasing the information per channel and minimizing interferometric cross-talk. In conventional systems, incoherent interference occurs when beat signals from adjacent channels fall within the receiver bandwidth. This generates noise if the relative phase is random, e.g., where independent lasers are used for each channel. However, if the optical phase difference between adjacent channels is controlled, the interference signal is deterministic. Therefore, if each channel is modulated with a data signal, any interference effect is distributed in the same way from one bit slot to another, and the relative optical phases may be aligned to either increase or decrease the eye opening. This interference control may be achieved by controlling the phase of each laser individually with optical phase locked loops, or by replacing the typical bank of lasers with one or more coherent comb sources. The wavelengths of adjacent channels are thus phased locked to each other, and the data are encoded with an array of modulators that preserves this relative optical phase. The proposed technique, Coherent WDM, exploits this optical phase-locking mechanism in a simple and cost-effective configuration because it is based on a comb generation (multi-wavelength source) via the use of sine-wave-driven amplitude modulators (generating side-bands), followed by data encoding at the same rate. Recent results show significant improvement in performance over conventional systems. More improvement may come when a combination of approaches is used.

  2. Polarization ray tracing in anisotropic optically active media

    NASA Technical Reports Server (NTRS)

    Mcclain, Stephen C.; Chipman, Russell A.

    1992-01-01

    Procedures for performing polarization ray tracing through birefringent media are presented in a form compatible with the standard methods of geometric ray tracing. The birefringent materials treated include the following: anisotropic optically active materials such as quartz, non-optically active uniaxial materials such as calcite, and isotropic optically active materials such as mercury sulfide or organic liquids. Refraction and reflection algorithms are presented which compute both ray directions and wave directions. Methods for computing polarization modes, refractive indices, optical path lengths, and Fresnel transmission and reflection coefficients are also specified.

  3. Steady-state heating of active fibres under optical pumping

    SciTech Connect

    Gainov, V V; Shaidullin, R I; Ryabushkin, Oleg A

    2011-07-31

    We have measured the temperature in the core of rare-earth-doped optical fibres under lasing conditions at high optical pump powers using a fibre Mach - Zehnder interferometer and probe light of wavelength far away from the absorption bands of the active ions. From the observed heating kinetics of the active medium, the heat transfer coefficient on the polymer cladding - air interface has been estimated. The temperature of the active medium is shown to depend on the thermal and optical properties of the polymer cladding. (fiber and integrated optics)

  4. SPARCLE Optical System Design and Operational Characteristics

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Peters, Bruce R.; Li, Ye; Blackwell, Timothy S.; Reardon, Patrick

    1999-01-01

    The SPAce Readiness Coherent Lidar Experiment (SPARCLE) is the first demonstration of a coherent Doppler wind lidar in space. SPARCLE will be flown aboard a space shuttle In the middle part of 2001 as a stepping stone towards the development and deployment of a long-life-time operational instrument in the later part of next decade. SPARCLE is an ambitious project that is intended to evaluate the suitability of coherent lidar for wind measurements, demonstrate the maturity of the technology for space application, and provide a useable data set for model development and validation. This paper describes the SPARCLE's optical system design, fabrication methods, assembly and alignment techniques, and its anticipated operational characteristics. Coherent detection is highly sensitive to aberrations in the signal phase front, and to relative alignment between the signal and the local oscillator beams. Consequently, the performance of coherent lidars is usually limited by the optical quality of the transmitter/receiver optical system. For SPARCLE having a relatively large aperture (25 cm) and a very long operating range (400 km), compared to the previously developed 2-micron coherent lidars, the optical performance requirements are even more stringent. In addition with stringent performance requirements, the physical and environment constraints associated with this instrument further challenge the limit of optical fabrication technologies.

  5. Optical guidance system for industrial vehicles

    DOEpatents

    Dyer, Robert D.; Eschbach, Eugene A.; Griffin, Jeffrey W.; Lind, Michael A.; Buck, Erville C.; Buck, Roger L.

    1990-01-01

    An automatically guided vehicle system for steering a vehicle. Optical sensing detects an image of a segment of track mounted above the path of the vehicle. Electrical signals corresponding to the position of the track are generated. A control circuit then converts these signals into movements for the steering of the vehicle.

  6. Optical Blade Position Tracking System Test

    SciTech Connect

    Fingersh, L. J.

    2006-01-01

    The Optical Blade Position Tracking System Test measures the blade deflection along the span of the blade using simple off-the-shelf infrared security cameras along with blade-mounted retro-reflective tape and video image processing hardware and software to obtain these measurements.

  7. Active Learning Environment with Lenses in Geometric Optics

    ERIC Educational Resources Information Center

    Tural, Güner

    2015-01-01

    Geometric optics is one of the difficult topics for students within physics discipline. Students learn better via student-centered active learning environments than the teacher-centered learning environments. So this study aimed to present a guide for middle school teachers to teach lenses in geometric optics via active learning environment…

  8. The fiber-optic imaging and manipulation of neural activity during animal behavior.

    PubMed

    Miyamoto, Daisuke; Murayama, Masanori

    2016-02-01

    Recent progress with optogenetic probes for imaging and manipulating neural activity has further increased the relevance of fiber-optic systems for neural circuitry research. Optical fibers, which bi-directionally transmit light between separate sites (even at a distance of several meters), can be used for either optical imaging or manipulating neural activity relevant to behavioral circuitry mechanisms. The method's flexibility and the specifications of the light structure are well suited for following the behavior of freely moving animals. Furthermore, thin optical fibers allow researchers to monitor neural activity from not only the cortical surface but also deep brain regions, including the hippocampus and amygdala. Such regions are difficult to target with two-photon microscopes. Optogenetic manipulation of neural activity with an optical fiber has the advantage of being selective for both cell-types and projections as compared to conventional electrophysiological brain tissue stimulation. It is difficult to extract any data regarding changes in neural activity solely from a fiber-optic manipulation device; however, the readout of data is made possible by combining manipulation with electrophysiological recording, or the simultaneous application of optical imaging and manipulation using a bundle-fiber. The present review introduces recent progress in fiber-optic imaging and manipulation methods, while also discussing fiber-optic system designs that are suitable for a given experimental protocol. PMID:26427958

  9. Injection-seeded optical parametric oscillator and system

    DOEpatents

    Lucht, Robert P.; Kulatilaka, Waruna D.; Anderson, Thomas N.; Bougher, Thomas L.

    2007-10-09

    Optical parametric oscillators (OPO) and systems are provided. The OPO has a non-linear optical material located between two optical elements where the product of the reflection coefficients of the optical elements are higher at the output wavelength than at either the pump or idler wavelength. The OPO output may be amplified using an additional optical parametric amplifier (OPA) stage.

  10. The CEBAF fiber optic phase reference system

    SciTech Connect

    Crawford, K.; Simrock, S.; Hovater, C.; Krycuk, A.

    1995-12-31

    The specified phase stability of the CEBAF RF distribution system is 2.9{degree} rms per linac. Stability is achieved through the use of a temperature and pressure regulated coaxial drive line. Purpose of the fiber optic phase reference system is to monitor the relative phase at the beginning and ending of this drive line, between linacs, injector and separator to determine drift due to ambient temperature fluctuations. The system utilizes an Ortel 1310 nm single mode laser driving Sumitumo optical fiber to distribute a reference signal at 1497 MHz. Phase of this reference signal is compared to the 1427 MHz (LO) and the 70 MHz (IF) via a 360{degree} phase detector. The detected information is then routed to the CEBAF control system for display with a specified resolution of {+-}0.2{degree} over a 20{degree} phase delta.

  11. Birefringence insensitive optical coherence domain reflectometry system

    DOEpatents

    Everett, Matthew J.; Davis, Joseph G.

    2002-01-01

    A birefringence insensitive fiber optic optical coherence domain reflectometry (OCDR) system is provided containing non-polarization maintaining (non-PM) fiber in the sample arm and the reference arm without suffering from signal degradation caused by birefringence. The use of non-PM fiber significantly reduces the cost of the OCDR system and provides a disposable or multiplexed section of the sample arm. The dispersion in the reference arm and sample arm of the OCDR system are matched to achieve high resolution imaging. This system is useful in medical applications or for non-medical in situ probes. The disposable section of non-PM fiber in the sample arm can be conveniently replaced when contaminated by a sample or a patient.

  12. Progress with the lick adaptive optics system

    SciTech Connect

    Gavel, D T; Olivier, S S; Bauman, B; Max, C E; Macintosh, B

    2000-03-01

    Progress and results of observations with the Lick Observatory Laser Guide Star Adaptive Optics System are presented. This system is optimized for diffraction-limited imaging in the near infrared, 1-2 micron wavelength bands. We describe our development efforts in a number of component areas including, a redesign of the optical bench layout, the commissioning of a new infrared science camera, and improvements to the software and user interface. There is also an ongoing effort to characterize the system performance with both natural and laser guide stars and to fold this data into a refined system model. Such a model can be used to help plan future observations, for example, predicting the point-spread function as a function of seeing and guide star magnitude.

  13. Adaptive optics for directly imaging planetary systems

    NASA Astrophysics Data System (ADS)

    Bailey, Vanessa Perry

    In this dissertation I present the results from five papers (including one in preparation) on giant planets, brown dwarfs, and their environments, as well as on the commissioning and optimization of the Adaptive Optics system for the Large Binocular Telescope Interferometer. The first three Chapters cover direct imaging results on several distantly-orbiting planets and brown dwarf companions. The boundary between giant planets and brown dwarf companions in wide orbits is a blurry one. In Chapter 2, I use 3--5 mum imaging of several brown dwarf companions, combined with mid-infrared photometry for each system to constrain the circum-substellar disks around the brown dwarfs. I then use this information to discuss limits on scattering events versus in situ formation. In Chapters 3 and 4, I present results from an adaptive optics imaging survey for giant planets, where the target stars were selected based on the properties of their circumstellar debris disks. Specifically, we targeted systems with debris disks whose SEDs indicated gaps, clearings, or truncations; these features may possibly be sculpted by planets. I discuss in detail one planet-mass companion discovered as part of this survey, HD 106906 b. At a projected separation of 650 AU and weighing in at 11 Jupiter masses, a companion such as this is not a common outcome of any planet or binary star formation model. In the remaining three Chapters, I discuss pre-commissioning, on-sky results, and planned work on the Large Binocular Telescope Interferometer Adaptive Optics system. Before construction of the LBT AO system was complete, I tested a prototype of LBTI's pyramid wavefront sensor unit at the MMT with synthetically-generated calibration files. I present the methodology and MMT on-sky tests in Chapter 5. In Chapter 6, I present the commissioned performance of LBTIAO. Optical imperfections within LBTI limited the quality of the science images, and I describe a simple method to use the adaptive optics system

  14. Solar cell activation system

    SciTech Connect

    Apelian, L.

    1983-07-05

    A system for activating solar cells involves the use of phosphorescent paint, the light from which is amplified by a thin magnifying lens and used to activate solar cells. In a typical system, a member painted with phosphorescent paint is mounted adjacent a thin magnifying lens which focuses the light on a predetermined array of sensitive cells such as selenium, cadmium or silicon, mounted on a plastic board. A one-sided mirror is mounted adjacent the cells to reflect the light back onto said cells for purposes of further intensification. The cells may be coupled to rechargeable batteries or used to directly power a small radio or watch.

  15. Dynamic optical coupled system employing Dammann gratings

    NASA Astrophysics Data System (ADS)

    Di, Caihui; Zhou, Changhe; Ru, Huayi

    2004-10-01

    With the increasing of the number of users in optical fiber communications, fiber-to-home project has a larger market value. Then the need of dynamic optical couplers, especially of N broad-band couplers, becomes greater. Though some advanced fiber fusion techniques have been developed, they still have many shortcomings. In this paper we propose a dynamic optical coupled system employing even-numbered Dammann gratings, which have the characteristic that the phase distribution in the first half-period accurately equals to that in the second-period with π phase inversion. In our experiment, we divide a conventional even-numbered Dammann grating into two identical gratings. The system can achieve the beam splitter and combiner as the switch between them according to the relative shift between two complementary gratings. When there is no shift between the gratings, the demonstrated 1×8 dynamic optical coupler achieves good uniformity of 0.06 and insertion loss of around 10.8 dB for each channel as a splitter. When the two gratings have an accurate shift of a half-period between them, our system has a low insertion loss of 0.46 dB as a combiner at a wavelength of 1550 nm.

  16. Optical countermeasures against CLOS weapon systems

    NASA Astrophysics Data System (ADS)

    Toet, Alexander; Benoist, Koen W.; van Lingen, Joost N. J.; Schleijpen, H. Ric M. A.

    2013-10-01

    There are many weapon systems in which a human operator acquires a target, tracks it and designates it. Optical countermeasures against this type of systems deny the operator the possibility to fulfill this visual task. We describe the different effects that result from stimulation of the human visual system with high intensity (visible) light, and the associated potential operational impact. Of practical use are flash blindness, where an intense flash of light produces a temporary "blind-spot" in (part of) the visual field, flicker distraction, where strong intensity and/or color changes at a discomfortable frequency are produced, and disability glare where a source of light leads to contrast reduction. Hence there are three possibilities to disrupt the visual task of an operator with optical countermeasures such as flares or lasers or a combination of these; namely, by an intense flash of light, by an annoying light flicker or by a glare source. A variety of flares for this purpose is now available or under development: high intensity flash flares, continuous burning flares or strobe flares which have an oscillating intensity. The use of flare arrays seems particularly promising as an optical countermeasure. Lasers are particularly suited to interfere with human vision, because they can easily be varied in intensity, color and size, but they have to be directed at the (human) target, and issues like pointing and eye-safety have to be taken into account. Here we discuss the design issues and the operational impact of optical countermeasures against human operators.

  17. The Optical System of the SOFIA Telescope

    NASA Astrophysics Data System (ADS)

    Bittner, H.; Erdmann, M.

    1999-01-01

    The optical system of the SOFIA telescope consists of a Cassegrain telescope with an aperture of 2.5 m and a Nasmyth focus. The central optical part of the telescope is the monolithic 2.7-m Zerodur primary mirror. The lightweighting factor is 80 The primary mirror is supported by a very stiff CFRP structure. The secondary mirror is a lightweighted SiC mirror and has a chopping mechanism. The telescope has three built-in imagers for acquisition and tracking, one main-optics sharing focal plane imager and two boresighted imagers with a wide and a fine field of view. The poster presents the current status of the development.

  18. Cornea Optical Topographical Scan System (COTSS)

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The Cornea Optical Topographical Scan System (COTSS) is an instrument designed for use by opthalmologist to aid in performing surgical procedures such as radial keratotomy and to provide quick accurate data to aid in prescribing contact lenses and eyeglasses. A breadboard of the system was built and demonstrated in June of 1984. Additional refinements to the breadboard are needed to meet systems requirements prior to proceeding with prototype development. The present status of the COTSS instrument is given and the areas in which system refinements are required, are defined.

  19. Balloon borne optical disk mass storage system

    NASA Technical Reports Server (NTRS)

    Vanek, M. D.; Jennings, D. A.

    1991-01-01

    An on-board data recording system for balloon-borne interferometer using a vacuum operable, ruggedized WORM optical drive is presented. This system, as presently under development, provides 320 Mbytes of data storage (or approximately 11 hrs at the 64 kbits/sec telemetry rate of the experiment). It has the capability of recording the unmodified telemetry bit system as transmitted or doing some preprocessing of the data onboard. The system is compact and requires less than 28 watts of battery power to operate.

  20. Lasers and space optical systems study

    NASA Astrophysics Data System (ADS)

    Giuliano, Concetto; Annaballi, Angela L.

    1998-01-01

    The Air Force and other government organizations have considered the application of space-based lasers since the early 1970s. Recent studies have identified the enormous potential of lasers and optical systems in space to support the Full-Spectrum Dominance envisioned by the Joint Chiefs of Staff in ``Joint Vision 2010.'' The Air Force Research Laboratory has undertaken the LAsers and S_pace O_ptical S_ystems (LASSOS) Study to examine in detail how space lasers and optics (defined as any laser system based in space or any terrestrial-based laser whose beam transits space) could best be used to satisfy this critical need. This twelve-month study will identify promising technology concepts for space laser/optic systems, develop system concepts based on these technologies with special emphasis on systems capable of performing multiple missions, assess how well these systems can accomplish operational tasks in a quantitative manner, and design technology development roadmaps for selected concepts. Since work on the study had commenced only days before the publication deadline, this manuscript is necessarily limited to a description of the background, motivation, and organization of the study. The ``Concept Definition'' phase of the study is scheduled to be completed by the time of the STAIF conference. By that time, study participants will have identified key concepts that best satisfy criteria for timely and cost-effective augmentation of combat capability. A final report, which will be made available to authorized recipients, will be written after completion of the study in August 1998.

  1. Optical imaging of fast light-evoked fast neural activation in amphibian retina

    NASA Astrophysics Data System (ADS)

    Yao, Xin-Cheng; George, John S.

    2006-02-01

    High performance functional imaging is needed for dynamic measurements of neural processing in retina. Emerging techniques of visual prosthesis also require advanced methodology for reliable validation of electromagnetic stimulation of the retina. Imaging of fast intrinsic optical responses associated with neural activation promises a variety of technical advantages over traditional single and multi-channel electrophysiological techniques for these purposes, but the application of fast optical signals for neural imaging has been limited by low signal to noise ratio and high background light intensity. However, using optimized near infrared probe light and improved optical systems, we have improved the optical signals substantially, allowing single pass measurements. Fast photodiode measurements typically disclose dynamic transmitted light changes of whole retina at the level of 10 -4 dI/I, where dI is the dynamic optical change and I is the baseline light intensity. Using a fast high performance CCD, we imaged fast intrinsic optical responses from isolated retina activated by a visible light flash. Fast, high resolution imaging disclosed larger local optical responses, and showed evidence of multiple response components with both negative- and positive-going signals, on different timescales. Darkfield imaging techniques further enhanced the sensitivity of optical measurements. At single cell resolution, brightfield imaging disclosed maxima of optical responses ~5% dI/I, while darkfield imaging showed maxima of optical responses exceeding 10% dI/I. In comparison with simultaneous electrophysiological recording, optical imaging provided much better localized patterns of response over the activated area of the retina.

  2. Power system applications of fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Johnston, A. R.; Jackson, S. P.; Kirkham, H.; Yeh, C.

    1986-06-01

    This document is a progress report of work done in 1985 on the Communications and Control for Electric Power Systems Project at the Jet Propulsion Laboratory. These topics are covered: Electric Field Measurement, Fiber Optic Temperature Sensing, and Optical Power transfer. Work was done on the measurement of ac and dc electric fields. A prototype sensor for measuring alternating fields was made using a very simple electroscope approach. An electronic field mill sensor for dc fields was made using a fiber optic readout, so that the entire probe could be operated isolated from ground. There are several instances in which more precise knowledge of the temperature of electrical power apparatus would be useful. This report describes a number of methods whereby the distributed temperature profile can be obtained using a fiber optic sensor. The ability to energize electronics by means of an optical fiber has the advantage that electrical isolation is maintained at low cost. In order to accomplish this, it is necessary to convert the light energy into electrical form by means of photovoltaic cells. JPL has developed an array of PV cells in gallium arsenide specifically for this purpose. This work is described.

  3. Power system applications of fiber optic sensors

    NASA Technical Reports Server (NTRS)

    Johnston, A. R.; Jackson, S. P.; Kirkham, H.; Yeh, C.

    1986-01-01

    This document is a progress report of work done in 1985 on the Communications and Control for Electric Power Systems Project at the Jet Propulsion Laboratory. These topics are covered: Electric Field Measurement, Fiber Optic Temperature Sensing, and Optical Power transfer. Work was done on the measurement of ac and dc electric fields. A prototype sensor for measuring alternating fields was made using a very simple electroscope approach. An electronic field mill sensor for dc fields was made using a fiber optic readout, so that the entire probe could be operated isolated from ground. There are several instances in which more precise knowledge of the temperature of electrical power apparatus would be useful. This report describes a number of methods whereby the distributed temperature profile can be obtained using a fiber optic sensor. The ability to energize electronics by means of an optical fiber has the advantage that electrical isolation is maintained at low cost. In order to accomplish this, it is necessary to convert the light energy into electrical form by means of photovoltaic cells. JPL has developed an array of PV cells in gallium arsenide specifically for this purpose. This work is described.

  4. Boosted X Waves in Nonlinear Optical Systems

    SciTech Connect

    Arevalo, Edward

    2010-01-15

    X waves are spatiotemporal optical waves with intriguing superluminal and subluminal characteristics. Here we theoretically show that for a given initial carrier frequency of the system localized waves with genuine superluminal or subluminal group velocity can emerge from initial X waves in nonlinear optical systems with normal group velocity dispersion. Moreover, we show that this temporal behavior depends on the wave detuning from the carrier frequency of the system and not on the particular X-wave biconical form. A spatial counterpart of this behavior is also found when initial X waves are boosted in the plane transverse to the direction of propagation, so a fully spatiotemporal motion of localized waves can be observed.

  5. The future of large optical system verification

    NASA Astrophysics Data System (ADS)

    Matthews, Gary

    2005-08-01

    As optical systems grow in size, there becomes a point in which traditional system verification prior to launch will become impossible. This implies that observatory ground testing will not be completed. Our history does not support this premise and therefore results in an unacceptable programmatic risk. But, if the dream of building 20-30 meter systems is ever to become true, these realities must be accepted. To make this possible, new and better analytical tools and processes must be developed and certified on programs that can be tested on the ground. This change in paradigm does not eliminate critical testing; it just does it at different assembly levels and most likely adds alignment flexibility to correct optical errors after launch. This paper provides ideas on how the hardware, analysis tools, and testing may evolve to support these ambitious future programs.

  6. MTF measurement of infrared optical systems

    NASA Astrophysics Data System (ADS)

    Lengwenus, Andre; Erichsen, Patrik

    2009-09-01

    Advances in electro-optic and infrared systems have led to new ways in modeling complex objectives for IR imaging devices. One important indicator for the performance of an imaging system is the modulation transfer function (MTF). In this contribution we disclose the main aspects of IR-MTF measurement and focus on the ImageMaster® Universal IR product line from Trioptics GmbH Germany. These devices cover the whole spectral range from SWIR to LWIR and can be configured to measure optical systems with focal lengths between 1 mm and 2000 mm. The instrument is fully automatized to a very high degree, so it is suitable for laboratory use as well as instruments designed for the high volume production environment.

  7. Fiber coupled optical spark delivery system

    DOEpatents

    Yalin, Azer; Willson, Bryan; Defoort, Morgan

    2008-08-12

    A spark delivery system for generating a spark using a laser beam is provided, the spark delivery system including a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. In addition, the laser delivery assembly includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. In accordance with embodiments of the present invention, the assembly may be used to create a spark in a combustion engine. In accordance with other embodiments of the present invention, a method of using the spark delivery system is provided. In addition, a method of choosing an appropriate fiber for creating a spark using a laser beam is also presented.

  8. Fiber laser coupled optical spark delivery system

    DOEpatents

    Yalin, Azer; Willson, Bryan; Defoort, Morgan; Joshi, Sachin; Reynolds, Adam

    2008-03-04

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  9. Ultra Small Integrated Optical Fiber Sensing System

    PubMed Central

    Van Hoe, Bram; Lee, Graham; Bosman, Erwin; Missinne, Jeroen; Kalathimekkad, Sandeep; Maskery, Oliver; Webb, David J.; Sugden, Kate; Van Daele, Peter; Van Steenberge, Geert

    2012-01-01

    This paper introduces a revolutionary way to interrogate optical fiber sensors based on fiber Bragg gratings (FBGs) and to integrate the necessary driving optoelectronic components with the sensor elements. Low-cost optoelectronic chips are used to interrogate the optical fibers, creating a portable dynamic sensing system as an alternative for the traditionally bulky and expensive fiber sensor interrogation units. The possibility to embed these laser and detector chips is demonstrated resulting in an ultra thin flexible optoelectronic package of only 40 μm, provided with an integrated planar fiber pigtail. The result is a fully embedded flexible sensing system with a thickness of only 1 mm, based on a single Vertical-Cavity Surface-Emitting Laser (VCSEL), fiber sensor and photodetector chip. Temperature, strain and electrodynamic shaking tests have been performed on our system, not limited to static read-out measurements but dynamically reconstructing full spectral information datasets.

  10. Optical Control of Living Cells Electrical Activity by Conjugated Polymers.

    PubMed

    Martino, Nicola; Bossio, Caterina; Vaquero Morata, Susana; Lanzani, Guglielmo; Antognazza, Maria Rosa

    2016-01-01

    Hybrid interfaces between organic semiconductors and living tissues represent a new tool for in-vitro and in-vivo applications. In particular, conjugated polymers display several optimal properties as substrates for biological systems, such as good biocompatibility, excellent mechanical properties, cheap and easy processing technology, and possibility of deposition on light, thin and flexible substrates. These materials have been employed for cellular interfaces like neural probes, transistors for excitation and recording of neural activity, biosensors and actuators for drug release. Recent experiments have also demonstrated the possibility to use conjugated polymers for all-optical modulation of the electrical activity of cells. Several in-vitro study cases have been reported, including primary neuronal networks, astrocytes and secondary line cells. Moreover, signal photo-transduction mediated by organic polymers has been shown to restore light sensitivity in degenerated retinas, suggesting that these devices may be used for artificial retinal prosthesis in the future. All in all, light sensitive conjugated polymers represent a new approach for optical modulation of cellular activity. In this work, all the steps required to fabricate a bio-polymer interface for optical excitation of living cells are described. The function of the active interface is to transduce the light stimulus into a modulation of the cell membrane potential. As a study case, useful for in-vitro studies, a polythiophene thin film is used as the functional, light absorbing layer, and Human Embryonic Kidney (HEK-293) cells are employed as the biological component of the interface. Practical examples of successful control of the cell membrane potential upon stimulation with light pulses of different duration are provided. In particular, it is shown that both depolarizing and hyperpolarizing effects on the cell membrane can be achieved depending on the duration of the light stimulus. The reported

  11. Zoom optical system using tunable polymer lens

    NASA Astrophysics Data System (ADS)

    Liang, Dan; Wang, Xuan Yin

    2016-07-01

    This paper demonstrated a zoom optical system with variable magnification based on the tunable polymer lens. The designed system mainly consists of two polymer lenses, voice coil motors, a doublet lens and CMOS chip. The zoom magnification can be adjusted by altering the focal length of the two elastic polymer lenses synergistically through controlling the output displacement of the voice coil motor. A static doublet lens in combination with the polymer lenses stabilize the image plane at the CMOS chip. The optical structure of the zoom system is presented, as well as a detailed description including the lens materials and fabrication process. Images with each zoom magnification are captured, and the Spot diagram and MTF are simulated using Zemax software. A change in magnification from 0.13×to 8.44×is demonstrated within the tiny 0.4 mm variation of the displacement load, and produce a 16.1×full range of magnification experimentally. Simulation analyses show that all the radii of the spot diagram under different magnifications are less than 11.3 um, and the modulation transfer function reaches 107 line pairs per mm. The designed optical system shows the potential for developing stable, integrated, and low-cost zoom systems with large magnification range.

  12. Production Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Gallaway, Ann, Ed.

    This production systems guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, domains and objectives, a course description, and a content outline. The guide contains 30 modules on the following topics: production…

  13. Communication Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Sutherland, Barbara, Ed.

    This communication systems guide provides teachers with learning activities for secondary students. Introductory materials include an instructional planning outline and worksheet, an outline of essential elements, a list of objectives, a course description, and a content outline. The guide contains 32 modules on the following topics: story…

  14. Wavefront metrology for high resolution optical systems

    NASA Astrophysics Data System (ADS)

    Miyakawa, Ryan H.

    Next generation extreme ultraviolet (EUV) optical systems are moving to higher resolution optics to accommodate smaller length scales targeted by the semiconductor industry. As the numerical apertures (NA) of the optics become larger, it becomes increasingly difficult to characterize aberrations due to experimental challenges associated with high-resolution spatial filters and geometrical effects caused by large incident angles of the test wavefront. This dissertation focuses on two methods of wavefront metrology for high resolution optical systems. The first method, lateral shearing interferometry (LSI), is a self-referencing interferometry where the test wavefront is incident on a low spatial frequency grating, and the resulting interference between the diffracted orders is used to reconstruct the wavefront aberrations. LSI has many advantages over other interferometric tests such as phase-shifting point diffraction interferometry (PS/PDI) due to its experimental simplicity, stability, relaxed coherence requirements, and its ability to scale to high numerical apertures. While LSI has historically been a qualitative test, this dissertation presents a novel quantitative investigation of the LSI interferogram. The analysis reveals the existence of systematic aberrations due to the nonlinear angular response from the diffraction grating that compromises the accuracy of LSI at medium to high NAs. In the medium NA regime (0.15 < NA < 0.35), a holographic model is presented that derives the systematic aberrations in closed form, which demonstrates an astigmatism term that scales as the square of the grating defocus. In the high NA regime (0.35 < NA), a geometrical model is introduced that describes the aberrations as a system of transcendental equations that can be solved numerically. The characterization and removal of these systematic errors is a necessary step that unlocks LSI as a viable candidate for high NA EUV optical testing. The second method is a novel image

  15. Optical systems design for a stratospheric lidar system

    NASA Astrophysics Data System (ADS)

    McDermid, I. Stuart; Walsh, T. Daniel; Deslis, Apostolos; White, Mary L.

    1995-09-01

    The optical systems for the transmitter and receiver of a high-power lidar for stratospheric measurements have been designed and analyzed. The system requirements and design results are presented and explained. An important and driving factor of this design was the requirement for a small image diameter in the plane of an optical chopper to allow the high-intensity lidar returns from the lower atmosphere to be shielded from the detection system. Some results relevant to the optical performance of the system are presented. The resulting system has been constructed and is now in operation at the Mauna Loa Observatory, Hawaii, and is making regular measurements of stratospheric ozone, temperature, and aerosol profiles.

  16. Optical systems design for a stratospheric lidar system.

    PubMed

    McDermid, I S; Walsh, T D; Deslis, A; White, M L

    1995-09-20

    The optical systems for the transmitter and receiver of a high-power lidar for stratospheric measurements have been designed and analyzed. The system requirements and design results are presented and explained. An important and driving factor of this design was the requirement for a small image diameter in the plane of an optical chopper to allow the high-intensity lidar returns from the lower atmosphere to be shielded from the detection system. Some results relevant to the optical performance of the system are presented. The resulting system has been constructed and is now in operation at the Mauna Loa Observatory, Hawaii, and is making regular measurements of stratospheric ozone, temperature, and aerosol profiles. PMID:21060463

  17. Using modalmetric fiber optic sensors to monitor the activity of the heart

    NASA Astrophysics Data System (ADS)

    Życzkowski, M.; Uzięblo-Zyczkowska, B.; Dziuda, L.; Różanowski, K.

    2011-03-01

    The paper presents the concept of the modalmetric fiber optic sensor system for human psychophysical activity detection. A fiber optic sensor that utilizes intensity of propagated light to monitor a patient's vital signs such as respiration cardiac activity, blood pressure and body's physical movements. The sensor, which is non-invasive, comprises an multimode fiber proximately situated to the patient so that time varying acusto-mechanical signals from the patient are coupled by the singlemode optical fiber to detector. The system can be implemented in embodiments ranging form a low cost in-home to a high end product for in hospital use. We present the laboratory test of comparing their results with the known methods like EKG. addition, the article describes the work on integrated system to human psychophysiology activity monitoring. That system including a EMFIT, microwave, fiber optic and capacitive sensors.

  18. Optical signal monitoring in phase modulated optical fiber transmission systems

    NASA Astrophysics Data System (ADS)

    Zhao, Jian

    Optical performance monitoring (OPM) is one of the essential functions for future high speed optical networks. Among the parameters to be monitored, chromatic dispersion (CD) is especially important since it has a significant impact on overall system performance. In this thesis effective CD monitoring approaches for phase-shift keying (PSK) based optical transmission systems are investigated. A number of monitoring schemes based on radio frequency (RF) spectrum analysis and delay-tap sampling are proposed and their performance evaluated. A method for dispersion monitoring of differential phase-shift keying (DPSK) signals based on RF power detection is studied. The RF power spectrum is found to increase with the increase of CD and decrease with polarization mode dispersion (PMD). The spectral power density dependence on CD is studied theoretically and then verified through simulations and experiments. The monitoring sensitivity for nonreturn-to-zero differential phase-shift keying (NRZ-DPSK) and return-to-zero differential phase-shift keying (RZ-DPSK) based systems can reach 80ps/nm/dB and 34ps/nm/dB respectively. The scheme enables the monitoring of differential group delay (DGD) and CD simultaneously. The monitoring sensitivity of CD and DGD can reach 56.7ps/nm/dB and 3.1ps/dB using a bandpass filter. The effects of optical signal-to-noise ratio (OSNR), DGD, fiber nonlinearity and chirp on the monitoring results are investigated. Two RF pilot tones are employed for CD monitoring of DPSK signals. Specially selected pilot tone frequencies enable good monitoring sensitivity with minimum influence on the received signals. The dynamic range exceeding 35dB and monitoring sensitivity up to 9.5ps/nm/dB are achieved. Asynchronous sampling technique is employed for CD monitoring. A signed CD monitoring method for 10Gb/s NRZ-DPSK and RZ-DPSK systems using asynchronous delay-tap sampling technique is studied. The demodulated signals suffer asymmetric waveform distortion if

  19. 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.

  20. Doppler and range determination for deep space vehicles using active optical transponders.

    PubMed

    Kinman, P W; Gagliardi, R M

    1988-11-01

    This paper describes and analyzes two types of laser system employing active transponders that could accurately determine Doppler and range to deep space vehicles from earth-orbiting satellites. The first is a noncoherent optical system in which the Doppler effect on an intensity-modulating subcarrier is measured. The second is a coherent optical system in which the Doppler effect of the optical carrier itself is measured. Doppler and range measurement errors are mathematically modeled and, for three example systems, numerically evaluated. PMID:20539597

  1. Optical passive athermalization for infrared zoom system

    NASA Astrophysics Data System (ADS)

    Li, Shenghui; Yang, Changcheng; Zheng, Jia; Lan, Ning; Xiong, Tao; Li, Yong

    2007-12-01

    In an infrared zoom system, it is difficult to obtain the best thermal compensation for all effective focal length (EFL) simultaneously by moving a single lens group. According to the principle of optical passive athermalization, the equations of focal length, achromatization and athermalization of both long and short EFL are established respectively. By analyzing the thermal aberration value relations between long EFL and short EFL, the thermal aberration values of the switching groups for short EFL athermalization are calculated. Firstly, the athermalization of long EFL is designed. Then through reasonable optical materials matching of the switching groups, the short EFL achieves athermalization as well. In this paper, a re-imaging switching zoom system is designed. It has a relative aperture of f/4.0, 100% cold shield efficiency, the EFL of 180mm/30mm at 3.7-4.8μm. The long EFL includes four refractive elements and one hybrid refractive/diffractive element. The switching groups of short EFL have two types, one is composed of four refractive elements, and the other is composed of two refractive elements and one hybrid refractive/diffractive element. Both of the short EFL achieve athermalization. With the aluminum materials of system structures, the zoom system achieves optical passive athermalization. It has the diffraction limited image quality and stable image plane from -30°C to 70°C.

  2. Update on the Rochester Optical Streak System

    NASA Astrophysics Data System (ADS)

    Jaanimagi, P. A.

    2005-10-01

    The Rochester Optical Streak System (ROSS) is a modern, self-calibrating, remotely controlled streak camera platform capable of accepting a variety of different streak tubes. The optical calibration module (OCM) for the ROSS camera has been completed and integrated with the main streak tube housing. The OCM incorporates an achromatic Offner triplet that allows fiber-delivered input and free-space propagated signals to be simultaneously relayed to the photocathode. It also encloses of the light sources and reticles required to accomplish a full suite of system calibrations including: autofocus of the input and electron optics, geometric distortion and flat-field correction, time base, system gain, and linearity. We will present data illustrating the system capabilities and our latest results comparing the dynamic performance of the P510 and P820 streak tubes. This work was supported by the U.S. Department of Energy Office of Inertial Confinement Fusion under Cooperative Agreement No. DE-FC52-92SF19460.

  3. Progress in optical strain measurement system development

    NASA Technical Reports Server (NTRS)

    Lant, Christian T.; Qaqish, Walid

    1987-01-01

    A laser speckle strain measurement system has been built and tested for the NASA Lewis Research Center. The system is based on a speckle shift technique, which automatically corrects for error due to rigid body motion, and provides a near real time measure of strain. The first stage of a multiphase effort to develop an optical strain gauge capable of mapping in two dimensions the strain on the surface of a hot specimen is discussed. The objectives of this first phase have been to provide a noncontact, one-dimensional, differential strain gauge for experimental purposes, and to determine the maximum open air temperature limit of the system.

  4. Multifunctional optical system-on-a-chip for heterogeneous fiber optic sensor networks

    NASA Astrophysics Data System (ADS)

    Yu, Miao; Pang, Cheng; Gupta, Ashwani

    2015-08-01

    In this article, we review our recent progress on the development of a multifunctional optical system-on-a-chip platform, which can be used for achieving heterogeneous wireless fiber optical sensor networks. A multifunctional optical sensor platform based on the micro-electromechanical systems (MEMS) technology is developed. The key component of the multifunctional optical sensor platform is a MEMS based tunable Fabry-Pérot (FP) filter, which can be used as a phase modulator or a wavelength tuning device in a multifunctional optical sensing system. Mechanics model of the FP filter and optics model of the multifunctional optical sensing system are developed to facilitate the design of the filter. The MEMS FP filter is implemented in a multifunctional optical sensing system including both Fabry-Perot interferometer based sensors and Fiber Bragg grating sensors. The experimental results indicate that this large dynamic range tunable filter can enable high performance heterogeneous optical sensing for many applications.

  5. Active learning in optics and photonics: Fraunhofer diffraction

    NASA Astrophysics Data System (ADS)

    Ghalila, H.; Ben Lakhdar, Z.; Lahmar, S.; Dhouaidi, Z.; Majdi, Y.

    2014-07-01

    "Active Learning in Optics and Photonics" (ALOP), funded by UNESCO within its Physics Program framework with the support of ICTP (Abdus Salam International Centre for Theoretical Physics) and SPIE (Society of Photo-Optical Instrumentation Engineers), aimed to helps and promotes a friendly and interactive method in teaching optics using simple and inexpensive equipment. Many workshops were organized since 2005 the year when Z. BenLakhdar, whom is part of the creators of ALOP, proposed this project to STO (Société Tunisienne d'Optique). These workshops address several issues in optics, covering geometrical optics, wave optics, optical communication and they are dedicated to both teachers and students. We focus this lecture on Fraunhofer diffraction emphasizing the facility to achieve this mechanism in classroom, using small laser and operating a slit in a sheet of paper. We accompany this demonstration using mobile phone and numerical modeling to assist in the analysis of the diffraction pattern figure.

  6. Green photonics realized by optical complex systems

    NASA Astrophysics Data System (ADS)

    Nanri, Hiroto; Sasaki, Wakao

    2013-12-01

    We have experimentally demonstrated a new smart grid model which can control DC electric power flow autonomously among individual homes, by using an optical self-organized node with optical non-linear characteristics, and these homes are assumed to be installed by distributed power supplies, and electric power storage devices, and also supposed to be supplied partly by the commercial electric power grid utilities. An electric power network is composed of nodes and devises called Power Gate Unit (PGU). The nodes have optical nonlinearity for self-organizing informations about surplus or shortage of electric power as to individual homes. The PGU is a distributing unit of actual electric power based on above informations of power surplus or shortage at each home. The PGU at each home is electrically connected to both the onsite power supplies and household load such as a solar panel, a DC motor, and a storage battery as well as the commercial electric power grid utilities. In this work, we composed our experimental self-organized DC power grid with above components and supposed the supplied maximum power from the commercial electric power grid utilities to be limited to 5V-0.5A. In this network, information about surplus or shortage of electric power will propagate through the nodes. In the experiments, surplus electric current 0.4A at a particular node was distributed toward a PGU of another node suffering from shortage of electric current. We also confirmed in the experiments and simulations that even when signal propagation path was disconnected accidentally the network could recover an optimized path. The present smart grid system we have attained may be applied by optical fiber link in the near future because our essential components controlling PGU, i.e. the nodes are electro-optical hybrid which are easily applicable to fiber optical link so as to control electric power transmission line.

  7. Dynamic analysis of mental sweating and the peripheral vessels for the activity of the autonomic nervous system by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Ohmi, Masato; Takada, Daisuke; Wada, Yuki; Haruna, Masamitsu

    2012-01-01

    OCT is highly potential for dynamic analysis of physiological functions of mental sweating and peripheral vessels as demonstrated by the authors. Both mental sweating and the peripheral vessels reflect the activity of the sympathetic nerve of the autonomic nervous system (ANS). The sympathetic nerve also exhibits the LF/HF ratio of the heart rate variability (HRV). In this paper, we demonstrate dynamic analysis of mental sweating and the peripheral vessels for the external stimulus by SS-OCT. In the experiment, the Kraepelin test as a continuous stimulus was applied to the volunteer to discuss in detail dynamics of the physiological function of such small organs in response to the HRV.

  8. Development of silicon optics for an integrated micro-optical system-on-a-chip

    NASA Astrophysics Data System (ADS)

    Ng, David C.; Kandasamy, Sasikaran; Skafidas, Efstratios

    2013-12-01

    Development of silicon-based passive optical components such as reflectors, waveguides, and beam splitters coupled with active elements such as light emitters and detectors enable miniaturisation of a low-cost system-on-a-chip sensing device. In this work, we investigate methods to fabricate passive silicon elements on a chip. We use a combination of wet and dry etching techniques to realise angled and vertical sidewalls normal to the surface of a silicon wafer, respectively. For wet etching, we used Triton-X, a surfactant, added to an alkaline solution TMAH as the etchant. This allows perfect 45° inclined sidewalls to be fabricated. Dry etching using DRIE is to be performed on the reverse-side of the same wafer to realize through-hole vias with straight vertical sidewalls. A final Au metal layer can then be coated onto the sidewalls to realize reflective surfaces. Photolithography masks used in the wet and dry etch processes were designed and fabricated. By careful alignment of these masks using a mask aligner, we can fabricate a combination of inclined and vertical sidewalls to build optical reflectors and beam splitters with complex geometries. When integrated with active Si-optical devices, a fully integrated micro-optical system-on-a-chip can be realised.

  9. Optical memory system having track following

    SciTech Connect

    Hsieh, D.; LaBudde, E.V.

    1984-02-14

    A high density optical storage system is disclosed which employs a laser beam for reading data in a track on a rotating optical disk containing a large number of concentric tracks. Track following is provided using a galvanometer-controlled mirror in the path of the beam which is angularly deflected during track following in response to detected track deviations, whereby the beam is controlled to accurately follow the track. Provision is also made for detecting the angular position of the mirror. A linear motor responsive to the detected angular position moves the mirror in a direction which reduces the deflection required to be provided by the mirror in order to maintain the beam accurately following the track. The mirror is also controlled in response to the rate of change of the linear motor velocity for providing greater system stability.

  10. Quantum optical properties in plasmonic systems

    SciTech Connect

    Ooi, C. H. Raymond

    2015-04-24

    Plasmonic metallic particle (MP) can affect the optical properties of a quantum system (QS) in a remarkable way. We develop a general quantum nonlinear formalism with exact vectorial description for the scattered photons by the QS. The formalism enables us to study the variations of the dielectric function and photon spectrum of the QS with the particle distance between QS and MP, exciting laser direction, polarization and phase in the presence of surface plasmon resonance (SPR) in the MP. The quantum formalism also serves as a powerful tool for studying the effects of these parameters on the nonclassical properties of the scattered photons. The plasmonic effect of nanoparticles has promising possibilities as it provides a new way for manipulating quantum optical properties of light in nanophotonic systems.

  11. Adaptive Optics Imaging of Solar System Objects

    NASA Technical Reports Server (NTRS)

    Roddier, Francois; Owen, Toby

    1999-01-01

    Most solar system objects have never been observed at wavelengths longer than the R band with an angular resolution better than 1". The Hubble Space Telescope itself has only recently been equipped to observe in the infrared. However, because of its small diameter, the angular resolution is lower than that one can now achieved from the ground with adaptive optics, and time allocated to planetary science is limited. We have successfully used adaptive optics on a 4-m class telescope to obtain 0.1" resolution images of solar system objects in the far red and near infrared (0.7-2.5 microns), aE wavelengths which best discl"lmlnate their spectral signatures. Our efforts have been put into areas of research for which high angular resolution is essential.

  12. Adaptive Optics Imaging of Solar System Objects

    NASA Technical Reports Server (NTRS)

    Roddier, Francois; Owen, Toby

    1997-01-01

    Most solar system objects have never been observed at wavelengths longer than the R band with an angular resolution better than 1 sec. The Hubble Space Telescope itself has only recently been equipped to observe in the infrared. However, because of its small diameter, the angular resolution is lower than that one can now achieved from the ground with adaptive optics, and time allocated to planetary science is limited. We have been using adaptive optics (AO) on a 4-m class telescope to obtain 0.1 sec resolution images solar system objects at far red and near infrared wavelengths (0.7-2.5 micron) which best discriminate their spectral signatures. Our efforts has been put into areas of research for which high angular resolution is essential, such as the mapping of Titan and of large asteroids, the dynamics and composition of Neptune stratospheric clouds, the infrared photometry of Pluto, Charon, and close satellites previously undetected from the ground.

  13. Distributed fiber optic moisture intrusion sensing system

    DOEpatents

    Weiss, Jonathan D.

    2003-06-24

    Method and system for monitoring and identifying moisture intrusion in soil such as is contained in landfills housing radioactive and/or hazardous waste. The invention utilizes the principle that moist or wet soil has a higher thermal conductance than dry soil. The invention employs optical time delay reflectometry in connection with a distributed temperature sensing system together with heating means in order to identify discrete areas within a volume of soil wherein temperature is lower. According to the invention an optical element and, optionally, a heating element may be included in a cable or other similar structure and arranged in a serpentine fashion within a volume of soil to achieve efficient temperature detection across a large area or three dimensional volume of soil. Remediation, moisture countermeasures, or other responsive action may then be coordinated based on the assumption that cooler regions within a soil volume may signal moisture intrusion where those regions are located.

  14. Optically triggered fire set/detonator system

    DOEpatents

    Chase, Jay B.; Pincosy, Philip A.; Chato, Donna M.; Kirbie, Hugh; James, Glen F.

    2007-03-20

    The present invention is directed to a system having a plurality of capacitor discharge units (CDUs) that includes electrical bridge type detonators operatively coupled to respective explosives. A pulse charging circuit is adapted to provide a voltage for each respective capacitor in each CDU. Such capacitors are discharged through the electrical bridge type detonators upon receiving an optical signal to detonate respective operatively coupled explosives at substantially the same time.

  15. Optical Security System with Fourier Plane encoding

    NASA Astrophysics Data System (ADS)

    Javidi, Bahram; Ahouzi, Esmail

    1998-09-01

    We propose a new technique for security verification of personal documents and other forms of personal identifications such as ID cards, passports, or credit cards. In this technique a primary pattern that might be a phase-encoded image is convolved by a random code. The information is phase encoded on the personal document. Therefore the information cannot be reproduced by an intensity detector such as a CCD camera. An optical processor based on the nonlinear joint transform correlator is used to perform the verification and the validation of documents with this technique. By verification of the biometrics information and the random code simultaneously, the proposed optical system determines whether a card is authentic or is being used by an authorized person. We tested the performance of the optical system for security and validation in the presence of input noise and in the presence of distortion of the information on the card. The performance of the proposed method is evaluated by use of a number of metrics. Statistical analysis of the system is performed to investigate the noise tolerance and the discrimination against false inputs for security verification.

  16. Optical Security System with Fourier Plane encoding.

    PubMed

    Javidi, B; Ahouzi, E

    1998-09-10

    We propose a new technique for security verification of personal documents and other forms of personal identifications such as ID cards, passports, or credit cards. In this technique a primary pattern that might be a phase-encoded image is convolved by a random code. The information is phase encoded on the personal document. Therefore the information cannot be reproduced by an intensity detector such as a CCD camera. An optical processor based on the nonlinear joint transform correlator is used to perform the verification and the validation of documents with this technique. By verification of the biometrics information and the random code simultaneously, the proposed optical system determines whether a card is authentic or is being used by an authorized person. We tested the performance of the optical system for security and validation in the presence of input noise and in the presence of distortion of the information on the card. The performance of the proposed method is evaluated by use of a number of metrics. Statistical analysis of the system is performed to investigate the noise tolerance and the discrimination against false inputs for security verification. PMID:18286124

  17. Digital optical recorder-reproducer system

    NASA Technical Reports Server (NTRS)

    Reddersen, Brad R. (Inventor); Zech, Richard G. (Inventor); Roberts, Howard N. (Inventor)

    1980-01-01

    A mass archival optical recording and reproduction system includes a recording light source such as a laser beam focussed and directed upon an acousto-optic linear modulator array (or page composer) that receives parallel blocks of data converted from a serial stream of digital data to be stored. The page composer imparts to the laser beam modulation representative of a plurality of parallel channels of data and through focussing optics downstream of the page composer parallel arrays of optical spots are recorded upon a suitable recording medium such as a photographic film floppy disc. The recording medium may be substantially frictionlessly and stably positioned for recording at a record/read station by an air-bearing platen arrangement which is preferably thermodynamically non-throttling so that the recording film may be positioned in the path of the information-carrying light beam in a static or dynamic mode. During readout, the page composer is bypassed and a readout light beam is focussed directly upon the recording medium containing an array of previously recorded digital spots, a sync bit, data positioning bits, and a tracking band. The readout beam which has been directed through the recording medium is then imaged upon a photodetector array, the output of which may be coupled to suitable electronic processing circuitry, such as a digital multiplexer, whereby the parallel spot array is converted back into the original serial data stream.

  18. THE NATURE OF OPTICALLY DULL ACTIVE GALACTIC NUCLEI IN COSMOS

    SciTech Connect

    Trump, Jonathan R.; Impey, Chris D.; Gabor, Jared M.; Taniguchi, Yoshi; Nagao, Tohru; Shioya, Yasuhiro; Brusa, Marcella; Civano, Francesca; Elvis, Martin; Kelly, Brandon C.; Huchra, John P.; Jahnke, Knud; Koekemoer, Anton M.; Salvato, Mara; Capak, Peter; Scoville, Nick Z.; Kartaltepe, Jeyhan S.; Lanzuisi, Giorgio; McCarthy, Patrick J.; Maineri, Vincenzo

    2009-11-20

    We present infrared, optical, and X-ray data of 48 X-ray bright, optically dull active galactic nuclei (AGNs) in the COSMOS field. These objects exhibit the X-ray luminosity of an AGN but lack broad and narrow emission lines in their optical spectrum. We show that despite the lack of optical emission lines, most of these optically dull AGNs are not well described by a typical passive red galaxy spectrum: instead they exhibit weak but significant blue emission like an unobscured AGN. Photometric observations over several years additionally show significant variability in the blue emission of four optically dull AGNs. The nature of the blue and infrared emission suggest that the optically inactive appearance of these AGNs cannot be caused by obscuration intrinsic to the AGNs. Instead, up to approx70% of optically dull AGNs are diluted by their hosts, with bright or simply edge-on hosts lying preferentially within the spectroscopic aperture. The remaining approx30% of optically dull AGNs have anomalously high f{sub X} /f{sub O} ratios and are intrinsically weak, not obscured, in the optical. These optically dull AGNs are best described as a weakly accreting AGN with a truncated accretion disk from a radiatively inefficient accretion flow.

  19. ADASY (Active Daylighting System)

    NASA Astrophysics Data System (ADS)

    Vázquez-Moliní, Daniel; González-Montes, Mario; Fernández-Balbuena, Antonio Á.; Bernabéu, Eusebio; García-Botella, Ángel; García-Rodríguez, Lucas; Pohl, Wilfried

    2009-08-01

    The main objective of ADASY (Active Daylighting System) work is to design a façade static daylighting system oriented to office applications, mainly. The goal of the project is to save energy by guiding daylight into a building for lighting purpose. With this approach we can reduce the electrical load for artificial lighting, completing it with sustainable energy. The collector of the system is integrated on a vertical façade and its distribution guide is always horizontal inside of the false ceiling. ADASY is designed with a specific patent pending caption system, a modular light-guide and light extractor luminaire system. Special care has been put on the final cost of the system and its building integration purpose. The current ADASY configuration is able to illuminate 40 m2 area with a 300lx-400lx level in the mid time work hours; furthermore it has a good enough spatial uniformity distribution and a controlled glare. The data presented in this study are the result of simulation models and have been confirmed by a physical scaled prototype. ADASY's main advantages over regular illumination systems are: -Low maintenance; it has not mobile pieces and therefore it lasts for a long time and require little attention once installed. - No energy consumption; solar light continue working even if there has been a power outage. - High quality of light: the colour rendering of light is very high - Psychological benefits: People working with daylight get less stress and more comfort, increasing productivity. - Health benefits

  20. An optical tracking system for virtual reality

    NASA Astrophysics Data System (ADS)

    Hrimech, Hamid; Merienne, Frederic

    2009-03-01

    In this paper we present a low-cost 3D tracking system which we have developed and tested in order to move away from traditional 2D interaction techniques (keyboard and mouse) in an attempt to improve user's experience while using a CVE. Such a tracking system is used to implement 3D interaction techniques that augment user experience, promote user's sense of transportation in the virtual world as well as user's awareness of their partners. The tracking system is a passive optical tracking system using stereoscopy a technique allowing the reconstruction of three-dimensional information from a couple of images. We have currently deployed our 3D tracking system on a collaborative research platform for investigating 3D interaction techniques in CVEs.

  1. Bioferroelectricity and optical properties of biological systems

    NASA Astrophysics Data System (ADS)

    Bystrov, Vladimir; Bystrova, Natalia

    2003-08-01

    A bioferroelectric approach to analysis of ferroelectric behavior of biological systems is presented. The optical properties of nerve fibers, biomembrane ion channels, and purple membrane films containing bacteriorhodopsin are analyzed. The features, influence of the proton subsystem and proton transfer on the hydrogen-bonded biomolecular structures are analyzed within the ferroelectric liquid-crystal model and possible biomedical applications discussed. The ferroelectric behavior of biological systems and the set of various bioferroelectric effects are considered within the limits of phenomenological theory of ferroelectrics. The nonlinear response to weak actions under conditions critical to human organism is one of specific features characterizing biological objects on molecular, cell and organism levels.

  2. Hybrid plasmonic lattices with tunable magneto-optical activity.

    PubMed

    Kataja, Mikko; Pourjamal, Sara; Maccaferri, Nicolò; Vavassori, Paolo; Hakala, Tommi K; Huttunen, Mikko J; Törmä, Päivi; van Dijken, Sebastiaan

    2016-02-22

    We report on the optical and magneto-optical response of hybrid plasmonic lattices that consist of pure nickel and gold nanoparticles in a checkerboard arrangement. Diffractive far-field coupling between the individual emitters of the lattices results in the excitation of two orthogonal surface lattice resonance modes. Local analyses of the radiation fields indicate that both the nickel and gold nanoparticles contribute to these collective resonances and, thereby, to the magneto-optical activity of the hybrid arrays. The strong effect of noble metal nanoparticles on the magneto-optical response of hybrid lattices opens up new avenues for the realization of sensitive and tunable magneto-plasmonic nanostructures. PMID:26907022

  3. Active fiber optic technologies used as tamper-indicating devices

    SciTech Connect

    Horton, P.R.V.; Waddoups, I.G.

    1995-11-01

    The Sandia National Laboratories (SNL) Safeguards and Seals Evaluation Program is evaluating new fiber optic active seal technologies for use at Department of Energy (DOE) facilities. The goal of the program is to investigate active seal technologies that can monitor secured containers storing special nuclear materials (SNM) within DOE vaults. Specifically investigated were active seal technologies that can be used as tamper-indicating devices to monitor secured containers within vaults while personnel remain outside the vault area. Such a system would allow minimal access into vaults while ensuring container content accountability. The purpose of this report is to discuss tamper-indicating devices that were evaluated for possible DOE use. While previous seal evaluations (Phase I and II) considered overall facility applications, this discussion focuses specifically on their use in vault storage situations. The report will highlight general background information, specifications and requirements, and test procedures. Also discussed are the systems available from four manufacturers: Interactive Technologies, Inc., Fiber SenSys, Inc., Inovonics, Inc., and Valve Security Systems.

  4. Gaseous hydrogen leakage optical fibre detection system

    NASA Astrophysics Data System (ADS)

    Trouillet, Alain; Veillas, Colette; Sigronde, E.; Gagnaire, Henri; Clement, Michel

    2004-06-01

    Liquid hydrogen has been intensively used in aerospace applications during the past forty years and is of great interest for fuel cells technologies and future automotive applications. Following upon major explosive risks due to the use of hydrogen in air, previous studies were carried out in our laboratory in order to develop optical fiber sensors for the detection of hydrogen leakage. This communication is aimed towards a prototype optical fiber system designed for the detection of gaseous hydrogen leakage near the conecting flanges of the liquid hydrogen pipes on the test bench of the engine Vulcain of the rocket ARIANE V. Depending on the configuration, the prototype sensor provides a two-level alarm signal and the detection of gaseous hydrogen leakage is possible for concentrations lower than the lower explosive limit in air (between 0.1 and 4%) with alarm response times lower than 10 seconds in a wide range of temperatures between -35°C and 300°C. The sensing principle based on palladium-hydrogen interaction is presented as well as the detection system composed of an optical fiber probe and an optoelectronic device.

  5. Document Indexing for Image-Based Optical Information Systems.

    ERIC Educational Resources Information Center

    Thiel, Thomas J.; And Others

    1991-01-01

    Discussion of image-based information retrieval systems focuses on indexing. Highlights include computerized information retrieval; multimedia optical systems; optical mass storage and personal computers; and a case study that describes an optical disk system which was developed to preserve, access, and disseminate military documents. (19…

  6. Optical multi-species gas monitoring sensor and system

    NASA Technical Reports Server (NTRS)

    Polzin, Kurt A. (Inventor); Korman, Valentin (Inventor)

    2012-01-01

    The system includes at least one light source generating light energy having a corresponding wavelength. The system's sensor is based on an optical interferometer that receives light energy from each light source. The interferometer includes a free-space optical path disposed in an environment of interest. The system's sensor includes an optical device disposed in the optical path that causes light energy of a first selected wavelength to continue traversing the optical path whereas light energy of at least one second selected wavelength is directed away from the optical path. The interferometer generates an interference between the light energy of the first selected wavelength so-traversing the optical path with the light energy at the corresponding wavelength incident on the optical interferometer. A first optical detector detects the interference. At least one second detector detects the light energy at the at least one second selected wavelength directed away from the optical path.

  7. Temporally-stable active precision mount for large optics.

    PubMed

    Reinlein, Claudia; Damm, Christoph; Lange, Nicolas; Kamm, Andreas; Mohaupt, Matthias; Brady, Aoife; Goy, Matthias; Leonhard, Nina; Eberhardt, Ramona; Zeitner, Uwe; Tünnermann, Andreas

    2016-06-13

    We present a temporally-stable active mount to compensate for manufacturing-induced deformations of reflective optical components. In this paper, we introduce the design of the active mount, and its evaluation results for two sample mirrors: a quarter mirror of 115 × 105 × 9 mm3, and a full mirror of 228 × 210 × 9 mm3. The quarter mirror with 20 actuators shows a best wavefront error rms of 10 nm. Its installation position depending deformations are addressed by long-time measurements over 14 weeks indicating no significance of the orientation. Size-induced differences of the mount are studied by a full mirror with 80 manual actuators arranged in the same actuator pattern as the quarter mirror. This sample shows a wavefront error rms of (27±2) nm over a measurement period of 46 days. We conclude that the developed mount is suitable to compensate for manufacturing-induced deformations of large reflective optics, and likely to be included in the overall systems alignment procedure. PMID:27410369

  8. Third MACAO-VLTI Curvature Adaptive Optics System now installed

    NASA Astrophysics Data System (ADS)

    Arsenault, R.; Donaldson, R.; Dupuy, C.; Fedrigo, E.; Hubin, N.; Ivanescu, L.; Kasper, M.; Oberti, S.; Paufique, J.; Rossi, S.; Silber, A.; Delabre, B.; Lizon, J.-L.; Gigan, P.

    2004-09-01

    IN JULY of this year the MACAO team returned to Paranal for the third time to install another MACAOVLTI system. These are 4 identical 60 element curvature adaptive optics systems, located in the Coudé room of each UT whose aim is to feed a turbulence corrected wavefront to the VLTI Recombination Laboratory. This time the activities took place on Yepun (UT4). The naming convention has been to associate the MACAO-VLTI number to the UT number where it is installed. Therefore, although we speak here of MACAO#4, it is the third system installed in Paranal.

  9. Integration of Optical Manipulation and Electrophysiological Tools to Modulate and Record Activity in Neural Networks

    NASA Astrophysics Data System (ADS)

    Difato, F.; Schibalsky, L.; Benfenati, F.; Blau, A.

    2011-07-01

    We present an optical system that combines IR (1064 nm) holographic optical tweezers with a sub-nanosecond-pulsed UV (355 nm) laser microdissector for the optical manipulation of single neurons and entire networks both on transparent and non-transparent substrates in vitro. The phase-modulated laser beam can illuminate the sample concurrently or independently from above or below assuring compatibility with different types of microelectrode array and patch-clamp electrophysiology. By combining electrophysiological and optical tools, neural activity in response to localized stimuli or injury can be studied and quantified at sub-cellular, cellular, and network level.

  10. Recent development of plasma optical systems (invited)

    NASA Astrophysics Data System (ADS)

    Goncharov, A. A.

    2016-02-01

    The article devotes a brief description of the recent development and current status of an ongoing research of plasma optical systems based on the fundamental plasma optical idea magnetic electron isolation, equipotentialization magnetic field lines, and the axi-symmetric cylindrical electrostatic plasma lens (PL) configuration. The experimental, theoretical, and simulation investigations have been carried out over recent years collaboratively between IP NASU (Kiev), LBNL (Berkeley, USA), and HCEI RAS (Tomsk). The crossed electric and magnetic fields inherent the PL configuration that provides the attractive method for establishing a stable plasma discharge at low pressure. Using PL configuration, several high reliability plasma devices were developed. These devices are attractive for many high-tech applications.

  11. Optical imaging module for astigmatic detection system.

    PubMed

    Wang, Wei-Min; Cheng, Chung-Hsiang; Molnar, Gabor; Hwang, Ing-Shouh; Huang, Kuang-Yuh; Danzebrink, Hans-Ulrich; Hwu, En-Te

    2016-05-01

    In this paper, an optical imaging module design for an astigmatic detection system (ADS) is presented. The module is based on a commercial optical pickup unit (OPU) and it contains a coaxial illuminant for illuminating a specimen. Furthermore, the imaging module facilitates viewing the specimen and the detection laser spot of the ADS with a lateral resolution of approximately 1 μm without requiring the removal of an element of the OPU. Two polarizers and one infrared filter are used to eliminate stray laser light in the OPU and stray light produced by the illuminant. Imaging modules designed for digital versatile disks (DVDs) and Blu-ray DVDs were demonstrated. Furthermore, the module can be used for imaging a small cantilever with approximate dimensions of 2 μm (width) × 5 μm (length), and therefore, it has the potential to be used in high-speed atomic force microscopy. PMID:27250434

  12. Recent development of plasma optical systems (invited).

    PubMed

    Goncharov, A A

    2016-02-01

    The article devotes a brief description of the recent development and current status of an ongoing research of plasma optical systems based on the fundamental plasma optical idea magnetic electron isolation, equipotentialization magnetic field lines, and the axi-symmetric cylindrical electrostatic plasma lens (PL) configuration. The experimental, theoretical, and simulation investigations have been carried out over recent years collaboratively between IP NASU (Kiev), LBNL (Berkeley, USA), and HCEI RAS (Tomsk). The crossed electric and magnetic fields inherent the PL configuration that provides the attractive method for establishing a stable plasma discharge at low pressure. Using PL configuration, several high reliability plasma devices were developed. These devices are attractive for many high-tech applications. PMID:26932073

  13. Optical steam quality measurement system and method

    DOEpatents

    Davidson, James R.; Partin, Judy K.

    2006-04-25

    An optical measurement system is presented that offers precision on-line monitoring of the quality of steam. Multiple wavelengths of radiant energy are passed through the steam from an emitter to a detector. By comparing the amount of radiant energy absorbed by the flow of steam for each wavelength, a highly accurate measurement of the steam quality can be determined on a continuous basis in real-time. In an embodiment of the present invention, the emitter, comprises three separate radiant energy sources for transmitting specific wavelengths of radiant energy through the steam. In a further embodiment, the wavelengths of radiant energy are combined into a single beam of radiant energy for transmission through the steam using time or wavelength division multiplexing. In yet a further embodiment, the single beam of radiant energy is transmitted using specialized optical elements.

  14. Optical activity of chitosan films with induced anisotropy

    NASA Astrophysics Data System (ADS)

    Gegel, Natalia O.; Shipovskaya, Anna B.

    2016-04-01

    The optical anisotropy and optical activity of salt and basic chitosan films, both initial and modified in formic acid vapor were studied. The modification of such films was found to be accompanied by induced time-stable optical anisotropy, by varying the values of specific optical rotation [α] and an inversion of the sign of [α]. The angular dependences (indicatrices) of the specific optical rotation of films on the orientation angle of the sample relative to the direction of the polarization vector of the incident light beam in a plane perpendicular to the beam were obtained. The indicatrices of the initial chitosan films have an almost symmetrical character while those of the films modified in formic acid vapor are irregular. It is concluded of the formation of a vitrified cholesteric mesophase in the chitosan films with induced optical anisotropy.

  15. Optical materials for space based laser systems

    NASA Technical Reports Server (NTRS)

    Buoncristiani, A. M.; Armagan, G.; Byvik, C. E.; Albin, S.

    1989-01-01

    The design features and performance characteristics of a sensitized holmium laser applicable to differential lidar and Doppler windshear measurements are presented, giving attention to the optimal choice of sensitizing/activating dopant ions. This development of a 2-micron region eye-safe laser, where holmium is sensitized by either hulium or erbium, has called for interionic energy transfer processes whose rate will not result in gain-switched pulses that are excessively long for atmospheric lidar and Doppler windshear detection. The application of diamond films for optical component hardening is noted.

  16. DKIST Adaptive Optics System: Simulation Results

    NASA Astrophysics Data System (ADS)

    Marino, Jose; Schmidt, Dirk

    2016-05-01

    The 4 m class Daniel K. Inouye Solar Telescope (DKIST), currently under construction, will be equipped with an ultra high order solar adaptive optics (AO) system. The requirements and capabilities of such a solar AO system are beyond those of any other solar AO system currently in operation. We must rely on solar AO simulations to estimate and quantify its performance.We present performance estimation results of the DKIST AO system obtained with a new solar AO simulation tool. This simulation tool is a flexible and fast end-to-end solar AO simulator which produces accurate solar AO simulations while taking advantage of current multi-core computer technology. It relies on full imaging simulations of the extended field Shack-Hartmann wavefront sensor (WFS), which directly includes important secondary effects such as field dependent distortions and varying contrast of the WFS sub-aperture images.

  17. Solar-blind ultraviolet optical system design for missile warning

    NASA Astrophysics Data System (ADS)

    Chen, Yu; Huo, Furong; Zheng, Liqin

    2015-03-01

    Solar-blind region of Ultraviolet (UV) spectrum has very important application in military field. The spectrum range is from 240nm to 280nm, which can be applied to detect the tail flame from approaching missile. A solar-blind UV optical system is designed to detect the UV radiation, which is an energy system. iKon-L 936 from ANDOR company is selected as the UV detector, which has pixel size 13.5μm x 13.5 μm and active image area 27.6mm x 27.6 mm. CaF2 and F_silica are the chosen materials. The original structure is composed of 6 elements. To reduce the system structure and improve image quality, two aspheric surfaces and one diffractive optical element are adopted in this paper. After optimization and normalization, the designed system is composed of five elements with the maximum spot size 11.988μ m, which is less than the pixel size of the selected CCD detector. Application of aspheric surface and diffractive optical element makes each FOV have similar spot size, which shows the system almost meets the requirements of isoplanatic condition. If the focal length can be decreased, the FOV of the system can be enlarged further.

  18. Statistically Comparing Three Optical Cd Measurement Systems

    NASA Astrophysics Data System (ADS)

    Acree, David A.; Lee, Chen-Show

    1989-07-01

    The rapid technological change in the VLSI industry has resulted in a constant upgrading of measurement equipment. One question to be asked is whether the upgrades recommended really improve the measurement system. Precise measurement equipment is one of the most important components in the next generation of VLSI technology. A systematic approach to measurement equipment upgrades in one micron technology can save much grief and remove uncertainty. In order to compare three optical CD measurement systems simultaneously, a statistically designed systematic approach was employed. The major contributors of variation were identified and quantified. The precision of each optical CD system was then compared. Findings from the study showed the upgraded system reduced variability associated with machine repeatability by a third, but only reduced overall measurement variation by a tenth. The same methods used here can apply in most cases where one piece of equipment is evaluated or several are compared. Vendor claims can be easily tested through the approach described. Reductions in measurement variation associated with an upgrade can be actually quantified allowing management to weigh benefits against costs.

  19. Optical encryption system using quadrature multiplexing

    NASA Astrophysics Data System (ADS)

    Islam, Mohammed Nazrul; Alam, Mohammad S.

    2006-08-01

    Optical security systems have attracted much research interest recently for information security and fraud deterrent applications. A number of encryption techniques have been proposed in the literature, which includes double random-phase encryption, polarization encoding, encryption and verification using a multiplexed minimum average correlation energy phase-encrypted filter. Most of these reports employ a pseudo-random code for each information to be encrypted, where it requires individual storage capacity or transmission channel for further processing of each information. The objective of this paper is to develop an optical encryption system employing quadrature multiplexing to enhance the storage/transmission capacity of the system. Two information signals are encrypted using the same code but employing two orthogonal functions and then they are multiplexed together in the same domain. As the orthogonal functions have zero cross-correlation between them, so the encrypted information are expected to be unaffected by each other. Each encryption and multiplexing process can accommodate two information signals for a single code and a single storage cell or transmission channel. The same process can be performed in multiple steps to increase the multiplexing capability of the system. For decryption purpose, the composite encoded signal is correlated using the appropriate code and the appropriate function. The proposed technique has been found to work excellent in computer simulation with binary as well as gray level images. It has also been verified that the encrypted images remain secure, because no unwanted reproduction is possible without having the appropriate code and function.

  20. Integrated communications and optical navigation system

    NASA Astrophysics Data System (ADS)

    Mueller, J.; Pajer, G.; Paluszek, M.

    2013-12-01

    The Integrated Communications and Optical Navigation System (ICONS) is a flexible navigation system for spacecraft that does not require global positioning system (GPS) measurements. The navigation solution is computed using an Unscented Kalman Filter (UKF) that can accept any combination of range, range-rate, planet chord width, landmark, and angle measurements using any celestial object. Both absolute and relative orbit determination is supported. The UKF employs a full nonlinear dynamical model of the orbit including gravity models and disturbance models. The ICONS package also includes attitude determination algorithms using the UKF algorithm with the Inertial Measurement Unit (IMU). The IMU is used as the dynamical base for the attitude determination algorithms. This makes the sensor a more capable plug-in replacement for a star tracker, thus reducing the integration and test cost of adding this sensor to a spacecraft. Recent additions include an integrated optical communications system which adds communications, and integrated range and range rate measurement and timing. The paper includes test results from trajectories based on the NASA New Horizons spacecraft.

  1. Planar Waveguiding Systems for Optical Sensing

    NASA Astrophysics Data System (ADS)

    Lambeck, Paul V.; Hoekstra, Hugo J. W. M.

    Driving force of the research in Integrated Optics is the optical (tele-) communication, but in its slipstream a lot of research on Integrated Optical (IO-) sensors has been performed during last decade.

  2. Solid-state detector and optical system for microchip analyzers

    DOEpatents

    Mathies, Richard A.; Kamei, Toshihiro; Scherer, James R.; Street, Robert A.

    2005-03-15

    A miniaturized optical excitation and detector system is described for detecting fluorescently labeled analytes in electrophoretic microchips and microarrays. The system uses miniature integrated components, light collection, optical fluorescence filtering, and an amorphous a-Si:H detector for detection. The collection of light is accomplished with proximity gathering and/or a micro-lens system. Optical filtering is accomplished by integrated optical filters. Detection is accomplished utilizing a-Si:H detectors.

  3. Neutron activation analysis system

    DOEpatents

    Taylor, M.C.; Rhodes, J.R.

    1973-12-25

    A neutron activation analysis system for monitoring a generally fluid media, such as slurries, solutions, and fluidized powders, including two separate conduit loops for circulating fluid samples within the range of radiation sources and detectors is described. Associated with the first loop is a neutron source that emits s high flux of slow and thermal neutrons. The second loop employs a fast neutron source, the flux from which is substantially free of thermal neutrons. Adjacent to both loops are gamma counters for spectrographic determination of the fluid constituents. Other gsmma sources and detectors are arranged across a portion of each loop for deterMining the fluid density. (Official Gazette)

  4. Power budget considerations for optically activated conventional sensors and actuators

    NASA Astrophysics Data System (ADS)

    Liu, Kexing

    1991-02-01

    Optically powered conventional instrumentation with optical fiber links that combine the advantages of a familiar technology and of fiber optics is described. A number of examples are given of the development of pneumatic pressure sensors and actuators with reduced power consumption that are operated by optical power and incorporated with fiber-optic links. Their performance and power budget are discussed. They are particularly applicable to transmissions through regions having high EM interference, high EM pulses, and explosive, radiative, or corrosive hazards, such as in nuclear power plants, process plants, aircraft, or spacecraft. These low-optical-power transmission and operation characteristics will help to meet safety requirements and to reduce the system cost.

  5. A Study of Synchronization Techniques for Optical Communication Systems

    NASA Technical Reports Server (NTRS)

    Gagliardi, R. M.

    1975-01-01

    The study of synchronization techniques and related topics in the design of high data rate, deep space, optical communication systems was reported. Data cover: (1) effects of timing errors in narrow pulsed digital optical systems, (2) accuracy of microwave timing systems operating in low powered optical systems, (3) development of improved tracking systems for the optical channel and determination of their tracking performance, (4) development of usable photodetector mathematical models for application to analysis and performance design in communication receivers, and (5) study application of multi-level block encoding to optical transmission of digital data.

  6. Optical monitoring system for a turbine engine

    DOEpatents

    Lemieux, Dennis H; Smed, Jan P; Williams, James P; Jonnalagadda, Vinay

    2013-05-14

    The monitoring system for a gas turbine engine including a viewing tube assembly having an inner end and an outer end. The inner end is located adjacent to a hot gas flow path within the gas turbine engine and the outer end is located adjacent to an outer casing of the gas turbine engine. An aperture wall is located at the inner end of the viewing tube assembly and an optical element is located within the viewing tube assembly adjacent to the inner end and is spaced from the aperture wall to define a cooling and purge chamber therebetween. An aperture is defined in the aperture wall for passage of light from the hot gas flow path to the optical element. Swirl passages are defined in the viewing tube assembly between the aperture wall and the optical element for passage of cooling air from a location outside the viewing tube assembly into the chamber, wherein swirl passages effect a swirling movement of air in a circumferential direction within the chamber.

  7. A fiber optic synchronization system for LUX

    SciTech Connect

    Wilcox, R.B.; Staples, J.W.; Doolittle, L.R.

    2004-06-30

    The LUX femtosecond light source concept would support pump-probe experiments that need to synchronize laser light pulses with electron-beam-generated X-ray pulses to less than 50 fs at the experimenter endstations. To synchronize multiple endstation lasers with the X-ray pulse, we are developing a fiber-distributed optical timing network. A high frequency clock signal is distributed via fiber to RF cavities (controlling X-ray probe pulse timing) and mode-locked lasers at endstations (controlling pump pulse timing). The superconducting cavities are actively locked to the optical clock phase. Most of the RF timing error is contained within a 10 kHz bandwidth, so these errors and any others affecting X-ray pulse timing (such as RF gun phase) can be detected and transmitted digitally to correct laser timing at the endstations. Time delay through the fibers will be stabilized by comparing a retro-reflected pulse from the experimenter endstation end with a reference pulse from the sending en d, and actively controlling the fiber length.

  8. Fiber optically isolated and remotely stabilized data transmission system

    DOEpatents

    Nelson, M.A.

    1992-11-10

    A fiber optically isolated and remotely stabilized data transmission systems described wherein optical data may be transmitted over an optical data fiber from a remote source which includes a data transmitter and a power supply at the remote source. The transmitter may be remotely calibrated and stabilized via an optical control fiber, and the power source may be remotely cycled between duty and standby modes via an optical control fiber. 3 figs.

  9. Fiber optically isolated and remotely stabilized data transmission system

    DOEpatents

    Nelson, Melvin A.

    1992-01-01

    A fiber optically isolated and remotely stabilized data transmission system s described wherein optical data may be transmitted over an optical data fiber from a remote source which includes a data transmitter and a power supply at the remote source. The transmitter may be remotely calibrated and stabilized via an optical control fiber, and the power source may be remotely cycled between duty and standby modes via an optical control fiber.

  10. Optical Diagnostic System for the TLS

    SciTech Connect

    Kuan, C. K.; Tseng, T. C.; Wang, D. J.; Hsiung, G. Y.; Perng, S. Y.; Tsai, Z. D.; Ueng, T. S.; Hsueh, H. P.; Chen, J. R.

    2007-01-19

    The Taiwan light source (TLS) uses a photon beam intensity system (Io monitor) to index the electron beam stability. This index combines the information of the fluctuations of electron beam position and size. For understanding the impact of these fluctuations to the electron beam instability, a set of the optical diagnostic system was installed in the TLS BL10 diagnostics beamline. This system includes the photon beam position monitor (PBPM), the beam size monitor (BSM) and the Io monitor. From the result, we concluded that about one-third impact of beam instability came from the fluctuation of electron beam position and about two-thirds impact of beam instability came from the fluctuation of electron beam size. The hardware configuration is described in this paper.

  11. An optimized optical system for backlit imaging.

    PubMed

    Ghandhi, J B; Heim, D M

    2009-05-01

    An optimized optical system for back-illuminated imaging was developed and was applied to automotive-type fuel injectors; the system provides significantly higher light collection efficiency than standard flood illumination. An engineered diffuser is used to distribute an extended light source through a controlled range of angles, and a field lens is used to redirect the light to the camera. A ray tracing analysis provides the required source size and diffuser angle to ensure that the necessary range of ray angles is included to allow fully diffuse imaging. Direct comparison with a flood illumination system showed that the collection efficiency increased by more than two orders of magnitude without any degradation of image quality. PMID:19485542

  12. Photographic optical systems with nonrotational aspheric surfaces.

    PubMed

    Plummer, W T; Baker, J G; Van Tassell, J

    1999-06-01

    Sections of nonrotational aspheric surfaces can be useful in a variety of optical situations. In several examples, image-forming objectives, as for photographic or electronic camera products, are described in which suitably located asymmetric pairs of refractive surfaces are devised, such that relative rotation about a displaced axis of one with respect to the other can be used to produce a focusing effect that is satisfactory for imaging purposes over reasonable fields of view and for practicable apertures and achromatic corrections. Taylor expansions about assignable reference points in any given surface of a sequence, together with suitable coordinate systems, can be employed to relate performance to shape parameters. PMID:18319960

  13. Strategies for precision adhesive bonding of micro-optical systems

    NASA Astrophysics Data System (ADS)

    Müller, Tobias; Kotnur Venu, Vyshak; Haag, Sebastian; Zontar, Daniel; Sauer, Sebastian; Wenzel, Christian; Brecher, Christian

    2015-02-01

    Today's piezo-based micromanipulator technology allows for highly precise manipulation of optical components. A crucial question for the quality of optical assemblies is the misalignment after curing. The challenge of statistical deviations in the curing process requires a sophisticated knowledge on the relevant process parameters. An approach to meet these requirements is the empirical analysis such as characterization of shrinkage. Gaining sophisticated knowledge about the statistical process of adhesive bonding advances the quality of related production steps like beam-shaping optics, mounting of turning mirrors for fiber coupling or building resonators evaluating power, mode characteristics and beam shape. Maximizing the precision of these single assembly steps fosters the scope of improving the overall efficiency of the entire laser system. At Fraunhofer IPT research activities on the identification of relevant parameters for improved adhesive bonding precision have been undertaken and are ongoing. The influence of the volumetric repeatability of different automatic and manual dispensing methods play an important role. Also, the evaluation of UV-light sources and the relating illumination properties have a significant influence on the bonding result. Furthermore, common UV-curing adhesives are being examined on their performance and reliability for both highest precision prototyping, as well as their application as robust bonding medium in automated optics assembly cells. This paper sums up the parameters of most influence. Overall goal of these activities is the development of a prediction model for optimized shrinkage compensation and thus improved assembly quality.

  14. Application of optical design software in the analysis of "unknown" optical systems

    NASA Astrophysics Data System (ADS)

    Roudnicky, Dunja S.

    1998-08-01

    Optical design software is not very usable in designing new optical systems only, but also in analysis of `unknown' systems. When measurements of radii of curvature, focal lengths and axial thickness of elements are done, we use SIGMA 2100 Optical design software (Kidger Optics). We determine which optical glass fits the nearest measured focal length of each element. We also get aberration curves of elements and the whole system. In such a way we analyze elements of an eyepiece which is the part of a compound panoramic sight. Since we now have all specifications of this eyepiece, it is possible to optimize glasses and radii to the more convenient ones, without a risk to change the performance of the whole optical system. This method gives us a possibility of reparation and adaptation of `unknown' optical systems with a high yield.

  15. Micro-optics technology and sensor systems applications

    NASA Technical Reports Server (NTRS)

    Gal, George; Herman, B.; Anderson, W.; Whitney, R.; Morrow, H.

    1993-01-01

    The current generation of electro-optical sensors utilizing refractive and reflective optical elements require sophisticated, complex, and expensive designs. Advanced-technology-based electro-optical sensors of minimum size and weight require miniaturization of optical, electrical, and mechanical devices with an increasing trend toward integration of various components. Micro-optics technology has the potential in a number of areas to simplify optical design with improved performance. This includes internally cooled apertures, hybrid optical design, microlenses, dispersive multicolor microlenses, active dither, electronically controlled optical beam steer, and microscopic integration of micro-optics, detectors, and signal processing layers. This paper describes our approach to the development of micro-optics technology with our main emphasis for sensors applications.

  16. Minimal-effort planning of active alignment processes for beam-shaping optics

    NASA Astrophysics Data System (ADS)

    Haag, Sebastian; Schranner, Matthias; Müller, Tobias; Zontar, Daniel; Schlette, Christian; Losch, Daniel; Brecher, Christian; Roßmann, Jürgen

    2015-03-01

    In science and industry, the alignment of beam-shaping optics is usually a manual procedure. Many industrial applications utilizing beam-shaping optical systems require more scalable production solutions and therefore effort has been invested in research regarding the automation of optics assembly. In previous works, the authors and other researchers have proven the feasibility of automated alignment of beam-shaping optics such as collimation lenses or homogenization optics. Nevertheless, the planning efforts as well as additional knowledge from the fields of automation and control required for such alignment processes are immense. This paper presents a novel approach of planning active alignment processes of beam-shaping optics with the focus of minimizing the planning efforts for active alignment. The approach utilizes optical simulation and the genetic programming paradigm from computer science for automatically extracting features from a simulated data basis with a high correlation coefficient regarding the individual degrees of freedom of alignment. The strategy is capable of finding active alignment strategies that can be executed by an automated assembly system. The paper presents a tool making the algorithm available to end-users and it discusses the results of planning the active alignment of the well-known assembly of a fast-axis collimator. The paper concludes with an outlook on the transferability to other use cases such as application specific intensity distributions which will benefit from reduced planning efforts.

  17. Systems and methods for free space optical communication

    DOEpatents

    Harper, Warren W [Benton City, WA; Aker, Pamela M [Richland, WA; Pratt, Richard M [Richland, WA

    2011-05-10

    Free space optical communication methods and systems, according to various aspects are described. The methods and systems are characterized by transmission of data through free space with a digitized optical signal acquired using wavelength modulation, and by discrimination between bit states in the digitized optical signal using a spectroscopic absorption feature of a chemical substance.

  18. Physical-layer network coding in coherent optical OFDM systems.

    PubMed

    Guan, Xun; Chan, Chun-Kit

    2015-04-20

    We present the first experimental demonstration and characterization of the application of optical physical-layer network coding in coherent optical OFDM systems. It combines two optical OFDM frames to share the same link so as to enhance system throughput, while individual OFDM frames can be recovered with digital signal processing at the destined node. PMID:25969046

  19. Precision-analog fiber-optic transmission system

    SciTech Connect

    Stover, G.

    1981-06-01

    This article describes the design, experimental development, and construction of a DC-coupled precision analog fiber optic link. Topics to be covered include overall electrical and mechanical system parameters, basic circuit organization, modulation format, optical system design, optical receiver circuit analysis, and the experimental verification of the major design parameters.

  20. Throughput of Coded Optical CDMA Systems with AND Detectors

    NASA Astrophysics Data System (ADS)

    Memon, Kehkashan A.; Umrani, Fahim A.; Umrani, A. W.; Umrani, Naveed A.

    2012-09-01

    Conventional detection techniques used in optical code-division multiple access (OCDMA) systems are not optimal and result in poor bit error rate performance. This paper analyzes the coded performance of optical CDMA systems with AND detectors for enhanced throughput efficiencies and improved error rate performance. The results show that the use of AND detectors significantly improve the performance of an optical channel.

  1. European Neutron Activation System.

    2013-01-11

    Version 03 EASY-2010 (European Activation System) consists of a wide range of codes, data and documentation all aimed at satisfying the objective of calculating the response of materials irradiated in a neutron flux. The main difference from the previous version is the upper energy limit, which has increased from 20 to 60 MeV. It is designed to investigate both fusion devices and accelerator based materials test facilities that will act as intense sources of high-energymore » neutrons causing significant activation of the surrounding materials. The very general nature of the calculational method and the data libraries means that it is applicable (with some reservations) to all situations (e.g. fission reactors or neutron sources) where materials are exposed to neutrons below 60 MeV. EASY can be divided into two parts: data and code development tools and user tools and data. The former are required to develop the latter, but EASY users only need to be able to use the inventory code FISPACT and be aware of the contents of the EAF library (the data source). The complete EASY package contains the FISPACT-2007 inventory code, the EAF-2003, EAF-2005, EAF-2007 and EAF-2010 libraries, and the EASY User Interface for the Window version. The activation package EASY-2010 is the result of significant development to extend the upper energy range from 20 to 60 MeV so that it is capable of being used for IFMIF calculations. The EAF-2010 library contains 66,256 reactions, almost five times more than in EAF-2003 (12,617). Deuteron-induced and proton-induced cross section libraries are also included, and can be used with EASY to enable calculations of the activation due to deuterons and proton [2].« less

  2. Analyses of space environment effects on active fiber optic links orbited aboard the LDEF

    NASA Technical Reports Server (NTRS)

    Taylor, Edward W.; Monarski, T. W.; Berry, J. N.; Sanchez, A. D.; Padden, R. J.; Chapman, S. P.

    1993-01-01

    The results of the 'Preliminary Analysis of WL Experiment no. 701, Space Environment Effects on Operating Fiber Optic Systems,' is correlated with space simulated post retrieval terrestrial studies performed on the M0004 experiment. Temperature cycling measurements were performed on the active optical data links for the purpose of assessing link signal to noise ratio and bit error rate performance some 69 months following the experiment deployment in low Earth orbit. The early results indicate a high correlation between pre-orbit, orbit, and post-orbit functionality of the first known and longest space demonstration of operating fiber optic systems.

  3. Navy explosive ordnance disposal project: Optical ordnance system development. Final report

    SciTech Connect

    Merson, J.A.; Salas, F.J.; Helsel, F.M.

    1996-03-01

    An optical ordnance firing system consisting of a portable hand held solid state rod laser and an optically ignited detonator has been developed for use in explosive ordnance disposal (EOD) activities. Solid state rod laser systems designed to have an output of 150 mJ in a 500 microsecond pulse have been produced and evaluated. A laser ignited detonator containing no primary explosives has been designed and fabricated. The detonator has the same functional output as an electrically fired blasting cap. The optical ordnance firing system has demonstrated the ability to reliably detonate Comp C-4 through 1000 meters of optical fiber.

  4. High resolution underwater fiber optic threat detection system

    NASA Astrophysics Data System (ADS)

    Berger, Alexander; Hermesh, Shalmon; Durets, Eugene; Kempen, Lothar U.

    2006-10-01

    Current underwater protection systems are complex expensive devices consisting of multiple electronic sensing elements. The detection and identification of divers and small submerged watercraft requires very high image resolution. The high price of an array of conventional piezoelectric transducers and associated electronic components makes this solution feasible for localized implementations, but the protection of large stretches of coastline requires a different approach. We present a novel multichannel sonar design that augments current active sonar transducers with a passive fiber-optic multichannel acoustic emission sensing array. The system provides continuous monitoring of the acoustic wave reflections emitted by a single projector, yielding information about the size and shape of approaching objects. A novel fiber hydrophone enclosure is utilized to dramatically enhance the sensor response to the sonar frequency, while suppressing out-of-band sound sources and noise. The ability of a fiber hydrophone to respond to acoustic emissions is based on established fiber Bragg grating sensing techniques. In this approach, the energy of an acoustic wave is converted into the modulation of the in-fiber optical transducer's optical properties. The obtained results demonstrate significant response of the designed fiber optic hydrophone to the incident acoustic wave over the frequency domain from 1-80 kHz. Our approach allows selective tuning of the sensor to a particular acoustic frequency, as well as potential extension of the spectral response to 300- 400kHz.2

  5. High efficiency source coupler for optical waveguide illumination system

    DOEpatents

    Siminovitch, Michael J.

    2000-01-01

    A fiber optic or optical waveguide illumination system includes a source coupling system. The source coupling system includes an optical channel with an internal cavity. A light source is disposed inside the driving circuit. Coupling losses are minimized by placing the light source within the optical channel. The source cavity and the source optical channel can be shaped to enhance the amount of light captured in the channel by total internal reflection. Multiple light distribution waveguides can be connected to the source coupling channel to produce an illumination system.

  6. Optical Properties of Active Regions in Terahertz Quantum Cascade Lasers

    NASA Astrophysics Data System (ADS)

    Dyksik, M.; Motyka, M.; Rudno-Rudziński, W.; Sęk, G.; Misiewicz, J.; Pucicki, D.; Kosiel, K.; Sankowska, I.; Kubacka-Traczyk, J.; Bugajski, M.

    2016-07-01

    In this work, AlGaAs/GaAs superlattice, with layers' sequence and compositions imitating the active and injector regions of a quantum cascade laser designed for emission in the terahertz spectral range, was investigated. Three independent absorption-like optical spectroscopy techniques were employed in order to study the band structure of the minibands formed within the conduction band. Photoreflectance measurements provided information about interband transitions in the investigated system. Common transmission spectra revealed, in the target range of intraband transitions, mainly a number of lines associated with the phonon-related processes, including two-phonon absorption. In contrast, differential transmittance realized by means of Fourier-transform spectroscopy was utilized to probe the confined states of the conduction band. The obtained energy separation between the second and third confined electron levels, expected to be predominantly contributing to the lasing, was found to be ~9 meV. The optical spectroscopy measurements were supported by numerical calculations performed in the effective mass approximation and XRD measurements for layers' width verification. The calculated energy spacings are in a good agreement with the experimental values.

  7. Bridge SHM system based on fiber optical sensing technology

    NASA Astrophysics Data System (ADS)

    Li, Sheng; Fan, Dian; Fu, Jiang-hua; Huang, Xing; Jiang, De-sheng

    2015-09-01

    The latest progress of our lab in recent 10 years on the area of bridge structural health monitoring (SHM) based on optical fiber sensing technology is introduced. Firstly, in the part of sensing technology, optical fiber force test-ring, optical fiber vibration sensor, optical fiber smart cable, optical fiber prestressing loss monitoring method and optical fiber continuous curve mode inspection system are developed, which not only rich the sensor types, but also provides new monitoring means that are needed for the bridge health monitoring system. Secondly, in the optical fiber sensing network and computer system platform, the monitoring system architecture model is designed to effectively meet the integration scale and effect requirement of engineering application, especially the bridge expert system proposed integration of sensing information and informatization manual inspection to realize the mode of multi index intelligence and practical monitoring, diagnosis and evaluation. Finally, the Jingyue bridge monitoring system as the representative, the research on the technology of engineering applications are given.

  8. Optical alignment of Centaur's inertial guidance system

    NASA Technical Reports Server (NTRS)

    Gordan, Andrew L.

    1987-01-01

    During Centaur launch operations the launch azimuth of the inertial platform's U-accelerometer input axis must be accurately established and maintained. This is accomplished by using an optically closed loop system with a long-range autotheodolite whose line of sight was established by a first-order survey. A collimated light beam from the autotheodolite intercepts a reflecting Porro prism mounted on the platform azimuth gimbal. Thus, any deviation of the Porro prism from its predetermined heading is optically detected by the autotheodolite. The error signal produced is used to torque the azimuth gimbal back to its required launch azimuth. The heading of the U-accelerometer input axis is therefore maintained automatically. Previously, the autotheodolite system could not distinguish between vehicle sway and rotational motion of the inertial platform unless at least three prisms were used. One prism was mounted on the inertial platform to maintain azimuth alignment, and two prisms were mounted externally on the vehicle to track sway. For example, the automatic azimuth-laying theodolite (AALT-SV-M2) on the Saturn vehilce used three prisms. The results of testing and modifying the AALT-SV-M2 autotheodolite to simultaneously monitor and maintain alignment of the inertial platform and track the sway of the vehicle from a single Porro prism.

  9. Distributed fiber optic fuel leak detection system

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar; Kempen, C.; Esterkin, Yan; Sun, Sonjian

    2013-05-01

    With the increase worldwide demand for hydrocarbon fuels and the vast development of new fuel production and delivery infrastructure installations around the world, there is a growing need for reliable fuel leak detection technologies to provide safety and reduce environmental risks. Hydrocarbon leaks (gas or liquid) pose an extreme danger and need to be detected very quickly to avoid potential disasters. Gas leaks have the greatest potential for causing damage due to the explosion risk from the dispersion of gas clouds. This paper describes progress towards the development of a fast response, high sensitivity, distributed fiber optic fuel leak detection (HySenseTM) system based on the use of an optical fiber that uses a hydrocarbon sensitive fluorescent coating to detect the presence of fuel leaks present in close proximity along the length of the sensor fiber. The HySenseTM system operates in two modes, leak detection and leak localization, and will trigger an alarm within seconds of exposure contact. The fast and accurate response of the sensor provides reliable fluid leak detection for pipelines, tanks, airports, pumps, and valves to detect and minimize any potential catastrophic damage.

  10. Distributed fiber optic fuel leak detection system

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar; Kempen, C.; Esterkin, Yan; Sun, Sunjian

    2013-05-01

    With the increase worldwide demand for hydrocarbon fuels and the vast development of new fuel production and delivery infrastructure installations around the world, there is a growing need for reliable fuel leak detection technologies to provide safety and reduce environmental risks. Hydrocarbon leaks (gas or liquid) pose an extreme danger and need to be detected very quickly to avoid potential disasters. Gas leaks have the greatest potential for causing damage due to the explosion risk from the dispersion of gas clouds. This paper describes progress towards the development of a fast response, high sensitivity, distributed fiber optic fuel leak detection (HySensTM) system based on the use of an optical fiber that uses a hydrocarbon sensitive fluorescent coating to detect the presence of fuel leaks present in close proximity along the length of the sensor fiber. The HySenseTM system operates in two modes, leak detection and leak localization, and will trigger an alarm within seconds of exposure contact. The fast and accurate response of the sensor provides reliable fluid leak detection for pipelines, tanks, airports, pumps, and valves to detect and minimize any potential catastrophic damage.

  11. Actively stabilized optical fiber interferometry technique for online/in-process surface measurement

    SciTech Connect

    Wang Kaiwei; Martin, Haydn; Jiang Xiangqian

    2008-02-15

    In this paper, we report the recent progress in optical-beam scanning fiber interferometry for potential online nanoscale surface measurement based on the previous research. It attempts to generate a robust and miniature measurement device for future development into a multiprobe array measurement system. In this research, both fiber-optic-interferometry and the wavelength-division-multiplexing techniques have been used, so that the optical probe and the optical interferometer are well spaced and fast surface scanning can be carried out, allowing flexibility for online measurement. In addition, this system provides a self-reference signal to stabilize the optical detection with high common-mode noise suppression by adopting an active phase tracking and stabilization technique. Low-frequency noise was significantly reduced compared with unstabilized result. The measurement of a sample surface shows an attained repeatability of 3.3 nm.

  12. Indexing system for optical beam steering

    NASA Technical Reports Server (NTRS)

    Sullivan, Mark T.; Cannon, David M.; Debra, Daniel B.; Young, Jeffrey A.; Mansfield, Joseph A.; Carmichael, Roger E.; Lissol, Peter S.; Pryor, G. M.; Miklosy, Les G.; Lee, Jeffrey H.

    1990-01-01

    This paper describes the design and testing of an indexing system for optical-beam steering. The cryogenic beam-steering mechanism is a 360-degree rotation device capable of discrete, high-precision alignment positions. It uses low-precision components for its rough alignment and kinematic design to meet its stringent repeatability and stability requirements (of about 5 arcsec). The principal advantages of this design include a decoupling of the low-precision, large angular motion from the high-precision alignment, and a power-off alignment position that potentially extends the life or hold time of cryogenic systems. An alternate design, which takes advantage of these attributes while reducing overall motion, is also presented. Preliminary test results show the kinematic mount capable of sub-arc second repeatability.

  13. Optical response and activity of ultrathin films of topological insulators

    NASA Astrophysics Data System (ADS)

    Parhizgar, Fariborz; Moghaddam, Ali G.; Asgari, Reza

    2015-07-01

    We investigate the optical properties of ultrathin film of a topological insulator in the presence of an in-plane magnetic field. We show that due to the combination of the overlap between the surface states of the two layers and the magnetic field, the optical conductivity can show strong anisotropy. This leads to the effective optical activity of the ultrathin film by influencing the circularly polarized incident light. Intriguingly, for a range of magnetic fields, the reflected and transmitted lights exhibit elliptic character. Even for certain values almost linear polarizations are obtained, indicating that the thin film can act as a polaroid in reflection. All these features are discussed in the context of the time-reversal symmetry breaking as one of the key ingredients for the optical activity.

  14. Active Learning Strategies for Introductory Light and Optics

    ERIC Educational Resources Information Center

    Sokoloff, David R.

    2016-01-01

    There is considerable evidence that traditional approaches are ineffective in teaching physics concepts, including light and optics concepts. A major focus of the work of the Activity Based Physics Group has been on the development of active learning curricula like RealTime Physics (RTP) labs and Interactive Lecture Demonstrations (ILDs). Among…

  15. Active eye-tracking for an adaptive optics scanning laser ophthalmoscope

    PubMed Central

    Sheehy, Christy K.; Tiruveedhula, Pavan; Sabesan, Ramkumar; Roorda, Austin

    2015-01-01

    We demonstrate a system that combines a tracking scanning laser ophthalmoscope (TSLO) and an adaptive optics scanning laser ophthalmoscope (AOSLO) system resulting in both optical (hardware) and digital (software) eye-tracking capabilities. The hybrid system employs the TSLO for active eye-tracking at a rate up to 960 Hz for real-time stabilization of the AOSLO system. AOSLO videos with active eye-tracking signals showed, at most, an amplitude of motion of 0.20 arcminutes for horizontal motion and 0.14 arcminutes for vertical motion. Subsequent real-time digital stabilization limited residual motion to an average of only 0.06 arcminutes (a 95% reduction). By correcting for high amplitude, low frequency drifts of the eye, the active TSLO eye-tracking system enabled the AOSLO system to capture high-resolution retinal images over a larger range of motion than previously possible with just the AOSLO imaging system alone. PMID:26203370

  16. Integrated modeling of the GMT laser tomography adaptive optics system

    NASA Astrophysics Data System (ADS)

    Piatrou, Piotr

    2014-08-01

    Laser Tomography Adaptive Optics (LTAO) is one of adaptive optics systems planned for the Giant Magellan Telescope (GMT). End-to-end simulation tools that are able to cope with the complexity and computational burden of the AO systems to be installed on the extremely large telescopes such as GMT prove to be an integral part of the GMT LTAO system development endeavors. SL95, the Fortran 95 Simulation Library, is one of the software tools successfully used for the LTAO system end-to-end simulations. The goal of SL95 project is to provide a complete set of generic, richly parameterized mathematical models for key elements of the segmented telescope wavefront control systems including both active and adaptive optics as well as the models for atmospheric turbulence, extended light sources like Laser Guide Stars (LGS), light propagation engines and closed-loop controllers. The library is implemented as a hierarchical collection of classes capable of mutual interaction, which allows one to assemble complex wavefront control system configurations with multiple interacting control channels. In this paper we demonstrate the SL95 capabilities by building an integrated end-to-end model of the GMT LTAO system with 7 control channels: LGS tomography with Adaptive Secondary and on-instrument deformable mirrors, tip-tilt and vibration control, LGS stabilization, LGS focus control, truth sensor-based dynamic noncommon path aberration rejection, pupil position control, SLODAR-like embedded turbulence profiler. The rich parameterization of the SL95 classes allows to build detailed error budgets propagating through the system multiple errors and perturbations such as turbulence-, telescope-, telescope misalignment-, segment phasing error-, non-common path-induced aberrations, sensor noises, deformable mirror-to-sensor mis-registration, vibration, temporal errors, etc. We will present a short description of the SL95 architecture, as well as the sample GMT LTAO system simulation

  17. Quasi-optical solid-state power combining for millimeter-wave active seeker applications

    NASA Astrophysics Data System (ADS)

    Halladay, R. H.; Terrill, S. D.; Bowling, D. R.; Gagnon, D. R.

    1992-05-01

    Consideration is given to quasi-optical power combining techniques, state-of-the-art demonstrated performance, and system issues as they apply to endoatmospheric homing seeker insertion. Quasi-optical power combining is based on combining microwave and millimeter-wave solid-state device power in space through the use of antennas and lenses. It is concluded that quasi-optical power combining meets the severe electrical requirements and packaging constraints of active MMW seekers for endoatmospheric hit-to-kill missiles. The approach provides the possibility of wafer-scale integration of major components for low cost production and offers high reliability. Critical issues include thermal loading and system integration, which must be resolved before the quasi-optical power combining technology will be applied to an active MMW seeker.

  18. Quasi-optical solid-state power combining for millimeter-wave active seeker applications

    SciTech Connect

    Halladay, R.H.; Terrill, S.D.; Bowling, D.R.; Gagnon, D.R. U.S. Navy, Naval Air Warfare Center, China Lake, CA )

    1992-05-01

    Consideration is given to quasi-optical power combining techniques, state-of-the-art demonstrated performance, and system issues as they apply to endoatmospheric homing seeker insertion. Quasi-optical power combining is based on combining microwave and millimeter-wave solid-state device power in space through the use of antennas and lenses. It is concluded that quasi-optical power combining meets the severe electrical requirements and packaging constraints of active MMW seekers for endoatmospheric hit-to-kill missiles. The approach provides the possibility of wafer-scale integration of major components for low cost production and offers high reliability. Critical issues include thermal loading and system integration, which must be resolved before the quasi-optical power combining technology will be applied to an active MMW seeker. 18 refs.

  19. Coherent optical monolithic phased-array antenna steering system

    DOEpatents

    Hietala, Vincent M.; Kravitz, Stanley H.; Vawter, Gregory A.

    1994-01-01

    An optical-based RF beam steering system for phased-array antennas comprising a photonic integrated circuit (PIC). The system is based on optical heterodyning employed to produce microwave phase shifting by a monolithic PIC constructed entirely of passive components. Microwave power and control signal distribution to the antenna is accomplished by optical fiber, permitting physical separation of the PIC and its control functions from the antenna. The system reduces size, weight, complexity, and cost of phased-array antenna systems.

  20. Active stabilization of the optical part in fiber optic quantum cryptography

    NASA Astrophysics Data System (ADS)

    Balygin, K. A.; Klimov, A. N.; Kulik, S. P.; Molotkov, S. N.

    2016-03-01

    The method of active stabilization of the polarization and other parameters of the optical part of a two-pass fiber optic quantum cryptography has been proposed and implemented. The method allows the completely automated maintenance of the visibility of interference close to an ideal value ( V ≥ 0.99) and the reduction of the instrumental contribution to the error in primary keys (QBER) to 0.5%.

  1. Asymmetric bioreduction of activated alkenes to industrially relevant optically active compounds

    PubMed Central

    Winkler, Christoph K.; Tasnádi, Gábor; Clay, Dorina; Hall, Mélanie; Faber, Kurt

    2012-01-01

    Ene-reductases from the ‘Old Yellow Enzyme’ family of flavoproteins catalyze the asymmetric reduction of various α,β-unsaturated compounds at the expense of a nicotinamide cofactor. They have been applied to the synthesis of valuable enantiopure products, including chiral building blocks with broad industrial applications, terpenoids, amino acid derivatives and fragrances. The combination of these highly stereoselective biocatalysts with a cofactor recycling system has allowed the development of cost-effective methods for the generation of optically active molecules, which is strengthened by the availability of stereo-complementary enzyme homologues. PMID:22498437

  2. Frequency up-conversion of optical microwaves for multichannel optical microwave system on a WDM network

    NASA Astrophysics Data System (ADS)

    Shin, Myunghun; Kumar, Prem

    2012-07-01

    We propose a multichannel optical microwave system employing a frequency up-converting optoelectronic oscillator (FU-OEO) [FU-OEO: frequency up-converting optoelectronic oscillator] as a low-phase noise local oscillator (LO) and a multichannel frequency up-converter. Employing the FU-OEO, we demonstrated an optical microwave system capable of 16 optical microwave links in the C-band on a WDM network; the generated optical microwaves were distributed to their designated remote stations according to the channel wavelength. When the FU-OEO was used as the system LO, the phase noise of the optical microwaves was under -80 dBc/Hz at a 10 kHz offset from a 20 GHz carrier frequency. As a frequency up-converter, the FU-OEO simultaneously up-converted all optical data channels at a 1.25 Gbps data rate for optical microwaves in the 20 GHz band of an optical carrier suppression mode having almost 100% modulation depth. The overall system performance was verified by measuring the bit error rates (BER) of the data recovered from optical microwaves received through single-mode fibers. The measured BER indicated that the system can transmit over 50 km with a power penalty of less than 1 dB. This method can be useful for high-frequency applications where the generation and transmission of optical microwaves are greatly restricted by optical or electrical bandwidths.

  3. SIRT1 Activation Confers Neuroprotection in Experimental Optic Neuritis

    PubMed Central

    Shindler, Kenneth S.; Ventura, Elvira; Rex, Tonia S.; Elliott, Peter; Rostami, Abdolmohamad

    2007-01-01

    Purpose Axonal damage and loss of neurons correlate with permanent vision loss and neurologic disability in patients with optic neuritis and multiple sclerosis (MS). Current therapies involve immunomodulation, with limited effects on neuronal damage. The authors examined potential neuroprotective effects in optic neuritis by SRT647 and SRT501, two structurally and mechanistically distinct activators of SIRT1, an enzyme involved in cellular stress resistance and survival. Methods Experimental autoimmune encephalomyelitis (EAE), an animal model of MS, was induced by immunization with proteolipid protein peptide in SJL/J mice. Optic neuritis developed in two thirds of eyes with significant retinal ganglion cell (RGC) loss detected 14 days after immunization. RGCs were labeled in a retrograde fashion with fluorogold by injection into superior colliculi. Optic neuritis was detected by inflammatory cell infiltration of the optic nerve. Results Intravitreal injection of SIRT1 activators 0, 3, 7, and 11 days after immunization significantly attenuated RGC loss in a dose-dependent manner. This neuroprotective effect was blocked by sirtinol, a SIRT1 inhibitor. Treatment with either SIRT1 activator did not prevent EAE or optic nerve inflammation. A single dose of SRT501 on day 11 was sufficient to limit RGC loss and to preserve axon function. Conclusions SIRT1 activators provide an important potential therapy to prevent the neuronal damage that leads to permanent neurologic disability in optic neuritis and MS patients. Intravitreal administration of SIRT1 activators does not suppress inflammation in this model, suggesting that their neuroprotective effects will be additive or synergistic with current immunomodulatory therapies. PMID:17652729

  4. 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.

  5. 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.

  6. The curvature adaptive optics system modeling

    NASA Astrophysics Data System (ADS)

    Yang, Qiang

    A curvature adaptive optics (AO) simulation system has been built. The simulation is based on the Hokupa'a-36 AO system for the NASA IRTF 3m telescope and the Hokupa'a-85 AO system for the Gemini Near Infrared Coronagraphic Imager. Several sub-models are built separately for the AO simulation system, and they are: (1) generation and propagation of atmospheric phase screens, (2) the bimorph deformable mirror (DM), (3) the curvature wave-front sensor (CWFS), (4) generation of response functions, interaction matrices and calculation of command matrices, (5) Fresnel propagation from the DM pupil to the lenslet pupil, (6) AO servo loop, and (7) post processing. The AO simulation system is then applied to the effects of DM hysteresis, and to the optimization of DM actuator patterns for the Hokupa'a-85 and Hokupa'a-36 AO systems. In the first application, an enhancing Coleman-Hodgdon model is introduced to approximate the hysteresis curves, and then the Lambert W function is introduced to calculate the inverse of the Coleman-Hodgdon equation. Step response, transfer functions and Strehl Ratios from the AO system have been compared under the cases with/without DM hysteresis. The servo-loop results show that the bandwidth of an AO system is improved greatly after the DM hysteresis is corrected. In the second application, many issues of the bimorph mirror will be considered to optimize the DM patterns, and they include the type and length of the edge benders, gap size of electrodes, DM size, and DM curvature limit.

  7. All-optical virtual private network and ONUs communication in optical OFDM-based PON system.

    PubMed

    Zhang, Chongfu; Huang, Jian; Chen, Chen; Qiu, Kun

    2011-11-21

    We propose and demonstrate a novel scheme, which enables all-optical virtual private network (VPN) and all-optical optical network units (ONUs) inter-communications in optical orthogonal frequency-division multiplexing-based passive optical network (OFDM-PON) system using the subcarrier bands allocation for the first time (to our knowledge). We consider the intra-VPN and inter-VPN communications which correspond to two different cases: VPN communication among ONUs in one group and in different groups. The proposed scheme can provide the enhanced security and a more flexible configuration for VPN users compared to the VPN in WDM-PON or TDM-PON systems. The all-optical VPN and inter-ONU communications at 10-Gbit/s with 16 quadrature amplitude modulation (16 QAM) for the proposed optical OFDM-PON system are demonstrated. These results verify that the proposed scheme is feasible. PMID:22109510

  8. Integrated modeling of advanced optical systems

    NASA Astrophysics Data System (ADS)

    Briggs, Hugh C.; Needels, Laura; Levine, B. Martin

    1993-02-01

    This poster session paper describes an integrated modeling and analysis capability being developed at JPL under funding provided by the JPL Director's Discretionary Fund and the JPL Control/Structure Interaction Program (CSI). The posters briefly summarize the program capabilities and illustrate them with an example problem. The computer programs developed under this effort will provide an unprecedented capability for integrated modeling and design of high performance optical spacecraft. The engineering disciplines supported include structural dynamics, controls, optics and thermodynamics. Such tools are needed in order to evaluate the end-to-end system performance of spacecraft such as OSI, POINTS, and SMMM. This paper illustrates the proof-of-concept tools that have been developed to establish the technology requirements and demonstrate the new features of integrated modeling and design. The current program also includes implementation of a prototype tool based upon the CAESY environment being developed under the NASA Guidance and Control Research and Technology Computational Controls Program. This prototype will be available late in FY-92. The development plan proposes a major software production effort to fabricate, deliver, support and maintain a national-class tool from FY-93 through FY-95.

  9. The optical design of a visible adaptive optics system for the Magellan Telescope

    NASA Astrophysics Data System (ADS)

    Kopon, Derek

    The Magellan Adaptive Optics system will achieve first light in November of 2012. This AO system contains several subsystems including the 585-actuator concave adaptive secondary mirror, the Calibration Return Optic (CRO) alignment and calibration system, the CLIO 1-5 microm IR science camera, the movable guider camera and active optics assembly, and the W-Unit, which contains both the Pyramid Wavefront Sensor (PWFS) and the VisAO visible science camera. In this dissertation, we present details of the design, fabrication, assembly, alignment, and laboratory performance of the VisAO camera and its optical components. Many of these components required a custom design, such as the Spectral Differential Imaging Wollaston prisms and filters and the coronagraphic spots. One component, the Atmospheric Dispersion Corrector (ADC), required a unique triplet design that had until now never been fabricated and tested on sky. We present the design, laboratory, and on-sky results for our triplet ADC. We also present details of the CRO test setup and alignment. Because Magellan is a Gregorian telescope, the ASM is a concave ellipsoidal mirror. By simulating a star with a white light point source at the far conjugate, we can create a double-pass test of the whole system without the need for a real on-sky star. This allows us to test the AO system closed loop in the Arcetri test tower at its nominal design focal length and optical conjugates. The CRO test will also allow us to calibrate and verify the system off-sky at the Magellan telescope during commissioning and periodically thereafter. We present a design for a possible future upgrade path for a new visible Integral Field Spectrograph. By integrating a fiber array bundle at the VisAO focal plane, we can send light to a pre-existing facility spectrograph, such as LDSS3, which will allow 20 mas spatial sampling and R˜1,800 spectra over the band 0.6-1.05 microm. This would be the highest spatial resolution IFU to date, either

  10. Multiparameter fiber optic sensing system for monitoring enhanced geothermal systems

    SciTech Connect

    Challener, William A

    2014-12-04

    The goal of this project was to design, fabricate and test an optical fiber cable which supports multiple sensing modalities for measurements in the harsh environment of enhanced geothermal systems. To accomplish this task, optical fiber was tested at both high temperatures and strains for mechanical integrity, and in the presence of hydrogen for resistance to darkening. Both single mode (SM) and multimode (MM) commercially available optical fiber were identified and selected for the cable based on the results of these tests. The cable was designed and fabricated using a tube-within-tube construction containing two MM fibers and one SM fiber, and without supporting gel that is not suitable for high temperature environments. Commercial fiber optic sensing instruments using Raman DTS (distributed temperature sensing), Brillouin DTSS (distributed temperature and strain sensing), and Raleigh COTDR (coherent optical time domain reflectometry) were selected for field testing. A microelectromechanical systems (MEMS) pressure sensor was designed, fabricated, packaged, and calibrated for high pressure measurements at high temperatures and spliced to the cable. A fiber Bragg grating (FBG) temperature sensor was also spliced to the cable. A geothermal well was selected and its temperature and pressure were logged. The cable was then deployed in the well in two separate field tests and measurements were made on these different sensing modalities. Raman DTS measurements were found to be accurate to ±5°C, even with some residual hydrogen darkening. Brillouin DTSS measurements were in good agreement with the Raman results. The Rayleigh COTDR instrument was able to detect some acoustic signatures, but was generally disappointing. The FBG sensor was used to determine the effects of hydrogen darkening, but drift over time made it unreliable as a temperature or pressure sensor. The MEMS sensor was found to be highly stable and accurate to better than its 0.1% calibration.

  11. Synthesis and biological evaluation of optically active Ki16425.

    PubMed

    Sato, Takanao; Sugimoto, Kenji; Inoue, Asuka; Okudaira, Shinichi; Aoki, Junken; Tokuyama, Hidetoshi

    2012-07-01

    An enantionselective synthesis of both enantiomers of Ki16425, which possesses selective LPA antagonistic activity, was achieved. The isoxazole core was constructed by a 1,3-dipolar cycloaddition of nitrile oxide with alkyne and condensation with the optically active α-phenethyl alcohol segment, which was prepared by an enantioselective reduction of arylmethylketone. Biological evaluation of both enantiomers of Ki16425 revealed that the (R)-isomer showed much higher antagonistic activity for LPA(1) and LPA(3) receptors. PMID:22658556

  12. Simulating Astronomical Adaptive Optics Systems Using Yao

    NASA Astrophysics Data System (ADS)

    Rigaut, François; Van Dam, Marcos

    2013-12-01

    Adaptive Optics systems are at the heart of the coming Extremely Large Telescopes generation. Given the importance, complexity and required advances of these systems, being able to simulate them faithfully is key to their success, and thus to the success of the ELTs. The type of systems envisioned to be built for the ELTs cover most of the AO breeds, from NGS AO to multiple guide star Ground Layer, Laser Tomography and Multi-Conjugate AO systems, with typically a few thousand actuators. This represents a large step up from the current generation of AO systems, and accordingly a challenge for existing AO simulation packages. This is especially true as, in the past years, computer power has not been following Moore's law in its most common understanding; CPU clocks are hovering at about 3GHz. Although the use of super computers is a possible solution to run these simulations, being able to use smaller machines has obvious advantages: cost, access, environmental issues. By using optimised code in an already proven AO simulation platform, we were able to run complex ELT AO simulations on very modest machines, including laptops. The platform is YAO. In this paper, we describe YAO, its architecture, its capabilities, the ELT-specific challenges and optimisations, and finally its performance. As an example, execution speed ranges from 5 iterations per second for a 6 LGS 60x60 subapertures Shack-Hartmann Wavefront sensor Laser Tomography AO system (including full physical image formation and detector characteristics) up to over 30 iterations/s for a single NGS AO system.

  13. Optical design of the adaptive optics laser guide star system

    SciTech Connect

    Bissinger, H.

    1994-11-15

    The design of an adaptive optics package for the 3 meter Lick telescope is presented. This instrument package includes a 69 actuator deformable mirror and a Hartmann type wavefront sensor operating in the visible wavelength; a quadrant detector for the tip-tile sensor and a tip-tilt mirror to stabilize atmospheric first order tip-tile errors. A high speed computer drives the deformable mirror to achieve near diffraction limited imagery. The different optical components and their individual design constraints are described. motorized stages and diagnostics tools are used to operate and maintain alignment throughout observation time from a remote control room. The expected performance are summarized and actual results of astronomical sources are presented.

  14. Smart Optical Material Characterization System and Method

    NASA Technical Reports Server (NTRS)

    Choi, Sang Hyouk (Inventor); Park, Yeonjoon (Inventor)

    2015-01-01

    Disclosed is a system and method for characterizing optical materials, using steps and equipment for generating a coherent laser light, filtering the light to remove high order spatial components, collecting the filtered light and forming a parallel light beam, splitting the parallel beam into a first direction and a second direction wherein the parallel beam travelling in the second direction travels toward the material sample so that the parallel beam passes through the sample, applying various physical quantities to the sample, reflecting the beam travelling in the first direction to produce a first reflected beam, reflecting the beam that passes through the sample to produce a second reflected beam that travels back through the sample, combining the second reflected beam after it travels back though the sample with the first reflected beam, sensing the light beam produced by combining the first and second reflected beams, and processing the sensed beam to determine sample characteristics and properties.

  15. Self-amplified optical pattern recognition system

    NASA Technical Reports Server (NTRS)

    Liu, Hua-Kuang (Inventor)

    1994-01-01

    A self amplifying optical pattern recognizer includes a geometric system configuration similar to that of a Vander Lugt holographic matched filter configuration with a photorefractive crystal specifically oriented with respect to the input beams. An extraordinarily polarized, spherically converging object image beam is formed by laser illumination of an input object image and applied through a photorefractive crystal, such as a barium titanite (BaTiO.sub.3) crystal. A volume or thin-film dif ORIGIN OF THE INVENTION The invention described herein was made in the performance of work under a NASA contract, and is subject to the provisions of Public Law 96-517 (35 USC 202) in which the Contractor has elected to retain title.

  16. Optics in complex systems; Proceedings of the 15th Congress of the International Commission for Optics, Garmisch-Partenkirchen, Federal Republic of Germany, Aug. 5-10, 1990

    NASA Astrophysics Data System (ADS)

    Lanzl, F.; Weigelt, G.; Preuss, H.-J.

    Various papers on optics in complex systems are presented. The general topics addressed include: physical optics, quantum optics, lasers, statistical optics, nonlinear optics, nonlinear effects in fibers, guided waves and integrated optics, interconnects, optical storage and memories, optical computing, neural networks, interferometry, holography, metrology, periodical structures, 3D sensing, image processing, astronomical optics and methods, microscopy, microoptics, spectroscopy, fiber optics and methods, X-ray optics, atmospheric optics, scattering, rough surfaces, optical properties of materials, optical design and testing, remote sensing.

  17. All-optical SOA latch fail-safe alarm system

    NASA Astrophysics Data System (ADS)

    McAulay, Alastair D.

    2004-11-01

    Emergency alarm systems, for example, that switch off critical processes in process plant, are vulnerable to deliberate or accidental sabotage through coupling of electromagnetic pulses (EMP) to wires and/or from sparks due to broken wires. A proposed system significantly reduces vulnerability by using a fast all-optical latch in conjunction with an optical sensor and optical fibers. Sparks cannot be created on breaking an optical beam and electromagnetic field transients have negligible effect on optical signals. The optical latch uses optical semiconductor amplifiers (SOAs) configured to form a flip-flop. The flip-flop latches after the occurrence of an intrusion that may be as short as a few nanoseconds, much faster than most environmental changes occur. Detection of an emergency or any break in connections causes the light to drop, triggering the alarm. Computer simulation shows that the all-optical latch is fast and effective.

  18. Polarized Raman optical activity of menthol and related molecules

    NASA Astrophysics Data System (ADS)

    Barron, L. D.; Hecht, L.; Blyth, S. M.

    1989-01-01

    Polarized and depolarized Raman optical activity spectra of menthol, menthyl chloride, neomenthol and neothiomenthol from 800 to 1500 cm -1 are reported. Despite axial symmetry in all the bonds, the presence of the heteroatoms O or S seems to induce large deviations from the expected ratio of 2:1 between the polarized and depolarized Raman optical activity intensities, but Cl does not. These deviations might originate in large electric quadrupole contributions induced by excited state interactions involving O or S Rydberg p orbitals and valence orbitals on other parts of the molecule. Such interactions appear to undermine the bond polarizability theory of Raman intensities.

  19. Active optics for space applications: an ESA perspective

    NASA Astrophysics Data System (ADS)

    Zuccaro Marchi, Alessandro; Hallibert, Pascal; Pereira do Carmo, Joao; Wille, Eric

    2014-07-01

    Active optics for Space is relatively new field that takes advantage of lessons learnt on ground, and together with the tighter constrains of space environment it allows operation of larger mirrors apertures for space telescopes and better image quality. Technical developments are crucial to guarantee proper technological readiness for applications on new missions whose performance can be driven also by these novelties. This paper describes the philosophy pursued at ESA, providing an overview of the activities run within the Agency, as well as perspectives for new developments. The Optics Section of the Directorate of Technical and Quality Management of ESA/ESTEC is currently running three projects. Two examples are here addressed.

  20. Giant optical activity of sugar in thin soap films.

    PubMed

    Emile, Janine; Emile, Olivier; Ghoufi, Aziz; Moréac, Alain; Casanova, Federico; Ding, Minxia; Houizot, Patrick

    2013-10-15

    We report on enhanced experimental optical activity measurements of thin soap films in the presence of sugar. This unusual optical activity is linked to the intramolecular chiral conformation of the glucose molecules at the air/liquid interface. Choosing sodium dodecylsulfate (SDS) as a model surfactant and glucose as model sugar, favorable interactions between the anionic group -OSO3(-)- and the glucose molecules are highlighted. This induces an interfacial anchoring of glucose molecules leading to a perturbing influence of the asymmetric chiral environment. PMID:23932406

  1. Technology Systems. Laboratory Activities.

    ERIC Educational Resources Information Center

    Brame, Ray; And Others

    This guide contains 43 modules of laboratory activities for technology education courses. Each module includes an instructor's resource sheet and the student laboratory activity. Instructor's resource sheets include some or all of the following elements: module number, course title, activity topic, estimated time, essential elements, objectives,…

  2. Collection optics design for KSTAR Thomson scattering system

    SciTech Connect

    Oh, S.; Lee, J. H.

    2010-10-15

    The collection optics designs are described for the Thomson scattering diagnostic of the Korea superconducting tokamak advanced research (KSTAR) device. The optical systems collecting the light emission induced through the interaction between the plasma electrons and a laser beam are key components for the Thomson scattering system. A duo-lens system was examined, and the final optical designs were derived for Thomson scattering diagnostic of KSTAR.

  3. Optical design and tolerancing of an ophthalmological system

    NASA Astrophysics Data System (ADS)

    Sieber, Ingo; Martin, Thomas; Yi, Allen; Li, Likai; Rübenach, Olaf

    2014-09-01

    Tolerance analysis by means of simulation is an essential step in system integration. Tolerance analysis allows for predicting the performance of a system setup of real manufactured parts and for an estimation of the yield with respect to evaluation figures, such as performance requirements, systems specification or cost demands. Currently, optical freeform optics is gaining importance in optical systems design. The performance of freeform optics often strongly depends on the manufacturing accuracy of the surfaces. For this reason, a tolerance analysis with respect to the fabrication accuracy is of crucial importance. The characterization of form tolerances caused by the manufacturing process is based on the definition of straightness, flatness, roundness, and cylindricity. In case of freeform components, however, it is often impossible to define a form deviation by means of this standard classification. Hence, prediction of the impact of manufacturing tolerances on the optical performance is not possible by means of a conventional tolerance analysis. To carry out a tolerance analysis of the optical subsystem, including freeform optics, metrology data of the fabricated surfaces have to be integrated into the optical model. The focus of this article is on design for manufacturability of freeform optics with integrated alignment structures and on tolerance analysis of the optical subsystem based on the measured surface data of manufactured optical freeform components with respect to assembly and manufacturing tolerances. This approach will be reported here using an ophthalmological system as an example.

  4. Rugged spinel optics for space based imaging systems

    NASA Astrophysics Data System (ADS)

    Bayya, Shyam; Villalobos, Guillermo; Hunt, Michael; Kim, Woohong; Plunkett, Simon; Sanghera, Jasbinder

    2016-05-01

    Space environment is very harsh for optical systems. Currently available optical materials for space applications are susceptible to surface and bulk damage due to high-speed impacts from dust and debris found in the space environment. Impacts lead to surface pitting and fracturing that may compromise structural integrity and degrade the optical performance of imaging systems. We are developing polycrystalline spinel as a rugged optics material. With its 3x hardness and 5x strength, as compared to BK7 glass, spinel is a very promising optical material for space imaging applications. Spinel's broad transmission from 160 nm to 5000 nm will also enable multispectral imaging from ultraviolet to midwave infrared.

  5. Fiber Optic Control System Integration program: for optical flight control system development

    NASA Astrophysics Data System (ADS)

    Weaver, Thomas L.; Seal, Daniel W.

    1994-10-01

    Hardware and software were developed for optical feedback links in the flight control system of an F/A-18 aircraft. Developments included passive optical sensors and optoelectronics to operate the sensors. Sensors with different methods of operation were obtained from different manufacturers and integrated with common optoelectronics. The sensors were the following: Air Data Temperature; Air Data Pressure; and Leading Edge Flap, Nose Wheel Steering, Trailing Edge Flap, Pitch Stick, Rudder, Rudder Pedal, Stabilator, and Engine Power Lever Control Position. The sensors were built for a variety of aircraft locations and harsh environments. The sensors and optoelectronics were as similar as practical to a production system. The integrated system was installed by NASA for flight testing. Wavelength Division Multiplexing proved successful as a system design philosophy. Some sensors appeared to be better choices for aircraft applications than others, with digital sensors generally being better than analog sensors, and rotary sensors generally being better than linear sensors. The most successful sensor approaches were selected for use in a follow-on program in which the sensors will not just be flown on the aircraft and their performance recorded; but, the optical sensors will be used in closing flight control loops.

  6. Frequency Independent Design of Quasi-optical Systems

    NASA Astrophysics Data System (ADS)

    Gonzalez, Alvaro

    2016-02-01

    Beam propagation at millimeter and submillimeter wavelengths is well described by Gaussian beams and quasi-optical theory. Due to the general progress in THz technology, receiver and other quasi-optical systems in the THz range demand increasingly larger bandwidths. In this context, this paper presents a general design methodology for frequency independent quasi-optical systems, based on system matrix analysis. After the presentation of the general ideas, useful design equations are derived for the most common quasi-optical systems. Finally, the derived equations are validated by application to already deployed radio astronomy receivers.

  7. Integrated Formation Optical Communication and Estimation System

    NASA Technical Reports Server (NTRS)

    Scharf, Daniel; Kuhnert, Andreas; Kovalik, Joseph; Hadaegh, Fred; Shaddock, Daniel

    2008-01-01

    An architecture has been designed that integrates formation estimation methodologies, precision formation sensing, and high-bandwidth formation communication into a robust, strap-on system that meets knowledge and communication requirements for the majority of planned, precision formation missions. Specifically, the integrated system supports (a) sub-millimeter metrology, (b) multiple greater than 10 Mbps communication channels over a large, 10 deg field-of-view (FOV), and (c) generalized formation estimation methodologies. The sensing sub-system consists of several absolute, metrology gauges with up to 0.1 mm precision that use amplitude-modulated lasers and a LISA-heritage phase meter. Since amplitude modulation is used, inexpensive and robust diode lasers may be used instead of complex, frequency-stabilized lasers such as for nanometer-level metrology. The metrology subsystem laser transceivers consist of a laser diode, collecting optics, and an avalanche photo diode (APD) for detecting incoming laser signals. The APD is necessary since received power is small due to the large (for optical applications) FOV. The phase meter determines the phase of the incoming amplitude modulations as measured by the APD. This phase is equivalent to time-of-flight and, therefore, distance. By placing three laser transceivers on each spacecraft, 18 clock-offset-corrupted distances are calculated. These measurements are communicated and averaged to obtain nine correct distances between the transceivers. From these correct distances, the range and bearing between spacecraft and their relative attitude are determined. Next, communication is integrated on the laser carrier through spectral separation. Metrology amplitude modulations are limited to the 45-50 MHz band, leaving 0-45 MHz for communication. Through careful design of coding scheme, error correction, and filters, six independent 10 Mbps receive channels are possible. Hence, a spacecraft can simultaneously broadcast at 10

  8. Active optics experiments. II - Measurement of mirror deformation by holographic method

    NASA Astrophysics Data System (ADS)

    Itoh, Noboru; Mikami, Izumi; Miyawaki, Keizou; Sasaki, Aki; Tabata, Masao

    An active optics experiment was performed to study the feasibility of using an active correction system for the Japanese National Large Telescope (Wilson, 1986). A thin mirror was deformed with an active support mechanism and the mirror surface was measured by a holographic method. The experiment is performed for several cases of excess force distributions assigned at the supporting points. The results show good agreement with predictions from FEM analysis.

  9. Panoramic alignment system for optical wireless communication systems

    NASA Astrophysics Data System (ADS)

    Shen, Thomas C.; Drost, Robert J.; Rzasa, John; Sadler, Brian M.; Davis, Christopher C.

    2015-03-01

    Free space optical communication may provide a viable adjunct to radio frequency (RF) technology for mobile communications, especially in "RF-denied" settings in which RF-based communication may be prohibited or impractical. These settings may include military tactical environments or settings which suffer from RF jamming or interference. Unlike many RF communication systems, point-to-point optical communications between mobile nodes typically require establishing and maintaining alignment, which requires each node to have awareness of the locations of neighboring nodes. We propose a method to create this situational awareness between nodes using purely optical means. This method uses a camera that is focused on a hyperboloidal mirror, thus providing a 360-degree view of the surrounding environment. The camera and mirror are used to detect light emitted from the beacon transmitters from neighboring nodes, with the location of the beacon image in the sensor plane of the camera yielding elevation and azimuth information of the beacon. The beacon transmitter itself is modulated, allowing it to be distinguished from the environment. In discussing our experimental realization of this system, we assess its performance.

  10. Realistic Instrumentation Platform for Active and Passive Optical Remote Sensing.

    PubMed

    Brydegaard, Mikkel; Merdasa, Aboma; Gebru, Alem; Jayaweera, Hiran; Svanberg, Sune

    2016-02-01

    We describe the development of a novel versatile optical platform for active and passive remote sensing of environmental parameters. Applications include assessment of vegetation status and water quality. The system is also adapted for ecological studies, such as identification of flying insects including agricultural pests. The system is based on two mid-size amateur astronomy telescopes, continuous-wave diode lasers at different wavelengths ranging from violet to the near infrared, and detector facilities including quadrant photodiodes, two-dimensional and line scan charge-coupled device cameras, and a compact digital spectrometer. Application examples include remote Ramanlaser-induced fluorescence monitoring of water quality at 120 m distance, and insect identification at kilometer ranges using the recorded wing beat frequency and its spectrum of overtones. Because of the low cost this developmental platform is very suitable for advanced research projects in developing countries and has, in fact, been multiplied during hands-on workshops and is now being used by a number of groups at African universities. PMID:26772187

  11. Optic neuropathy associated with systemic sarcoidosis

    PubMed Central

    Burton, Ben J.; Graham, Elizabeth M.; Plant, Gordon T.

    2016-01-01

    Objective: To identify and follow a series of 52 patients with optic neuropathy related to sarcoidosis. Methods: Prospective observational cohort study. Results: The disorder was more common in women and affected a wide age range. It was proportionately more common in African and Caribbean ethnic groups. Two clinical subtypes were identified: the more common was a subacute optic neuropathy resembling optic neuritis; a more slowly progressive optic neuropathy arose in the remaining 17%. Sixteen (31%) were bilateral. Concurrent intraocular inflammation was seen in 36%. Pain arose in only 27% of cases. An optic perineuritis was seen in 2 cases, and predominate involvement of the chiasm in one. MRI findings showed optic nerve involvement in 75% of cases, with adjacent and more widespread inflammation in 31%. Treatment with corticosteroids was helpful in those with an inflammatory optic neuropathy, but not those with mass lesions. Relapse of visual signs arose in 25% of cases, necessitating an increase or escalation of treatment, but relapse was not a poor prognostic factor. Conclusions: This is a large prospective study of the clinical characteristics and outcome of treatment in optic neuropathy associated with sarcoidosis. Patients who experience an inflammatory optic neuropathy respond to treatment but may relapse. Those with infiltrative or progressive optic neuropathies improve less well even though the inflammatory disorder responds to therapy. PMID:27536707

  12. Design of an Optically Controlled MR-Compatible Active Needle

    PubMed Central

    Ryu, Seok Chang; Quek, Zhan Fan; Koh, Je-Sung; Renaud, Pierre; Black, Richard J.; Moslehi, Behzad; Daniel, Bruce L.; Cho, Kyu-Jin; Cutkosky, Mark R.

    2015-01-01

    An active needle is proposed for the development of magnetic resonance imaging (MRI)-guided percutaneous procedures. The needle uses a low-transition-temperature shape memory alloy (LT SMA) wire actuator to produce bending in the distal section of the needle. Actuation is achieved with internal optical heating using laser light transported via optical fibers and side coupled to the LT SMA. A prototype, with a size equivalent to a standard 16-gauge biopsy needle, exhibits significant bending, with a tip deflection of more than 14° in air and 5° in hard tissue. A single-ended optical sensor with a gold-coated tip is developed to measure the curvature independently of temperature. The experimental results in tissue phantoms show that human tissue causes fast heat dissipation from the wire actuator; however, the active needle can compensate for typical targeting errors during prostate biopsy. PMID:26512231

  13. Human brain activity with functional NIR optical imager

    NASA Astrophysics Data System (ADS)

    Luo, Qingming

    2001-08-01

    In this paper we reviewed the applications of functional near infrared optical imager in human brain activity. Optical imaging results of brain activity, including memory for new association, emotional thinking, mental arithmetic, pattern recognition ' where's Waldo?, occipital cortex in visual stimulation, and motor cortex in finger tapping, are demonstrated. It is shown that the NIR optical method opens up new fields of study of the human population, in adults under conditions of simulated or real stress that may have important effects upon functional performance. It makes practical and affordable for large populations the complex technology of measuring brain function. It is portable and low cost. In cognitive tasks subjects could report orally. The temporal resolution could be millisecond or less in theory. NIR method will have good prospects in exploring human brain secret.

  14. Advanced optical system simulation in a coupled CAD/optical analysis package

    NASA Astrophysics Data System (ADS)

    Stevenson, Michael A.; Campillo, Chris J.; Jenkins, David G.

    1999-05-01

    Software packages capable of simulating complex optical systems have the power to shorten the design process for non-imaging illumination, projection display, and other imaging illumination systems, Breault Research Organization's Advanced Systems Analysis Program (ASAP) and Robert McNeel and Associates' Rhinoceros computer aided design software, together, allow complicated optical systems to be simulated and analyzed. Through the use of Rhinoceros, an optical system can be accurately modeled in a 3D design environment. ASAP is then used to assign optical properties to the Rhinoceros CAD model. After the optical system has been characterized, it can be analyzed and optimized, by way of features specific to the ASAP optical analysis engine. Using this simulation technique, an HID arc source manufactured by Ushio America, Inc. is accurately represented. 2D CCD images are gathered for the source's emitting-volume across its spectral bandwidth. The images are processed within ASAP, via the inverse Abel command, to produce a 3D emitting-volume. This emitting-volume is combined with an accurate model of the source geometry and its optical properties, to finalize a functioning virtual source model. The characterized source is then joined with a simulated optical system for detailed performance analysis: namely, a projection display system.

  15. Advanced Fiber Optic-Based Sensing Technology for Unmanned Aircraft Systems

    NASA Technical Reports Server (NTRS)

    Richards, Lance; Parker, Allen R.; Piazza, Anthony; Ko, William L.; Chan, Patrick; Bakalyar, John

    2011-01-01

    This presentation provides an overview of fiber optic sensing technology development activities performed at NASA Dryden in support of Unmanned Aircraft Systems. Examples of current and previous work are presented in the following categories: algorithm development, system development, instrumentation installation, ground R&D, and flight testing. Examples of current research and development activities are provided.

  16. Cost-effective and monitoring-active technique for TDM-passive optical networks

    NASA Astrophysics Data System (ADS)

    Chi, Chang-Chia; Lin, Hong-Mao; Tarn, Chen-Wen; Lin, Huang-Liang

    2014-08-01

    A reliable, detection-active and cost-effective method which employs the hello and heartbeat signals for branched node distinguishing to monitor fiber fault in any branch of distribution fibers of a time division multiplexing passive optical network (TDM-PON) is proposed. With this method, the material cost of building an optical network monitor system for a TDM-PON with 168 ONUs and the time of identifying a multiple branch faults is significantly reduced in a TDM-PON system of any scale. A fault location in a 1 × 32 TDM-PON system using this method to identify the fault branch is demonstrated.

  17. The Multi Optical Transition Radiation System

    SciTech Connect

    Faus-Golfe, A.; Alabau-Gonzalvo, J.; Blanch Gutierrez, C.; McCormick, D.; Cruz, J.; Woodley, M.; White, G.; /SLAC

    2012-04-19

    The determination and monitoring of the transverse phase space in ATF2 is crucial in order to meet their performances specifications. Since the beam sizes at the Interaction Point (IP) depend strongly on the aberrations in the Final Focus System (FFS), accurate measurement upstream of the FFS is required to tune the beam sizes at the IP. The beam sizes as well as the emittance are measured in several locations in the beam diagnostic section of the Extraction Line (EXT line) of ATF2. The vertical beam sizes in the diagnostic section are of the order of 10 {mu}m this means that the devices have to image spot sizes as small as 5 {mu}m, with 10% accuracy a 2 {mu}m resolution device is necessary. The ATF2 EXT line is a beam line with low power and low repetition rate that make usable devices using solid targets. In contrast to a ring machine, where an individual bunch can be measured many times as it passes around the ring, the beam size and the emittance measurement in the LC or in the beam lines have to be performed in a single pass. This requires that the wire scan device types (laser or solid) sample across successive bunches within a train, often with an over-estimation of the beam size due to beam position and intensity jitter, and can take up to half a minute to complete the measurement. Although some of these effects could be corrected, as the jitter effect could be subtracted by using the nearby BPMs signals, this can be avoided by using Optical Transition Radiation (OTR) Monitors. These monitors are based on the transition radiation effect, a light cone emitted when the charged particle crosses a metallic interface. This light is emitted in a specular fashion so it can be focused on to a CCD and produces an image of the beam. OTRs are able to take many fast measurements and therefore to measure the emittance with high statistics, giving a low error and a good understanding of the emittance jitter. In this article, simulations of the expected beam sizes and

  18. Tunable diffractive optical elements on various electro active polymers

    NASA Astrophysics Data System (ADS)

    Döring, Sebastian; Kollosche, Matthias; Hildebrandt, Niko; Stumpe, Joachim; Kofod, Guggi

    2010-05-01

    An innovative approach for voltage-tunable optical gratings based on dielectric elastomer actuators (DEAs) using electro active polymers is presented. Sinusoidal surface gratings, holographically written into azobenzene containing films, are transferred via nanoimprinting to DEAs of different carrier materials. We demonstrate that the surface relief deformation depends on the mechanical and geometrical properties of the actuators. The tested DEAs were made using commercially available elastomers, including a tri-block copolymer poly-styrene-ethylene-butadiene-styrene (SEBS), a silicone polydimethylsiloxane rubber (PDMS) and commonly used polyacrylic glue. The polyacrylic glue is ready to use, whereas the SEBS and the PDMS precursors have to be processed into thin films via different casting methods. The DEA material was pre-stretched, fixed to a stiff frame and coated with stretchable electrodes in appropriate designs. Since the actuation strain of the DEA depends strongly upon the conditions such as material properties, pre-stretch and geometry, the desired voltage-controllable deformations can be optimized during manufacturing of the DEA and also in the choice of materials in the grating transfer process. A full characterization of the grating deformation includes measurements of the grating pitch and depth modulation, plus the change of the diffraction angle and efficiency. The structural surface distortion was characterized by measuring the shape of the transmitted and diffracted laser beam with a beam profiling system while applying an electro-mechanical stress to the grating. Such surface distortions may lead to decreasing diffraction efficiency and lower beam quality. With properly chosen manufacturing parameters, we found a period shift of up to 9 % in a grating with 1 μm pitch. To describe the optical behavior, a model based on independently measured material parameters is presented.

  19. Extremely aspheric mirrors: prototype development of an innovative manufacturing process based on active optics

    NASA Astrophysics Data System (ADS)

    Challita, Zalpha; Hugot, Emmanuel; Ferrari, Marc; Le Merrer, Joël.; Le Mignant, David; Cuby, Jean-Gabriel

    2012-09-01

    The next generation of focal-plane astronomical instruments requires technological breakthroughs to reduce their system complexity while increasing their scientific performances. Applied to the optical systems, recent studies show that the use of freeform reflective optics allows competitive compact systems with less optical components. In this context, our challenge is to supply an active freeform mirror system, using a combination of different active optics techniques. The optical shape will be provided during the fabrication using the mechanical property of metals to plasticize and will be coupled with a specific actuator system to compensate for the residual form errors, during the instrument operation phase. We present in this article the development of an innovative manufacturing process based on cold hydro-forming method, with the aim to adapt it for VIS/NIR requirements in terms of optical surface quality. It can operate on thin and flat polished initial substrates. The realization of a first prototype for a 100 mm optical diameter mirror is in progress, to compare the mechanical behaviours obtained by tests and by Finite Element Analysis (FEA), for different materials. Then, the formed samples will be characterized optically. The opto-mechanical results will allow a fine tuning of FEA parameters to optimize the residual form errors obtained through this process. It concerns the microstructure considerations, the springback effects and the work hardening evolutions of the samples, depending on the initial substrate properties and the boundary conditions applied. Modeling and tests have started with axi-symmetric spherical and aspherical shapes and will continue with highly aspherics and freeforms.

  20. Absolute enantioselective separation: optical activity ex machina.

    PubMed

    Bielski, Roman; Tencer, Michal

    2005-11-01

    The paper describes methodology of using three independent macroscopic factors affecting molecular orientation to accomplish separation of a racemic mixture without the presence of any other chiral compounds, i. e., absolute enantioselective separation (AES) which is an extension of a concept of applying these factors to absolute asymmetric synthesis. The three factors may be applied simultaneously or, if their effects can be retained, consecutively. The resulting three mutually orthogonal or near orthogonal directors constitute a true chiral influence and their scalar triple product is the measure of the chirality of the system. AES can be executed in a chromatography-like microfluidic process in the presence of an electric field. It may be carried out on a chemically modified flat surface, a monolithic polymer column made of a mesoporous material, each having imparted directional properties. Separation parameters were estimated for these media and possible implications for the natural homochirality are discussed. PMID:16342798

  1. High speed hybrid active system

    NASA Astrophysics Data System (ADS)

    Gonzalez, Ignacio F.; Chang, Fu-Kuo; Qing, Peter X.; Kumar, Amrita; Zhang, David

    2005-05-01

    A novel piezoelectric/fiber-optic system is developed for long-term health monitoring of aerospace vehicles and structures. The hybrid diagnostic system uses the piezoelectric actuators to input a controlled excitation to the structure and the fiber optic sensors to capture the corresponding structural response. The aim of the system is to detect changes in structures such as those found in aerospace applications (damage, cracks, aging, etc.). This system involves the use of fiber Bragg gratings, which may be either bonded to the surface of the material or embedded within it in order to detect the linear strain component produced by the excitation waves generate by an arbitrary waveform generator. Interrogation of the Bragg gratings is carried out using a high speed fiber grating demodulation unit and a high speed data acquisition card to provide actuation input. With data collection and information processing; is able to determine the condition of the structure. The demands on a system suitable for detecting ultrasonic acoustic waves are different than for the more common strain and temperature systems. On the one hand, the frequency is much higher, with typical values for ultrasonic frequencies used in non-destructive testing ranging from 100 kHz up to several MHz. On the other hand, the related strain levels are much lower, normally in the μstrain range. Fiber-optic solutions for this problem do exist and are particularly attractive for ultrasonic sensing as the sensors offer broadband detection capability.

  2. Optimization of a heterogeneous reaction system for the production of optically active D-amino acids using thermostable D-hydantoinase.

    PubMed

    Lee, D C; Kim, H S

    1998-12-20

    A thermostable D-hydantoinase from Bacillus stearothermophilus SD-1 was previously mass-produced by batch cultivation of the recombinant E. coli harboring the gene encoding the enzyme (Lee et al., 1997). In this work, we attempted to optimize the process for the production of N-carbamoyl-D-p-hydroxyphenylglycine, which is readily hydrolyzed to D-p-hydroxyphenylglycine under acidic conditions, from 5-(4-hydroxyphenyl)hydantoin using the mass-produced D-hydantoinase. In an effort to overcome the low solubility of the substrate, enzyme reaction was carried out in a heterogeneous system consisting of a high substrate concentration up to 300 g/L. In this reaction system, most of substrate is present in suspended particles. Optimal temperature and pH were determined to be 45 degrees C and 8.5, respectively, by taking into account the reaction rate and conversion yield. When the free enzyme was employed as a biocatalyst, enzyme loading higher than 300 unit/g-substrate was required to achieve maximum conversion. Use of whole cell enzyme resulted in maximum conversion even at lower enzyme loadings than the free enzyme, showing 96% conversion yield at 300 g/L substrate. The heterogeneous reaction system used in this work might be applied to the enzymatic production of other valuable compounds from a rarely water-soluble substrate. PMID:10099482

  3. Genetically encoded optical activation of DNA recombination in human cells.

    PubMed

    Luo, J; Arbely, E; Zhang, J; Chou, C; Uprety, R; Chin, J W; Deiters, A

    2016-06-30

    We developed two tightly regulated, light-activated Cre recombinase enzymes through site-specific incorporation of two genetically-encoded photocaged amino acids in human cells. Excellent optical off to on switching of DNA recombination was achieved. Furthermore, we demonstrated precise spatial control of Cre recombinase through patterned illumination. PMID:27277957

  4. Characterization of low cost optical imaging system based on optical holography

    NASA Astrophysics Data System (ADS)

    Darwiesh, M.; El Sherif, Ashraf F.

    2013-03-01

    Optical imaging systems are widely used in different applications including tracking for portable scanners; input pointing devices for laptop computers, cell phones, and cameras; and fingerprint-identification scanners. Also in optical navigation (military target tracking where tracking sensors follow airplanes, missiles, and other targets [1-4]. Since the two main parameters affecting the performance of the optical imaging systems are the optical source and the surface nature. So; The aim of the paper is to study how the optical source affects the performance of the optical imaging systems by exchange the operating surface of the optical imaging system with a standard diffuse object (Gabbor holograms) to study and analyze laser speckle pattern and Circular interference fringes produced by illuminating these standard diffusers using different optical sources [coherent (3mW diode laser, and 10mW He-Ne laser) or partially coherent light (LEDs)]. The Circular interference fringes were used to display the relations between the fringes order and its radii. From these relations we found that the electronic sensor can deliver the same accuracy of laser diodes when replacing it by commercial LEDs. So, we can design a new cheaper, high performance optical imaging system using commercial LED sources.

  5. Multicolour Optical Photometry of Active Geostationary Satellites

    NASA Astrophysics Data System (ADS)

    Jolley, A.; Wade, G.; Bedard, D.

    Although broadband photometry has been used to infer information about artificial satellites since soon after the launch of Sputnik 1, the development of photometric techniques for non-resolved space object identification or characterisation has been hampered by the large number of variables involved. Many individual studies, and some long ongoing experiments, have used costly metre-class telescopes to obtain data despite other experiments demonstrating that much more flexible and affordable small aperture telescopes may be suitable for the task. In addition, due to the highly time consuming and weather dependent nature of obtaining photometric observations, many studies have suffered from data sets of limited size, or relied upon simulations to support their claims. With this in mind, an experiment was conducted with the aim of determining the utility of small aperture telescopes for conducting broadband photometry of satellites for the purpose of non-resolved space object identification and characterisation. A 14 inch Celestron CG-14 telescope was used to gain multiple night-long, high temporal resolution data sets of six active geostationary satellites. The results of the experiment cast doubt on the efficacy of some of the previous approaches to obtaining and analysing photometric data. It was discovered that geostationary satellite lightcurves can vary to a greater degree than has generally been recognised, and colour ratios vary considerably with changes in the illumination/observation geometry, making it difficult to use colour for satellite discrimination. Evidence was also detected of variations in the spectral energy distribution of sunlight reflected off satellite surface materials, which could have implications for surface material characterisation and techniques that aim to separate satellite body and solar panel contributions to the total observed spectra.

  6. Session: CSP Advanced Systems: Optical Materials (Presentation)

    SciTech Connect

    Kennedy, C.

    2008-04-01

    The Optical Materials project description is to characterize advanced reflector, perform accelerated and outdoor testing of commercial and experimental reflector materials, and provide industry support.

  7. Optical module to extend any Fourier-domain optical coherence tomography system into a polarisation-sensitive system

    NASA Astrophysics Data System (ADS)

    Rivet, Sylvain; Marques, Manuel J.; Bradu, Adrian; Podoleanu, Adrian

    2016-06-01

    This article presents a theoretical study on an optical module (OM) that can be inserted between an object under investigation and a Fourier-domain optical coherence tomography system, transforming the latter into a polarisation-sensitive optical coherence tomography optical coherence tomography (OCT) system. The module consists of two electro-optic modulators, a Faraday rotator, a linear polariser and a quarter-wave plate. A detailed description on how the module can be used to extract both the net retardance and the fast axis orientation of a linear birefringent sample is presented. This is achieved by taking two sequential measurements for different values of retardance produced by the electro-optic modulator. The module keeps measurements free from undesired polarimetric effects due to birefringence in the single-mode optical fibre and diattenuation in fibre-based couplers within OCT systems. Simulations have been carried out in order to evaluate the effects of chromatic behaviour of the components within the OM.

  8. Power selective optical filter devices and optical systems using same

    DOEpatents

    Koplow, Jeffrey P

    2014-10-07

    In an embodiment, a power selective optical filter device includes an input polarizer for selectively transmitting an input signal. The device includes a wave-plate structure positioned to receive the input signal, which includes at least one substantially zero-order, zero-wave plate. The zero-order, zero-wave plate is configured to alter a polarization state of the input signal passing in a manner that depends on the power of the input signal. The zero-order, zero-wave plate includes an entry and exit wave plate each having a fast axis, with the fast axes oriented substantially perpendicular to each other. Each entry wave plate is oriented relative to a transmission axis of the input polarizer at a respective angle. An output polarizer is positioned to receive a signal output from the wave-plate structure and selectively transmits the signal based on the polarization state.

  9. Optical two-beam traps in microfluidic systems

    NASA Astrophysics Data System (ADS)

    Berg-Sørensen, Kirstine

    2016-08-01

    An attractive solution for optical trapping and stretching by means of two counterpropagating laser beams is to embed waveguides or optical fibers in a microfluidic system. The microfluidic system can be constructed in different materials, ranging from soft polymers that may easily be cast in a rapid prototyping manner, to hard polymers that could even be produced by injection moulding, or to silica in which waveguides may either be written directly, or with grooves for optical fibers. Here, we review different solutions to the system and also show results obtained in a polymer chip with DUV written waveguides and in an injection molded polymer chip with grooves for optical fibers.

  10. Fiber optics based jet engine augmenter viewing system

    NASA Astrophysics Data System (ADS)

    Murphy, P. J.; Jones, D. W.; Jones, R. R., III; Lennert, A. E.

    1988-06-01

    An augmenter viewing system employing a coherent fiber-optic array was developed for use in jet engine testing applications at AEDC. Real-time viewing of the test article afterburner was obtained in a severe environment under high temperature and vibration levels. The optical system consisted of a conventional front-end lens assembly coupled with the fiber-optic array, and a solid-state color video camera mounted inside the test cell. The advantages and problems associated with a fiber-optics-based viewing system will be discussed in comparison with more conventional viewing techniques for this application.

  11. Optical-disk-based imaging system to be used as an optical microscope

    NASA Astrophysics Data System (ADS)

    Shima, Takayuki; Fujimaki, Makoto; Awazu, Koichi

    2016-07-01

    An optical disk surface is scanned spirally by laser light, as in the case of digital versatile discs, and a reflectance image is formed by rearranging the scanned intensity results. A prototype system is developed for imaging with a rotary encoder equipped to precisely control the disk rotation angle. We measured Escherichia coli dispersed on an optical disk sample surface and successfully obtained an image that is identical to that obtained using an optical microscope. The system is advantageous as an optical sensor for detecting sub-micrometer- to micrometer-order substances on a large-area surface.

  12. Passive thermo-optic feedback for robust athermal photonic systems

    SciTech Connect

    Rakich, Peter T.; Watts, Michael R.; Nielson, Gregory N.

    2015-06-23

    Thermal control devices, photonic systems and methods of stabilizing a temperature of a photonic system are provided. A thermal control device thermally coupled to a substrate includes a waveguide for receiving light, an absorption element optically coupled to the waveguide for converting the received light to heat and an optical filter. The optical filter is optically coupled to the waveguide and thermally coupled to the absorption element. An operating point of the optical filter is tuned responsive to the heat from the absorption element. When the operating point is less than a predetermined temperature, the received light is passed to the absorption element via the optical filter. When the operating point is greater than or equal to the predetermined temperature, the received light is transmitted out of the thermal control device via the optical filter, without being passed to the absorption element.

  13. Optical Correlator for Face Recognition Using Collinear Holographic System

    NASA Astrophysics Data System (ADS)

    Watanabe, Eriko; Kodate, Kashiko

    2006-08-01

    We have constructed an optical correlator for fast face recognition. Recognition rate can be markedly improved, if reference images are optically recorded and can be accessed directly without converting them to digital signals. In addition, a large capacity of optical storage allows us to increase the size of the reference database. We propose a new optical correlator that integrates the optical correlation technology used in our face recognition system and collinear holography. From preliminary correlation experiments using the collinear optical set-up, we achieved excellent performance of high correlation peaks and low error rates. We expect an optical correlation of 10 μs/frame, i.e., 100,000 face/s when applied to face recognition. This system can also be applied to various image searches.

  14. Multiplexing and networking through fiber optic links for SCADA systems

    SciTech Connect

    Damsker, D.

    1982-07-01

    The Supervisory Control and Data Acquisition (SCADA) systems of the future might consist of local computer networks tied together through long haul links, using a packet-switching technique. This paper assesses fiber optic link characteristics as potential components of SCADA systems. Essentially, a fiber optic link is constrained to a simplex communication from transmitter to receiver. Such a simplex link is analyzed for its capability to convey baseband signaling and time-, frequency-, and spectral-division multiplexing. The combination of a microcomputer and a simplex fiber optic link is a building block for several configurations of local computer networks. Such a building block is called the Universal Intelligent Optical Communication Link (UIOCL). The paper examines prospective optical networking techniques and evaluates several optical couplers for various network configurations as well as for full- and halfduplex communications. The feasibility of long haul fiber optic links and networks is considered further in the paper.

  15. Optical imaging of neural and hemodynamic brain activity

    NASA Astrophysics Data System (ADS)

    Schei, Jennifer Lynn

    Optical imaging technologies can be used to record neural and hemodynamic activity. Neural activity elicits physiological changes that alter the optical tissue properties. Specifically, changes in polarized light are concomitant with neural depolarization. We measured polarization changes from an isolated lobster nerve during action potential propagation using both reflected and transmitted light. In transmission mode, polarization changes were largest throughout the center of the nerve, suggesting that most of the optical signal arose from the inner nerve bundle. In reflection mode, polarization changes were largest near the edges, suggesting that most of the optical signal arose from the outer sheath. To overcome irregular cell orientation found in the brain, we measured polarization changes from a nerve tied in a knot. Our results show that neural activation produces polarization changes that can be imaged even without regular cell orientations. Neural activation expends energy resources and elicits metabolic delivery through blood vessel dilation, increasing blood flow and volume. We used spectroscopic imaging techniques combined with electrophysiological measurements to record evoked neural and hemodynamic responses from the auditory cortex of the rat. By using implantable optics, we measured responses across natural wake and sleep states, as well as responses following different amounts of sleep deprivation. During quiet sleep, evoked metabolic responses were larger compared to wake, perhaps because blood vessels were more compliant. When animals were sleep deprived, evoked hemodynamic responses were smaller following longer periods of deprivation. These results suggest that prolonged neural activity through sleep deprivation may diminish vascular compliance as indicated by the blunted vascular response. Subsequent sleep may allow vessels to relax, restoring their ability to deliver blood. These results also suggest that severe sleep deprivation or chronic

  16. Origin of optical activity in the purple bacterial photoreaction center

    SciTech Connect

    Mar, T.; Gingras, G.

    1995-07-18

    The photoreaction center (RC) of purple bacteria contains four bacteriochlorophyll (Bph) and two bacteriopheophytin (Bph) molecules as prosthetic groups. Their optical activity, as measured by circular dichroism (CD) spectroscopy, is largely increased in situ as compared to organic solutions. The all-exciton hypothesis posits that this enhanced optical activity is entirely due to excitonic interactions between the electronic transitions of all six bacteriochlorin molecules. Using the simple exciton theory, this model predicts that the near-infrared CD spectra should be conservative. The fact that they are not, whether the special pair of Bch (SP) that constitutes the primary electron donor is reduced or oxidized, has been explained by hyperchromic effects. The present work tests this hypothesis by successively eliminating the absorption and, therefore, the optical activity of the Bphs and of the non-special-pair (non-SP) Bchs. This was accomplished by trapping these pigments in their reduced state. RC preparations with the four non-SP bacteriochlorins trapped in their reduced state and, therefore, with an intact SP displayed conservative CD spectra. RC preparations with only the electronic transitions of SP and of one non-SP Bch also showed conservative CD spectra. These conservative CD spectra and their corresponding absorption spectra were simulated using simple exciton theory without assuming hyperchromic effects. Bleaching half of the 755-nm absorption band by phototrapping one of the two Bph molecules led to the complete disappearance of the corresponding CD band. This cannot be explained by the all-exciton hypothesis. These results suggest that the optical activity of the SP alone, or with one non-SP Bch, is due to excitonic interactions. They also suggest that the optical activity of the other three bacteriochlorins is due to other factors, such as pigment-protein interaction. 32 refs., 9 figs., 2 tabs.

  17. Isoplanatism in a multiconjugate adaptive optics system.

    PubMed

    Tokovinin, A; Le Louarn, M; Sarazin, M

    2000-10-01

    Turbulence correction in a large field of view by use of an adaptive optics imaging system with several deformable mirrors (DM's) conjugated to various heights is considered. The residual phase variance is computed for an optimized linear algorithm in which a correction of each turbulent layer is achieved by applying a combination of suitably smoothed and scaled input phase screens to all DM's. Finite turbulence outer scale and finite spatial resolution of the DM's are taken into account. A general expression for the isoplanatic angle thetaM of a system with M mirrors is derived in the limiting case of infinitely large apertures and Kolmogorov turbulence. Like Fried's isoplanatic angle theta0,thetaM is a function only of the turbulence vertical profile, is scalable with wavelength, and is independent of the telescope diameter. Use of angle thetaM permits the gain in the field of view due to the increased number of DM's to be quantified and their optimal conjugate heights to be found. Calculations with real turbulence profiles show that with three DM's a gain of 7-10x is possible, giving the typical and best isoplanatic field-of-view radii of 16 and 30 arcseconds, respectively, at lambda = 0.5 microm. It is shown that in the actual systems the isoplanatic field will be somewhat larger than thetaM owing to the combined effects of finite aperture diameter, finite outer scale, and optimized wave-front spatial filtering. However, this additional gain is not dramatic; it is less than 1.5x for large-aperture telescopes. PMID:11028530

  18. First-order optical systems with unimodular eigenvalues.

    PubMed

    Bastiaans, Martin J; Alieva, Tatiana

    2006-08-01

    It is shown that a lossless first-order optical system whose real symplectic ray transformation matrix can be diagonalized and has only unimodular eigenvalues is similar to a separable fractional Fourier transformer in the sense that the ray transformation matrices of the unimodular system and the separable fractional Fourier transformer are related by means of a similarity transformation. Moreover, it is shown that the system that performs this similarity transformation is itself a lossless first-order optical system. Based on the fact that Hermite-Gauss functions are the eigenfunctions of a fractional Fourier transformer, the eigenfunctions of a unimodular first-order optical system can be formulated and belong to the recently introduced class of orthonormal Hermite-Gaussian-type modes. Two decompositions of a unimodular first-order optical system are considered, and one of them is used to derive an easy optical realization in more detail. PMID:16835644

  19. Entanglement of Coupled Optomechanical Systems Improved by Optical Parametric Amplifiers

    NASA Astrophysics Data System (ADS)

    Pan, Guixia; Xiao, Ruijie; Zhou, Ling

    2016-04-01

    A scheme to generate the stationary entanglement of two distant coupled optical cavities placed optical parametric amplifiers is proposed. We study how the optical parametric amplifiers can affect the entanglement behaviors of the movable mirrors and the cavity fields. With the existence of optical parametric amplifiers, we show that larger stationary entanglement of optical and mechanical modes can be obtained and the entanglement increases with the increasing parametric gain. Especially, the degree of entanglement between the two cavity fields is more pronouncedly enhanced. Moreover, for a fixed parametric gain, the entanglement of distant cavity optomechanical systems increases as the input laser power is increased.

  20. Entanglement of Coupled Optomechanical Systems Improved by Optical Parametric Amplifiers

    NASA Astrophysics Data System (ADS)

    Pan, Guixia; Xiao, Ruijie; Zhou, Ling

    2016-08-01

    A scheme to generate the stationary entanglement of two distant coupled optical cavities placed optical parametric amplifiers is proposed. We study how the optical parametric amplifiers can affect the entanglement behaviors of the movable mirrors and the cavity fields. With the existence of optical parametric amplifiers, we show that larger stationary entanglement of optical and mechanical modes can be obtained and the entanglement increases with the increasing parametric gain. Especially, the degree of entanglement between the two cavity fields is more pronouncedly enhanced. Moreover, for a fixed parametric gain, the entanglement of distant cavity optomechanical systems increases as the input laser power is increased.

  1. Integrated Atom Chip System for Optical Lattice Experiments

    NASA Astrophysics Data System (ADS)

    Salim, Evan A.; Ivory, Megan K.; Straatsma, Cameron J. E.; Anderson, Dana Z.

    2015-05-01

    We present an ultracold atom system incorporating a hybrid magnetic/optical atom chip for optical lattice experiments. The atom chip uses integrated, millimeter-scale optical elements to enable the production of optical lattice potentials near the atom chip traces and within a few hundred microns of a high-quality vacuum window. Due to their proximity to a window, the atoms are addressable by optics outside of vacuum operating at numerical apertures as high as 0.8. Demonstration of Bose-Einstein condensation in the chip trap and Landau-Zener tunneling in a 1D lattice are presented.

  2. Optical observations of X-ray systems

    NASA Astrophysics Data System (ADS)

    Gudets, R.

    The significance of optical observations of X-ray sources is discussed. A short review of X-ray and optical observations of X-ray stars in socialist countries, carried out by the Intercosmos program and by multilateral cooperation of the Academies of Sciences of Socialist Countries is given. Some examples and results of observations are presented.

  3. Systemic corticosteroids in nonarteritic ischemic optic neuropathy

    PubMed Central

    Al-Zubidi, Nagham; Zhang, Jason; Spitze, Arielle; Lee, Andrew G

    2014-01-01

    Nonarteritic ischemic optic neuropathy (NAION) is one of the most prevalent optic nerve disorders seen in ophthalmic practice. The role of corticosteroid therapy in NAION remains a highly controversial area of debate in ophthalmology. This brief review will provide an overview of the current clinical evidence on this topic as well as some comment on the medical debate. PMID:25449939

  4. Kepler Observations of Rapid Optical Variability in Active Galactic Nuclei

    NASA Technical Reports Server (NTRS)

    Mushotzky, R. F.; Edelson, R.; Baumgartner, W. H.; Gandhi, P.

    2012-01-01

    Over three quarters in 2010 - 2011, Kepler monitored optical emission from four active galactic nuclei (AGN) with approx 30 min sampling, > 90% duty cycle and approx < 0.1% repeatability. These data determined the AGN optical fluctuation power spectral density functions (PSDs) over a wide range in temporal frequency. Fits to these PSDs yielded power law slopes of -2.6 to -3.3, much steeper than typically seen in the X-rays. We find evidence that individual AGN exhibit intrinsically different PSD slopes. The steep PSD fits are a challenge to recent AGN variability models but seem consistent with first order MRI theoretical calculations of accretion disk fluctuations.

  5. Active radiation hardening technology for fiber-optic source

    NASA Astrophysics Data System (ADS)

    Yang, Yuanhong; Suo, Xinxin; Yang, Mingwei

    2013-09-01

    We demonstrated an active radiation hardening technology for fiber optic source developed for high performance fiber optic gyroscope. The radiation characteristic of erbium-doped fiber was studied experimentally. The radiation induced attenuation (RIA) at 980nm pump light was identified to be the main reason for the degradation and there was photo-bleaching effect in EDF too. A variable parameters control technology was proposed and taken to keep the 980nm and 1550nm light energy stable and high stability and radiation-resistance fiber source with gauss profile spectrum was realized .The source can stand against more than 50 krad (Si) total radiation dose.

  6. N-methyl-D-aspartate receptors strongly regulate postsynaptic activity levels during optic nerve regeneration.

    PubMed

    Kolls, Brad J; Meyer, Ronald L

    2013-10-01

    During development, neuronal activity is used as a cue to guide synaptic rearrangements to refine connections. Many studies, especially in the visual system, have shown that the N-methyl-D-aspartate receptor (NMDAr) plays a key role in mediating activity-dependent refinement through long-term potentiation (LTP)-like processes. Adult goldfish can regenerate their optic nerve and utilize neuronal activity to generate precise topography in their projection onto tectum. Although the NMDAr has been implicated in this process, its precise role in regeneration has not been extensively studied. In examining NMDAr function during regeneration, we found salient differences compared with development. By using field excitatory postsynaptic potential (fEPSP) recordings, the contribution of the NMDAr at the primary optic synapse was measured. In contrast to development, no increase in NMDAr function was detectable during synaptic refinement. Unlike development, LTP could not be reliably elicited during regeneration. Unexpectedly, we found that NMDAr exerted a major effect on regulating ongoing tectal (postsynaptic) activity levels during regeneration. Blocking NMDAr strongly suppressed spontaneous activity during regeneration but had no significant effect in the normal projection. This difference could be attributed to an occlusion effect of strong optic drive in the normal projection, which dominated ongoing tectal activity. During regeneration, this optic drive is largely absent. Optic nerve stimulation further indicated that the NMDAr had little effect on the ability of optic fibers to evoke early postsynaptic impulse activity but was important for late network activity. These results indicate that, during regeneration, the NMDAr may play a critical role in the homeostatic regulation of ongoing activity and network excitability. PMID:23873725

  7. Nonlinear optical signal processing for high-speed, spectrally efficient fiber optic systems and networks

    NASA Astrophysics Data System (ADS)

    Zhang, Bo

    The past decade has witnessed astounding boom in telecommunication network traffic. With the emergence of multimedia over Internet, the high-capacity optical transport systems have started to shift focus from the core network towards the end users. This trend leads to diverse optical networks with transparency and reconfigurability requirement. As single channel data rate continues to increase and channel spacing continues to shrink for high capacity, high spectral efficiency, the workload on conventional electronic signal processing elements in the router nodes continues to build up. Performing signal processing functions in the optical domain can potentially alleviate the speed bottleneck if the unique optical properties are efficiently leveraged to assist electronic processing methodologies. Ultra-high bandwidth capability along with the promise for multi-channel and format-transparent operation make optical signal processing an attractive technology which is expected to have great impact on future optical networks. For optical signal processing applications in fiber-optic network and systems, a laudable goal would be to explore the unique nonlinear optical processes in novel photonic devices. This dissertation investigates novel optical signal processing techniques through simulations and experimental demonstrations, analyzes limitations of these nonlinear processing elements and proposes techniques to enhance the system performance or designs for functional photonic modules. Two key signal-processing building blocks for future optical networks, namely slow-light-based tunable optical delay lines and SOA-based high-speed wavelength converters, are presented in the first part of the dissertation. Phase preserving and spectrally efficient slow light are experimentally demonstrated using advanced modulation formats. Functional and novel photonic modules, such as multi-channel synchronizer and variable-bit-rate optical time division multiplexer are designed and

  8. Optical encoder feedback system for levitating rotor system

    NASA Astrophysics Data System (ADS)

    Khanna, Shrey; Ho, Joe N.; Irwen, Jonathan; Rakka, Gurjinder; Wang, Weichih

    2010-03-01

    This paper describes the design and fabrication of feedback control system for a three phase motor with a diamagnetically levitating rotor. The planar rotor described in this paper uses a triangular configuration of magnets that rotates due to nine electric coils evenly spaced around the rotor. An optical mechanical feedback system controls the frequency at which the rotor spins. The current input to the coil is controlled by a mechanical relay circuit which latches based on a DC pulse signal generated by a PID control algorithm. The mechanical relay circuit allows current to flow to each coils (the actuators of this system), which then produces a magnetic field strong enough to spin the rotor.

  9. Zero-distance phase front of an isoplanar optical system

    NASA Astrophysics Data System (ADS)

    Gitin, Andrey

    2016-05-01

    The concept of "the zero-distance phase front" of an isoplanar optical system is used to describe its aberration. It is shown that Walther's wave interpretation of eikonals allows treating "the zero-distance phase front" as the wave aberration function of the optical system and calculating its transverse aberrations.

  10. An electrically tunable optical zoom system with separated focusing and zooming functions

    NASA Astrophysics Data System (ADS)

    Chen, Ming-Syuan; Chen, Po-Ju; Lin, Yi-Hsin

    2013-09-01

    In this paper, we demonstrated an electrically tunable optical zoom system with separated focusing and zooming functions. The optical mechanism is discussed. The focusing distance and magnification of the image can be controlled separately by focusing lenses and zooming lenses. As a result, the zoom ratio is independent of objective distance and only depends on the tunable range of the lens power of the active-optical elements. This study helps designing many applications with an optical zoom function, such as cell phones, holographic projectors, pico projectors and endoscopes.

  11. Electron-optical systems for planar gyrotrons

    NASA Astrophysics Data System (ADS)

    Manuilov, V. N.; Zaslavsky, V. Yu.; Ginzburg, N. S.; Glyavin, M. Yu.; Kuftin, A. N.; Zotova, I. V.

    2014-02-01

    The methodology of designing an electron-optical system (EOS) that forms sheet helical electron beams (HEBs) for high-power gyrotrons is developed. As an example, we consider the EOS for a 140-GHz gyrotron operated at the first harmonic of the cyclotron frequency with an accelerating voltage of 50 kV, a beam current of 30 A, and a magnetic field compression of 36. A planar geometry of the magnetron-injection gun (MIG) is suggested. The adiabatic theory of MIGs modified for the planar geometry of EOS is used for preliminary estimations of MIG parameters. Numerical simulation of the HEB properties based on the CST STUDIO SUITE 3D code is performed to find the optimal configuration of a planar MIG. The accuracy of the calculated data is discussed. The main factors that affect the HEB quality are considered. It is shown that a sheet HEB with a pitch-factor of 1.3 and velocity spread not exceeding 25%-30% can be formed; this is quite acceptable for high-efficiency operation of modern gyrotrons. Calculation of the beam-wave interaction with the obtained HEB parameters proved that a high output power with a sufficiently good efficiency of about 20% can be reached. Simulations show the feasibility of the experimental implementation of a novel planar EOS and its use in short-wave planar gyrotrons. The developed technique can be used for the study and optimization of planar gyrotrons of different frequency bands and power levels.

  12. Optical behavior of current ceramic systems.

    PubMed

    Raptis, Nicolas V; Michalakis, Konstantinos X; Hirayama, Hiroshi

    2006-02-01

    The restoration of anterior teeth is a difficult task, even for an experienced operator. Currently there are many different ceramic systems that can be used to achieve highly esthetic results. These include metal-ceramics with porcelain margins, Dicor, In-Ceram, Cerestore, Hi-Ceram, IPS-Empress, Cerapearl, Optec, and CAD/CAM ceramics. While metal-ceramics have been used for more than four decades, the quest for a material that transmits and refracts light like a natural tooth has inspired research into all-ceramic restorations. The purpose of this paper is to briefly discuss the properties of each of the above-mentioned materials and clinically evaluate the optical behavior of: (1) metal-ceramic crowns with castings 2 mm short of the shoulder preparation and 360-degree porcelain margins; (2) In-Ceram Spinell restorations; and (3) IPS Empress restorations, and to compare these with metal-ceramic crowns with copings to the shoulder preparation and 180-degree porcelain margins. Light transmission characteristics and color matching were subjectively evaluated by five experienced prosthodontists who did not participate in this clinical study. PMID:16515094

  13. Optical music recognition system which learns

    NASA Astrophysics Data System (ADS)

    Fujinaga, Ichiro

    1993-01-01

    This paper describes an optical music recognition system composed of a database and three interdependent processes: a recognizer, an editor, and a learner. Given a scanned image of a musical score, the recognizer locates, separates, and classifies symbols into musically meaningful categories. This classification is based on the k-nearest neighbor method using a subset of the database that contains features of symbols classified in previous recognition sessions. Output of the recognizer is corrected by a musically trained human operator using a music notation editor. The editor provides both visual and high-quality audio feedback of the output. Editorial corrections made by the operator are passed to the learner which then adds the newly acquired data to the database. The learner's main task, however, involves selecting a subset of the database and reweighing the importance of the features to improve accuracy and speed for subsequent sessions. Good preliminary results have been obtained with everything from professionally engraved scores to hand-written manuscripts.

  14. Digital optical computers at the optoelectronic computing systems center

    NASA Technical Reports Server (NTRS)

    Jordan, Harry F.

    1991-01-01

    The Digital Optical Computing Program within the National Science Foundation Engineering Research Center for Opto-electronic Computing Systems has as its specific goal research on optical computing architectures suitable for use at the highest possible speeds. The program can be targeted toward exploiting the time domain because other programs in the Center are pursuing research on parallel optical systems, exploiting optical interconnection and optical devices and materials. Using a general purpose computing architecture as the focus, we are developing design techniques, tools and architecture for operation at the speed of light limit. Experimental work is being done with the somewhat low speed components currently available but with architectures which will scale up in speed as faster devices are developed. The design algorithms and tools developed for a general purpose, stored program computer are being applied to other systems such as optimally controlled optical communication networks.

  15. An image stabilization optical system using deformable freeform mirrors.

    PubMed

    Hao, Qun; Cheng, Xuemin; Kang, Jiqiang; Jiang, Yuhua

    2015-01-01

    An image stabilization optical system using deformable freeform mirrors is proposed that enables the ray sets to couple dynamically in the object and image space. It aims to correct image blurring and degradation when there is relative movement between the imaging optical axis and the object. In this method, Fermat's principle and matrix methods are used to describe the optical path of the entire optical system with a shift object plane and a fixed corresponding image plane in the carrier coordinate system. A constant optical path length is determined for each ray set, so the correspondence between the object and the shift free image point is used to calculate the solution to the points on the surface profile of the deformable mirrors (DMs). Off-axis three-mirror anastigmats are used to demonstrate the benefits of optical image stabilization with one- and two-deformable mirrors. PMID:25599423

  16. An Image Stabilization Optical System Using Deformable Freeform Mirrors

    PubMed Central

    Hao, Qun; Cheng, Xuemin; Kang, Jiqiang; Jiang, Yuhua

    2015-01-01

    An image stabilization optical system using deformable freeform mirrors is proposed that enables the ray sets to couple dynamically in the object and image space. It aims to correct image blurring and degradation when there is relative movement between the imaging optical axis and the object. In this method, Fermat's principle and matrix methods are used to describe the optical path of the entire optical system with a shift object plane and a fixed corresponding image plane in the carrier coordinate system. A constant optical path length is determined for each ray set, so the correspondence between the object and the shift free image point is used to calculate the solution to the points on the surface profile of the deformable mirrors (DMs). Off-axis three-mirror anastigmats are used to demonstrate the benefits of optical image stabilization with one- and two-deformable mirrors. PMID:25599423

  17. Optical packaging activities at Institute of Microelectronics (IME), Singapore

    NASA Astrophysics Data System (ADS)

    Teo, Keng-Hwa; Sudharsanam, Krishnamachari; Pamidighantam, Ramana V.; Yeo, Yongkee; Iyer, Mahadevan K.

    2002-08-01

    The development of optoelectronic components for gigabit Ethernet communications is converging towards access networks where the cost of device makes a significant impact on the market acceptance. Device fabrication and packaging cost have to be brought down with novel assembly and packaging methods. Singapore has established a reputation in semiconductor device development and fabrication with excellent process and packaging facilities. Institute of Microelectronics (IME) was founded in 1991 to add value to the Singapore electronics industry. IME is involved in the development of active and passive photonics components using Silicon and polymer materials. We present a brief report on the development activities taking place in the field of optical component packaging at IME in recent years. We present a review of our competence and some of the optical device packaging activities that are being undertaken.

  18. Optical Diagnostic System for Solar Sails: Phase 1 Final Report

    NASA Technical Reports Server (NTRS)

    Pappa, Richard S.; Blandino, Joseph R.; Caldwell, Douglas W.; Carroll, Joseph A.; Jenkins, Christopher H. M.; Pollock, Thomas C.

    2004-01-01

    NASA's In-Space Propulsion program recently selected AEC-ABLE Engineering and L'Garde, Inc. to develop scale-model solar sail hardware and demonstrate its functionality on the ground. Both are square sail designs with lightweight diagonal booms (<100 g/m) and ultra-thin membranes (<10 g/sq m). To support this technology, the authors are developing an integrated diagnostics instrumentation package for monitoring solar sail structures such as these in a near-term flight experiment. We refer to this activity as the "Optical Diagnostic System (ODS) for Solar Sails" project. The approach uses lightweight optics and photogrammetric techniques to measure solar sail membrane and boom shape and dynamics, thermography to map temperature, and non-optical sensors including MEMS accelerometers and load cells. The diagnostics package must measure key structural characteristics including deployment dynamics, sail support tension, boom and sail deflection, boom and sail natural frequencies, sail temperature, and sail integrity. This report summarizes work in the initial 6-month Phase I period (conceptual design phase) and complements the final presentation given in Huntsville, AL on January 14, 2004.

  19. Fast optical signals in the peripheral nervous system

    NASA Astrophysics Data System (ADS)

    Tong, Yunjie; Martin, Jeffrey M.; Sassaroli, Angelo; Clervil, Patricia R.; Bergethon, Peter R.; Fantini, Sergio

    2006-07-01

    We present a study of the near-infrared optical response to electrical stimulation of peripheral nerves. The sural nerve of six healthy subjects between the ages of 22 and 41 was stimulated with transcutaneous electrical pulses in a region located approximately 10 cm above the ankle. A two-wavelength (690 and 830 nm) tissue spectrometer was used to probe the same sural nerve below the ankle. We measured optical changes that peaked 60 to 160 ms after the electrical stimulus. On the basis of the strong wavelength dependence of these fast optical signals, we argue that their origin is mostly from absorption rather than scattering. From these absorption changes, we obtain oxy- and deoxy-hemoglobin concentration changes that describe a rapid hemodynamic response to electrical nerve activation. In five out of six subjects, this hemodynamic response is an increase in total (oxy+deoxy) hemoglobin concentration, consistent with a fast vasodilation. Our findings support the hypothesis that the peripheral nervous system undergoes neurovascular coupling, even though more data is needed to prove such hypothesis.

  20. Optical Breath Gas Sensor for Extravehicular Activity Application

    NASA Technical Reports Server (NTRS)

    Wood, William R.; Casias, Miguel E.; Vakhtin, Andrei B.; Pilgrim, Jeffrey S.; Chullen, Cinda; Falconi, Eric A.; McMillin, Summer

    2013-01-01

    The function of the infrared gas transducer used during extravehicular activity in the current space suit is to measure and report the concentration of carbon dioxide (CO2) in the ventilation loop. The next generation portable life support system (PLSS) requires next generation CO2 sensing technology with performance beyond that presently in use on the Space Shuttle/International Space Station extravehicular mobility unit (EMU). Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. A laser diode spectrometer based on wavelength modulation spectroscopy is being developed for this purpose by Vista Photonics, Inc. Two prototype devices were delivered to NASA Johnson Space Center (JSC) in September 2011. The sensors incorporate a laser diode-based CO2 channel that also includes an incidental water vapor (humidity) measurement and a separate oxygen channel using a vertical cavity surface emitting laser. Both prototypes are controlled digitally with a field-programmable gate array/microcontroller architecture. The present development extends and upgrades the earlier hardware to the Advanced PLSS 2.0 test article being constructed and tested at JSC. Various improvements to the electronics and gas sampling are being advanced by this project. The combination of low power electronics with the performance of a long wavelength laser spectrometer enables multi-gas sensors with significantly increased performance over that presently offered in the EMU.

  1. Active optics correction forces for the VST 2.6m primary mirror

    NASA Astrophysics Data System (ADS)

    Schipani, P.; Perrotta, F.; Marty, L.

    2006-06-01

    In active optics systems obviously a fundamental role is played be the choice of polynomials to describe the primary mirror deformations. The well known Zernike polynomials are widely used because of their immediate interpretation in terms of optical aberrations. Nevertheless in an active optics correction system context, the choice of the so called "minimum energy modes" as the polynomials to represent the mechanical deformations is best justified by their derivation from mechanical properties. This is the approach followed for the 2.6m primary mirror of the VST telescope, to be hosted on top of the Cerro Paranal ESO observatory. The calibration forces to compensate a given amount of each aberration mode are computed and discussed.

  2. Optical Design of Telescopes and other Reflective Systems using SLIDERS

    NASA Technical Reports Server (NTRS)

    Howard, Joseph M.

    2007-01-01

    Optical design tools are presented to provide automatic generation of reflective optical systems for design studies and educational use. The tools are graphical in nature and use an interactive slider interface with freely available optical design software, OSLO EDU. Operation of the sliders provides input to adjust first-order and other system parameters (e.g. focal length), while appropriate system construction parameters are automatically updated to correct aberrations. Graphical output is also presented in real-time (e.g. a lens drawing) to provide the opportunity for a truly visual approach to optical design. Available systems include two- three- and four-mirror telescopes, relays, and afocal systems, either rotationally symmetric or having just a plane of symmetry. Demonstrations are presented, including a brief discussion of interfacing optical design software to MATLAB, and general research opportunities at NASA.

  3. A novel optical scattering collection system for particulate monitoring applications

    SciTech Connect

    Bernacki, B.E.; Miller, A.C. Jr.; Nuspliger, R.J.

    1996-05-01

    Light collecting systems often require radically different optical surfaces than those commonly found in optical imaging systems. An optical particulate monitor must probe a volume in emission stacks to obtain a good statistical distribution of suspended particles. However, ideal imaging systems map object planes into conjugate image planes and can probe only small volumes. The authors describe the design, fabrication and performance of a novel optical scattering collection system that exploits precision-engineered reflective conical surfaces (axicons) in a telescopic arrangement that maps a line in object space onto the detector plane in image space. Such non-spherical surfaces are nearly impossible to fabricate using traditional methods, but can readily be made using the deterministic method of single-point diamond turning. In addition to complex optical surfaces, single-point diamond turning also makes possible the precision engineering of reference surfaces useful for built-in alignment of multiple surfaces and rapid assembly of the finished system.

  4. Coherent detection in optical fiber systems.

    PubMed

    Ip, Ezra; Lau, Alan Pak Tao; Barros, Daniel J F; Kahn, Joseph M

    2008-01-21

    The drive for higher performance in optical fiber systems has renewed interest in coherent detection. We review detection methods, including noncoherent, differentially coherent, and coherent detection, as well as a hybrid method. We compare modulation methods encoding information in various degrees of freedom (DOF). Polarization-multiplexed quadrature-amplitude modulation maximizes spectral efficiency and power efficiency, by utilizing all four available DOF, the two field quadratures in the two polarizations. Dual-polarization homodyne or heterodyne downconversion are linear processes that can fully recover the received signal field in these four DOF. When downconverted signals are sampled at the Nyquist rate, compensation of transmission impairments can be performed using digital signal processing (DSP). Linear impairments, including chromatic dispersion and polarization-mode dispersion, can be compensated quasi-exactly using finite impulse response filters. Some nonlinear impairments, such as intra-channel four-wave mixing and nonlinear phase noise, can be compensated partially. Carrier phase recovery can be performed using feedforward methods, even when phase-locked loops may fail due to delay constraints. DSP-based compensation enables a receiver to adapt to time-varying impairments, and facilitates use of advanced forward-error-correction codes. We discuss both single- and multi-carrier system implementations. For a given modulation format, using coherent detection, they offer fundamentally the same spectral efficiency and power efficiency, but may differ in practice, because of different impairments and implementation details. With anticipated advances in analog-to-digital converters and integrated circuit technology, DSP-based coherent receivers at bit rates up to 100 Gbit/s should become practical within the next few years. PMID:18542153

  5. Optically active surfaces formed by ion implantation and thermal treatment

    SciTech Connect

    Gea, L.A.; Boatner, L.A.; Evans, H.M.; Zuhr, R.

    1996-08-01

    Embedded VO{sub 2} precipitates have been formed in single-crystal sapphire by the ion co-implantation of vanadium and oxygen and subsequent thermal annealing. The embedded VO{sub 2} particles have been shown to exhibit an optical switching behavior that is comparable to that of continuous thin films. In this work, the mechanisms of formation of these optically active particles are investigated. It is shown that precipitation of the vanadium dioxide phase is favored when the thermal treatment is performed on an ion-damaged but still crystalline (rather than amorphized) Al{sub 2}O{sub 3} substrate. The best optical switching behavior is observed in this case, and this behavior is apparently correlated with a more-favorable dispersion of VO{sub 2} small particles inside the matrix.

  6. Implementation, Control and Programming of Digital Optical Systems

    NASA Astrophysics Data System (ADS)

    Craig, Robert George Alexander

    Available from UMI in association with The British Library. Optical technology is playing an increasingly important role in modern computer systems including such areas as communications via fiber optic systems and data storage in the form of the optical compact disk (CD-ROM's). One of the aims of research into this technology has been to extend and enhance existing electronic computing systems. This thesis represents work carried out on the implementation of one particular form of parallel digital optical computing architecture known as the optical cellular logic image processor. This architecture performs the information processing all-optically and in parallel while making use of electronic technology for timing and control. One particular component required in this architecture is some form of programmable processing unit. Experimental studies involving the construction of single channel optical processing units were successfully completed. These units had multi-function capability and could be programmed optically under electronic control. Expansion upon one of these basic units to include iterative feedback resulted in the successful implementation of a single channel of the cellular logic image processor architecture. It allowed eight functions to be programmed in real time and demonstrated some of the world's first all-optical digital processing of arbitrary optical data. Further expansion of the system to include 256 simultaneous processing channels using similar technology was also partially completed. A full description is presented of the design concepts, components and the systems that have been developed. Attention is also given to both the hardware and software aspects related to electronic control of the optical systems. Finally, limitations associated with present optical technology are discussed and future possibilities suggested.

  7. Multiwavelength optical code-division-multiple-access communication systems

    NASA Astrophysics Data System (ADS)

    Lam, Cedric Fung

    1999-10-01

    There has been tremendous interest in applying spread spectrum and code division multiple access (CDMA) techniques to fiber optic communication systems. In this dissertation, we review the previous work on optical CDMA systems, and we propose and then demonstrate new optical CDMA system designs. The explosive growth in bandwidth demand during the recent years have compelled engineers to achieve one bit per hertz or more bandwidth utilization in optical fibers. We point out that in order to achieve efficient bandwidth utilization, full orthogonality is required in optical CDMA system. At the same time, one would like to avoid having an optical local oscillator, which significantly increases the system complexity. We have studied two spectrally encoded optical CDMA systems, both of which give us full orthogonality. A balanced optical detector, which `computes' the difference between two photodetectors signals, is used to obtain negative outputs from positive-only optical intensity signals, thus achieving full orthogonality in both systems. The first system, complementary spectral intensity encoding, is a fully non-coherent. A novel balanced transmitter has been invented for this system. Unfortunately, the performance of this system is limited by beat noise interference, sometimes called speckle noise. In the second system, spectral phase encoding, a multi-wavelength mode-locked laser source is employed. Spectral phase encoding is applied to various frequency components. By sending the unmodulated carrier along the optical fiber to the receiver, we can achieve the effect of coherent demodulation without using an optical local oscillator. While this system can avoid speckle noise, it is eventually limited by cumulative shot noise. We will show in this dissertation, that cumulative shot noise is unavoidable in all optical CDMA systems. Therefore the ultimate achievable performance of optical CDMA systems under shot noise limitation will be analyzed in this work. Lastly

  8. Advancements in integrated structural/thermal/optical (STOP) analysis of optical systems

    NASA Astrophysics Data System (ADS)

    Stoeckel, Gerhard; Crompton, David; Perron, Gerard

    2007-09-01

    Applications involving optical systems with a variety of transient loading conditions in conjunction with tight optical error budgets require new tools to assess system performance accurately and quickly. For example, an optical telescope in geostationary orbit (e.g.: laser communications or weather satellite) may be required to maintain excellent optical performance with sun intermittently crossing near, or even within the telescope's field of view. To optimize the design, the designer would wish to analyze a large number of time steps through the orbit without sacrificing accuracy of the results. Historically, shortcuts have been taken to make the analysis effort manageable: contributing errors are combined in a root-sum-squared fashion; non-linear optical sensitivities to optical motions are made linear; and the surface deformation of non-circular optics and/or footprints are fit with zernike polynomials. L-3 SSG-Tinsley presents a method that eliminates these errors while allowing very fast processing of many cases. The method uses a software application that interfaces with both structural and optical analysis codes, and achieves raytrace-generated results from the optical model. This technique is shown to provide more accurate results than previous methods, as well as provide critical insights into the performance of the system that may be exploited in the design process. Results from the Advanced Baseline Imager ABI telescope are presented as an example.

  9. Optical System Critical Design Review (CDR) Flight Software Summary

    NASA Technical Reports Server (NTRS)

    Khorrami, Mori

    2006-01-01

    The Mid Infrared Instrument (MIRI FSW presentation covers: (1) Optical System FSW only and Cooling System FSW is covered at its CDR (2) Requirements & Interfaces (3) Relationship with the ISIM FSW (4) FSW Design Drivers & Solutions.

  10. Residential solar-heating system uses pyramidal optics

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Report describes reflective panels which optimize annual solar energy collection in attic installation. Subunits include collection, storage, distribution, and 4-mode control systems. Pyramid optical system heats single-family and multi-family dwellings.

  11. Optical systems fabricated by printing-based assembly

    DOEpatents

    Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred J.; Motala, Michael; Ahn, Jong-Hyun; Park, Sang-II; Yu; Chang-Jae; Ko, Heung-Cho; Stoykovich; Mark; Yoon, Jongseung

    2011-07-05

    Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

  12. Optical systems fabricated by printing-based assembly

    DOEpatents

    Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred J; Motala, Michael; Ahn, Jong-Hyun; Park, Sang-Il; Yu, Chang-Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung

    2014-05-13

    Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

  13. Optical systems fabricated by printing-based assembly

    DOEpatents

    Rogers, John; Nuzzo, Ralph; Meitl, Matthew; Menard, Etienne; Baca, Alfred; Motala, Michael; Ahn, Jong -Hyun; Park, Sang -Il; Yu, Chang -Jae; Ko, Heung Cho; Stoykovich, Mark; Yoon, Jongseung

    2015-08-25

    Provided are optical devices and systems fabricated, at least in part, via printing-based assembly and integration of device components. In specific embodiments the present invention provides light emitting systems, light collecting systems, light sensing systems and photovoltaic systems comprising printable semiconductor elements, including large area, high performance macroelectronic devices. Optical systems of the present invention comprise semiconductor elements assembled, organized and/or integrated with other device components via printing techniques that exhibit performance characteristics and functionality comparable to single crystalline semiconductor based devices fabricated using conventional high temperature processing methods. Optical systems of the present invention have device geometries and configurations, such as form factors, component densities, and component positions, accessed by printing that provide a range of useful device functionalities. Optical systems of the present invention include devices and device arrays exhibiting a range of useful physical and mechanical properties including flexibility, shapeability, conformability and stretchablity.

  14. Observation of "True" Optical Vortices in a Laser System

    NASA Astrophysics Data System (ADS)

    Barland, S.; Caboche, E.; Genevet, P.; Hachair, X.; Giudici, M.; Pedaci, F.; Tredicce, J. R.

    We briefly review a series of experiments performed at the Institut Nonlineaire de Nice on localized structures in semiconductor optical devices. We concentrate our attention on the observation of localized single addressable optical vortices. This type of optical vortices, predicted theoretically more than 30 years ago, have been only observed recently in a system formed by two vertical cavity surface emitter lasers (VCSELs) in a face-to-face configuration. We describe the experimental setup and we discuss the results and the reasons for which such a system is able to display "true" optical vortices.

  15. Technique to reduce scattered light in optical systems

    NASA Astrophysics Data System (ADS)

    Wirick, M. P.

    1985-01-01

    In this patent application, in order to reduce the amount of internally scattered radiant energy in an optical system having a collecting optical chamber and a secondary optical chamber, a moving aperture device is positioned in a first focal plane between the chambers; the aperture device has a continuous moving metal band that has staggered slits therein. The band is sprocket driven and cryogenically cooled to reduce thermal emission. The band can be synced with other scanning detectors in the optical system such as one might find in an infrared telescope used in outer space.

  16. Design methodology of focusing elements for multilevel planar optical systems in optical interconnects

    NASA Astrophysics Data System (ADS)

    Al Hafiz, Md. Abdullah; MacKenzie, Mark R.; Kwok, Chee-Yee

    2009-12-01

    We present a simple technique to determine the design parameters of an optical interconnect system that uses integral planar lenses. The technique is based on the ABCD transformation matrix method. This analysis technique is significantly simpler and more efficient than the previously published methods for finding the design parameters and predicting the coupling efficiency of the system. The proposed method is applied to compute the coupling efficiency of single- and two-level optical systems.

  17. 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.

  18. Advances in lasers and optical micro-nano-systems

    NASA Astrophysics Data System (ADS)

    Laurell, F.; Fazio, E.

    2010-09-01

    Lasers represent a well consolidated technology: nevertheless, research in this field remains very active and productive, in both basic and applied directions. At the moment significant attention is given to those sources that bring together high power and compactness. Such high power lasers find important applications for material treatments and such applications are presented by Ehsani et al and Saiedeh Saghafi et al, in the treatment of dielectric thin films (Alteration of optical and morphological properties of polycarbonate illuminated by visible/IR laser beams) or of biological tissues like pistachio seeds (Investigating the effects of laser beams (532 and 660 nm) in annihilation of pistachio mould fungus using spectrophotometry analysis). In particular the latter paper show how laser sources can find very important applications in new domains, preserving goods and food without the need for preservatives or pesticides by simply sterilizing them using light. Optical Micro and Nano Systems presents a new domain for exploration. In this framework this special issue is very attractive, because it assembles papers reporting new results in three directions: new techniques for monitoring integrated micro- and nano-systems, new integrated systems and novel high performance metamaterial configurations. Integrated micro-components can be monitored and controlled using reflectance measurements as presented by Piombini et al (Toward the reflectance measurement of micro components). Speckle formation during laser beam reflection can also be a very sophisticated tool for detecting ultra-precise displacements, as presented by Filter et al (High resolution displacement detection with speckles : accuracy limits in linear displacement speckle metrology). Three dimensional integrated optical structures is indeed a big challenge and a peculiarity of photonics, they can be formed through traditional holography or using more sophisticated and novel ! technologies. Thus, special

  19. Portable active interrogation system.

    SciTech Connect

    Moss, C. E.; Brener, M. W.; Hollas, C. L.; Myers, W. L.

    2004-01-01

    The system consists of a pulsed DT neutron generator (5 x 10{sup 7} n/s) and a portable but high intrinsic efficiency, custom-designed, polyethylene-moderated {sup 3}He neutron detector. A multichannel scaler card in a ruggedized laptop computer acquires the data. A user-friendly LabVIEW program analyzes and displays the data. The program displays a warning message when highly enriched uranium or any other fissionable materials is detected at a specified number of sigmas above background in the delayed region between pulses. This report describes the system and gives examples of the response of the system to highly enriched uranium and some other fissionable materials, at several distances and with various shielding materials.

  20. NIF Final Optics System: Frequency Conversion and Beam Conditioning

    SciTech Connect

    Wegner, P; Auerbach, J; Biesiada, T; Dixit, S; Lawson, J; Menapace, J; Parham, T; Swift, D; Whitman, P; Williams, W

    2004-01-28

    Installation and commissioning of the first of forty-eight Final Optics Assemblies on the National Ignition Facility was completed this past year. This activity culminated in the delivery of first light to a target. The final optics design is described and selected results from first-article commissioning and performance tests are presented.