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Sample records for active optical components

  1. Passive and Active Fiber Optic Components

    NASA Astrophysics Data System (ADS)

    Digonnet, Michel Jean-Francois

    This thesis is concerned with the development and characterization of both passive and active fiber-optic components for applications in single-mode fiber systems, in particular in the new technology of fiber sensors and signal processors. These components include single-mode fiber directional couplers, vital to many optical fiber systems, all-fiber wavelength multiplexers, with potential applications in communication systems and active fiber devices, and single-crystal fiber lasers and amplifiers as miniature light sources and signal regenerators. The fiber directional couplers involved in this work, fabricated by a polishing process, are described in detail. Experimental characterization of their coupling, loss and unique tuning properties, and their respective dependence on the coupler geometrical parameters, are reported. A theoretical model of fiber-to-fiber coupling is also developed and shown to be a very useful and accurate tool in the design and study of this type of fiber couplers. The dependence of the coupling properties of fiber couplers on the signal wavelength is studied both theoretically and experimentally for applications in wavelength division multiplexing. All-fiber multiplexers exhibiting a good wavelength selectivity and unique tunability are described and shown to operate according to the coupler model. Work on active fiber devices explores the potential of the new technology of single-crystal fibers grown by the laser-heated floating-zone technique. The status of crystal fiber growth is reported, together with the basic physical and optical characteristics of these fibers. A theoretical model of the effects of fiber model structure on the gain and laser operation of active fibers is also developed to predict the performance of lasers and amplifiers in a fiber form. Several conceptual pumping schemes are described which offer solutions to the difficult problem of optically pumping small diameter fiber amplifiers. The experimental

  2. Active reflective components for adaptive optical zoom systems

    NASA Astrophysics Data System (ADS)

    Jungwirth, Matthew Edward Lewis

    This dissertation presents the theoretical and experimental exploration of active reflective components specifically for large-aperture adaptive optical zoom systems. An active reflective component can change its focal length by physically deforming its reflecting surface. Adaptive optical zoom (AOZ) utilizes active components in order to change magnification and achieve optical zoom, as opposed to traditional zooming systems that move elements along the optical axis. AOZ systems are theoretically examined using a novel optical design theory that enables a full-scale tradespace analysis, where optical design begins from a broad perspective and optimizes to a particular system. The theory applies existing strategies for telescope design and aberration simulation to AOZ, culminating in the design of a Cassegrain objective with a 3.3X zoom ratio and a 375mm entrance aperture. AOZ systems are experimentally examined with the development of a large-aperture active mirror constructed of a composite material called carbon fiber reinforced polymer (CFRP). The active CFRP mirror uses a novel actuation method to change radius of curvature, where actuators press against two annular rings placed on the mirror's back. This method enables the radius of curvature to increase from 2000mm to 2010mm. Closed-loop control maintains good optical performance of 1.05 waves peak-to-valley (with respect to a HeNe laser) when the active CFRP mirror is used in conjunction with a commercial deformable mirror.

  3. Extraction of Neural Activity from In Vivo Optical Recordings Using Multiple Independent Component Analysis

    NASA Astrophysics Data System (ADS)

    Yoshida, Takamasa; Sakagami, Masanori; Yamazaki, Kyoko; Katura, Takusige; Iwamoto, Mitsumasa; Tanaka, Naoki

    A multiple independent component analysis (ICA) method based on the noisy time-delayed decorrelation algorithm is described that overcomes the problems and improves the usefulness of conventional ICA, which is commonly used for extracting the actual neural activity from data measured using optical recording with a voltage-sensitive dye to visualize neural activities in cortical areas as two-dimensional images. The problems with conventional ICA extraction include the lack of an a priori guarantee that the solution will be appropriate, the linear mixing of mutually independent random variables although the mixtures are not random variables but time signals in many applications, and the general requirement for repetitive calculation of large matrices. Application of multiple ICA to the extraction of neural activities in the guinea pig auditory cortex evoked by both click sounds and pure tones from optical recordings made using a voltage sensitive dye demonstrated that it effectively removes pulsatile and respiratory components from the measurement data and extracts neural activities from the optical recordings.

  4. Revealing Optical Components

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Optical Vector Analyzer (OVA) 1550 significantly reduces the time and cost of testing sophisticated optical components. The technology grew from the research Luna Technologies' Dr. Mark Froggatt conducted on optical fiber strain measurement while working at Langley Research Center. Dr. Froggatt originally developed the technology for non- destructive evaluation testing at Langley. The new technique can provide 10,000 independent strain measurements while adding less than 10 grams to the weight of the vehicle. The OVA is capable of complete linear characterization of single-mode optical components used in high- bit-rate applications. The device can test most components over their full range in less than 30 seconds, compared to the more than 20 minutes required by other testing methods. The dramatically shortened measurement time results in increased efficiency in final acceptance tests of optical devices, and the comprehensive data produced by the instrument adds considerable value for component consumers. The device eliminates manufacturing bottlenecks, while reducing labor costs and wasted materials during production.

  5. 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.

  6. On the determination of the diagonal components of the optical activity tensor in chiral molecules

    NASA Astrophysics Data System (ADS)

    Pelloni, Stefano; Lazzeretti, Paolo

    2014-02-01

    It is shown that the diagonal components of the mixed electric-magnetic dipole polarizability tensor, used to rationalize the optical rotatory power of chiral molecules, are origin independent, if they are referred to the coordinate system defined by the eigenvectors of the dynamic electric dipole polarizability, for a given value ω of the frequency of a monochromatic wave impinging on an ordered sample. Within this reference frame, the individual diagonal components of the mixed electric-magnetic dipole polarizability are separately measurable properties. The theoretical method is applied via a test calculation to the cyclic 1,2-M enantiomer of the dioxin molecule, using a large Gaussian basis set to estimate near Hartree-Fock values within a series of dipole length, velocity, and acceleration representations.

  7. Additive manufacturing of optical components

    NASA Astrophysics Data System (ADS)

    Heinrich, Andreas; Rank, Manuel; Maillard, Philippe; Suckow, Anne; Bauckhage, Yannick; Rößler, Patrick; Lang, Johannes; Shariff, Fatin; Pekrul, Sven

    2016-08-01

    The development of additive manufacturing methods has enlarged rapidly in recent years. Thereby, the work mainly focuses on the realization of mechanical components, but the additive manufacturing technology offers a high potential in the field of optics as well. Owing to new design possibilities, completely new solutions are possible. This article briefly reviews and compares the most important additive manufacturing methods for polymer optics. Additionally, it points out the characteristics of additive manufactured polymer optics. Thereby, surface quality is of crucial importance. In order to improve it, appropriate post-processing steps are necessary (e.g. robot polishing or coating), which will be discussed. An essential part of this paper deals with various additive manufactured optical components and their use, especially in optical systems for shape metrology (e.g. borehole sensor, tilt sensor, freeform surface sensor, fisheye lens). The examples should demonstrate the potentials and limitations of optical components produced by additive manufacturing.

  8. Simulation of Raman optical activity of multi-component monosaccharide samples.

    PubMed

    Melcrová, Adéla; Kessler, Jiří; Bouř, Petr; Kaminský, Jakub

    2016-01-21

    Determination of the saccharide structure in solution is a laborious process that can be significantly enhanced by optical spectroscopies. Raman optical activity (ROA) spectra are particularly sensitive to the chirality and conformation. However, the interpretation of them is largely dependent on computational tools providing a limited precision only. To understand the limitations and the link between spectral shapes and the structure, in the present study we measured and interpreted using a combination of molecular dynamics (MD) and density functional theory (DFT) Raman and ROA spectra of glucose and mannose solutions. Factors important for analyses of mixtures of conformers, anomers, and different monosaccharides are discussed as well. The accuracy of the simulations was found to be strongly dependent on the quality of the hydration model; the dielectric continuum solvent model provided lower accuracy than averaging of many solvent-solute clusters. This was due to different conformer weighting rather than direct involvement of water molecules in scattering recorded as ROA. However, the cluster-based simulations also failed to correctly reproduce the ratios of principal monosaccharide forms. The best results were obtained by a combined MD/DFT simulation, with the ratio of α- and β-anomers and the -CH2OH group rotamers determined experimentally by NMR. Then a decomposition of experimental spectra into calculated subspectra provided realistic results even for the glucose and mannose mixtures. Raman spectra decomposition provided a better overall accuracy (∼5%) than ROA (∼10%). The combination of vibrational spectroscopy with theoretical simulations represents a powerful tool for analysing the saccharide structure. Conversely, the ROA and Raman data can be used to verify the quality of MD force fields and other parameters of computational modeling. PMID:26689801

  9. Multi-segmented piezoelectric mirrors as active/adaptive optics components.

    PubMed

    Signorato, R; Hignette, O; Goulon, J

    1998-05-01

    The angular acceptance of piezoelectric (Pzt) bimorph mirrors is limited by the maximum length of commercially available Pzt ceramic plates. To overcome this limit and manufacture longer devices, several (2n + 1) 150 mm-long bimorph Pzt stacks were assembled side-to-side. Two prototype mirrors, 450 (n = 1) and 750 (n = 2) mm long, were designed, assembled, polished and optically characterized. They are fully UHV compatible and are now installed in the monochromatic section of the ESRF beamlines ID26 and ID32. Both mirrors cover the full range of required bending radii (1 km concave-3.5 km convex). Junctions between segments do not spoil the optical surface quality. The surface slope error r.m.s. can be kept well below 1 arcsec over the full bending range. Adaptive compensation for low-frequency figure errors was shown to be easy and reliable. After compensation, residual shape errors are of the order of 40 nm r.m.s. over 700 mm. PMID:15263657

  10. Advanced micromoulding of optical components

    NASA Astrophysics Data System (ADS)

    Bauer, Hans-Dieter; Ehrfeld, Wolfgang; Paatzsch, Thomas; Smaglinski, Ingo; Weber, Lutz

    1999-09-01

    There is a growing need for micro-optical components in the field of tele- and datacom applications. Such components have to be very precise and should be available in reasonable numbers. Microtechnology provides manufacturing techniques that fulfill both requirements. Using micro electro discharge machining, laser micromachining, ultra precision milling and deep lithography with subsequent electroforming methods, complex tools for the replication of highly precise plastic parts have been manufactured. In many cases a combination of methods enumerated above gives a tool which shows both functionality and cost-efficiency. As examples we present the realization of integrated-optical components with passive fiber-waveguide coupling used as components in optical networks and as velocity sensors for two-phase flows, like liquids containing small gas bubbles or particles. In the first case multimode 4 X 4 star couplers have been manufactured in a pilot series that show excess loss values below 3 dB and a uniformity better than 3 dB at 830 nm. This performance becomes possible by using a compression molding process. By stamping the microstructured mold into a semifinished PMMA plate exact replication of the molds as well as very low surface roughness of the waveguide side walls could be observed. In the second case the waveguide channels of the flow sensors show dimensions of between 20 micrometer and 100 micrometer and an aspect ratio of about 20. These structures have been replicated by injection molding of PMMA using variotherm process treatment with a cycle time of about 2 - 3 min.

  11. Fiber optic 3-component seismometer

    NASA Astrophysics Data System (ADS)

    Han, Jing; Zhang, Wentao; Jiang, Dongshan; Wang, Zhaogang; Li, Fang

    2014-06-01

    An all-metal 3-component optical fiber seismometer was proposed and experimentally demonstrated. The theoretical analysis was given based on the electro-mechanical theory. Calibration results showed that the axis sensitivity was about 41 dB (re: 0 dB=1 rad/g) with a fluctuation ±2 dB in the frequency bandwidth of 5 Hz-400 Hz. A transverse sensitivity of about -40 dB was achieved. The fluctuation of the acceleration sensitivity for the three accelerometers in the seismometer was within ±2.5 dB. The minimum phase demodulation detection accuracy of the phase-generated carrier (PGC) was 10-5 rad/√Hz, and the minimum detectable acceleration was calculated to be 90 ng/√Hz.

  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. Fabrication of an optical component

    DOEpatents

    Nichols, Michael A.; Aikens, David M.; Camp, David W.; Thomas, Ian M.; Kiikka, Craig; Sheehan, Lynn M.; Kozlowski, Mark R.

    2000-01-01

    A method for forming optical parts used in laser optical systems such as high energy lasers, high average power lasers, semiconductor capital equipment and medical devices. The optical parts will not damage during the operation of high power lasers in the ultra-violet light range. A blank is first ground using a fixed abrasive grinding method to remove the subsurface damage formed during the fabrication of the blank. The next step grinds and polishes the edges and forms bevels to reduce the amount of fused-glass contaminants in the subsequent steps. A loose abrasive grind removes the subsurface damage formed during the fixed abrasive or "blanchard" removal process. After repolishing the bevels and performing an optional fluoride etch, the surface of the blank is polished using a zirconia slurry. Any subsurface damage formed during the loose abrasive grind will be removed during this zirconia polish. A post polish etch may be performed to remove any redeposited contaminants. Another method uses a ceria polishing step to remove the subsurface damage formed during the loose abrasive grind. However, any residual ceria may interfere with the optical properties of the finished part. Therefore, the ceria and other contaminants are removed by performing either a zirconia polish after the ceria polish or a post ceria polish etch.

  14. Optical access: networks and components (overview)

    NASA Astrophysics Data System (ADS)

    Mynbaev, Djafar K.

    2004-09-01

    The exponential gtowth of traffic delivered to an individual customer both for business and personal needs puts tremendous pressure on the telecommunications networks. Because the development of the long-haul and metro networks has advanced rapidly and their capacity much eceeds demand, tremendous pressure now falls in the local networks to provide customers with access to the global telecom infrastructure. Building a broadband access network enabling fast delivery of high-volume traffic is the current task of network operators. A brief review of broadband access networks brings us to the conclusion that only wired optical networks can serve as an immediate and future solution to the "last-mile" problem. After discussin goptical access network classification, we focus mainly on passive optical networks (PON) because PON is a major technology today. From the network standpoint, we discuss the principle of PON operation, architectures, topologies, protocols and standards, design issues, and network management and services. We also discuss the main problems with PON and the use of WDM technology. From the hardware standpoint, we consider both active and passive components. We analyze the structure and elements of these components, including their technical characteristics.

  15. 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.

  16. Degradation of optical components in space

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1993-01-01

    This report concerns two types of optical components: multilayer filters and mirrors, and self-scanned imaging arrays using charge coupled device (CCD) readouts. For the filters and mirrors, contamination produces a strong reduction in transmittance in the ultraviolet spectral region, but has little or no effect in the visible and infrared spectral regions. Soft substrates containing halides are unsatisfactory as windows or substrates. Materials choice for dielectric layers should also reflect such considerations. Best performance is also found for the harder materials. Compaction of the layers and interlayer diffusion causes a blue shift in center wavelength and loss of throughput. For sensors using CCD's, shifts in gate voltage and reductions in transfer efficiency occur. Such effects in CCD's are in accord with expectations of the effects of the radiation dose on the device. Except for optical fiber, degradation of CCD's represents the only ionizing-radiation induced effect on the Long Duration Exposure Facility (LDEF) optical systems components that has been observed.

  17. Plasma surface figuring of large optical components

    NASA Astrophysics Data System (ADS)

    Jourdain, R.; Castelli, M.; Morantz, P.; Shore, P.

    2012-04-01

    Fast figuring of large optical components is well known as a highly challenging manufacturing issue. Different manufacturing technologies including: magnetorheological finishing, loose abrasive polishing, ion beam figuring are presently employed. Yet, these technologies are slow and lead to expensive optics. This explains why plasma-based processes operating at atmospheric pressure have been researched as a cost effective means for figure correction of metre scale optical surfaces. In this paper, fast figure correction of a large optical surface is reported using the Reactive Atom Plasma (RAP) process. Achievements are shown following the scaling-up of the RAP figuring process to a 400 mm diameter area of a substrate made of Corning ULE®. The pre-processing spherical surface is characterized by a 3 metres radius of curvature, 2.3 μm PVr (373nm RMS), and 1.2 nm Sq nanometre roughness. The nanometre scale correction figuring system used for this research work is named the HELIOS 1200, and it is equipped with a unique plasma torch which is driven by a dedicated tool path algorithm. Topography map measurements were carried out using a vertical work station instrumented by a Zygo DynaFiz interferometer. Figuring results, together with the processing times, convergence levels and number of iterations, are reported. The results illustrate the significant potential and advantage of plasma processing for figuring correction of large silicon based optical components.

  18. Compact component for integrated quantum optic processing.

    PubMed

    Sahu, Partha Pratim

    2015-01-01

    Quantum interference is indispensable to derive integrated quantum optic technologies (1-2). For further progress in large scale integration of quantum optic circuit, we have introduced first time two mode interference (TMI) coupler as an ultra compact component. The quantum interference varying with coupling length corresponding to the coupling ratio is studied and the larger HOM dip with peak visibility ~0.963 ± 0.009 is found at half coupling length of TMI coupler. Our results also demonstrate complex quantum interference with high fabrication tolerance and quantum visibility in TMI coupler.

  19. Key optical components for spaceborne lasers

    NASA Astrophysics Data System (ADS)

    Löhring, J.; Winzen, M.; Faidel, H.; Miesner, J.; Plum, D.; Klein, J.; Fitzau, O.; Giesberts, M.; Brandenburg, W.; Seidel, A.; Schwanen, N.; Riesters, D.; Hengesbach, S.; Hoffmann, H.-D.

    2016-03-01

    Spaceborne lidar (light detection and ranging) systems have a large potential to become powerful instruments in the field of atmospheric research. Obviously, they have to be in operation for about three years without any maintenance like readjusting. Furthermore, they have to withstand strong temperature cycles typically in the range of -30 to +50 °C as well as mechanical shocks and vibrations, especially during launch. Additionally, the avoidance of any organic material inside the laser box is required, particularly in UV lasers. For atmospheric research pulses of about several 10 mJ at repetition rates of several 10 Hz are required in many cases. Those parameters are typically addressed by DPSSL that comprise components like: laser crystals, nonlinear crystals in pockels cells, faraday isolators and frequency converters, passive fibers, diode lasers and of course a lot of mirrors and lenses. In particular, some components have strong requirements regarding their tilt stability that is often in the 10 μrad range. In most of the cases components and packages that are used for industrial lasers do not fulfil all those requirements. Thus, the packaging of all these key components has been developed to meet those specifications only making use of metal and ceramics beside the optical component itself. All joints between the optical component and the laser baseplate are soldered or screwed. No clamps or adhesives are used. Most of the critical properties like tilting after temperature cycling have been proven in several tests. Currently, these components are used to build up first prototypes for spaceborne systems.

  20. Development of optical components for METIS instrument

    NASA Astrophysics Data System (ADS)

    Nardello, M.; Zuccon, S.; Corso, A. J.; Zuppella, P.; Naletto, G.; Fineschi, S.; Antonucci, E.; Pelizzo, M. G.

    2014-09-01

    The ESA mission Solar Orbiter (SOLO) is dedicated to the study of Solar Atmosphere and Heliosphere. As a part of the payload, the instrument METIS (Multi Element Telescope for Imaging and Spectroscopy) will provide images of the corona, both in the visible range and at the hydrogen Lyman-α emission line (121.6 nm). The realization of optical coatings, based on Al and MgF2, able to reflect/transmit such spectral component is therefore necessary. Since optical characteristics of materials in the VUV range are not well studied and greatly varying with realization process, we implemented a study of their properties in different deposition conditions. This is aimed to the realization of a custom designed filter, able to transmit the 121.6 nm while reflecting the visible light, and thus separate visible from UV light paths in the METIS instrument.

  1. Automated assembly of micro-optical components

    NASA Astrophysics Data System (ADS)

    Eberhardt, Ramona; Scheller, Torsten; Tittelbach, Guenther; Guyenot, Volker

    1998-01-01

    In the field of microsystem technologies one future trend is recognized. Manufacturing microsystems monolithically is becoming less reasonable and practicable with increasing applications and complexity. Assembly processes will be needed for the majority of microsystems due to difficulties arising in manufacturing complex structure out of one piece, the need for components to be manufactured by different processes, or simply to connect the microsystem with the macroscopic environment. Additionally, high production output at competitive costs is attainable only by replacing manual assembly with new automatic handling, positioning and joining technologies. To assist in development of microassembly processes, techniques from macroassembly technology may be transferred. Especially in microoptics existing know-how from macroscopic lens-assemblies might be transferred. The microsystem presented a microoptical beam forming system consisting of one SELFOC- and two GRIN- microlenses joined by adhesive bonding, fixed in a protection-mount, which serves additionally as a coupling unit of a multimode fiber, and finally adjusted to a laser diode at a defined distance according to an optical design. Besides complications due to the sensitive optical surfaces and the small and varying geometries of the system components, there is the additional requirement of high accuracies, of 0.1 to 2 micrometers and down to 1 arcsec, needed to realize the optical function of the microsystem. The assembly system, based on a six-axis-precision robot accurate to less than 1 micrometers , consists of a modular designed tool changing system, specially-adapted, self- adjusting grippers, several sensors to monitor positioning, dosage devices to dispense measured quantities of adhesive, in the range of nanoliters, and a specially designed assembly platform to clamp microparts of different geometries.

  2. Stochastic optical active rheology

    NASA Astrophysics Data System (ADS)

    Lee, Hyungsuk; Shin, Yongdae; Kim, Sun Taek; Reinherz, Ellis L.; Lang, Matthew J.

    2012-07-01

    We demonstrate a stochastic based method for performing active rheology using optical tweezers. By monitoring the displacement of an embedded particle in response to stochastic optical forces, a rapid estimate of the frequency dependent shear moduli of a sample is achieved in the range of 10-1-103 Hz. We utilize the method to probe linear viscoelastic properties of hydrogels at varied cross-linker concentrations. Combined with fluorescence imaging, our method demonstrates non-linear changes of bond strength between T cell receptors and an antigenic peptide due to force-induced cell activation.

  3. Optical activity and evolution.

    PubMed

    Khasanov, M M; Gladyshev, G P

    1980-09-01

    It is noted that the chemical reactions occurring in rarefied cosmic clouds (molecular concentration less than or approximately to 10(2) cm-3) differ from similar laboratory reactions by the much greater effect on the outcome of external force fields. In this light it is hypothesized that the synthesis of optically active substances may occur in the outer space under the conjoint stereospecific effect of a magnetic and other molecule-orienting field. It is further conjectured that the optically active substances of the Solar System had been produced in the course of its formation out of the primal rarefield cloud.

  4. Fiber optic three-component seismometer

    NASA Astrophysics Data System (ADS)

    Jiang, Dongshan; Zhang, Wentao; Li, Fang

    2013-09-01

    Three-component seismometer is widely used in oil or gas exploration, earth quake monitoring. In this paper, an allmetal 3-component optical fiber seismometer is proposed and experimentally demonstrated. The theoretical analysis is given based on electro-mechanical theory. Calibration results show that axis sensitivity is 41 dB (re: 0 dB=1 rad/g) with a fluctuation +/-2 dB in frequency bandwidth of 5~400 Hz. A transverse sensitivity of about -40 dB is achieved. The fluctuation of the acceleration sensitivity for the three accelerometers in the seismometer is within +/-2.5 dB. The minimum phase demodulation detection accuracy of the phase-generated carrier (PGC) is 10-5 rad/√Hz, and the minimum detectable acceleration is calculated to be 90 ng/√Hz. With an all-metal structure, the proposed seismometer is expected to improve reliability of long-term use in harsh environment such as ocean bottom seismic wave monitoring in oil or gas exploration.

  5. COMPONENTS AND PARAMETERS OF LASER SYSTEMS: Thermal depolarization of optical radiation in a laser active element made of GSGG:Cr3+:Nd3+ crystal

    NASA Astrophysics Data System (ADS)

    Danilov, A. A.; Nikol'skiĭ, M. Yu; Shcherbakov, Ivan A.

    1987-08-01

    Investigations were made of the thermal depolarization in a gadolinium scandium gallium garnet (GSGG) crystal doped with neodymium and chromium. It was found that at average optical pump powers higher than 250-300 W, inhomogeneities of the active medium make a substantial contribution to the thermal depolarization. A method is proposed for the control of the thermal depolarization by additional heating of the active element.

  6. Actively Controlled Components. Chapter 2

    NASA Technical Reports Server (NTRS)

    Horn, W.; Hiller, S.-J.; Pfoertner, H.; Schadow, K.; Rosenfeld, T.; Garg, S.

    2009-01-01

    Active Control can help to meet future engine requirements by an active improvement of the component characteristics. The concept is based on an intelligent control logic, which senses actual operating conditions and reacts with adequate actuator action. This approach can directly improve engine characteristics as performance, operability, durability and emissions on the one hand. On the other hand active control addresses the design constrains imposed by unsteady phenomena like inlet distortion, compressor surge, combustion instability, flow separations, vibration and noise, which only occur during exceptional operating conditions. The feasibility and effectiveness of active control technologies have been demonstrated in lab-scale tests. This chapter describes a broad range of promising applications for each engine component. Significant efforts in research and development remain to implement these technologies in engine rig and finally production engines and to demonstrate today s engine generation airworthiness, safety, reliability, and durability requirements. Active control applications are in particular limited by the gap between available and advanced sensors and actuators, which allow an operation in the harsh environment in an aero engine. The operating and performance requirements for actuators and sensors are outlined for each of the gas turbine sections from inlet to nozzle.

  7. Integral window hermetic fiber optic components

    SciTech Connect

    Dalton, R.D.; Kramer, D.P.; Massey, R.T.; Waker, D.A.

    1994-12-31

    In the fabrication of igniters, actuators, detonators, and other pyrotechnic devices to be activated by a laser beam, an integral optical glass window is formed by placing a preform in the structural member of the device and then melting the glass and sealing it in place by heating at a temperature between the ceramming temperature of the glass and the melting point of the metal, followed by rapid furnace cooling to avoid devitrification. No other sealing material is needed to achieve hermeticity. A preferred embodiment of this type of device is fabricated by allowing the molten glass to flow further and form a plano-convex lens integral with and at the bottom of the window. The lens functions to decrease the beam divergence caused by refraction of the laser light passing through the window when the device is fired by means of a laser beam.

  8. Nondispersive optical activity of meshed helical metamaterials.

    PubMed

    Park, Hyun Sung; Kim, Teun-Teun; Kim, Hyeon-Don; Kim, Kyungjin; Min, Bumki

    2014-11-17

    Extreme optical properties can be realized by the strong resonant response of metamaterials consisting of subwavelength-scale metallic resonators. However, highly dispersive optical properties resulting from strong resonances have impeded the broadband operation required for frequency-independent optical components or devices. Here we demonstrate that strong, flat broadband optical activity with high transparency can be obtained with meshed helical metamaterials in which metallic helical structures are networked and arranged to have fourfold rotational symmetry around the propagation axis. This nondispersive optical activity originates from the Drude-like response as well as the fourfold rotational symmetry of the meshed helical metamaterials. The theoretical concept is validated in a microwave experiment in which flat broadband optical activity with a designed magnitude of 45° per layer of metamaterial is measured. The broadband capabilities of chiral metamaterials may provide opportunities in the design of various broadband optical systems and applications.

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

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1995-01-01

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

  10. Electro-optic component mounting device

    DOEpatents

    Gruchalla, M.E.

    1994-09-13

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

  11. Electro-optic component mounting device

    DOEpatents

    Gruchalla, Michael E.

    1994-01-01

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

  12. Improved evaluation of optical depth components from Langley plot data

    NASA Technical Reports Server (NTRS)

    Biggar, S. F.; Gellman, D. I.; Slater, P. N.

    1990-01-01

    A simple, iterative procedure to determine the optical depth components of the extinction optical depth measured by a solar radiometer is presented. Simulated data show that the iterative procedure improves the determination of the exponent of a Junge law particle size distribution. The determination of the optical depth due to aerosol scattering is improved as compared to a method which uses only two points from the extinction data. The iterative method was used to determine spectral optical depth components for June 11-13, 1988 during the MAC III experiment.

  13. Considerations for tolerancing aspheric optical components.

    PubMed

    Wilson, Randall H; Brost, Randy C; Strip, David R; Sudol, Ronald J; Youngworth, Richard N; McLaughlin, Paul O

    2004-01-01

    Optical designs often specify both surface form and centering (tilt and lateral displacement) tolerances on aspheric surfaces. In contrast to spherical surfaces, form and centering errors are coupled for aspheric surfaces. Current standards do not specify how to interpret such tolerances, and in particular they do not define the position of an aspheric surface that has form errors. The straightforward definition that uses the best-fit surface position that minimizes rms error has subtle problems. The best-fit surface position for aspheric surfaces is influenced by power error and can be highly sensitive to surface form errors when the derivative of aspheric departure is small. We analyze the conditions under which form and centering tolerances may be considered compatible when the best-fit surface-position definition is used. We propose alternative definitions of surface position that do not suffer from the same problems and consider their consequences for optical design and metrology.

  14. Novel ternary component Ag-SrTa2O6/g-C3N4 photocatalyst: Synthesis, optical properties and visible light photocatalytic activity

    NASA Astrophysics Data System (ADS)

    Su, Yiguo; Zhao, Yanxia; Zhao, Yingjie; Lang, Junyu; Xin, Xin; Wang, Xiaojing

    2015-12-01

    In this work, we report on the synthesis of a novel ternary component Ag-SrTa2O6/g-C3N4 photocatalytic system with efficient visible light photocatalytic activity toward Cr(VI) photoreduction and methyl orange degradation. The samples were carefully characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-vis diffuse reflectance spectroscopy, Fourier transformed infrared spectroscopy and photocatalytic test. It is found that SrTa2O6 was deposited on the surface of g-C3N4 and that obtained SrTa2O6/g-C3N4 heterojunction photocatalyst showed strong absorption in the visible light region. Photocatalytic test indicated that the as-prepared SrTa2O6/g-C3N4 heterojunction showed increased photocatalytic activity toward Cr(VI) photoreduction and methyl orange degradation in comparison with the bare SrTa2O6 and g-C3N4 under visible light irradiation. The matching of the band structure between SrTa2O6 and g-C3N4 induced an efficient photogenerated electron transfer from the conduction band of g-C3N4 to the conduction band of SrTa2O6, resulting in efficient separation of the photogenerated electron-hole pairs and the subsequent promotion of photocatalytic activity. Moreover, the decoration of Ag on SrTa2O6/g-C3N4 led to the formation of ternary component Ag-SrTa2O6/g-C3N4 photocatalyst, which can highly enhance the visible light absorption efficiency and robustlypromote the photocatalytic activity by a factor of 2.8 for Cr(VI) photoreduction and 4.6 for methyl orange degradation, respectively. Ag decoration on SrTa2O6/g-C3N4 can not only extend the visible light absorption region due to surface plasmon resonance effects, but also act as an electron mediator for efficient migration of photogenerated electrons and simultaneously prevent the recombination of photogenerated electron-hole pairs as much as possible. Finally, a possible photocatalytic mechanism of the charge transfer in Ag-SrTa2O6/g-C3N4 photocatalyst was proposed.

  15. Induced activation in accelerator components

    NASA Astrophysics Data System (ADS)

    Bungau, Cristian; Bungau, Adriana; Cywinski, Robert; Barlow, Roger; Edgecock, Thomas Robert; Carlsson, Patrick; Danared, Hâkan; Mezei, Ferenc; Holm, Anne Ivalu Sander; Møller, Søren Pape; Thomsen, Heine Dølrath

    2014-08-01

    The residual activity induced in particle accelerators is a serious issue from the point of view of radiation safety as the long-lived radionuclides produced by fast or moderated neutrons and impact protons cause problems of radiation exposure for staff involved in the maintenance work and when decommissioning the facility. This paper presents activation studies of the magnets and collimators in the High Energy Beam Transport line of the European Spallation Source due to the backscattered neutrons from the target and also due to the direct proton interactions and their secondaries. An estimate of the radionuclide inventory and induced activation are predicted using the GEANT4 code.

  16. Lightweight Thermoformed Structural Components and Optics

    NASA Technical Reports Server (NTRS)

    Zeiders, Glenn W.; Bradford, Larry J.

    2004-01-01

    A technique that involves the use of thermoformed plastics has been developed to enable the design and fabrication of ultra-lightweight structural components and mirrors for use in outer space. The technique could also be used to produce items for special terrestrial uses in which minimization of weight is a primary design consideration. Although the inherent strengths of thermoplastics are clearly inferior to those of metals and composite materials, thermoplastics offer a distinct advantage in that they can be shaped, at elevated temperatures, to replicate surfaces (e.g., prescribed mirror surfaces) precisely. Furthermore, multiple elements can be bonded into structures of homogeneous design that display minimal thermal deformation aside from simple expansion. The design aspect of the present technique is based on the principle that the deflection of a plate that has internal structure depends far more on the overall thickness than on the internal details; thus, a very stiff, light structure can be made from thin plastic that is heatformed to produce a sufficiently high moment of inertia. General examples of such structures include I beams and eggcrates.

  17. Integrated optical components in thin films of polymers

    NASA Technical Reports Server (NTRS)

    Sarkisov, Sergey; Abdeldayem, Hossin; Venkateswarlu, Putcha; Teague, Zedric

    1995-01-01

    /sq.cm pump power) demonstrated emission spectrum narrowing near 616 nm peak with 18% power conversion slope efficiency. In this case emission spectrum modification was caused by the enhanced light absorption along the direction of propagating waveguide modes. Changing length, thickness, and other morphlogical waveguide parameters one can modify emission spectrum in predictable direction. The results show that polymeric waveguides, especially based on high temperature polymers such as Pl, can be used to produce a varietiy of active and passive silicon compatible integrated optical components for aerospace applications.

  18. 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

  19. 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.

  20. 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.

  1. Polyguide polymeric technology for optical interconnect circuits and components

    NASA Astrophysics Data System (ADS)

    Booth, Bruce L.; Marchegiano, Joseph E.; Chang, Catherine T.; Furmanak, Robert J.; Graham, Douglas M.; Wagner, Richard G.

    1997-04-01

    The expanding information revolution has been made possible by the development of optical communication technology. To meet the escalating demand for information transmitted and processed at high data rates and the need to circumvent the growing electronic circuit bottlenecks, mass deployment of not only optical fiber networks but manufacturable optical interconnect circuits, components and connectors for interfacing fibers and electronics that meet economic and performance constraints are absolutely necessary. Polymeric waveguide optical interconnection are considered increasingly important to meet these market needs. DuPont's polyguide polymeric integrated optic channel waveguide system is thought by many to have considerable potential for a broad range of passive optical interconnect applications. In this paper the recent advances, status, and unique attributes of the technology are reviewed. Product and technology developments currently in progress including parallel optical ink organization and polymer optical interconnect technology developments funded by DARPA are used as examples to describe polyguide breadth and potential for manufacture and deployment of optical interconnection products for single and multimode telecom and datacom waveguide applications.

  2. Low-temperature hermetic sealing of optical fiber components

    DOEpatents

    Kramer, Daniel P.

    1996-10-22

    A method for manufacturing low-temperature hermetically sealed optical fi components is provided. The method comprises the steps of: inserting an optical fiber into a housing, the optical fiber having a glass core, a glass cladding and a protective buffer layer disposed around the core and cladding; heating the housing to a predetermined temperature, the predetermined temperature being below a melting point for the protective buffer layer and above a melting point of a solder; placing the solder in communication with the heated housing to allow the solder to form an eutectic and thereby fill a gap between the interior of the housing and the optical fiber; and cooling the housing to allow the solder to form a hermetic compression seal between the housing and the optical fiber.

  3. Low-temperature hermetic sealing of optical fiber components

    DOEpatents

    Kramer, D.P.

    1996-10-22

    A method for manufacturing low-temperature hermetically sealed optical fiber components is provided. The method comprises the steps of: inserting an optical fiber into a housing, the optical fiber having a glass core, a glass cladding and a protective buffer layer disposed around the core and cladding; heating the housing to a predetermined temperature, the predetermined temperature being below a melting point for the protective buffer layer and above a melting point of a solder; placing the solder in communication with the heated housing to allow the solder to form an eutectic and thereby fill a gap between the interior of the housing and the optical fiber; and cooling the housing to allow the solder to form a hermetic compression seal between the housing and the optical fiber. 5 figs.

  4. Performance evaluation of fiber optic components in nuclear plant environments

    SciTech Connect

    Hastings, M.C.; Miller, D.W.; James, R.W.

    1996-03-01

    Over the past several years, the Electric Power Research Institute (EPRI) has funded several projects to evaluate the performance of commercially available fiber optic cables, connective devices, light sources, and light detectors under environmental conditions representative of normal and abnormal nuclear power plant operating conditions. Future projects are planned to evaluate commercially available fiber optic sensors and to install and evaluate performance of instrument loops comprised of fiber optic components in operating nuclear power plant applications. The objective of this research is to assess the viability of fiber optic components for replacement and upgrade of nuclear power plant instrument systems. Fiber optic instrument channels offer many potential advantages: commercial availability of parts and technical support, small physical size and weight, immunity to electromagnetic interference, relatively low power requirements, and high bandwidth capabilities. As existing nuclear power plants continue to replace and upgrade I&C systems, fiber optics will offer a low-cost alternative technology which also provides additional information processing capabilities. Results to date indicate that fiber optics are a viable technology for many nuclear applications, both inside and outside of containments. This work is funded and manage& under the Operations & Maintenance Cost Control research target of EPRI`s Nuclear Power Group. The work is being performed by faculty and students in the Mechanical and Nuclear Engineering Departments and the staff of the Nuclear Reactor Laboratory of the Ohio State University.

  5. Qualification and Lessons Learned with Space Flight Fiber Optic Components

    NASA Technical Reports Server (NTRS)

    Ott, Melanie

    2007-01-01

    This presentation covers lessons learned during the design, development, manufacturing and qualification of space flight fiber optic components. Changes at NASA, including short-term projects and decreased budgets have brought about changes to vendors and parts. Most photonics for NASA needs are now commercial off the shelf (COTS) products. The COTS Tecnology Assurance approach for space flight and qualification plans are outlined.

  6. Optical and optomechanical ultralightweight C/SiC components

    NASA Astrophysics Data System (ADS)

    Papenburg, Ulrich; Pfrang, Wilhelm; Kutter, G. S.; Mueller, Claus E.; Kunkel, Bernd P.; Deyerler, Michael; Bauereisen, Stefan

    1999-11-01

    Optical and optomechanical structures based on silicon carbide (SiC) ceramics are becoming increasingly important for ultra- lightweight optical systems that must work in adverse environments. At IABG and Dornier Satellite Systems (DSS) in Munich, a special form of SiC ceramics carbon fiber reinforced silicon carbide (C/SiCR) has been developed partly under ESA and NASA contracts. C/SiCR is a light-weight, high- strength engineering material that features tunable mechanical and thermal properties. It offers exceptional design freedom due to its reduced brittleness and negligible volume shrinkage during processing in comparison to traditional, powder-based ceramics. Furthermore, its rapid fabrication process produces near-net-shape components using conventional NC machining/milling equipment and, thus, provides substantial schedule, cost, and risk savings. These characteristics allow C/SiCR to overcome many of the problems associated with more traditional optical materials. To date, C/SiCR has been used to produce ultra-lightweight mirrors and reflectors, antennas, optical benches, and monolithic and integrated reference structures for a variety of space and terrestrial applications. This paper describes the material properties, optical system and structural design aspects, the forming and manufacturing process including high-temperature joining technology, precision grinding and cladding techniques, and the performance results of a number of C/SiCR optical components we have built.

  7. Hybrid optical (freeform) components--functionalization of nonplanar optical surfaces by direct picosecond laser ablation.

    PubMed

    Kleindienst, Roman; Kampmann, Ronald; Stoebenau, Sebastian; Sinzinger, Stefan

    2011-07-01

    The performance of optical systems is typically improved by increasing the number of conventionally fabricated optical components (spheres, aspheres, and gratings). This approach is automatically connected to a system enlargement, as well as potentially higher assembly and maintenance costs. Hybrid optical freeform components can help to overcome this trade-off. They merge several optical functions within fewer but more complex optical surfaces, e.g., elements comprising shallow refractive/reflective and high-frequency diffractive structures. However, providing the flexibility and precision essential for their realization is one of the major challenges in the field of optical component fabrication. In this article we present tailored integrated machining techniques suitable for rapid prototyping as well as the fabrication of molding tools for low-cost mass replication of hybrid optical freeform components. To produce the different feature sizes with optical surface quality, we successively combine mechanical machining modes (ultraprecision micromilling and fly cutting) with precisely aligned direct picosecond laser ablation in an integrated fabrication approach. The fabrication accuracy and surface quality achieved by our integrated fabrication approach are demonstrated with profilometric measurements and experimental investigations of the optical performance. PMID:21743521

  8. Airborne molecular contamination: quality criterion for laser and optical components

    NASA Astrophysics Data System (ADS)

    Otto, Michael

    2015-02-01

    Airborne molecular contaminations (AMCs) have been recognized as a major problem in semiconductor fabrication. Enormous technical and financial efforts are made to remove or at least reduce these contaminations in production environments to increase yield and process stability. It can be shown that AMCs from various sources in laser devices have a negative impact on quality and lifetime of lasers and optical systems. Outgassing of organic compounds, especially condensable compounds were identified as the main source for deterioration of optics. These compounds can lead to hazing on surfaces of optics, degradation of coating, reducing the signal transmission or the laser signal itself and can enhance the probability of laser failure and damage. Sources of organic outgassing can be molding materials, resins, seals, circuit boards, cable insulation, coatings, paints and others. Critical compounds are siloxanes, aromatic amines and high boiling aromatic hydrocarbons like phthalates which are used as softeners in plastic materials. Nowadays all sensitive assembly steps are performed in controlled cleanroom environments to reduce risks of contamination. We will demonstrate a high efficient air filter concept to remove AMCs for production environments with special AMC filters and methods for the qualification and monitoring of these environments. Additionally, we show modern techniques and examples for the pre-qualification of materials. For assembled components, we provide sampling concepts for a routine measurement for process, component and product qualification. A careful selection of previously tested and certified materials and components is essential to guarantee the quality of lasers and optical devices.

  9. Highly precise and robust packaging of optical components

    NASA Astrophysics Data System (ADS)

    Leers, Michael; Winzen, Matthias; Liermann, Erik; Faidel, Heinrich; Westphalen, Thomas; Miesner, Jörn; Luttmann, Jörg; Hoffmann, Dieter

    2012-03-01

    In this paper we present the development of a compact, thermo-optically stable and vibration and mechanical shock resistant mounting technique by soldering of optical components. Based on this technique a new generation of laser sources for aerospace applications is designed. In these laser systems solder technique replaces the glued and bolted connections between optical component, mount and base plate. Alignment precision in the arc second range and realization of long term stability of every single part in the laser system is the main challenge. At the Fraunhofer Institute for Laser Technology ILT a soldering and mounting technique has been developed for high precision packaging. The specified environmental boundary conditions (e.g. a temperature range of -40 °C to +50 °C) and the required degrees of freedom for the alignment of the components have been taken into account for this technique. In general the advantage of soldering compared to gluing is that there is no outgassing. In addition no flux is needed in our special process. The joining process allows multiple alignments by remelting the solder. The alignment is done in the liquid phase of the solder by a 6 axis manipulator with a step width in the nm range and a tilt in the arc second range. In a next step the optical components have to pass the environmental tests. The total misalignment of the component to its adapter after the thermal cycle tests is less than 10 arc seconds. The mechanical stability tests regarding shear, vibration and shock behavior are well within the requirements.

  10. Optical component interface scatter characterization by selective polarization extinction.

    PubMed

    Georges, Gaëlle; Deumié, Carole; Amra, Claude

    2011-03-20

    A procedure for the selective extinction of the scattered light based on "null ellipsometry" [R. M. A. Azzam and N. M. Bashara, Ellipsometry and Polarized Light (North-Holland, 1977)] is presented. The technique allows scattering measurement from individual layers of a multilayer component by extinguishing the scattered light from the other layer interfaces. The technique is easily applicable to multilayer components with nearly identical surface profiles at every interface and little significant bulk scattering. Analysis is provided to determine the conditions required to extinguish the light from the excluded interfaces isolating the scattered light from the desired interface. An analysis of sensitivity of the extinction conditions to experimental parameters and to layer optical thickness is also provided. Experimental data collected using the technique are compared with measurements made using a white-light optical surface profilometry.

  11. Degradation effects of optical components in the low orbit

    NASA Astrophysics Data System (ADS)

    Schmitt, Dirk-Roger; Ringel, Gabriele; Kratz, Frank; Neubauer, Rudolf; Swoboda, Helmut; Hampe, Jans

    1994-09-01

    Optical components which are being used for space instrumentation have been exposed to space conditions to examine degradation effects. The samples have been mounted into the SESAM (Surface Effects Sample Monitor) instrument which was integrated on the ASTRO-SPAS Satellite. Exposition occurred during the STS-51 mission. It was found out that especially supersmooth glass samples made of BK7 show damage effects which increase the roughness from i.e. 0.05 nm to 0.19 nm.

  12. Laser damage testing of optical components under cryogenic conditions

    NASA Astrophysics Data System (ADS)

    Oulehla, Jindrich; Pokorný, Pavel; Lazar, Josef

    2012-11-01

    In this contribution we present a technology for deposition and testing of interference coatings for optical components designed to operate in power pulsed lasers. The aim of the technology is to prepare components for high power laser facilities such as ELI (Extreme Light Infrastructure) or HiLASE. ELI is a part of the European plan to build a new generation of large research facilities selected by the European Strategy Forum for Research Infrastructures (ESFRI). These facilities rely on the use of diode pumped solid state lasers (DPSSL). The choice of the material for the lasers' optical components is critical. Some of the most important properties include the ability to be antireflection and high reflection coated to reduce the energy losses and increase the overall efficiency. As large amounts of heat need to be dissipated during laser operation, cryogenic cooling is necessary. The conducted experiments served as preliminary tests of laser damage threshold measurement methodology that we plan to use in the future. We designed a special apparatus consisting of a vacuum chamber and a cooling system. The samples were placed into the vacuum chamber which was evacuated and then the samples were cooled down to approximately 120K and illuminated by a pulsed laser. Pulse duration was in the nanosecond region. Multiple test sites on the sample's surface were used for different laser pulse energies. We used optical and electron microscopy and spectrophotometer measurements for coating investigation after the conducted experiments.

  13. Laser damage testing of optical components under cryogenic conditions

    NASA Astrophysics Data System (ADS)

    Oulehla, Jindřich; Pokorný, Pavel; Lazar, Josef

    2012-01-01

    In this contribution we present a technology for deposition and testing of interference coatings for optical components designed to operate in power pulsed lasers. The aim of the technology is to prepare components for high power laser facilities such as ELI (Extreme Light Infrastructure) or HiLASE. ELI is a part of the Eropean plan to build a new generation of large research facilities selected by the the Eropean Strategy Forum for Research Infrastructures (ESFRI). These facilities rely on the use of diode pumped solid state lasers (DPSSL). The choice of the material or the lasers' optical components is critical. Some of the most important properties include the ability to be antireflection and high reflection coated to reduce the energy losses and increase the overall efficiency. As large amounts of hear need to be dissipated during laser operation, cryogenic cooling is necessary. The conducted experiments served as preliminary tests of laser damage threshold measurement methodology that we plan to use in the future. We designed a special apparatus consistion of a vacuum chamber an a cooling system. The samples were placed into the vacuum chamber which was evacuated and them the samples were cooled down to approximately 120K and illuminated by a pulsed laser. Pulse duration was in the nanosecond region. Multiple test sites on the sample's surface were used for different laser pulse energies. We used optical and electron microscopy and spectrophotometer measurements for coating investigation after the conducted experiments.

  14. 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.

  15. Evaluation of systems and components for hybrid optical firing sets

    SciTech Connect

    Landry, M.J.; Rupert, J.W.; Mittas, A.

    1989-06-01

    High-energy density light appears to be a unique energy form that may be used to enhance the nuclear safety of weapon systems. Hybrid optical firing sets (HOFS) utilize the weak-link/strong-link exclusion region concept for nuclear safety; this method is similar to present systems, but uses light to transmit power across the exclusion region barrier. This report describes the assembling, operating, and testing of fourteen HOFS. These firing sets were required to charge a capacitor-discharge unit to 2.0 and 2.5 kV (100 mJ) in less than 1 s. First, we describe the components, the measurement techniques used to evaluate the components, and the different characteristics of the measured components. Second, we describe the HOFS studied, the setups used for evaluating them, and the resulting characteristics. Third, we make recommendations for improving the overall performance and suggest the best HOFS for packaging. 36 refs., 145 figs., 14 tabs.

  16. Degradation of electro-optic components aboard LDEF

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1993-01-01

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

  17. Degradation of electro-optic components aboard LDEF

    NASA Astrophysics Data System (ADS)

    Blue, M. D.

    1993-04-01

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

  18. 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.

  19. Reduced cost and improved figure of sapphire optical components

    NASA Astrophysics Data System (ADS)

    Walters, Mark; Bartlett, Kevin; Brophy, Matthew R.; DeGroote Nelson, Jessica; Medicus, Kate

    2015-10-01

    Sapphire presents many challenges to optical manufacturers due to its high hardness and anisotropic properties. Long lead times and high prices are the typical result of such challenges. The cost of even a simple 'grind and shine' process can be prohibitive. The high precision surfaces required by optical sensor applications further exacerbate the challenge of processing sapphire thereby increasing cost further. Optimax has demonstrated a production process for such windows that delivers over 50% time reduction as compared to traditional manufacturing processes for sapphire, while producing windows with less than 1/5 wave rms figure error. Optimax's sapphire production process achieves significant improvement in cost by implementation of a controlled grinding process to present the best possible surface to the polishing equipment. Following the grinding process is a polishing process taking advantage of chemical interactions between slurry and substrate to deliver excellent removal rates and surface finish. Through experiments, the mechanics of the polishing process were also optimized to produce excellent optical figure. In addition to reducing the cost of producing large sapphire sensor windows, the grinding and polishing technology Optimax has developed aids in producing spherical sapphire components to better figure quality. In addition to reducing the cost of producing large sapphire sensor windows, the grinding and polishing technology Optimax has developed aids in producing spherical sapphire components to better figure quality. Through specially developed polishing slurries, the peak-to-valley figure error of spherical sapphire parts is reduced by over 80%.

  20. Correlation of Test Data from Some NIF Small Optical Components

    SciTech Connect

    Chow, R; McBurney, M; Eickelberg, W K; Williams, W H; Thomas, M D

    2001-06-12

    The NIF injection laser system requires over 8000 precision optical components. Two special requirements for such optics are wavefront and laser damage threshold. Wavefront gradient is an important specification on the NIF ILS optics. The gradient affects the spot size and, in the second order, the contrast ratio of the laser beam. Wavefront errors are specified in terms of peak-to-valley, rms, and rms gradient, with filtering requirements. Typical values are lambda/8 PV, lambda/30 rms, and lambda/30/cm rms gradient determined after filtering for spatial periods greater than 2 mm. One objective of this study is to determine whether commercial software supplied with common phase measuring interferometers can filter, perform the gradient analysis, and produce numbers comparable to that by CVOS, the LLNL wavefront analysis application. Laser survivability of optics is another important specification for the operational longevity of the laser system. Another objective of this study is to find alternate laser damage test facilities. The addition of non-NIF testing would allow coating suppliers to optimize their processes according to their test plans and NIF integrators to validate the coatings from their sub-tiered suppliers. The maximum level required for anti-reflective, 45-degree high reflector, and polarizer coatings are 20, 30, and 5 J/cm{sup 2} (1064 nm, 3 ns pulse-width), respectively. The damage threshold correlation between a common set of samples tested by LLNL and a commercial test service is given.

  1. Thin film technologies for optoelectronic components in fiber optic communication

    NASA Astrophysics Data System (ADS)

    Perinati, Agostino

    1998-02-01

    will grow at an annual average rate of 22 percent from 1.3 million fiber-km in 1995 to 3.5 million fiber-km in 2000. The worldwide components market-cable, transceivers and connectors - 6.1 billion in 1994, is forecasted to grow and show a 19 percent combined annual growth rate through the year 2000 when is predicted to reach 17.38 billion. Fiber-in-the-loop and widespread use of switched digital services will dominate this scenario being the fiber the best medium for transmitting multimedia services. As long as communication will partially replace transportation, multimedia services will push forward technology for systems and related components not only for higher performances but for lower cost too in order to get the consumers wanting to buy the new services. In the long distance transmission area (trunk network) higher integration of electronic and optoelectronic functions are required for transmitter and receiver in order to allow for higher system speed, moving from 2.5 Gb/s to 5, 10, 40 Gb/s; narrow band wavelength division multiplexing (WDM) filters are required for higher transmission capacity through multiwavelength technique and for optical amplifier. In the access area (distribution network) passive components as splitters, couplers, filters are needed together with optical amplifiers and transceivers for point-to-multipoint optical signal distribution: main issue in this area is the total cost to be paid by the customer for basic and new services. Multimedia services evolution, through fiber to the home and to the desktop approach, will be mainly affected by the availability of technologies suitable for component consistent integration, high yield manufacturing processes and final low cost. In this paper some of the optoelectronic components and related thin film technologies expected to mainly affect the fiber optic transmission evolution, either for long distance telecommunication systems or for subscriber network, are presented.

  2. Degradation of optical components in a space environment

    NASA Technical Reports Server (NTRS)

    Dehainaut, Linda L.; Kenemuth, John; Tidler, Cynthia E.; Seegmiller, David W.

    1992-01-01

    The objective of the Phillips Laboratory (PL) Long Duration Exposure Facility (LDEF) experiment is to determine the adverse effects of the natural space environment on laser optical component and coating materials. The LDEF experiment provides a unique opportunity for the study of optical material response to an extended low earth orbit space exposure. The PL samples consist of 10 sets of the six materials each. The materials are uncoated fused silica, magnesium fluoride coated fused silica, uncoated molybdenum, molybdenum coated with chromium, silver and thorium fluoride, diamond turned copper, and diamond turned nickel plated copper. Performance degradation will be correlated to establish trends between sample location, duration of exposure, atomic oxygen exposure and other space environmental conditions. This paper discusses the results of the tests thus far performed on the LDEF samples and the plans for the future.

  3. 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.

  4. Optical component of the European Airborne Remote Sensing Capabilities (EARSEC)

    NASA Astrophysics Data System (ADS)

    Carrere, Veronique; Oertel, Dieter; Verdebout, Jean; Maracci, G.; Schmuck, Guido; Sieber, Alois J.

    1995-06-01

    The European Ariborne Remote Sensing Capabilities (EARSEC) is a program of the Commission of the European Union in coordination with the European Space Agency. Its goal is to establish an independent European state-of-the-art capability in remote sensing for a wide range of applications. The core instrument of the 'Optical' component of EARSEC is an Imaging Spectrometer (the Digital Airborne Imaging Spectrometer 7915 or DIAS 7915) built by Geophysical & Environmental Research Corporation (GER) and operated by DLR, Oberpfaffenhofen, in collaboration with JRC. The 79 channel high resolution Imaging Spectrometer (IS) covers the 0.4 to 12.3 micrometers wavelength range with a spectral resolution varying from 16 to 2000 nm. Operated from a Dornier 228 aircraft, the spatial resolution can vary between 3 and 15 m. The instrument is calibrated and improved at DLR and should be operational in 1995 for campaigns over Europe. The 'Optical' component of EARSEC also includes ground facilities, mainly an electro-optical (EO) processor developed for JRC by Earth Observation Sciences Limited in the United Kingdom for DAIS 7915 data processing. This processor will generate four levels of products, from simple ingestion, to calibration into physical units of radiance, to geolocation and geocoding. Collaborations are foreseen with European groups operating other advanced optical sensors such as the Italian LARA project, operating the MIVIS (IS comparable to the DAIS), and DLR, operating the ROSIS (developed for marine applications, covering the 430-850 nm region). The EO processor could be adapted in the future to handle other IS data for a more universal use.

  5. Reference beam laser Doppler velocimeter incorporating fiber optic components

    SciTech Connect

    James, S.W.; Lockey, R.A.; Egan, D.; Tatam, R.P.

    1995-12-31

    A compact reference beam laser Doppler velocimeter, constructed using a semiconductor laser diode, optical fiber components and semiconductor detectors, is reported. The device has been designed to overcome many of the problems commonly associated with reference beam configurations. The anemometer may be operated with the laser diode operating in cw and pulsed modes, demonstrating its applicability to wavelength and time division multiplexing schemes for 3D laser Doppler velocimetry. The probe is used to measure the velocity of a spinning disk in the range {minus}20 m/s to +20 m/s.

  6. 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.

  7. Picosecond laser welding of optical to metal components

    NASA Astrophysics Data System (ADS)

    Carter, Richard M.; Troughton, Michael; Chen, Jinanyong; Elder, Ian; Thomson, Robert R.; Lamb, Robert A.; Esser, M. J. Daniel; Hand, Duncan P.

    2016-03-01

    We report on practical, industrially relevant, welding of optical components to themselves and aluminum alloy components. Weld formation is achieved through the tight focusing of a 5.9ps, 400kHz Trumpf laser operating at 1030nm. By selecting suitable surface preparation, clamping and laser parameters, the plasma can be confined, even with comparatively rough surfaces, by exploiting the melt properties of the glass. The short interaction time allows for a permanent weld to form between the two materials with heating limited to a region ~300 µm across. Practical application of these weld structures is typically limited due to the induced stress within the glass and, critically, the issues surrounding post-weld thermal expansion. We report on the measured strength of the weld, with a particular emphasis on laser parameters and surface preparation.

  8. Two-component polariton condensate in an optical microcavity

    NASA Astrophysics Data System (ADS)

    Zhang, Yong-Chang; Zhou, Xiang-Fa; Guo, Guang-Can; Zhou, Xingxiang; Pu, Han; Zhou, Zheng-Wei

    2014-05-01

    We present a scheme for engineering the extended two-component Bose-Hubbard model using polariton condensate supported by an optical microcavity. Compared to the usual two-component Bose-Hubbard model with only Kerr nonlinearity, our model includes a nonlinear tunneling term which depends on the number difference of the particle in the two modes. In the mean-field treatment, this model is an analog to a nonrigid pendulum with a variable pendulum length whose sign can be also changed. We study the dynamic and ground-state properties of this model and show that there exists a first-order phase transition as the strength of the nonlinear tunneling rate is varied. Furthermore, we propose a scheme to obtain the polariton condensate wave function.

  9. The optical components of the NIRSpec wheel mechanisms

    NASA Astrophysics Data System (ADS)

    Ellenrieder, Marc M.; Weidlich, K.; Nelles, B.; Ploss, B.; Bruynooghe, S.; Köhler, J.; Te Plate, M.

    2008-07-01

    The Near-Infrared Spectrograph (NIRSPEC) on board the James Webb Space Telescope can be reconfigured in space for astronomical observation in a range of NIR sub-bands as well as spectral resolutions. Reconfiguration of the NIRSpec instrument will be achieved using a Filter Wheel Mechanism (FWA) which carries 7 transmission filters and one reflective mirror and a Grating Wheel Mechanism (GWA) which carries six gratings and one prism. The dispersive components on the grating wheel (GWA) cooperate with the edge transmission filters mounted on the filter wheel (FWA) which block the higher dispersion orders of the gratings. The paper gives an overview on the design of all optical elements, their key requirements and the employed manufacturing approach. Test results from breadboard and component level qualification phase are also given.

  10. Neutron activation of NIF Final Optics Assemblies

    NASA Astrophysics Data System (ADS)

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

    2010-08-01

    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 within10 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.

  11. Optical calibration of a new two-way optical component network analyzer

    NASA Astrophysics Data System (ADS)

    Tsao, Shyh-Lin; Ko, Chih-Han; Liou, Tai-Chi

    2003-12-01

    High-speed fiber communications show promising results recently [1,2]. Using of lightwave technology for measuring S parameters with optical component becoming important. For this purpose to develop a two-way network analyzer has been reported [3]. In this paper, we report the calibration method of a new two-way lightwave component analyze for applying in fiber optical signal processing elements. The background error and circulator wavelength response are all calibrated. We have designed a new probe for two-way optical component network analyzer. The probe is composed of frequency division multiplexer(FDM), electrical circulator, optical transmitter, optical receiver, and an optical circulator. We design 2-D grating structures as frequency division. The PCB we adopted is Kinstan GD1530 160 whose relative dielectric constantɛ= 4.3, length= 120 mm, and height= 1.8 mm. Two dimensional non-metal covered array square pads are designed on FR4 Glass-Epoxy board for FDM. The FDM can be achieved by the two dimensional non-metalized covered array square pads. Finally we use a single fiber ring resonator filter as our test samples. Comparing the numerical and experimental results, test the device we made. References [1] D. D. Curtis and E. E. Ames,"Optical Test Set for Microwave Fiber-Optic Network Analysis," IEEE Transactions on Microwave Theory and Techniques. , vol. 38, NO.5, pp. 552-559, 1990. [2] J. A. C. Bingham,"Multicarrier modulation for data transmission: an idea whose time has come," IEEE Commun. Magazine., pp. 5 -14, 1990. [3] M. Nakazawa, K. Suzuki, and Y. Kimura, " 3.2-5 Gbps 100km error-free soliton transmission with erbium amplifiers and repenters," IEEE Photonics Tech Lett.,vol.2,pp.216-219,1990.

  12. Plastic micro-optical components with the LIGA technology

    NASA Astrophysics Data System (ADS)

    Singleton, Laurence; Detemple, Peter; Frese, I.; Klotzbuecher, Thomas; Bauer, Hans-Dieter

    2003-01-01

    Moulding of plastics enables optical features to be integrated into a single unit. This is particularly an advantage for product designs that impose space and weight constraints. Therefore, the use of plastic for biomedical and non telecommunications orientated optical applications continues to grow as design engineers take advantage of the ease of fabrication and the material flexibility. Deep X-ray LIGA presents itself as a method ideally suited for the production of moulds for the manufacture of plastic microcomponents. LIGA is synonymous for the lithography preferably carried out with synchrotron radiation X-rays, although many other lithography and non-lithography methods for master production have been developed in the last few years. Nevertheless, the exceptional resist heights, the enormous accuracy and low runout as well as the low sidewall roughnesses cannot be copied by these other methods of master production. In particular, the low sidewall roughnesses achieved through deep X-ray LIGA is essential for the manufacture of waveguide coupling systems based on polymers. The design and conceptualisation of such waveguides systems is presented here. In addition however, the exceptional resist heights and low runout can be employed to produce passive structures for the packaging of optical components. This paper provides an overview of the deep X-ray LIGA technology, emphasizing its strengths and application areas. Considerations for the design and manufacture of the plastic structures are also elucidated.

  13. 78 FR 64009 - Certain Optical Disc Drives, Components Thereof, and Products Containing the Same; Institution of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-25

    ... COMMISSION Certain Optical Disc Drives, Components Thereof, and Products Containing the Same; Institution of... certain optical disc drives, components thereof, and products containing the same by reason of... sale within the United States after importation of certain optical disc drives, components thereof,...

  14. 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.

  15. Validation of Commercial Fiber Optic Components for Aerospace Environments

    NASA Technical Reports Server (NTRS)

    Ott, Melanie N.

    2005-01-01

    Full qualification for commercial photonic parts as defined by the Military specification system in the past, is not feasible. Due to changes in the photonic components industry and the Military specification system that NASA had relied upon so heavily in the past, an approach to technology validation of commercial off the shelf parts had to be devised. This approach involves knowledge of system requirements, environmental requirements and failure modes of the particular components under consideration. Synthesizing the criteria together with the major known failure modes to formulate a test plan is an effective way of establishing knowledge based "qualification". Although this does not provide the type of reliability assurance that the Military specification system did in the past, it is an approach that allows for increased risk mitigation. The information presented will introduce the audience to the technology validation approach that is currently applied at NASA for the usage of commercial-off-the-shelf (COTS) fiber optic components for space flight environments. The focus will be on how to establish technology validation criteria for commercial fiber products such that continued reliable performance is assured under the harsh environmental conditions of typical missions. The goal of this presentation is to provide the audience with an approach to formulating a COTS qualification test plan for these devices. Examples from past NASA missions will be discussed.

  16. Performance and production requirements for the optical components in a high-average-power laser system

    SciTech Connect

    Chow, R.; Doss, F.W.; Taylor, J.R.; Wong, J.N.

    1999-07-02

    Optical components needed for high-average-power lasers, such as those developed for Atomic Vapor Laser Isotope Separation (AVLIS), require high levels of performance and reliability. Over the past two decades, optical component requirements for this purpose have been optimized and performance and reliability have been demonstrated. Many of the optical components that are exposed to the high power laser light affect the quality of the beam as it is transported through the system. The specifications for these optics are described including a few parameters not previously reported and some component manufacturing and testing experience. Key words: High-average-power laser, coating efficiency, absorption, optical components

  17. Polarization optical components of the Daniel K. Inouye Solar Telescope

    NASA Astrophysics Data System (ADS)

    Sueoka, Stacey Ritsuyo

    The Daniel K Inouye Solar Telescope (DKIST), when completed in 2019 will be the largest solar telescope built to date. DKIST will have a suite of first light polarimetric instrumentation requiring broadband polarization modulation and calibration optical elements. Compound crystalline retarders meet the design requirements for efficient modulators and achromatic calibration retarders. These retarders are the only possible large diameter optic that can survive the high flux, 5 arc minute field, and ultraviolet intense environment of a large aperture solar telescope at Gregorian focus. This dissertation presents work performed for the project. First, I measured birefringence of the candidate materials necessary to complete designs. Then, I modeled the polarization effects with three-dimensional ray-tracing codes as a function of angle of incidence and field of view. Through this analysis I learned that due to the incident converging F/13 beam on the calibration retarders, the previously assumed linear retarder model fails to account for effects above the project polarization specifications. I discuss modeling strategies such as Mueller matrix decompositions and simplifications of those strategies while still meeting fit error requirements. Finally, I present characterization techniques and how these were applied to prototype components.

  18. Automated packaging platform for low-cost high-performance optical components manufacturing

    NASA Astrophysics Data System (ADS)

    Ku, Robert T.

    2004-05-01

    Delivering high performance integrated optical components at low cost is critical to the continuing recovery and growth of the optical communications industry. In today's market, network equipment vendors need to provide their customers with new solutions that reduce operating expenses and enable new revenue generating IP services. They must depend on the availability of highly integrated optical modules exhibiting high performance, small package size, low power consumption, and most importantly, low cost. The cost of typical optical system hardware is dominated by linecards that are in turn cost-dominated by transmitters and receivers or transceivers and transponders. Cost effective packaging of optical components in these small size modules is becoming the biggest challenge to be addressed. For many traditional component suppliers in our industry, the combination of small size, high performance, and low cost appears to be in conflict and not feasible with conventional product design concepts and labor intensive manual assembly and test. With the advent of photonic integration, there are a variety of materials, optics, substrates, active/passive devices, and mechanical/RF piece parts to manage in manufacturing to achieve high performance at low cost. The use of automation has been demonstrated to surpass manual operation in cost (even with very low labor cost) as well as product uniformity and quality. In this paper, we will discuss the value of using an automated packaging platform.for the assembly and test of high performance active components, such as 2.5Gb/s and 10 Gb/s sources and receivers. Low cost, high performance manufacturing can best be achieved by leveraging a flexible packaging platform to address a multitude of laser and detector devices, integration of electronics and handle various package bodies and fiber configurations. This paper describes the operation and results of working robotic assemblers in the manufacture of a Laser Optical Subassembly

  19. An analytical study of thermal invariance of polymeric nanolayer gradient index optical components

    NASA Astrophysics Data System (ADS)

    Fein, Howard; Ponting, Michael

    2016-05-01

    Specially formulated Gradient-Index polymeric optical materials offer capabilities not possible in conventional GRIN or homogenous optics. A novel technology that enables large scale processing of nanolayered polymer films into real, performance-enhancing lenses and other optical components for Defense-related optical systems is currently being employed. Polymeric nanoLayer GRIN materials (LGRIN) offer the ability to design and fabricate optics with custom gradient refractive index profiles in optical components up to 90 mm in diameter and approaching 5 cm thick. High performance achromatic singlet lenses were designed using specially developed ZEMAX design tools and exceptionally high quality lenses were fabricated from the LGRIN materials. Optical performance of LGRIN optics is shown to be significantly better than with conventional monolithic optics while also significantly reducing optical system mass, volume, and optical element count. Understanding the thermal behavior of such optical components is essential to their operational capability. An experimental study of the effects of elevated operational environments to validate the feasibility of deploying LGRIN optics into real-world operational environments was carried out. Interferometric and physical measurements of structure and optical performance of LGRIN lenses was completed over a 30° - 50°C temperature range. It is shown that nanolayered LGRIN optics and components exhibit no significant variation in optical performance with temperature as compared with commercial, homogenous acrylic optics in the designed operational thermal range.

  20. The electron temperature and optical emission structure of the central component of CTB 80

    NASA Technical Reports Server (NTRS)

    Blair, William P.; Fesen, Robert A.; Becker, Robert H.

    1988-01-01

    Optical spectra on the central component of the galactic supernova remnant CTB 80 are presented. Long slit CCD spectra reveal relative line-intensity variations among individual filaments, the presence of Balmer-dominated emission in the core's east and west optical lobes, and no radial velocities in excess of 300 km/s. Aperture spectrophotometry of the temperature-sensitive forbiddden O III lines suggests Te = 25,000 K, thus favoring a shock-heated interpretation for the remnant's optical core emission. These results indicate that fundamental differences exist betweem the optical emission of CTB 80's central core component and the Crab Nebula, despite similarities in these remnants' radio and X-ray properties. The optical emission from CTB 80's core is likely to be a direct result of the interaction of an active pulsar with its adjacent partially neutral interstellar medium. The size of CTB 80's outer structure and the absence of either high velocity or enhanced abundances in the region local to CTB 80's pulsar argue for a considerably larger age for CTB 80 than the Crab Nebula's 1000 yr. A qualitative picture for CTB 80 that can plausibly explain many of the core's properties is proposed.

  1. 76 FR 66750 - Certain Projectors With Controlled-Angle Optical Retarders, Components Thereof, and Products...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-27

    ... COMMISSION Certain Projectors With Controlled-Angle Optical Retarders, Components Thereof, and Products... Optical Retarders, Components Thereof, And Products Containing Same, DN 2849; the Commission is soliciting... within the United States after importation of certain projectors with controlled-angle optical...

  2. 78 FR 55292 - Certain Optical Disc Drives, Components Thereof, and Products Containing the Same; Notice of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-10

    ... COMMISSION Certain Optical Disc Drives, Components Thereof, and Products Containing the Same; Notice of... ] Commission has received a complaint entitled Certain Optical Disc Drives, Components Thereof, and Products..., and the sale within the United States after importation of certain optical disc drives,...

  3. Universe Interactive: Static Displays with Active Components

    NASA Astrophysics Data System (ADS)

    Larson, Michelle B.

    2005-01-01

    As the World Year of Physics (WYP) approaches, the AAPT WYP Committee would like to encourage everyone to consider ways to engage those around us in celebrating the science that makes us the proud geeks we are. The geek sentiment is my own, and does not necessarily reflect the views and opinions of the committee. This paper offers simple and inexpensive astronomy-related ideas for a bulletin-board-type display. The particular ideas presented below are hands-on classroom activities that I've adapted for display purposes. The display is static in that once constructed it does not require a personal facilitator, but each component invites interaction. At the end of the paper I revisit the idea of building a sundial1 as a highly visible and artistic way to engage students and communities in physics. The activities presented here are available for use when constructing your own display. In addition, these examples are meant to illustrate how instructional products might be modified for display purposes, and I encourage others to consider their favorite activities for an interactive display.

  4. Residual activation of thin accelerator components

    SciTech Connect

    Mokhov, N.V.; Rakhno, E.I.; Rakhno, I.L.; /Fermilab

    2006-05-01

    A method to calculate residual activation of thin accelerator components is presented. A model for residual dose estimation for thick objects made of arbitrary composite materials for arbitrary irradiation and cooling times is employed in this study. A scaling procedure is described to apply the model to thin objects with linear dimensions less than a fraction of a nuclear interaction length. The scaling has been performed for various materials and corresponding factors have been determined for objects of certain shapes (slab, solid and hollow cylinder) which are important from practical standpoint and can serve as models for beam pipes, magnets and collimators. Both contact residual dose and dose attenuation in air outside the objects were considered. A comparison between calculations and measurements performed at the Fermi National Accelerator Laboratory using a 120 GeV proton beam is presented.

  5. Method of making an integral window hermetic fiber optic component

    DOEpatents

    Dalton, R.D.; Kramer, D.P.; Massey, R.T.; Waker, D.A.

    1996-11-12

    In the fabrication of igniters, actuators, detonators, and other pyrotechnic devices to be activated by a laser beam, an integral optical glass window is formed by placing a preform in the structural member of the device and then melting the glass and sealing it in place by heating at a temperature between the ceramming temperature of the glass and the melting point of the metal, followed by rapid furnace cooling to avoid devitrification. No other sealing material is needed to achieve hermeticity. A preferred embodiment of this type of device is fabricated by allowing the molten glass to flow further and form a plano-convex lens integral with and at the bottom of the window. The lens functions to decrease the beam divergence caused by refraction of the laser light passing through the window when the device is fired by means of a laser beam. 9 figs.

  6. Method of making an integral window hermetic fiber optic component

    DOEpatents

    Dalton, Rick D.; Kramer, Daniel P.; Massey, Richard T.; Waker, Damon A.

    1996-11-12

    In the fabrication of igniters, actuators, detonators, and other pyrotechnic devices to be activated by a laser beam, an integral optical glass window is formed by placing a preform in the structural member of the device and then melting the glass and sealing it in place by heating at a temperature between the ceramming temperature of the glass and the melting point of the metal, followed by rapid furnace cooling to avoid devitrification. No other sealing material is needed to achieve hermeticity. A preferred embodiment of this type of device is fabricated by allowing the molten glass to flow further and form a plano-convex lens integral with and at the bottom of the window. The lens functions to decrease the beam divergence caused by refraction of the laser light passing through the window when the device is fired by means of a laser beam.

  7. Hybrid solar collector using nonimaging optics and photovoltaic components

    NASA Astrophysics Data System (ADS)

    Winston, Roland; Yablonovitch, Eli; Jiang, Lun; Widyolar, Bennett K.; Abdelhamid, Mahmoud; Scranton, Gregg; Cygan, David; Kozlov, Alexandr

    2015-08-01

    The project team of University of California at Merced (UC-M), Gas Technology Institute, and Dr. Eli Yablonovitch of University of California at Berkeley developed a novel hybrid concentrated solar photovoltaic thermal (PV/T) collector using nonimaging optics and world record single-junction Gallium arsenide (GaAs) PV components integrated with particle laden gas as thermal transfer and storage media, to simultaneously generate electricity and high temperature dispatchable heat. The collector transforms a parabolic trough, commonly used in CSP plants, into an integrated spectrum-splitting device. This places a spectrum-sensitive topping element on a secondary reflector that is registered to the thermal collection loop. The secondary reflector transmits higher energy photons for PV topping while diverting the remaining lower energy photons to the thermal media, achieving temperatures of around 400°C even under partial utilization of the solar spectrum. The collector uses the spectral selectivity property of Gallium arsenide (GaAs) cells to maximize the exergy output of the system, resulting in an estimated exergy efficiency of 48%. The thermal media is composed of fine particles of high melting point material in an inert gas that increases heat transfer and effectively stores excess heat in hot particles for later on-demand use.

  8. Material selection for lightweight optical components in fieldable military optical test set

    NASA Astrophysics Data System (ADS)

    Engelhaupt, Darell E.; Ahmad, Anees; Lewis, George R.; George, Gene

    1994-10-01

    Material selection and suitable low cost manufacturing processes for production of rugged man-portable lightweight optical test set components are described. Field requirements for an ultra lightweight optical test set comprised of an off-axis two mirror collimator plus source and detector optics mandated selection of extremely stable materials. The requirements include temporal, thermal and mechanical performance suitable for portable and transportable military applications. The environmental stability requirement includes operating over a temperature range of 130 degrees fahrenheit. Also military shock and vibration requirements for transportable equipment are imposed on the entire test set. The total weight budget is 5 pounds for the mirrors and the large supporting structure. The structure volume is only about 1% of the occupied space. A near-net fabrication process such as casting or HIP fabrication was required. A comparison of materials and manufacturing methods has resulted in the selection of a hypereutectic aluminum alloy containing 23% by weight silicon with stabilizing elements. This material can be cast and heat treated to produce uniform properties at low cost. The coefficient of thermal expansion (CTE) is much lower than other aluminum alloys and the modulus of elasticity is 50% higher. The alloy was machined with conventional tools and plated with nickel phosphorous of the same CTE to produce stable optics.

  9. Achromatic registration of quadrature components of the optical spectrum in spectral domain optical coherence tomography

    SciTech Connect

    Shilyagin, P A; Gelikonov, G V; Gelikonov, V M; Moiseev, A A; Terpelov, D A

    2014-07-31

    We have thoroughly investigated the method of simultaneous reception of spectral components with the achromatised quadrature phase shift between two portions of a reference wave, designed for the effective suppression of the 'mirror' artefact in the resulting image obtained by means of spectral domain optical coherence tomography (SD OCT). We have developed and experimentally tested a phase-shifting element consisting of a beam divider, which splits the reference optical beam into the two beams, and of delay lines being individual for each beam, which create a mutual phase difference of π/2 in the double pass of the reference beam. The phase shift achromatism over a wide spectral range is achieved by using in the delay lines the individual elements with different dispersion characteristics. The ranges of admissible adjustment parameters of the achromatised delay line are estimated for exact and inexact conformity of the geometric characteristics of its components to those calculated. A possibility of simultaneous recording of the close-to-quadrature spectral components with a single linear photodetector element is experimentally confirmed. The suppression of the artefact mirror peak in the OCT-signal by an additional 9 dB relative to the level of its suppression is experimentally achieved when the air delay line is used. Two-dimensional images of the surface positioned at an angle to the axis of the probe beam are obtained with the correction of the 'mirror' artefact while maintaining the dynamic range of the image. (laser biophotonics)

  10. Conceptual design of an on-board optical processor with components

    NASA Technical Reports Server (NTRS)

    Walsh, J. R.; Shackelford, R. G.

    1977-01-01

    The specification of components for a spacecraft on-board optical processor was investigated. A space oriented application of optical data processing and the investigation of certain aspects of optical correlators were examined. The investigation confirmed that real-time optical processing has made significant advances over the past few years, but that there are still critical components which will require further development for use in an on-board optical processor. The devices evaluated were the coherent light valve, the readout optical modulator, the liquid crystal modulator, and the image forming light modulator.

  11. 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.

  12. Overview of advanced components for fiber optic systems

    NASA Technical Reports Server (NTRS)

    Depaula, Ramon P.; Stowe, David W.

    1986-01-01

    The basic operating principles and potential performance of several state-of-the-art fiber-optic devices are illustrated with diagrams and briefly characterized. Technologies examined include high-birefringence polarization-maintaining fibers and directional couplers, single-mode fiber polarizers and cut-off polarizers, optical-fiber modulators with radially poled piezoactive polymer (PVF2) jackets, and piezoelectric-squeezer polarization modulators. The need for improved manufacturing techniques to make such fiber-optic devices cost-competitive with their thin-film integrated-optics analogs is indicated.

  13. 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.

  14. 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.

  15. Occupational Doses from the use of Thoriated Optical Components.

    PubMed

    Schirmer, Andreas; Kersting, Marc; Uschmann, Katja

    2016-08-01

    As a compound of high refractive optical glasses, thorium still is present in some professionally used systems-especially in optical equipment with military use. The possible exposure concerns the head and especially the eye lens, whose radiation sensitivity has been reevaluated. The dose rate measurements of the contribution of beta- and gamma-emission by the nuclei of the decay chain of Th are presented for isolated lenses and for the entire optical system, and the dose quantities H'(0.07) and H*(10) are identified. Exposure scenarios for optical technicians and users are evaluated separately. The levels of dose rates for the inspected optical systems are below those requiring radiation protection measures even for extended working time or unintentional use. PMID:27356053

  16. NASA SBIR Subtopic S2.04 "Advanced Optical Components"

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip

    2009-01-01

    The primary purpose of this subtopic is to develop and demonstrate technologies to manufacture ultra-low-cost precision optical systems for very large x-ray, UV/optical or infrared telescopes. Potential solutions include but are not limited to direct precision machining, rapid optical fabrication, slumping or replication technologies to manufacture 1 to 2 meter (or larger) precision quality mirror or lens segments (either normal incidence for uv/optical/infrared or grazing incidence for x-ray). An additional key enabling technology for UV/optical telescopes is a broadband (from 100 nm to 2500 nm) high-reflectivity mirror coating with extremely uniform amplitude and polarization properties which can be deposited on 1 to 3 meter class mirror.

  17. Activation of Inactive Nitrogenase by Acid-Treated Component I

    PubMed Central

    Nagatani, H. H.; Shah, Vinod K.; Brill, Winston J.

    1974-01-01

    When Azotobacter vinelandii was derepressed for nitrogenase synthesis in a N-free medium containing tungstate instead of molybdate, an inactive component I was synthesized. Although this inactive component I could be activated in vivo upon addition of molybdate to the medium, it could not be activated in vitro when molybdate was added to the extracts. Activation occurred, however, when an acid-treated component I was added to extracts of cells derepressed in medium containing tungstate. Acid treatment completely abolished component I activity. Mutant strains UW45 and UW10 were unable to fix N2. Both strains synthesized normal levels of component II but produced inactive component I. Acid-treated component I activated inactive component I in extracts of mutant strain UW45 but not mutant strain UW10. This activating factor could be obtained from N2-fixing Klebsiella pneumoniae, Clostridium pasteurianum, and Rhodospirillum rubrum. PMID:4218230

  18. Optical coupling of bare optoelectronic components and flexographically printed polymer waveguides in planar optronic systems

    NASA Astrophysics Data System (ADS)

    Wang, Yixiao; Wolfer, Tim; Lange, Alex; Overmeyer, Ludger

    2016-05-01

    Large scale, planar optronic systems allowing spatially distributed functionalities can be well used in diverse sensor networks, such as for monitoring the environment by measuring various physical quantities in medicine or aeronautics. In these systems, mechanically flexible and optically transparent polymeric foils, e.g. polymethyl methacrylate (PMMA) and polyethylene terephthalate (PET), are employed as carrier materials. A benefit of using these materials is their low cost. The optical interconnections from light sources to light transmission structures in planar optronic systems occupy a pivotal position for the sensing functions. As light sources, we employ the optoelectronic components, such as edgeemitting laser diodes, in form of bare chips, since their extremely small structures facilitate a high integration compactness and ensure sufficient system flexibility. Flexographically printed polymer optical waveguides are deployed as light guiding structures for short-distance communication in planar optronic systems. Printing processes are utilized for this generation of waveguides to achieve a cost-efficient large scale and high-throughput production. In order to attain a high-functional optronic system for sensing applications, one of the most essential prerequisites is the high coupling efficiency between the light sources and the waveguides. Therefore, in this work, we focus on the multimode polymer waveguide with a parabolic cross-section and investigate its optical coupling with the bare laser diode. We establish the geometrical model of the alignment based on the previous works on the optodic bonding of bare laser diodes and the fabrication process of polymer waveguides with consideration of various parameters, such as the beam profile of the laser diode, the employed polymer properties of the waveguides as well as the carrier substrates etc. Accordingly, the optical coupling of the bare laser diodes and the polymer waveguides was simulated

  19. Localization of two-component Bose-Einstein condensates in optical lattices.

    PubMed

    Ostrovskaya, Elena A; Kivshar, Yuri S

    2004-05-01

    We study nonlinear localization of a two-component Bose-Einstein condensate (BEC) in a one-dimensional optical lattice. Our theory shows that spin-dependent optical lattices can be used to effectively manipulate the nonlinear interactions between the BEC components, and to observe composite localized states of a BEC in both bands and gaps of the matter-wave spectrum.

  20. Wavefront control of optical components by laser-ablative figuring

    NASA Astrophysics Data System (ADS)

    Jitsuno, Takahisa; Akashi, Tomoyoshi; Nakatsuka, Masahiro; Nakai, Sadao; Tokumura, Keiu

    1997-12-01

    A new method for figuring the surface profile of optical plastics and optical glass have been proposed and demonstrated. An ArF excimer laser is used to ablate very thin layer of the surface of the substrates. The shape of the ablated surface is monitored by an interferometer in site condition. The ablation rate of PMMA is 0.08 micrometers per pulse at the energy density of 50 mJ/cm2. The optical glass (BK-7) can be ablated 0.15 micrometers per pulse at the fluence of 1.5 J/cm2.

  1. Components for optical qubits encoded in sideband modes

    SciTech Connect

    Huntington, E.H.; Ralph, T.C.

    2004-04-01

    We describe a scheme for the encoding and manipulation of single photon qubits in optical sideband modes using standard optical elements. We propose and analyze the radio frequency half-wave plate, which may be used to make arbitrary rotations of a state in the frequency basis, and the frequency beamsplitter, which may be used to separate (or combine) photons of different frequencies into (from) different spatial modes.

  2. Hybrid optical TDM/WDM network technology and architecture: Component and subsystem development

    NASA Astrophysics Data System (ADS)

    Zhou, Deyu

    The ever-growing Internet has driven high demands on bandwidth. The supply of the transmission and networking bandwidth is not catching up with the insatiable demands on capacity at a satisfactory level quality of service with an affordable price. In the past ten to fifteen years, wavelength division multiplexing (WDM) has revolutionized communications research and development. WDM technologies relieve the much-needed bandwidth at its fastest pace and at an affordable price. However wavelengths themselves are scare resource due to the limited bandwidth of optical amplifiers. With fixed wavelength spacing between adjacent optical signal channels, there is a limited number of channels available for WDM networks with moderately high bit rate at which the electronics multiplexing/demultiplexing are possible. As the industry tries to continually push narrow the channel spacing, they meet ever increasing challenges due to linear and nonlinear interactions within each individual signal channel and among different signal channels. There is a limit in how small the inter-channel spacing can be. Without increasing the bit rate of each individual channel, eventually, the bandwidth will reach its limits. Researchers throughout the world are now actively looking an alternative: combination of aggregating WDM channels and increasing the bit rate of each channel by optical time division multiplexing (OTDM), that is, seeking hybrid OTDM/WDM networks and architectures to increase the supply of bandwidth. With the development of an all optical switch: terahertz optical asymmetric demultiplexer (TOAD) at Princeton and its variations in different configurations, it is now possible to extract a single bit from a single wavelength data stream at bit rate as high as 750Gbps with a 1.3ps switching window. Therefore, it is possible to bit interleave many smaller users into a single wavelength in OTDM. With hybrid OTDM/WDM networks becoming more desirable and more practical for supplying

  3. An integrated optical pickup with roll-to-roll fabricated diffractive components.

    PubMed

    Hsu, Jo-Han; Lee, Chi-Hung; Chen, Rongshun

    2011-07-01

    This work designed and fabricated an optical pickup system based on optical films using the roll-to-roll process. The design combined the advantages of the stacked and planar optical pickup system. Two blazed gratings were used as beam splitters for bending the optical path, while a cylindrical lens was used for astigmatic focus-error detection. The proposed design effectively reduces overall system configuration, component cost, and fabrication complexity.

  4. Active optics, adaptive optics, and laser guide stars.

    PubMed

    Hubin, N; Noethe, L

    1993-11-26

    Optical astronomy is crucial to our understanding of the universe, but the capabilities of ground-based telescopes are severely limited by the effects of telescope errors and of the atmosphere on the passage of light. Recently, it has become possible to construct inbuilt corrective devices that can compensate for both types of degradations as observations are conducted. For full use of the newly emerged class of 8-meter telescopes, such active corrective capabilities, known as active and adaptive optics, are essential. Some physical limitations in the adaptive optics field can be overcome by artificially created reference stars, called laser guide stars. These new technologies have lately been applied with success to some medium and very large telescopes. PMID:17736819

  5. Cultural Components of Physically Active Schools

    ERIC Educational Resources Information Center

    Rickwood, Greg

    2015-01-01

    It is well known that a large majority of school-age children and adolescents are not active enough to gain the physical and psychological benefits associated with regular moderate-to-vigorous physical activity. Schools can play a pivotal role in reversing this trend due to the time students spend in this setting. The purpose of this article is to…

  6. Updated optical read/write memory system components

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The fabrication of an updated block data composer and holographic storage array for a breadboard holographic read/write memory system is described. System considerations such as transform optics and controlled aberration lens design are described along with the block data composer, photoplastic recording materials, and material development.

  7. Laser and optics activities at CREOL

    SciTech Connect

    Stickley, C.M.

    1995-06-01

    CREOL is an interdisciplinary institute with a mission to foster and support research and education in the optical and laser sciences and engineering. CREOL`s principal members are its 21-strong faculty. The faculty are encouraged and supported in developing, maintaining, and expanding innovative and sponsored research programs, especially ones that are coupled to industry`s needs. The CREOL Director and Assistant Director, through empowerment by the CREOL faculty, coordinate and oversee the interactive, interdisciplinary projects of the faculty, the 85 graduate students and the 39 research staff. CREOL integrates these research efforts with the general educational mission and goals of the university, develops comprehensive course work in the optical and laser sciences and engineering, provides guidance and instruction to graduate students, administers MS and PhD programs, and provides facilities, funds, and administrative support to assist the faculty in carrying out CREOL`s mission and obtaining financial support for the research projects. CREOL`s specific areas of research activity include the following: IR systems; nonlinear optics; crystal growth; nonlinear integrated optics; new solid-state lasers; tunable far-infrared lasers; thin-film optics; theory; semiconductor lasers; x-ray/optical scattering; laser-induced damage; free-electron lasers; solid-state spectroscopy; x-ray sources and applications; laser propagation; laser processing of materials; optical design; optical limiting/sensor protection; diffractive optics; quantum well optoelectronics; dense plasmas/high-field physics; laser radar and remote sensing; diode-based lasers; and glass science.

  8. Thermo-optical pressure difference in one-component gas

    SciTech Connect

    Chermyaninov, I. V.; Chernyak, V. G.

    2014-09-15

    A new phenomenon—thermo-optical pressure difference in the gas (TOPD) is regarded. This effect is the steady state of the second order which arises in the gas located in a closed capillary in the presence of a fixed temperature gradient and a resonant optical radiation. TOPD is the result of imposition thermal transpiration and light-induced drift of gas in a capillary. The problem is solved on the basis of the linearized Boltzmann kinetic equations for excited and unexcited gaseous particles. Expressions for the kinetic coefficients and pressure drop in gas at the ends of the closed capillary are obtained. Possible cases of the steady state are regarded for atoms and molecules. Numerical estimates of this effect for atomic and molecular gases in the whole range of Knudsen numbers are given.

  9. Nanoradian angular stabilization of x-ray optical components

    SciTech Connect

    Stoupin, Stanislav; Lenkszus, Frank; Laird, Robert; Goetze, Kurt; Kim, Kwang-Je; Shvyd'ko, Yuri

    2010-05-15

    An x-ray free-electron laser oscillator (XFELO) has been recently proposed [K. Kim et al., Phys. Rev. Lett. 100, 244802 (2008)]. Angular orientation and position in space of Bragg mirrors of the XFELO optical cavity must be continuously adjusted to compensate for the instabilities and maximize the output intensity. An angular stability of about 10 nrad (rms) is required [K. Kim and Y. Shvyd'ko, Phys. Rev. ST Accel. Beams 12, 030703 (2009)]. To approach this goal, a feedback loop based on a null-detection principle was designed and used for stabilization of a high-energy-resolution x-ray monochromator ({Delta}E/E{approx_equal}4x10{sup -8}, E=23.7 keV) and a high-heat-load monochromator. Angular stability of about 13 nrad (rms) has been demonstrated for x-ray optical elements of the monochromators.

  10. Updated optical read/write memory system components

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A survey of the building blocks of the electro-optic read/write system was made. Critical areas and alternate paths are discussed. The latest PLZT block data composer is analyzed. Stricter controls in the production and fabrication of PLZT are implied by the performance of the BDC. A reverse charge before erase has eliminated several problems observed in the parallel plane charging process for photoconductor-thermoplastic hologram storage.

  11. Analysis of elastic micro optical components under large deformation

    NASA Astrophysics Data System (ADS)

    Hoshino, Kazunori; Shimoyama, Isao

    2003-01-01

    We describe a technique for analyzing the mechanical and optical properties of deformable optical elements that combines the finite element method, ray-tracing and birefringence measurement. We fabricated a pneumatically actuated microlens array on an elastic polydimethylsiloxane (PDMS) film to assess the proposed analysis technique. The lenses are 120 mum in diameter and arranged on the top surface of a 200 mum thick base film. The lenses are displaced by pneumatic actuators at the bottom of the film. The measured mechanical-optical properties of the PDMS test materials showed a good match with the calculation. The paths and retardation of light beams transmitted in the microlens array under several actuating conditions were then analyzed. The lens displacement of 21.8 mum was measured at an applied pressure of -45 kPa. At the same pressure, a ray-trace analysis showed that the actuator changed the visual axis of each lens by 5°, while the retardation was estimated to be within the order of 5 × 10-3 nm.

  12. 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

  13. Hard plastic cladding fiber (HPCF) based optical components for high speed short reach optical communications

    NASA Astrophysics Data System (ADS)

    Kim, Jun Ki; Kim, Dong Uk; Kim, Tae Young; Park, Chang Soo; Oh, Kyunghwan

    2006-09-01

    We developed the primary components applicable to HPCF links for short reach (SR) and very short reach (VSR) data communication systems. We fabricated 4x4 HPCF fused taper splitter, HPCF pigtailed VCSEL and PIN photodiode for high speed short reach communications and characterized back to back transmission performance of the link composed of these components by measuring eye diagrams and jitters. Adapting the fusion-tapering technique for glass optical fiber, we successfully fabricated a 4x4 HPCF fused taper coupler. The HPCF with a core diameter of 200μm and an outer diameter of 230μm had step refractive index of 1.45 and 1.40 for the core and the clad. The optimized fusion length and tapering waist which make minimum insertion loss of about 7dB and uniform output power splitting ratio with less than 0.5dB are 13mm and 150µm, respectively. As a light source for VSR networks, we chose a vertical cavity surface emitting laser (VCSEL) and developed a package with a HPCF pigtail. After positioning VCSEL and HPCF that made a minimum coupling loss, we glued the HPCF inside ceramic ferrule housing. In HPCF-PIN PD packaging, we added a micro polymer lens tip onto the HPCF ends to match the mode field area to the sensitive area of GaAs or InGaAs PIN PD. Coupling between a PIN PD chip and the lensed HPCF was optimized with the radius of curvature of 156µm with a low coupling loss of 0.3dB, which is compatible to conventional MMF-PD packaging. For 1.25 Gbps data rate, the eyes adequate to eye mask in gigabit Ethernet were wide open after all HPCF transmission link and no significant power penalty was observed.

  14. A COMPREHENSIVE STUDY OF GAMMA-RAY BURST OPTICAL EMISSION. I. FLARES AND EARLY SHALLOW-DECAY COMPONENT

    SciTech Connect

    Li Liang; Liang Enwei; Tang Qingwen; Chen Jiemin; Xi Shaoqiang; Zhang Bing; Lu Ruijing; Lue Lianzhong; Lue Houjun; Gao He; Zhang Jin; Wei Jianyan; Yi Shuangxi E-mail: zhang@physics.unlv.edu

    2012-10-10

    Well-sampled optical light curves of 146 gamma-ray bursts (GRBs) are compiled from the literature. By empirical fitting, we identify eight possible emission components and summarize the results in a 'synthetic' light curve. Both optical flare and early shallow-decay components are likely related to long-term central engine activities. We focus on their statistical properties in this paper. Twenty-four optical flares are obtained from 19 GRBs. The isotropic R-band energy is smaller than 1% of E{sub {gamma},iso}. The relation between the isotropic luminosities of the flares and gamma rays follows L{sup F}{sub R,iso}{proportional_to}L {sup 1.11{+-}0.27}{sub {gamma},iso}. Later flares tend to be wider and dimmer, i.e., w{sup F} {approx} t{sup F}{sub p}/2 and L{sup F}{sub R,iso}{proportional_to}[t{sup F}{sub p}/(1 + z)]{sup -1.15{+-}0.15}. The detection probability of the optical flares is much smaller than that of X-ray flares. An optical shallow-decay segment is observed in 39 GRBs. The relation between the break time and break luminosity is a power law, with an index of -0.78 {+-} 0.08, similar to that derived from X-ray flares. The X-ray and optical breaks are usually chromatic, but a tentative correlation is found. We suggest that similar to the prompt optical emission that tracks {gamma}-rays, the optical flares are also related to the erratic behavior of the central engine. The shallow-decay component is likely related to a long-lasting spinning-down central engine or piling up of flare materials onto the blast wave. Mixing of different emission components may be the reason for the diverse chromatic afterglow behaviors.

  15. 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

  16. 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.

  17. 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.

  18. Spectral optical monitoring of nitrate in inland and seawater with miniaturized optical components.

    PubMed

    Kröckel, L; Schwotzer, G; Lehmann, H; Wieduwilt, T

    2011-01-01

    Miniaturized spectral analytical systems become ever increasingly important for in situ monitoring of natural waters' nutrients, such as nitrate, phosphate or ammonium. A miniaturized UV spectral photometer has been developed for online detection using liquid core wave guides (LCW), UV transmitting optical fibers, a low-cost miniature polychromator, and a deuterium light source. The LCWs were manufactured by coating the insides of silica glass capillaries with Teflon(®) AF 1600. Due to this setup our instrument needs only a few microliters of sample for each measurement. Nitrate can be directly detected by UV absorption spectroscopy in a spectral range between 200 and 350 nm. To separate the nitrate absorption from the superposition of other UV absorbing contaminations, a multi component analysis (MCA) software was applied to the measured spectra. With this developed photometer, nitrate levels can be determined online in inland and seawater or, if needed, in situ. It was evaluated twice in the field and the results for the measured amounts of nitrate in reservoir samples and in the North Sea are also presented in this work.

  19. The effects of ionizing radiation on fiber optic systems and components for use in mobile platforms

    NASA Astrophysics Data System (ADS)

    Reddy, Mahesh; Krinsky, Jeff

    1991-02-01

    Many applications for fiber optic components and systems exist in mobile platforms. Some of the mobile platforms will be expected to operate through or survive exposure to ionizing radiation. Construction of systems that can survive the required radiation environments requires special design considerations. This paper describes the effects of ionizing radiation on some fiber optic components and systems for use in mobile platforms, and an example of transient radiation test data on a prototype analog two wavelength referenced system is presented.

  20. Improvement in the performance of laser based optical rotational sensor by reducing the stress co-efficient of optical component

    NASA Astrophysics Data System (ADS)

    Rasheed, I. Abdul; Naidu, V. Atchaiah; Gupta, Mahender Kumar; Chhabra, Inder Mohan; Karthikeyan, B.

    2016-05-01

    Laser based optical rotational sensors are used as an inertial rotation sensor for navigation purpose. The life time of the rotational sensor wholly depend on the type / quality of the optical components that are used. While developing the rotational sensors, based on the total internal reflection techniques, the laser is passing through the glass material. As the glass is having a high verdant constant the laser gets affected and suffers from the rotation of polarization. This phenomenon still gets enhanced if the components which are optically bonded are having a high order of non - uniformity. It creates the stress onto the prism as well on the Optical block and gives rise to a varying amount of stress induced Birefringes. Because of this observation, the performance of the rotational sensor gets deteriorated. This paper will present the techniques used for producing the highly flat surface, which will reduce the stress Birefringes and in turn improve the performance of the rotational sensor.

  1. 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.

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

    PubMed

    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. PMID:27415269

  3. Fiber optic gyroscope using an eight-component LiNbO3 integrated optic circuit

    NASA Technical Reports Server (NTRS)

    Minford, W. J.; Stone, F. T.; Youmans, B. R.; Bartman, R. K.

    1990-01-01

    A LiNbO3 integrated optic circuit (IOC) containing eight optical functions has been successfully incorporated into an interferometric fiber optic gyroscope. The IOC has the minimum configuration optical functions (a phase modulator, a polarizer, and two beam splitters) and Jet Propulsion Laboratory's novel beat detection circuit (a phase modulator, two optical taps, and a beam splitter) which provides a means of directly reading angular position and rotation rate. The optical subsystem consisting of the fiber-pigtailed IOC and a sensing coil of 945 meters of polarization-maintaining fiber has a loss of 18.7dB, which includes 9dB due to the architecture and unpolarized source. A random walk coefficient was measured using an edge-emitting LED as the source.

  4. Railway track component condition monitoring using optical fibre Bragg grating sensors

    NASA Astrophysics Data System (ADS)

    Buggy, S. J.; James, S. W.; Staines, S.; Carroll, R.; Kitson, P.; Farrington, D.; Drewett, L.; Jaiswal, J.; Tatam, R. P.

    2016-05-01

    The use of optical fibre Bragg grating (FBG) strain sensors to monitor the condition of safety critical rail components is investigated. Fishplates, switchblades and stretcher bars on the Stagecoach Supertram tramway in Sheffield in the UK have been instrumented with arrays of FBG sensors. The dynamic strain signatures induced by the passage of a tram over the instrumented components have been analysed to identify features indicative of changes in the condition of the components.

  5. Splitting up an optical beam in a polarized component added to an unpolarized component

    NASA Astrophysics Data System (ADS)

    Lacaze, Bernard

    2016-08-01

    The decomposition of an optical beam in a polarized part added to an unpolarized part was studied by G.G. Stokes among numerous other works. Today, the problem is no longer a trigonometric manipulation proper to monochromatic waves, but a problem handling stationary processes with band spectra. In literature, the question seems to be: given some spectral properties and some propagation medium, can we obtain a decomposition? Furthermore, in the case of a positive answer, we have to provide devices for exhibiting solutions. In a linear framework, the problem always has a solution (and even an infinity) whatever the chosen polarization direction. In this paper, we study the links which appear most often between the members of the decomposition.

  6. 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)

  7. Semantic-Aware Components and Services of ActiveMath

    ERIC Educational Resources Information Center

    Melis, Erica; Goguadze, Giorgi; Homik, Martin; Libbrecht, Paul; Ullrich, Carsten; Winterstein, Stefan

    2006-01-01

    ActiveMath is a complex web-based adaptive learning environment with a number of components and interactive learning tools. The basis for handling semantics of learning content is provided by its semantic (mathematics) content markup, which is additionally annotated with educational metadata. Several components, tools and external services can…

  8. A Large Aperture, High Energy Laser System for Optics and Optical Component Testing

    SciTech Connect

    Nostrand, M C; Weiland, T L; Luthi, R L; Vickers, J L; Sell, W D; Stanley, J A; Honig, J; Auerbach, J; Hackel, R P; Wegner, P J

    2003-11-01

    A large aperture, kJ-class, multi-wavelength Nd-glass laser system has been constructed at Lawrence Livermore National Lab which has unique capabilities for studying a wide variety of optical phenomena. The master-oscillator, power-amplifier (MOPA) configuration of this ''Optical Sciences Laser'' (OSL) produces 1053 nm radiation with shaped pulse lengths which are variable from 0.1-100 ns. The output can be frequency doubled or tripled with high conversion efficiency with a resultant 100 cm{sup 2} high quality output beam. This facility can accommodate prototype hardware for large-scale inertial confinement fusion lasers allowing for investigation of integrated system issues such as optical lifetime at high fluence, optics contamination, compatibility of non-optical materials, and laser diagnostics.

  9. Summary of the effects of radiation upon the passive optical components of the Versatile Link

    NASA Astrophysics Data System (ADS)

    Huffman, B. T.; Weidberg, A.

    2014-01-01

    The LHC luminosity upgrade, known as the High Luminosity LHC (HL-LHC) will require high-speed optical links to read out data from its detectors. The ATLAS and CMS experiments in collaboration with CERN have developed the Versatile Link in order to address the technical issues of optical data transmission within the harsh radiation environment experienced by any experiment within the HL-LHC. Passive optical components can suffer damage in the form of reduced optical transparency (radiation induced absorption or RIA), reduced bandwidth, and mechanical damage to the components themselves and their connection hardware. This paper summarizes the results of the optical and mechanical tests that have been performed on the Versatile Link's passive optical components. The authors conclude that two single mode and two multimode fibres, as well as standard connector components, can be qualified for use in the HL-LHC environment. The qualifying fibers are: Corning SMF-28e, DrakaElite® SRH-SMF, Corning Clearcurve® OM4 multimode graded index, and DrakaElite® SRH-MMF.

  10. 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.

  11. Independent Components of Neural Activity Carry Information on Individual Populations

    PubMed Central

    Głąbska, Helena; Potworowski, Jan; Łęski, Szymon; Wójcik, Daniel K.

    2014-01-01

    Local field potential (LFP), the low-frequency part of the potential recorded extracellularly in the brain, reflects neural activity at the population level. The interpretation of LFP is complicated because it can mix activity from remote cells, on the order of millimeters from the electrode. To understand better the relation between the recordings and the local activity of cells we used a large-scale network thalamocortical model to compute simultaneous LFP, transmembrane currents, and spiking activity. We used this model to study the information contained in independent components obtained from the reconstructed Current Source Density (CSD), which smooths transmembrane currents, decomposed further with Independent Component Analysis (ICA). We found that the three most robust components matched well the activity of two dominating cell populations: superior pyramidal cells in layer 2/3 (rhythmic spiking) and tufted pyramids from layer 5 (intrinsically bursting). The pyramidal population from layer 2/3 could not be well described as a product of spatial profile and temporal activation, but by a sum of two such products which we recovered in two of the ICA components in our analysis, which correspond to the two first principal components of PCA decomposition of layer 2/3 population activity. At low noise one more cell population could be discerned but it is unlikely that it could be recovered in experiment given typical noise ranges. PMID:25153730

  12. Refractive index variation in compression molding of precision glass optical components.

    PubMed

    Su, Lijuan; Chen, Yang; Yi, Allen Y; Klocke, Fritz; Pongs, Guido

    2008-04-01

    Compression molding of glass optical components is a high volume near net-shape precision fabrication method. In a compression molding process, a variation of the refractive index occurs along the radial direction of the glass component due to thermal treatment. The variation of refractive index is an important parameter that can affect the performance of optical lenses, especially lenses used for high precision optical systems. Refractive index variations in molded glass lenses under different cooling conditions were investigated using both an experimental approach and a numerical simulation. Specifically, refractive index variations inside molded glass lenses were evaluated by measuring optical wavefront variations with a Shack-Hartmann sensor system. The measured refractive index variations of the molded glass lenses were compared with the numerical simulation as a validation of the modeling approach.

  13. Towards do-it-yourself planar optical components using plasmon-assisted etching

    NASA Astrophysics Data System (ADS)

    Chen, Hao; Bhuiya, Abdul M.; Ding, Qing; Johnson, Harley T.; Toussaint, Kimani C., Jr.

    2016-01-01

    In recent years, the push to foster increased technological innovation and basic scientific and engineering interest from the broadest sectors of society has helped to accelerate the development of do-it-yourself (DIY) components, particularly those related to low-cost microcontroller boards. The attraction with DIY kits is the simplification of the intervening steps going from basic design to fabrication, albeit typically at the expense of quality. We present herein plasmon-assisted etching as an approach to extend the DIY theme to optics, specifically the table-top fabrication of planar optical components. By operating in the design space between metasurfaces and traditional flat optical components, we employ arrays of Au pillar-supported bowtie nanoantennas as a template structure. To demonstrate, we fabricate a Fresnel zone plate, diffraction grating and holographic mode converter--all using the same template. Applications to nanotweezers and fabricating heterogeneous nanoantennas are also shown.

  14. Towards do-it-yourself planar optical components using plasmon-assisted etching

    PubMed Central

    Chen, Hao; Bhuiya, Abdul M.; Ding, Qing; Johnson, Harley T.; Toussaint Jr, Kimani C.

    2016-01-01

    In recent years, the push to foster increased technological innovation and basic scientific and engineering interest from the broadest sectors of society has helped to accelerate the development of do-it-yourself (DIY) components, particularly those related to low-cost microcontroller boards. The attraction with DIY kits is the simplification of the intervening steps going from basic design to fabrication, albeit typically at the expense of quality. We present herein plasmon-assisted etching as an approach to extend the DIY theme to optics, specifically the table-top fabrication of planar optical components. By operating in the design space between metasurfaces and traditional flat optical components, we employ arrays of Au pillar-supported bowtie nanoantennas as a template structure. To demonstrate, we fabricate a Fresnel zone plate, diffraction grating and holographic mode converter—all using the same template. Applications to nanotweezers and fabricating heterogeneous nanoantennas are also shown. PMID:26814026

  15. Optical Microfibre Based Photonic Components and Their Applications in Label-Free Biosensing

    PubMed Central

    Wang, Pengfei; Bo, Lin; Semenova, Yuliya; Farrell, Gerald; Brambilla, Gilberto

    2015-01-01

    Optical microfibre photonic components offer a variety of enabling properties, including large evanescent fields, flexibility, configurability, high confinement, robustness and compactness. These unique features have been exploited in a range of applications such as telecommunication, sensing, optical manipulation and high Q resonators. Optical microfibre biosensors, as a class of fibre optic biosensors which rely on small geometries to expose the evanescent field to interact with samples, have been widely investigated. Due to their unique properties, such as fast response, functionalization, strong confinement, configurability, flexibility, compact size, low cost, robustness, ease of miniaturization, large evanescent field and label-free operation, optical microfibres based biosensors seem a promising alternative to traditional immunological methods for biomolecule measurements. Unlabeled DNA and protein targets can be detected by monitoring the changes of various optical transduction mechanisms, such as refractive index, absorption and surface plasmon resonance, since a target molecule is capable of binding to an immobilized optical microfibre. In this review, we critically summarize accomplishments of past optical microfibre label-free biosensors, identify areas for future research and provide a detailed account of the studies conducted to date for biomolecules detection using optical microfibres. PMID:26287252

  16. Integrated device with diffractive polarization components for a magneto-optical disk head

    NASA Technical Reports Server (NTRS)

    Haggans, Charles W.; Fujita, Teruo; Kostuk, Raymond K.

    1992-01-01

    The optical components in the detection train of a conventional magneto-optical (MO) disk head include a half-wave plate and a polarization beamsplitter. These polarization components are bulky and require specialized mounting hardware. In order to realize a more compact head, we propose that these elements be replaced by an integrated device composed of cascaded volume and surface-relief gratings. Herein, the proposed system is described in detail for the individual elements, theoretical and prototype element performance are compared, and the operational tolerances of these elements are discussed.

  17. Noise analysis in photonic true time delay systems based on broadband optical source and dispersion components.

    PubMed

    Xue, Xiaoxiao; Wen, He; Zheng, Xiaoping; Zhang, Hanyi; Guo, Yili; Zhou, Bingkun

    2009-02-01

    The noise in photonic true time delay systems based on broadband optical source and dispersion components is investigated. It is found that the beat noise induced by the optical source begins to dominate and grows far larger than other noise terms quickly, as long as the detected optical power is above some certain value P(thr). When the system dispersion is nonzero, the output carrier-to-noise ratio (CNR) will change periodically with the optical bandwidth due to the noise power increment and the dispersion induced radio frequency signal power degradation. The maximum CNR is the peak value of the first period. For a set of specified system conditions, the P(thr) is calculated to be -21 dBm, and the optimal optical bandwidth is 0.8 nm, at which the maximum CNR is 93.3 dB by considering the noise in a 1 Hz bandwidth. The results are verified experimentally.

  18. Radiation effects on optical components of a laser radar sensor designed for remote metrology in ITER

    SciTech Connect

    Menon, M.M.; Grann, E.B.; Slotwinski, A.

    1997-09-01

    A frequency modulated laser radar is being developed for in-vessel metrology and viewing of plasma-facing surfaces. Some optical components of this sensor must withstand intense gamma radiation (3 {times} 10{sup 6} rad/h) during operation. The authors have tested the effect of radiation on a silica core polarization maintaining optical fiber and on TeO{sub 2} crystals at doses up to {approximately} 10{sup 9} rad. Additional tests are planned for evaluating the performance of a complete acousto-optic (AO) scanning device. The progress made in these tests is also described.

  19. Active Star Architectures For Fiber Optics Ethernet

    NASA Astrophysics Data System (ADS)

    Linde, Yoseph L.

    1988-12-01

    Ethernet, and the closely related IEEE 802.3 CSMA/CD standard (Carrier Sense Multiple Access with Collision Detection), is probably the widest used method for high speed Local Area Networks (LANs). The original Ethernet medium was baseband coax but the wide acceptance of the system necessitated the ability to use Ethernet on a variety of media. So far the use of Ethernet on Thin Coax (CheaperNet), Twisted Pair (StarLan) and Broadband Coax has been standardized. Recently, an increased interest in Fiber Optic based LANs resulted in a formation of an IEEE group whose charter is to recommend approaches for Active and Passive Fiber Optic Ethernet systems. The various approaches which are being considered are described in this paper with an emphasis on Active Star based systems.

  20. Acousto-optical combined frequency splitters and shifters as components of a ring optical gyroscope

    SciTech Connect

    Kotov, V M

    1999-03-31

    An analysis is made of the task of symmetrisation of a Y-type directional coupler and of shifting the frequency of counterpropagating waves in a ring gyroscope by means of the relatively recently discovered new type of acousto-optical diffraction when the incident radiation is diffracted simultaneously into two orders. Anisotropic and isotropic acousto-optical diffraction in a uniaxial crystal is considered and expressions convenient for calculations are derived. Experiments carried out on isotropic diffraction in LiNbO{sub 3} confirm, on the whole, the theoretical predictions. (laser applications and other topics in quantum electronics)

  1. The components of an optical RS flip-flop for an integrated optical processor

    NASA Astrophysics Data System (ADS)

    Parker, Michael A.; Libby, Stuart I.; Swanson, Paul D.

    1992-07-01

    This report discusses the design, fabrication and test of an optical RS Flip-Flop as an integrated optical memory element. The Flip-Flop has three GaAs-AlGaAs heterostructure lasers with total internal reflection mirrors. A main laser incorporates a saturable absorber to develop the bistable output characteristics. A pump laser bleaches the absorber to set the logic 1 state. A third laser quenches the main laser to reset the device to logic 0. Experiments and data for the laser quenching and bistability are presented.

  2. 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.

  3. Galangal pungent component, 1'-acetoxychavicol acetate, activates TRPA1.

    PubMed

    Narukawa, Masataka; Koizumi, Kanako; Iwasaki, Yusaku; Kubota, Kikue; Watanabe, Tatsuo

    2010-01-01

    We investigated the activation of transient receptor potential cation channel (TRP) subfamily V, member 1 (TRPV1) and TRP subfamily A, member 1 (TRPA1) by 1'-acetoxychavicol acetate (ACA), the main pungent component in galangal. ACA did not activate TRPV1-expressing human embryonic kidney (HEK) cells, but strongly activated TRPA1-expressing HEK cells. ACA was more potent than allyl isothiocyanate, the typical TRPA1 agonist.

  4. 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.

  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. ESTIMATION OF INHERENT OPTICAL PROPERTIES AND THE WATER QUALITY COMPONENTS IN THE NEUSE RIVER-PAMLICO SOUND ESTUARINE SYSTEM

    EPA Science Inventory

    Field observations carried out in the Neuse River-Pamlico Sound Estuarine System (NRE-PS), North Carolina, USA were used to develop optical algorithms for assessing inherent optical properties, IOPs (absorption and backscattering) associated with water quality components (WQC).

  7. [Study on the active components of Nardostachys chinensis].

    PubMed

    Zhang, Xu; Lan, Zhou; Dong, Xiao-ping; Deng, Yun; Hu, Xiao-mei; Peng, Teng; Guo, Ping

    2007-01-01

    To study on the active components of Nardostachys chinensis Batal, the compounds were isolated and purified by chromatographic methods, with their structures identified by spectral analysis and comparison with published data. 9 compounds were obtained and their structures were identified as acaciin, ursolie acid, octacosanol, kanshone A, nardosinonediol, nardosinone, aristolen-9beta-ol, oleanolic acid and beta-sitosterol. Acaciin, ursolie acid and octacosanol were obtained from Nardostachys chinensis Batal. for the first time. Acaciin and ursolie are the active components of antihiotics and anti-inflammatory.

  8. Analysis of exposure due to work on activated components

    SciTech Connect

    Cossairt, J.D.

    1987-09-01

    In this brief note the author summarized analysis of the exposure incurred in various maintenance jobs involving activated accelerator and beam line components at Fermilab. A tabulation was made of parameters associated with each job. Included are rather terse descriptions of the various tasks. The author presented various plots of the quantities in the table. All exposure rates are mR/hr while all exposures accumulated are mR. The exposure rates were generally measured at the Fermilab standard one foot distance from the activated component. Accumulated exposures are taken from the self-reading pocket dosimeter records maintained by the radiation control technicians.

  9. 78 FR 77166 - Certain Optoelectronic Devices for Fiber Optic Communications, Components Thereof, and Products...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... From the Federal Register Online via the Government Publishing Office INTERNATIONAL TRADE COMMISSION Certain Optoelectronic Devices for Fiber Optic Communications, Components Thereof, and Products Containing the Same; Notice of Request for Statements on the Public Interest AGENCY: U.S. International...

  10. Solar cyclic tests of optical fiber components working in ammonia and high temperatures

    NASA Astrophysics Data System (ADS)

    Fidelus, Janusz D.; Stańczyk, Tomasz; Wysokiński, Karol; Lipiński, Stanisław; Tenderenda, Tadeusz; Rodriguez Garcia, José; Canadas Martinez, Inmaculada; Nasiłowski, Tomasz

    2015-12-01

    The paper reports on the metal (Cu, Ni, Au)-coated fibers annealed under concentrated solar radiation in ammonia and N2/H2 atmospheres at temperatures up to 580 °C. Tensile strength of the annealed fiber components was studied from the point of view of their possible application as a fiber optic sensors in urea chemical synthesis process control.

  11. Dielectric prisms would improve performance of quasi-optical microwave components

    NASA Technical Reports Server (NTRS)

    Carson, J. W.

    1967-01-01

    Properties of the Brewster angle and internal reflection in a dielectric prism are proposed as the basis of a new type of element for use in oversize waveguide in quasi-optical microwave components. Waveguide loss is reduced and precision broadband attenuators, phase shifters, and directional couplers can be constructed on the basis of the properties.

  12. Active optics control development at the LBT

    NASA Astrophysics Data System (ADS)

    Ashby, David S.; Biddick, Christopher; Hill, John M.

    2014-07-01

    The Large Binocular Telescope (LBT) is built around two 8.4 m-diameter primary mirrors placed with a centerline separation of 14.4 m in a common altitude/azimuth mount. Each side of the telescope can utilize a deployable prime focus instrument; alternatively, the beam can be directed to a Gregorian instrument by utilizing a deployable secondary mirror. The direct-Gregorian beam can be intercepted and redirected to several bent-Gregorian instruments by utilizing a deployable tertiary mirror. Two of the available bent-Gregorian instruments are interferometers, capable of coherently combining the beams from the two sides of the telescope. Active optics can utilize as many as 26 linearly independent degrees of freedom to position the primary, secondary and tertiary mirrors to control optical collimation while the telescope operates in its numerous observing modes. Additionally, by applying differential forces at 160 locations on each primary mirror, active optics controls the primary mirror figure. The authors explore the challenges associated with collimation and primary mirror figure control at the LBT and outline the ongoing related development aimed at optimizing image quality and preparing the telescope for interferometric operations.

  13. Biological Activity of Dolichandrone serrulata Flowers and Their Active Components.

    PubMed

    Phanthong, Phanida; Phumal, Noppawan; Chancharunee, Sirirat; Mangmool, Supachoke; Anantachoke, Natthinee; Bunyapraphatsara, Nuntavan

    2015-08-01

    Dolichandrone serrulata (DC.) Seem flowers are widely used as vegetables in northern and eastern Thailand. Biological studies of the methanolic extract of these flowers have shown promising antioxidant activity. Biological-guided separation of D. serrulata flowers yielded six compounds, identified as hallerone, protocatechuic acid, rengyolone, cleroindicin B, ixoside, and isomaltose. This is the first report on hallerone, protocatechuic acid, rengyolone, cleroindicin B, and isomaltose in D. serrulata. Protocatechuic acid was the most potent scavenger of 2,2-diphenyl-l-picrylhydrazyl and hydroxyl radicals with IC50 values of 25.6 +/- 0.6 and 29.6 +/- 0.4 microM, respectively. Hallerone and rengyolone showed moderate scavenging action on superoxide radicals and inhibited H202 induced reactive oxygen species production in HEK-293 cell. In addition, the other isolated compounds showed weak activity.

  14. Large-aperture active optical carbon fiber reinforced polymer mirror

    NASA Astrophysics Data System (ADS)

    Jungwirth, Matthew E. L.; Wilcox, Christopher C.; Wick, David V.; Baker, Michael S.; Hobart, Clinton G.; Milinazzo, Jared J.; Robichaud, Joseph; Romeo, Robert C.; Martin, Robert N.; Ballesta, Jerome; Lavergne, Emeric; Dereniak, Eustace L.

    2013-05-01

    An active reflective component can change its focal length by physically deforming its reflecting surface. Such elements exist at small apertures, but have yet to be fully realized at larger apertures. This paper presents the design and initial results of a large-aperture active mirror constructed of a composite material called carbon fiber reinforced polymer (CFRP). The active CFRP mirror uses a novel actuation method to change radius of curvature, where actuators press against two annular rings placed on the mirror's back. This method enables the radius of curvature to increase from 2000mm to 2010mm. Closed-loop control maintains good optical performance of 1.05 waves peak-to-valley (with respect to a HeNe laser) when the active CFRP mirror is used in conjunction with a commercial deformable mirror.

  15. Magnetic ordering of three-component ultracold fermionic mixtures in optical lattices

    NASA Astrophysics Data System (ADS)

    Sotnikov, Andrii; Hofstetter, Walter

    2014-06-01

    We study finite-temperature magnetic phases of three-component mixtures of ultracold fermions with repulsive interactions in optical lattices with simple cubic or square geometry by means of dynamical mean-field theory (DMFT). We focus on the case of one particle per site (1/3 band filling) at moderate interaction strength, where we observe a sequence of thermal phase transitions into two- and three-sublattice ordered states by means of the unrestricted real-space generalization of DMFT. From our quantitative analysis we conclude that long-range ordering in three-component mixtures should be observable at comparable temperatures as in two-component mixtures.

  16. A Sensing System for Simultaneous Detection of Urine and its Components Using Plastic Optical Fibers

    NASA Astrophysics Data System (ADS)

    Ejaz, Tahseen; Takemae, Tadashi; Egami, Chikara; Tsuboi, Naoyuki

    A sensing system using plastic optical fibers and reagent papers was developed for the detection of urine and abnormal level of its components simultaneously. Among several components of urine the detection of two main components namely, protein and glucose was confirmed experimentally. Three states of the papers namely dry and wet with and without change in color, were taken into consideration. These three states were divided by setting the lower and upper threshold voltages at 2.2 V and 5.5 V, respectively. This system is considered to be simple in construction, easy to operate and cost-efficient.

  17. 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

  18. Active and Passive RF Components for High-Power Systems

    NASA Astrophysics Data System (ADS)

    Tantawi, Sami G.; Nantista, Christopher D.

    2002-08-01

    In recent years, R&D for pulse compression and power distribution systems for the Next Linear Collider has led to the invention of many novel rf components, some of which must handle up to 600 MW of pulsed power at X-band. These include passive waveguide components, active switch designs, and non-reciprocal devices. Among the former is a class of multi-moded, highly efficient rf components based on planar geometries with overmoded rectangular ports. Multi-moding allows us, by means of input phasing, to direct power to different locations through the same waveguide. Planar symmetry allows the height to be increased to improve power handling capacity. Features that invite breakdown, such as coupling slots, irises and H-plane septa, are avoided. This class includes hybrids, directional couplers, an eight-port superhybrid/dual-mode launcher, a mode-selective extractor, mode-preserving bends, a rectangular mode converter, and mode-mixers. We are able to utilize such rectangular waveguide components in systems incorporating low-loss, circular waveguide delay lines by means of specially designed tapers that efficiently transform multiple rectangular waveguide modes into their corresponding circular waveguide modes, specifically TE10 and TE20 into circular TE11 and TE01. These extremely compact tapers can replace well-known mode converters such as the Marie type. Another component, a reflective TE01-TE02 mode converter in circular waveguide, allows us to double the delay in reflective or resonant delay lines. Ideas for multi-megawatt active components, such as switches, have also been pursued. Power-handling capacity for these is increased by making them also highly overmoded. We present a design methodology for active rf magnetic components which are suitable for pulse compression systems of future X-band linear colliders. We also present an active switch based on a PIN diode array. This component comprises an array of active elements arranged so that the electric fields

  19. Antioxidant activity of minor components of tree nut oils.

    PubMed

    Miraliakbari, H; Shahidi, F

    2008-11-15

    The antioxidative components of tree nut oils were extracted using a solvent stripping process. Tree nut oil extracts contained phospholipids, sphingolipids, sterols and tocopherols. The chloroform/methanol extracted oils had higher amounts of phenolic compounds than their hexane extracted counterparts. The antioxidant activity of tree nut oil minor component extracts were assessed using the 2,2-azino-bis (3-ethylbenzthiazoline sulphonate) (ABTS) radical scavenging activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity, β-carotene bleaching test, oxygen radical absorbance capacity (ORAC) and photochemiluminescence inhibition assays. Results of these studies demonstrated that extracts of chloroform/methanol extracted oils possessed higher antioxidant activities than extracts of their hexane extracted counterparts. Meanwhile the extract of chloroform/methanol extracted pecan oil possessed the highest antioxidant activity. PMID:26047445

  20. Active microstructured x-ray optical arrays

    NASA Astrophysics Data System (ADS)

    Michette, Alan G.; Pfauntsch, Slawka J.; Sahraei, Shahin; Shand, Matthew; Morrison, Graeme R.; Hart, David; Vojnovic, Boris; Stevenson, Tom; Parkes, William; Dunare, Camelia; Willingale, Richard; Feldman, Charlotte H.; Button, Tim W.; Zhang, Dou; Rodriguez-Sanmartin, Daniel; Wang, Hongchang; Smith, Andy D.

    2009-05-01

    The UK Smart X-Ray Optics consortium is developing novel reflective adaptive/active x-ray optics for small-scale laboratory applications, including studies of radiation-induced damage to biological material. The optics work on the same principle as polycapillaries, using configured arrays of channels etched into thin silicon, such that each x-ray photon reflects at most once off a channel wall. Using two arrays in succession provides two reflections and thus the Abbe sine condition can be approximately satisfied, reducing aberrations. Adaptivity is achieved by flexing one or both arrays using piezo actuation, which can provide further reduction of aberrations as well as controllable focal lengths. Modelling of such arrays for used on an x-ray microprobe, based on a microfocus source with an emitting region approximately 1μm in diameter, shows that a focused flux approximately two orders of magnitude greater than possible with a zone plate of comparable focal length is possible, assuming that the channel wall roughness is less than about 2nm.

  1. Optical activity and Alfred Werner's coordination chemistry.

    PubMed

    Ernst, Karl-Heinz; Berke, Heinz

    2011-03-01

    It is widely accepted, that Pasteur's seminal discovery of the opposite optical activity of ammonium sodium tartrate enantiomorphs in solution gave the spark to organic stereochemistry and led to the development of the tetrahedron model by van't Hoff and Le Bel. The proof that chirality is inherently connected to octahedral coordination chemistry fostered greatly Werner's spatial views of metal complexes and his coordination theory. The actual proof of principle was established via separation of diastereomeric camphor sulfonate salts of racemic metal complexes. PMID:20928897

  2. Vibrational Raman optical activity of biological molecules

    NASA Astrophysics Data System (ADS)

    Barron, L. D.; Gargaro, A. R.; Hecht, Lutz; Wen, Z. Q.; Hug, W.

    1991-05-01

    Advances in Raman optical activity (ROA) instrumentation based on the employment of a backscattering geometry together with a cooled CCD detector have now enhanced the sensitivity to the level necessary to provide vibrational ROA spectra of biological molecules in aqueous solution. Preliminary results on peptides and proteins show features originating in coupled Ca-H and N-H deformations of the peptide backbone which appear to be sensitive to the secondary conformation. Also carbohydrates show many features that appear to be characteristic of the central aspects of carbohydrate architecture with effects from the glycosidic link in di- and oligosaccharides particularly prominent. 1.

  3. Active microring based tunable optical power splitters

    NASA Astrophysics Data System (ADS)

    Peter, Eldhose; Thomas, Arun; Dhawan, Anuj; Sarangi, Smruti R.

    2016-01-01

    In this paper we propose a set of novel tunable optical power splitters based on active microring resonators. They work by operating ring resonators in the transient zone between full resonance and off-resonance states for a specific wavelength. We can achieve different split ratios by either varying the bias voltage, or by selectively enabling a given resonator with a specific split ratio among an array of ring resonators. We take 500 ps to tune the resonator, which is at least 10× better that competing designs. Its split ratio varies from 0.4 to 1.8 for an applied voltage range of 0-5 V.

  4. 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.}

  5. Measurement of the accumulation of water ice on optical components in cryogenic vacuum environments

    NASA Astrophysics Data System (ADS)

    Moeller, Trevor M.; Montgomery Smith, L.; Collins, Frank G.; Labello, Jesse M.; Rogers, James P.; Lowry, Heard S.; Crider, Dustin H.

    2012-11-01

    Standard vacuum practices mitigate the presence of water vapor and contamination inside cryogenic vacuum chambers. However, anomalies can occur in the facility that can cause the accumulation of amorphous water ice on optics and test articles. Under certain conditions, the amorphous ice on optical components shatters, which leads to a reduction in signal or failure of the component. An experiment was performed to study and measure the deposition of water (H2O) ice on optical surfaces under high-vacuum cryogenic conditions. Water was introduced into a cryogenic vacuum chamber, via a hydrated molecular sieve zeolite, through an effusion cell and impinged upon a quartz-crystal microbalance (QCM) and first-surface gold-plated mirror. A laser and photodiode setup, external to the vacuum chamber, monitored the multiple-beam interference reflectance of the ice-mirror configuration while the QCM measured the mass deposition. Data indicates that water ice, under these conditions, accumulates as a thin film on optical surfaces to thicknesses over 45 microns and can be detected and measured by nonintrusive optical methods which are based upon multiple-beam interference phenomena. The QCM validated the interference measurements. This experiment established proof-of-concept for a miniature system for monitoring ice accumulation within the chamber.

  6. A viscoplastic model for the active component in cardiac muscle.

    PubMed

    Rubin, M B

    2016-08-01

    The HMK model (Hunter et al. in Prog Biophys Mol Biol 69:289-331, 1998) proposes mechanobiological equations for the influence of intracellular calcium concentration [Formula: see text] on the evolution of bound calcium concentration [Formula: see text] and the tropomyosin kinetics parameter z, which model processes in the active component of the tension in cardiac muscle. The inelastic response due to actin-myosin crossbridge kinetics is modeled in the HMK model with a function Q that depends on the history of the rate of total stretch of the muscle fiber. Here, an alternative model is proposed which models the active component of the muscle fiber as a viscoplastic material. In particular, an evolution equation is proposed for the elastic stretch [Formula: see text] in the active component. Specific forms of the constitutive equations are proposed and used to match experimental data. The proposed viscoplastic formulation allows for separate modeling of three processes: the high rate deactivation of crossbridges causing rapid reduction in active tension; the high but lower rate reactivation of crossbridges causing recovery of active tension; and the low rate relaxation effects characterizing the Hill model of muscles.

  7. Testing of optical components to assure performance in a high acerage power environment

    SciTech Connect

    Chow, R.; Taylor, J.R.; Eickelberg, W.K.; Primdahl, K.A.

    1997-06-24

    Evaluation and testing of the optical components used in the Atomic Vapor Laser Isotope Separation (AVLIS) plant is critical for qualification of suppliers, development of new optical multilayer designs and monufacturing processes, and assurance of performance in the production cycle. The range of specifications requires development of specialized test equipment and methods which are not routine or readily available in industry. Specifications are given on material characteristics such as index homogeneity, subsurface damage left after polishing, microscopic surface defects and contamination, coating absorption, and high average power laser damage. The approach to testing these performance characteristics and assuring the quality throughout the production cycle is described.

  8. 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.

  9. Nanomechanics of Actively Controlled Deployable Optics

    NASA Technical Reports Server (NTRS)

    Peterson, Lee D.

    2000-01-01

    This document is the interim, annual report for the research grant entitled "Nanomechanics of Actively Controlled Deployed Optics." It is supported by NASA Langley Research Center Cooperative Agreement NCC-1 -281. Dr. Mark S. Lake is the technical monitor of the research program. This document reports activities for the year 1998, beginning 3/11/1998, and for the year 1999. The objective of this report is to summarize the results and the status of this research. This summary appears in Section 2.0. Complete details of the results of this research have been reported in several papers, publications and theses. Section 3.0 lists these publications and, when available, presents their abstracts. Each publication is available in electronic form from a web site identified in Section 3.0.

  10. 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

  11. Effect of component variations on the gate fidelity in linear optical networks

    NASA Astrophysics Data System (ADS)

    Crickmore, Jonathan; Frazer, Jonathan; Shaw, Scott; Kok, Pieter

    2016-08-01

    We investigate the effect of variations in beam-splitter transmissions and path-length differences in the nonlinear sign gate that is used for linear optical quantum computing. We identify two implementations of the gate and show that the sensitivity to variations in their components differs significantly between them. Therefore, circuits that require a precision implementation will generally benefit from additional circuit analysis of component variations to identify the most practical implementation. We suggest possible routes to efficient circuit analysis in terms of quantum parameter estimation.

  12. The whispering gallery as an optical component in the X-ray region

    SciTech Connect

    Howells, M.R.

    1995-08-01

    The whispering gallery phenomenon in acoustics has been known and studied for more than a century, and the same effect has been observed to take place with waves other than sound waves. In this paper we review the theoretical basis and attractive features of the whispering gallery as a soft x-ray optical component and indicate some of its potential applications. We then describe what may be its most unique capability which, in favorable cases, is to provide a way. to manipulate the phase difference between the s and p polarization components and thus to generate circularly or elliptically polarized soft x-rays.

  13. Human psychophysiological activity monitoring methods using fiber optic sensors

    NASA Astrophysics Data System (ADS)

    Zyczkowski, M.; Uzieblo-Zyczkowska, B.

    2010-10-01

    The paper presents the concept of fiber optic sensor system for human psycho-physical activity detection. A fiber optic sensor that utilizes optical phase interferometry or intensity in modalmetric 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 optical fiber interferometer that includes an optical fiber proximately situated to the patient so that time varying acusto-mechanical signals from the patient are coupled into the optical fiber. The system can be implemented in embodiments ranging form a low cost in-home to a high end product for in hospital use.

  14. Sub-picosecond laser induced damage test facility for petawatt reflective optical components characterizations

    NASA Astrophysics Data System (ADS)

    Sozet, Martin; Néauport, Jérôme; Lavastre, Eric; Roquin, Nadja; Gallais, Laurent; Lamaignère, Laurent

    2015-05-01

    While considering long pulse or short pulse high power laser facilities, optical components performances and in particular laser damage resistance are always factors limiting the overall system performances. Consequently, getting a detailed knowledge of the behavior of these optical components under irradiations with large beam in short pulse range is of major importance. In this context, a Laser Induced Damage Threshold test facility called DERIC has been developed at the Commissariat à l'Energie Atomique et aux Energies Alternatives, Bordeaux. It uses an Amplitude Systemes laser source which delivers Gaussian pulses of 500 fs at 1053 nm. 1-on-1, S-on-1 and RasterScan test procedures are implemented to study the behavior of monolayer and multilayer dielectric coatings.

  15. Optical formation of relief holograms in photopolymerizable mediums with neutral component

    NASA Astrophysics Data System (ADS)

    Mensov, S. N.; Romanov, A. V.; Batenkin, M. A.

    2008-05-01

    Process of optical creation of relief holograms from photopolymerizable compositions (PPC) was investigated theoretically and experimentally. Additional neutral components were suggested to use in the mix of the PPC. They are not concerned in the polymerization reaction, but allow increase the relief amplitude of polymeric holograms. A diffusion model was constructed for the process of these additives redistribution in not-uniformly polymerizing mediums. The model considers the polymer mobility in the initial stage of photopolymerization. It was shown, that neutral components, such as alcohol, are the most suitable for the optical formation of relief polymeric holograms. At the polymerization they spread themselves effectively, and owing to their high volatility any complementary treatments to make surface relief of a hologram are not necessary. The experimental results are represented for the relief holograms recording in the PPC, containing butyl alcohol.

  16. Mass specific optical absorption coefficients of mineral dust components measured by a multi wavelength photoacoustic spectrometer

    NASA Astrophysics Data System (ADS)

    Utry, N.; Ajtai, T.; Pintér, M.; Tombácz, E.; Illés, E.; Bozóki, Z.; Szabó, G.

    2014-09-01

    Mass specific optical absorption coefficients of various mineral dust components including silicate clays (illite, kaolin and bentonite), oxides (quartz, hematite and rutile), and carbonate (limestone) were determined at wavelengths of 1064, 532, 355 and 266 nm. These values were calculated from aerosol optical absorption coefficients measured by a multi-wavelength photoacoustic (PA) instrument, the mass concentration and the number size distribution of the generated aerosol samples as well as the size transfer functions of the measuring instruments. These results are expected to have considerable importance in global radiative forcing calculations. They can also serve as reference for validating calculated wavelength dependent imaginary parts (κ) of complex refractive indices which up to now have been typically deduced from bulk phase measurements by using indirect measurement methods. Accordingly, the presented comparison of the measured and calculated aerosol optical absorption spectra revealed the strong need for standardized sample preparation and measurement methodology in case of bulk phase measurements.

  17. Analysis of Photosynthetic Rate and Bio-Optical Components from Ocean Color Imagery

    NASA Technical Reports Server (NTRS)

    Kiefer, Dale A.; Stramski, Dariusz

    1997-01-01

    Our research over the last 5 years indicates that the successful transformation of ocean color imagery into maps of bio-optical properties will require continued development and testing of algorithms. In particular improvements in the accuracy of predicting from ocean color imagery the concentration of the bio-optical components of sea as well as the rate of photosynthesis will require progress in at least three areas: (1) we must improve mathematical models of the growth and physiological acclimation of phytoplankton; (2) we must better understand the sources of variability in the absorption and backscattering properties of phytoplankton and associated microparticles; and (3) we must better understand how the radiance distribution just below the sea surface varies as a function sun and sky conditions and inherent optical properties.

  18. Achromatic flat optical components via compensation between structure and material dispersions

    PubMed Central

    Li, Yang; Li, Xiong; Pu, Mingbo; Zhao, Zeyu; Ma, Xiaoliang; Wang, Yanqin; Luo, Xiangang

    2016-01-01

    Chromatism causes great quality degradation of the imaging system, especially for diffraction imaging. The most commonly method to overcome chromatism is refractive/diffractive hybrid optical system which, however, sacrifices the light weight and integration property of diffraction elements. A method through compensation between the structure dispersion and material dispersion is proposed to overcome the chromatism in flat integrated optical components. This method is demonstrated by making use of silver nano-slits waveguides to supply structure dispersion of surface plasmon polaritons (SPP) in metal-insulator-metal (MIM) waveguide to compensate the material dispersion of metal. A broadband deflector and lens are designed to prove the achromatic property of this method. The method demonstrated here may serve as a solution of broadband light manipulation in flat integrated optical systems. PMID:26794855

  19. High-stability optical components for semiconductor laser intersatellite link experiment (SILEX) project

    NASA Astrophysics Data System (ADS)

    Lepretre, Francois

    1994-09-01

    Within the framework of a MATRA MARCONI SPACE FRANC contract for the European Space Agency, MATRA DEFENSE - DOD/UAO have developed, produced and tested 9 laser diode collimators, 52 optical components (anamorphoser, mirrors, dichroic splitters, redundancy module) and 9 interferential filters. All these space equipments must be integrated into the optical head of the SILEX (Semi-conductor Laser Intersatellite Link Experiment) bench. The SILEX experiment consists in transferring data from a low altitude satellite (SPOT 4) to a satellite in geostationary orbit (ARTEMIS) via beam generated by a laser diode (60 mW Cw). Very low emitted flux and long distance between the two satellites gives rise to the following technical difficulties: high angular (1 (mu) rad) and transverse stability requirements, requirement for high transmission and high rejection narrow band filters, in order to differentiate the transmit and receive channels, necessity of a very good optical wavefront, wavelength range 815-825 nm, 843-853 nm.

  20. Light scattering characterization of optical components: BRDF, BTDF, and scatter losses

    NASA Astrophysics Data System (ADS)

    Schröder, Sven; Finck, Alexander; Katsir, Dina; Zeitner, Uwe; Duparré, Angela

    2014-11-01

    Light scattering caused by imperfections of optical components can critically affect the performance of optical systems in terms of losses and image degradation. Because of the numerous potential sources of scattering such as roughness, surface and sub-surface defects, bulk inhomogeneities, as well as coatings, scattering properties must be carefully specified and measured at the wavelengths of application. Bidirectional Reflectance and Transmittance Distribution Functions (BRDF / BTDF) are used to quantify the angle resolved scattering properties. The data can be used as an input for optical engineering software just as FRED, ASAP, ZEMAX for stray light modeling. In addition, analyzing the scattered light can provide valuable information about the relevant imperfections. The presentation provides an overview of instrumentation for light scattering measurements at wavelengths ranging from the visible to the extreme ultraviolet and the infrared spectral regions. Examples of applications will be discussed ranging from superpolished mirrors to diffraction gratings, interference coatings, and black absorbing coatings.

  1. Multiple component codes based generalized LDPC codes for high-speed optical transport.

    PubMed

    Djordjevic, Ivan B; Wang, Ting

    2014-07-14

    A class of generalized low-density parity-check (GLDPC) codes suitable for optical communications is proposed, which consists of multiple local codes. It is shown that Hamming, BCH, and Reed-Muller codes can be used as local codes, and that the maximum a posteriori probability (MAP) decoding of these local codes by Ashikhmin-Lytsin algorithm is feasible in terms of complexity and performance. We demonstrate that record coding gains can be obtained from properly designed GLDPC codes, derived from multiple component codes. We then show that several recently proposed classes of LDPC codes such as convolutional and spatially-coupled codes can be described using the concept of GLDPC coding, which indicates that the GLDPC coding can be used as a unified platform for advanced FEC enabling ultra-high speed optical transport. The proposed class of GLDPC codes is also suitable for code-rate adaption, to adjust the error correction strength depending on the optical channel conditions.

  2. New light-trapping concept by means of several optical components applied to compact holographic 3D concentration solar module

    NASA Astrophysics Data System (ADS)

    Villamarín Villegas, Ayalid M.; Pérez López, Francisco J.; Calo López, Antonio; Rodríguez San Segundo, Hugo-José

    2014-05-01

    A new light-trapping concept is presented, which joins broad bandwidth volume phase reflection holograms (VPRH) working together with three other optical components: specifically designed three-dimensional (3D) cavities, Total Internal Reflection (TIR) within an optical medium, and specular reflection by means of a highly reflective surface. This concept is applied to the design and development of both low concentration photovoltaic (LCPV) and solar thermal modules reaching a concentration factor of up to 3X. Higher concentrations are feasible for use in concentrated solar power (CSP) devices. The whole system is entirely made of polymeric materials (except for the solar cells or fluid carrying pipes), thus reducing cost by up to 40%. The module concentrates solar light onto solar cells - or fluid carrying pipes - with no need for active tracking of the sun, covering the whole seasonal and daily incident angle spectrum while it also minimizes optical losses. In this work we analyze the first experimentally measured optical characteristics and performance of VPRH in dichromated gelatin film (DCG) in our concept. The VPRH can reach high diffraction efficiencies (˜98%, ignoring Fresnel reflection losses). Thanks to specifically designed raw material, coating and developing process specifications, also very broad selective spectral (higher than 300 nm) and angular bandwidths (˜+20º) per grating are achieved. The VPRH was optimized to use silicon solar cells, but designs for other semiconductor devices or for fluid heating are feasible. The 3D shape, the hologram's and reflective surface's optical quality, the TIR effect and the correct coupling of all the components are key to high performance of the concentration solar module.

  3. Beyond the Alphabet Soup: Molecular Properties of Aerosol Components Influence Optics. (Invited)

    NASA Astrophysics Data System (ADS)

    Thompson, J. E.

    2013-12-01

    Components within atmospheric aerosols exhibit almost every imaginable model of chemical bonding and physical diversity. The materials run the spectrum from crystalline to amorphous, covalent to ionic, and have varying viscosities, phase, and hygroscopicity. This seminar will focus on the molecular properties of materials that influence the optical behavior of aerosols. Special focus will be placed on the polarizability of materials, hygroscopic growth, and particle phase.

  4. Optical and electrical properties of composites based on functional components of an electroluminescent layer

    NASA Astrophysics Data System (ADS)

    Avanesyan, V. T.; Rakina, A. V.; Sychov, M. M.; Vasina, E. S.

    2016-07-01

    Optical and electrical properties of cyanoethyl ether of polyvinyl alcohol with filling of barium titanate BaTiO3 modified by shungite carbon nanoparticles are studied. It is found that the modification affects the diffuse reflectance spectra and dispersion characteristics of the impedance components due to a change in the nature of interfacial interactions in the system. The values of the forbidden band width for various modifier and filler concentrations are determined.

  5. Design and component specifications for high average power laser optical systems

    SciTech Connect

    O'Neil, R.W.; Sawicki, R.H.; Johnson, S.A.; Sweatt, W.C.

    1987-01-01

    Laser imaging and transport systems are considered in the regime where laser-induced damage and/or thermal distortion have significant design implications. System design and component specifications are discussed and quantified in terms of the net system transport efficiency and phase budget. Optical substrate materials, figure, surface roughness, coatings, and sizing are considered in the context of visible and near-ir optical systems that have been developed at Lawrence Livermore National Laboratory for laser isotope separation applications. In specific examples of general applicability, details of the bulk and/or surface absorption, peak and/or average power damage threshold, coating characteristics and function, substrate properties, or environmental factors will be shown to drive the component size, placement, and shape in high-power systems. To avoid overstressing commercial fabrication capabilities or component design specifications, procedures will be discussed for compensating for aberration buildup, using a few carefully placed adjustable mirrors. By coupling an aggressive measurements program on substrates and coatings to the design effort, an effective technique has been established to project high-power system performance realistically and, in the process, drive technology developments to improve performance or lower cost in large-scale laser optical systems. 13 refs.

  6. A viscoelastic laryngeal muscle model with active components

    PubMed Central

    Smith, Simeon L.; Hunter, Eric J.

    2014-01-01

    Accurate definitions of both passive and active tissue characteristics are important to laryngeal muscle modeling. This report tested the efficacy of a muscle model which added active stress components to an accurate definition of passive properties. Using the previously developed three-network Ogden model to simulate passive stress, a Hill-based contractile element stress equation was utilized for active stress calculations. Model input parameters were selected based on literature data for the canine cricothyroid muscle, and simulations were performed in order to compare the model behavior to published results for the same muscle. The model results showed good agreement with muscle behavior, including appropriate tetanus response and contraction time for isometric conditions, as well as accurate stress predictions in response to dynamic strain with activation. PMID:25235002

  7. Relationship between large-aperture optical components of striated surface shape and focal spot characteristics in the far-field

    NASA Astrophysics Data System (ADS)

    Lei, Zemin; Sun, Xiaoyan; Yin, Xianhua; Lv, Fengnian; Zhang, Zhen; Lu, Xingqiang; Fan, Dianyuan

    2015-07-01

    Surface shape of optical components is an essential factor of the laser beam quality. Different types of surface correspond to different characteristics of the laser focal spot. Striated surface shape is one of common and typical cases of optical component surfaces in laser facilities, which have attracted great attention. For learning the impact of the component on focal spot in the far-field, a model component with the similar features was introduced in the study. Intensity distributions of focal spot in the far-field was simulated after laser beam went through the model component. Effects of the modulation depth and the modulation period on spot morphology were presented. Furthermore, the relations between these optical specifications and focal spots with some requirements had been analyzed. The results can enhance our understanding about striae degrees of optical elements and have reference values to guide the processing and the use of large-aperture components correctly.

  8. 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.

  9. Vibrational Raman optical activity of biological molecules

    NASA Astrophysics Data System (ADS)

    Barron, L. D.; Hecht, Lutz; Wen, Z. Q.; Ford, Steven J.; Bell, A. F.

    1993-06-01

    Advances in Raman optical activity (ROA) instrumentation based on the employment of a backscattering geometry together with a cooled backthinned CCD detector, a holographic notch filter, and a high-efficiency single-grating spectrograph have now enhanced the sensitivity to the level necessary to provide vibrational ROA spectra of most biological molecules in aqueous solution. Results on peptides and proteins show features originating in coupled C(alpha )-H and N-H deformations of the peptide backbone which appear to be sensitive to the secondary conformation including loop and turn structures. Also carbohydrates show many features characteristic of the central aspects of carbohydrate architecture, with effects from the glycosidic link in oligosaccharides particularly prominent. Preliminary ROA spectra of pyrimidine nucleosides appear to reflect the mutual orientation of the sugar and base rings and the dominant furanose conformations.

  10. Vibrational Raman optical activity of ketose monosaccharides

    NASA Astrophysics Data System (ADS)

    Bell, Alasdair F.; Hecht, Lutz; Barron, Laurence D.

    1995-07-01

    The vibrational Raman optical activity (ROA) spectra of the four ketose sugars D-fructose, L-sorbose, D-tagatose and D-psicose in aqueous solution, which have been measured in backscattering in the range ≈250-1500 cm -1, are reported. These results are combined with those from a previous ROA study of aldose and pentose sugars in an attempt to establish new vibrational assignments and to verify old ones. The high information content of these spectra provides a new perspective on all the central features of monosaccharide stereochemistry including dominant anomeric configuration, ring conformation, exocyclic CH 2OH group conformation and relative disposition of the hydroxyl groups around the ring.

  11. Disulfide chromophore and its optical activity.

    PubMed

    Maloň, Petr; Bednárová, Lucie; Straka, Michal; Krejčí, Lucie; Kumprecht, Lukáš; Kraus, Tomáš; Kubáňová, Markéta; Baumruk, Vladimír

    2010-01-01

    The compounds I-IV derived from α-D-cyclodextrin moiety by bridging and/or interconnecting with various patterns of disulfide bonds were chosen as models for the spectroscopic study of conformation of the disulfide bridge. The energy gap between the disulfide and cyclodextrin's electronic transitions allows us to investigate absorption and electronic circular dichroism spectra without disturbing spectral overlaps with amides or aromatic amino acids in peptides or proteins. Raman optical activity (ROA) spectra were measured and the bands due to S-S and C-S stretching motion identified. Comparison with the quantum mechanical calculations of simple models indicates that sense of disulfide twist follows sign of the measured S-S ROA band.

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

    PubMed

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

    2016-01-28

    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

  13. Polymer optical fiber grating as water activity sensor

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Webb, David J.

    2014-05-01

    Controlling the water content within a product has long been required in the chemical processing, agriculture, food storage, paper manufacturing, semiconductor, pharmaceutical and fuel industries. The limitations of water content measurement as an indicator of safety and quality are attributed to differences in the strength with which water associates with other components in the product. Water activity indicates how tightly water is "bound," structurally or chemically, in products. Water absorption introduces changes in the volume and refractive index of poly(methyl methacrylate) PMMA. Therefore for a grating made in PMMA based optical fiber, its wavelength is an indicator of water absorption and PMMA thus can be used as a water activity sensor. In this work we have investigated the performance of a PMMA based optical fiber grating as a water activity sensor in sugar solution, saline solution and Jet A-1 aviation fuel. Samples of sugar solution with sugar concentration from 0 to 8%, saline solution with concentration from 0 to 22%, and dried (10ppm), ambient (39ppm) and wet (68ppm) aviation fuels were used in experiments. The corresponding water activities are measured as 1.0 to 0.99 for sugar solution, 1.0 to 0.86 for saline solution, and 0.15, 0.57 and 1.0 for the aviation fuel samples. The water content in the measured samples ranges from 100% (pure water) to 10 ppm (dried aviation fuel). The PMMA based optical fiber grating exhibits good sensitivity and consistent response, and Bragg wavelength shifts as large as 3.4 nm when the sensor is transferred from dry fuel to wet fuel.

  14. 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

  15. Backward reflection analysis of transmitting channel of active laser ranging optics

    NASA Astrophysics Data System (ADS)

    Hong, Jinsuk; Koh, Hae Seog

    2013-09-01

    The designed Active LDR(Laser Detection and Ranging) System contains high-power Laser and its diameter is approximately 24mm. Although the laser transmitting channel and receiving optic channel are completely separated from each other and doesn't share any of the optical components in design, each channel shares 4 wedge scanners, which are to overcome the narrow FOV(Field of View) of the optical system. Any backward reflection back to the fiber laser end must be carefully studied since it can damage the LD(Laser Diodes), the inner components of the laser unit because of the high amplification factor of the laser unit. In this study, the stray light caused by the transmitting channel's laser and inner reflection by optical components were analyzed by ASAP(Advanced System Analysis Program) software. We also can confirm the operability and stability of the system by more than 6 months of operation of the system.

  16. Biochemical component identification by light scattering techniques in whispering gallery mode optical resonance based sensor

    NASA Astrophysics Data System (ADS)

    Saetchnikov, Vladimir A.; Tcherniavskaia, Elina A.; Saetchnikov, Anton V.; Schweiger, Gustav; Ostendorf, Andreas

    2014-03-01

    Experimental data on detection and identification of variety of biochemical agents, such as proteins (albumin, interferon, C reactive protein), microelements (Na+, Ca+), antibiotic of different generations, in both single and multi component solutions under varied in wide range concentration are represented. Analysis has been performed on the light scattering parameters of whispering gallery mode (WGM) optical resonance based sensor with dielectric microspheres from glass and PMMA as sensitive elements fixed by spin - coating techniques in adhesive layer on the surface of substrate or directly on the coupling element. Sensitive layer was integrated into developed fluidic cell with a digital syringe. Light from tuneable laser strict focusing on and scattered by the single microsphere was detected by a CMOS camera. The image was filtered for noise reduction and integrated on two coordinates for evaluation of integrated energy of a measured signal. As the entrance data following signal parameters were used: relative (to a free spectral range) spectral shift of frequency of WGM optical resonance in microsphere and relative efficiency of WGM excitation obtained within a free spectral range which depended on both type and concentration of investigated agents. Multiplexing on parameters and components has been realized using spatial and spectral parameters of scattered by microsphere light with developed data processing. Biochemical component classification and identification of agents under investigation has been performed by network analysis techniques based on probabilistic network and multilayer perceptron. Developed approach is demonstrated to be applicable both for single agent and for multi component biochemical analysis.

  17. 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

  18. Radiation studies of optical and electronic components used in astronomical satellite studies

    NASA Technical Reports Server (NTRS)

    Becher, J.; Kernell, R. L.

    1981-01-01

    The synchronous orbit of the IUE carries the satellite through Earth's outer electron belt. A 40 mCi Sr90 source was used to simulate these electrons. A 5 mCi source of Co60 was used to simulate bremmstrahlung. A 10 MeV electron Linac and a 1.7 MeV electron Van de Graaf wer used to investigate the energy dependence of radiation effects and to perform radiations at a high flux rate. A 100 MeV proton cyclotron was used to simulate cosmic rays. Results are presented for three instrument systems of the IUE and measurements for specific components are reported. The three instrument systems were the ultraviolet converter, the fine error sensor (FES), and the SEC vidicon camera tube. The components were optical glasses, electronic components, silicon photodiodes, and UV window materials.

  19. Degradation of electro-optic components aboard LDEF. [long duration exposure facility

    NASA Technical Reports Server (NTRS)

    Blue, M. D.

    1992-01-01

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

  20. An overview of micro-optical components and system technology: bulk, planar, and thin-film for laser initiated devices

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd

    2010-08-01

    There are a number of attractive micro optical elements or combinations of elements that are currently used or could be employed in optically initiated ordnance systems. When taking a broad-spectrum examination of optically initiated devices, the required key parameters become obviously straightforward for micro optics. Plainly stated, micro optics need to be simple, inexpensive, reliable, robust and compatible within their operational environment. This presentation focuses on the variety of optical elements and components available in the market place today that could be used to realize micro-optical beam shaping and delivery systems for optically initiated devices. A number of micro optical elements will be presented with specific bulk, planar optical and thin film optical devices, such as diffractive optics, micro prisms, axicons, waveguides, micro lenses, beam splitters and gratings. Further descriptions will be presented on the subject of coupling light from a laser beam into a multimode optical fiber. The use of micro optics for collimation of the laser source and conditioning of the laser beam to achieve the highest efficiency and matching the optical fiber NA will be explained. An emphasis on making these optical assemblies compact and rugged will be highlighted.

  1. A new generation active arrays for optical flexibility in astronomical instrumentation

    NASA Astrophysics Data System (ADS)

    Kroes, G.; Jaskó, A.; Pragt, J. H.; Venema, L.; De Haan, M.

    2012-09-01

    Throughout the history of telescopes and astronomical instrumentation, new ways were found to open up unexplored possibilities in fundamental astronomical research by increasing the telescope size and instrumentation complexity. The ever demanding requirements on instrument performance pushes instrument complexity to the edge. In order to take the next leap forward in instrument development the optical design freedom needs to be increased drastically. The use of more complex and more accurate optics allows for shorter optical trains with smaller sizes, smaller number of components and reduced fabrication and alignment verification time and costs. Current optics fabrication is limited in surface form complexity and/or accuracy. Traditional active and adaptive optics lack the needed intrinsic long term stability and simplicity in design, manufacturing, verification and control. This paper explains how and why active arrays literally provide a flexible but stable basis for the next generation optical instruments. Combing active arrays with optically high quality face sheets more complex and accurate optical surface forms can be provided including extreme a-spherical (freeform) surfaces and thus allow for optical train optimization and even instrument reconfiguration. A zero based design strategy is adopted for the development of the active arrays addressing fundamental issues in opto-mechanical engineering. The various choices are investigated by prototypes and Finite Element Analysis. Finally an engineering concept will be presented following a highly stable adjustment strategy allowing simple verification and control. The Optimization metrology is described in an additional paper for this conference by T. Agócs et al.

  2. 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.

  3. Mineral components and anti-oxidant activities of tropical seaweeds

    NASA Astrophysics Data System (ADS)

    Takeshi, Suzuki; Yumiko, Yoshie-Stark; Joko, Santoso

    2005-07-01

    Seaweeds are known to hold substances of high nutritional value; they are the richest resources of minerals important to the biochemical reactions in the human body. Seaweeds also hold non-nutrient compounds like dietary fiber and polyphenols. However, there is not enough information on the mineral compounds of tropical seaweeds. Also we are interested in the antioxidant activities of seaweeds, especially those in the tropical area. In this study, Indonesian green, brown and red algae were used as experimental materials with their mineral components analyzed by using an atomic absorption spectrophotometer. The catechins and flavonoids of these seaweeds were extracted with methanol and analyzed by high performance liquid chromatography (HPLC); the antioxidant activities of these seaweeds were evaluated in a fish oil emulsion system. The mineral components of tropical seaweeds are dominated by calcium, potassium and sodium, as well as small amounts of copper, iron and zinc. A green alga usually contains epigallocatechin, gallocatechin, epigallocatechin gallate and catechin. However, catechin and its isomers are not found in some green and red algae. In the presence of a ferrous ion catalyst, all the methanol extracts from the seaweeds show significantly lower peroxide values of the emulsion than the control, and that of a green alga shows the strongest antioxidant activity. The highest chelation on ferrous ions is also found in the extract of this alga, which is significantly different from the other methanol extracts in both 3 and 24 h incubations.

  4. Comparison of Materials for Use in the Precision Grinding of Optical Components

    SciTech Connect

    Evans, Boyd M. III; Miller, Arthur C. Jr.; Egert, Charles M.

    1997-12-31

    Precision grinding of optical components is becoming an accepted practice for rapidly and deterministically fabrication optical surfaces to final or near-final surface finish and figure. In this paper, a comparison of grinding techniques and materials is performed. Flat and spherical surfaces were ground in three different substrate materials: BK7 glass, chemical vapor deposited (CVD) silicon carbide ceramic, and sapphire. Spherical surfaces were used to determine the contouring capacity of the process, and flat surfaces were used for surface finish measurements. The recently developed Precitech Optimum 2800 diamond turning and grinding platform was used to grind surfaces in 40mm diameter substrates sapphire and silicon carbide substrates and 200 mm BK7 glass substrates using diamond grinding wheels. The results of this study compare the surface finish and figure for the three materials.

  5. Absorbed XFEL Dose in the Components of the LCLS X-Ray Optics

    SciTech Connect

    Hau-Riege, Stefan

    2010-12-03

    There is great concern that the short, intense XFEL pulse of the LCLS will damage the optics that will be placed into the beam. We have analyzed the extent of the problem by considering the anticipated materials and position of the optical components in the beam path, calculated the absorbed dose as a function of photon energy, and compared these doses with the expected doses required (i) to observe rapid degradation due to thermal fatigue, (ii) to reach the melting temperature, or (iii) to actually melt the material. We list the materials that are anticipated to be placed into the Linac Coherent Light Source (LCLS) x-ray free electron laser (XFEL) beam line, their positions, and the absorbed dose, and compare this dose with anticipated damage thresholds.

  6. Laser damage performance of large-aperture fused silica optical components at 351 nm

    NASA Astrophysics Data System (ADS)

    Huang, Wanqing; Han, Wei; Wang, Fang; Xiang, Yong; Li, Fuquan; Feng, Bin; Jing, Feng; Wei, Xiaofeng; Zheng, Wanguo; Zhang, Xiaomin

    2008-12-01

    High power laser facility for ICF will routinely operate at high fluence level. The damage on the large-area FOA optics is a key lifetime limiter. The optics should be checked after each laser shot for damage initiation and growth. On-line monitoring equipments are installed for this purpose. Damage pictures of a fused silica component are successfully taken and the luminance of the pictures could reflect the deterioration of the operational environment. Damage initiation and growth behaviors at 351nm high-fluence laser were observed. Damage density and damage growth are exponential with the shot number and some conclusions could be drawn. These results bring forward demands for future monitoring equipments and more experiments to establish a lifetime model.

  7. Staphylokinase as a Plasminogen Activator Component in Recombinant Fusion Proteins

    PubMed Central

    Szarka, S. J.; Sihota, E. G.; Habibi, H. R.; Wong, S.-L.

    1999-01-01

    The plasminogen activator staphylokinase (SAK) is a promising thrombolytic agent for treatment of myocardial infarction. It can specifically stimulate the thrombolysis of both erythrocyte-rich and platelet-rich clots. However, SAK lacks fibrin-binding and thrombin inhibitor activities, two functions which would supplement and potentially improve its thrombolytic potency. Creating a recombinant fusion protein is one approach for combining protein domains with complementary functions. To evaluate SAK for use in a translational fusion protein, both N- and C-terminal fusions to SAK were constructed by using hirudin as a fusion partner. Recombinant fusion proteins were secreted from Bacillus subtilis and purified from culture supernatants. The rate of plasminogen activation by SAK was not altered by the presence of an additional N- or C-terminal protein sequence. However, cleavage at N-terminal lysines within SAK rendered the N-terminal fusion unstable in the presence of plasmin. The results of site-directed mutagenesis of lysine 10 and lysine 11 in SAK suggested that a plasmin-resistant variant cannot be created without interfering with the plasmin processing necessary for activation of SAK. Although putative plasmin cleavage sites are located at the C-terminal end of SAK at lysine 135 and lysine 136, these sites were resistant to plasmin cleavage in vitro. Therefore, C-terminal fusions represent stable configurations for developing improved thrombolytic agents based on SAK as the plasminogen activator component. PMID:9925575

  8. Passive and active optical fibers for space and terrestrial applications

    NASA Astrophysics Data System (ADS)

    Alam, Mansoor; Abramczyk, Jaroslaw; Farroni, Julia; Manyam, Upendra; Guertin, Douglas

    2006-08-01

    Being the new frontier of science and technology, as the near earth space begins to attract attention, low cost and rapidly deployable earth observation satellites are becoming more important. Among other things these satellites are expected to carry out missions in the general areas of science and technology, remote sensing, national defense and telecommunications. Except for critical missions, constraints of time and money practically mandate the use of commercial-off-the-shelf (COTS) components as the only viable option. The near earth space environment (~50-50000 miles) is relatively hostile and among other things components/devices/systems are exposed to ionizing radiation. Photonic devices/systems are and will continue to be an integral part of satellites and their payloads. The ability of such devices/systems to withstand ionizing radiation is of extreme importance. Qualification of such devices/systems is time consuming and very expensive. As a result, manufacturers of satellites and their payloads have started to ask for radiation performance data on components from the individual vendors. As an independent manufacturer of both passive and active specialty silica optical fibers, Nufern is beginning to address this issue. Over the years, Nufern has developed fiber designs, compositions and processes to make radiation hard fibers. Radiation performance data (both gamma and proton) of a variety of singlemode (SM), multimode (MM), polarization maintaining (PM) and rare-earth doped (RED) fibers that find applications in space environment are presented.

  9. High quality actively cooled plasma facing components for fusion

    SciTech Connect

    Nygren, R.

    1993-12-31

    This paper interweaves some suggestions for developing actively-cooled PFCs (plasma facing components) for future fusion devices with supporting examples taken from the design, fabrication and operation of Tore Supra`s Phase III Outboard Pump Limiter (OPL). This actively-cooled midplane limiter, designed for heat and particle removal during long pulse operation, has been operated in essentially thermally steady state conditions. From experience with testing to identify braze flaws in the OPL, recommendations are made to analyze the impact of joining flaws on thermal-hydraulic performance of PFCs and to validate a method of inspection for such flaws early in the design development. Capability for extensive in-service monitoring of future PFCs is also recommended and the extensive calorimetry and IR thermography used to confirm and update safe operating limits for power handling of the OPL are reviewed.

  10. Sporicidal Activities of Various Surfactant Components against Bacillus subtilis Spores.

    PubMed

    Cho, Won-Il; Cheigh, Chan-Ick; Hwang, Hee-Jeong; Chung, Myong-Soo

    2015-06-01

    The sporicidal activities against Bacillus subtilis spores of surfactant components with hydrophilic and hydrophobic properties that can lead to the denaturation of various proteins comprising the spore structure were investigated. The reduction in spore numbers by each of the surfactant components bornyl acetate, geranyl acetate, pinene, p-cymene, camphene, citral, 2,3-dihydrobenzofuran, polylysine, and thiamine dilaurylsulfate at 1% was estimated at 1 to 2 log CFU/ml. The average hydrophilelipophile balance value of surfactants with sporicidal activity causing a reduction of 1 to 2 log CFU/ml was 9.3, with a range from 6.7 to 15.8, which is similar to the values of various chemical surfactants of 9.6 to 16.7. The results also showed that the surfactants that were hydrophobic were more effective than those that were hydrophilic in killing B. subtilis spores. Furthermore, the sporicidal effect of surfactants like geranyl acetate and γ-terpinene was significantly enhanced in the presence of a germinant, because L-alanine and synergistic cofactors (e.g., K(+) ions) trigger cortex hydrolysis in spores.

  11. Space Flight Requirements for Fiber Optic Components; Qualification Testing and Lessons Learned

    NASA Technical Reports Server (NTRS)

    Ott, Melanie N.; Jin, Xiaodan Linda; Chuska, Richard; Friedberg, Patricia; Malenab, Mary; Matuszeski, Adam

    2007-01-01

    "Qualification" of fiber optic components holds a very different meaning than it did ten years ago. In the past, qualification meant extensive prolonged testing and screening that led to a programmatic method of reliability assurance. For space flight programs today, the combination of using higher performance commercial technology, with shorter development schedules and tighter mission budgets makes long term testing and reliability characterization unfeasible. In many cases space flight missions will be using technology within years of its development and an example of this is fiber laser technology. Although the technology itself is not a new product the components that comprise a fiber laser system change frequently as processes and packaging changes occur. Once a process or the materials for manufacturing a component change, even the data that existed on its predecessor can no longer provide assurance on the newer version. In order to assure reliability during a space flight mission, the component engineer must understand the requirements of the space flight environment as well as the physics of failure of the components themselves. This can be incorporated into an efficient and effective testing plan that "qualifies" a component to specific criteria defined by the program given the mission requirements and the component limitations. This requires interaction at the very initial stages of design between the system design engineer, mechanical engineer, subsystem engineer and the component hardware engineer. Although this is the desired interaction what typically occurs is that the subsystem engineer asks the components or development engineers to meet difficult requirements without knowledge of the current industry situation or the lack of qualification data. This is then passed on to the vendor who can provide little help with such a harsh set of requirements due to high cost of testing for space flight environments. This presentation is designed to guide the

  12. 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.

  13. Anisotropic pair superfluidity of trapped two-component Bose gases in an optical lattice

    NASA Astrophysics Data System (ADS)

    Li, Yongqiang; He, Liang; Hofstetter, Walter

    2013-09-01

    We theoretically investigate the pair-superfluid phase of two-component ultracold gases with attractive inter-species interactions in an optical lattice. We establish the phase diagram for filling n = 1 at zero and finite temperatures, by applying bosonic dynamical mean-field theory, and observe stable pair-superfluid and charge-density wave quantum phases for asymmetric hopping of the two species. While the pair superfluid is found to be robust in the presence of a harmonic trap, we observe that it is destroyed already by a small population imbalance of the two species.

  14. Validating a nondestructive optical method for apportioning colored particulate matter into black carbon and additional components

    PubMed Central

    Yan, Beizhan; Kennedy, Daniel; Miller, Rachel L.; Cowin, James P.; Jung, Kyung-hwa; Perzanowski, Matt; Balletta, Marco; Perera, Federica P.; Kinney, Patrick L.; Chillrud, Steven N.

    2011-01-01

    Exposure of black carbon (BC) is associated with a variety of adverse health outcomes. A number of optical methods for estimating BC on Teflon filters have been adopted but most assume all light absorption is due to BC while other sources of colored particulate matter exist. Recently, a four-wavelength-optical reflectance measurement for distinguishing second hand cigarette smoke (SHS) from soot-BC was developed (Brook et al., 2010; Lawless et al., 2004). However, the method has not been validated for soot-BC nor SHS and little work has been done to look at the methodological issues of the optical reflectance measurements for samples that could have SHS, BC, and other colored particles. We refined this method using a lab-modified integrating sphere with absorption measured continuously from 350 nm to 1000 nm. Furthermore, we characterized the absorption spectrum of additional components of particulate matter (PM) on PM2.5 filters including ammonium sulfate, hematite, goethite, and magnetite. Finally, we validate this method for BC by comparison to other standard methods. Use of synthesized data indicates that it is important to optimize the choice of wavelengths to minimize computational errors as additional components (more than 2) are added to the apportionment model of colored components. We found that substantial errors are introduced when using 4 wavelengths suggested by Lawless et al. to quantify four substances, while an optimized choice of wavelengths can reduce model-derived error from over 10% to less than 2%. For environmental samples, the method was sensitive for estimating airborne levels of BC and SHS, but not mass loadings of iron oxides and sulfate. Duplicate samples collected in NYC show high reproducibility (points consistent with a 1:1 line, R2 = 0.95). BC data measured by this method were consistent with those measured by other optical methods, including Aethalometer and Smoke-stain Reflectometer (SSR); although the SSR looses sensitivity at

  15. Two-component Fermions in Optical Lattice with Spatially Alternating Interactions

    NASA Astrophysics Data System (ADS)

    Hoang, Anh-Tuan; Nguyen, Thi-Hai-Yen; Tran, Thi-Thu-Trang; Le, Duc-Anh

    2016-10-01

    We investigate two-component mass-imbalanced fermions in an optical lattice with spatially modulated interactions by using two-site dynamical mean field theory. At half-filling and zero temperature, the phase diagram of the system is analytically obtained, in which the metallic region is reduced with increasing the mass imbalance. The ground-state properties of the fermionic system are discussed from the behaviors of both the spin-dependent quasi-particle weight at the Fermi level and the double occupancy for each sublattice as functions of the local interaction strengths for various values of the mass imbalance.

  16. Cleaning of optical components for high-power laser-based firing systems

    SciTech Connect

    Sparrow, B.D.; Hendrix, J.L.

    1993-08-01

    This report discusses the progress of AlliedSignal Inc., Kansas City Division (KCD), in addressing the issues of cleaning of hardware and optical components for laser-based firing sets. These issues are acceptability of cleaning processes and techniques of other government programs to the quality, reliability, performance, stockpile life, materials compatibility issues, and, perhaps most important, environmentally conscious manufacturing requirements of the Department of Energy (DOE). A review of ``previous cleaning art`` is presented using Military Standards (MIL STDs) and Military Interim Specifications (MISs) as well as empirical data compiled by the authors. Observations on processes and techniques used in building prototype hardware and plans for future work are presented.

  17. Validating a nondestructive optical method for apportioning colored particulate matter into black carbon and additional components

    NASA Astrophysics Data System (ADS)

    Yan, Beizhan; Kennedy, Daniel; Miller, Rachel L.; Cowin, James P.; Jung, Kyung-hwa; Perzanowski, Matt; Balletta, Marco; Perera, Federica P.; Kinney, Patrick L.; Chillrud, Steven N.

    2011-12-01

    Exposure of black carbon (BC) is associated with a variety of adverse health outcomes. A number of optical methods for estimating BC on Teflon filters have been adopted but most assume all light absorption is due to BC while other sources of colored particulate matter exist. Recently, a four-wavelength-optical reflectance measurement for distinguishing second hand cigarette smoke (SHS) from soot-BC was developed (Brook et al., 2010; Lawless et al., 2004). However, the method has not been validated for soot-BC nor SHS and little work has been done to look at the methodological issues of the optical reflectance measurements for samples that could have SHS, BC, and other colored particles. We refined this method using a lab-modified integrating sphere with absorption measured continuously from 350 nm to 1000 nm. Furthermore, we characterized the absorption spectrum of additional components of particulate matter (PM) on PM 2.5 filters including ammonium sulfate, hematite, goethite, and magnetite. Finally, we validate this method for BC by comparison to other standard methods. Use of synthesized data indicates that it is important to optimize the choice of wavelengths to minimize computational errors as additional components (more than 2) are added to the apportionment model of colored components. We found that substantial errors are introduced when using 4 wavelengths suggested by Lawless et al. to quantify four substances, while an optimized choice of wavelengths can reduce model-derived error from over 10% to less than 2%. For environmental samples, the method was sensitive for estimating airborne levels of BC and SHS, but not mass loadings of iron oxides and sulfate. Duplicate samples collected in NYC show high reproducibility (points consistent with a 1:1 line, R2 = 0.95). BC data measured by this method were consistent with those measured by other optical methods, including Aethalometer and Smoke-stain Reflectometer (SSR); although the SSR looses sensitivity at

  18. Three-component fermionic atoms with repulsive interaction in optical lattices

    SciTech Connect

    Miyatake, Shin-ya; Inaba, Kensuke; Suga, Sei-ichiro

    2010-02-15

    We investigate three-component (colors) repulsive fermionic atoms in optical lattices using the dynamical mean-field theory. Depending on the anisotropy of the repulsive interactions, either a color density-wave state or a color-selective staggered state appears at half filling. In the former state, pairs of atoms with two of the three colors and atoms with the third color occupy different sites alternately. In the latter state, atoms with two of the three colors occupy different sites alternately and atoms with the third color are itinerant throughout the system. When the interactions are isotropic, both states are degenerate. We discuss the results using an effective model.

  19. Terahertz chiral metamaterials with giant and dynamically tunable optical activity

    SciTech Connect

    Zhou, Jiangfeng; Chowdhury, Dibakar Roy; Zhao, Rongkuo; Azad, Abul K.; Chen, Hou-Tong; Soukoulis, Costas M.; Taylor, Antoinette J.; O'Hara, John F.

    2012-07-27

    We demonstrated giant optical activity using a chiral metamaterial composed of an array of conjugated bilayer metal structures. The chiral metamaterials were further integrated with photoactive inclusions to accomplish a wide tuning range of the optical activity through illumination with near-infrared light. The strong chirality observed in our metamaterials results in a negative refractive index, which can also be well controlled by the near-infrared optical excitation.

  20. Vortices of a rotating two-component dipolar Bose-Einstein condensate in an optical lattice

    NASA Astrophysics Data System (ADS)

    Wang, Lin-Xue; Dong, Biao; Chen, Guang-Ping; Han, Wei; Zhang, Shou-Gang; Shi, Yu-Ren; Zhang, Xiao-Fei

    2016-01-01

    We consider a two-component Bose-Einstein condensate, which consists of both dipolar and scalar bosonic atoms, in a confinement that is composed of a harmonic oscillator and an underlying optical lattice set rotation. When the dipoles are polarized along the symmetry axis of the harmonic potential, the ground-state density distributions of such a system are investigated as a function of the relative strength between the dipolar and contact interactions, and of the rotation frequency. Our results show that the number of vortices and its related vortex structures of such a system depend strongly on such system parameters. The special two-component system considered here opens up alternate ways for exploring the rich physics of dipolar quantum gases.

  1. Photonic Beamformer Model Based on Analog Fiber-Optic Links’ Components

    NASA Astrophysics Data System (ADS)

    Volkov, V. A.; Gordeev, D. A.; Ivanov, S. I.; Lavrov, A. P.; Saenko, I. I.

    2016-08-01

    The model of photonic beamformer for wideband microwave phased array antenna is investigated. The main features of the photonic beamformer model based on true-time-delay technique, DWDM technology and fiber chromatic dispersion are briefly analyzed. The performance characteristics of the key components of photonic beamformer for phased array antenna in the receive mode are examined. The beamformer model composed of the components available on the market of fiber-optic analog communication links is designed and tentatively investigated. Experimental demonstration of the designed model beamforming features includes actual measurement of 5-element microwave linear array antenna far-field patterns in 6-16 GHz frequency range for antenna pattern steering up to 40°. The results of experimental testing show good accordance with the calculation estimates.

  2. Superfluid state of repulsively interacting three-component fermionic atoms in optical lattices

    NASA Astrophysics Data System (ADS)

    Suga, Sei-Ichiro; Inaba, Kensuke

    2013-03-01

    We investigate the superfluid state of repulsively interacting three-component (color) fermionic atoms in optical lattices using Feynman diagrammatic approaches and the dynamical mean field theory. When the anisotropy of the three repulsive interactions is strong, atoms of two of the three colors form Cooper pairs and atoms of the third color remain a Fermi liquid. This superfluid emerges close to half filling at which the Mott insulating state characteristic of the three-component repulsive fermions appears. An effective attractive interaction is induced by density fluctuations of the third-color atoms. The superfluid state is stable against the phase separation that occurs in the strongly repulsive region. We determine the phase diagrams in terms of temperature, filling, and the anisotropy of the repulsive interactions. This work was supported by Grant-in-Aid for Scientific Research (C) (No. 23540467) from the Japan Society for the Promotion of Science.

  3. Characterization of Optical Components for the Cosmology Large Angular Scale Surveyor (CLASS)

    NASA Astrophysics Data System (ADS)

    Zhang, Zhuo; Essinger-Hileman, Thomas; Xu, Zhilei; Marriage, Tobias

    2016-06-01

    Inflation theory posits a rapid expansion at the beginning of the universe that explains the homogeneity, isotropy and flatness of our universe. The theory postulates perturbations to space-time with both scalar and tensor components, the latter of which would give rise to a "B-mode" polarization in the Cosmic Microwave Background (CMB). The Cosmology Large Angular Scale Surveyor (CLASS), with its broadband frequency coverage and rapid front-end modulation, has the unique ability to map the entire B-mode angular power spectrum where there the inflationary signal is expected to dominate. In this poster, I give an overview of CLASS and present work on the characterization of CLASS optical components, including infrared filters, using a custom Fourier Transform Interferometer.

  4. Towards Depth-Resolved Optical Imaging of Cardiac Electrical Activity.

    PubMed

    Walton, Richard D; Bernus, Olivier

    2015-01-01

    The spatiotemporal dynamics of arrhythmias are likely to be complex three-dimensional phenomena. Yet, the lack of high-resolution three-dimensional imaging techniques, both in the clinic and the experimental lab, limits our ability to better understand the mechanisms of such arrhythmias. Optical mapping using voltage-sensitive dyes is a widely used tool in experimental electrophysiology. It has been known for decades that even in its most basic application, epi-fluorescence, the optical signal contains information from within a certain intramural volume. Understanding of this fundamental property of optical signals has paved the way towards novel three-dimensional optical imaging techniques. Here, we review our current understanding of the three-dimensional nature of optical signals; how penetration depths of cardiac optical imaging can be improved by using novel imaging modalities and finally, we highlight new techniques inspired from optical tomography and aiming at full depth-resolved optical mapping of cardiac electrical activity. PMID:26238062

  5. 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…

  6. Fiber optic chemical microsensors employing optically active silica microspheres

    NASA Astrophysics Data System (ADS)

    Pope, Edward J. A.

    1995-05-01

    Dye-doped porous silica microspheres can be prepared from liquid solution at temperatures near ambient. Microsphere diameter can be controlled between approximately 5.0 microns to in excess of a millimeter. The resulting microspheres can be attached to the distal end of an optical fiber in which the proximal end is attached to a spectrophotometer. Depending upon the organic species doped into the microsphere, a wide variety of sensing functions are possible. In this paper, the use of microsensors for measuring pH, temperature, and solvent content of aqueous solutions is demonstrated. Potential utility of this type of sensor to heavy metals detection and biomedical diagnostics is also discussed.

  7. An AeroCom Initial Assessment - Optical Properties in Aerosol Component Modules of Global Models

    SciTech Connect

    Kinne, Stefan; Schulz, M.; Textor, C.; Guibert, S.; Balkanski, Y.; Bauer, S.; Berntsen, T.; Berglen, T.; Boucher, Olivier; Chin, M.; Collins, W.; Dentener, F.; Diehl, T.; Easter, Richard C.; Feichter, H.; Fillmore, D.; Ghan, Steven J.; Ginoux, P.; Gong, S.; Grini, A.; Hendricks, J.; Herzog, M.; Horrowitz, L.; Isaksen, I.; Iversen, T.; Kirkevag, A.; Kloster, S.; Koch, D.; Kristjansson, J. E.; Krol, M.; Lauer, A.; Lamarque, J. F.; Lesins, G.; Liu, Xiaohong; Lohmann, U.; Montanaro, V.; Myhre, G.; Penner, Joyce E.; Pitari, G.; Reddy, S.; Seland, O.; Stier, P.; Takemura, T.; Tie, X.

    2006-05-29

    The AeroCom exercise diagnoses multi-component aerosol modules in global modeling. In an initial assessment global fields for mass and for mid-visible aerosol optical thickness (aot) were compared among aerosol component modules of 21 different global models. There is general agreement among models for the annual global mean of component combined aot. At 0.12 to 0.14, simulated aot values are at the lower end of global averages suggested by remote sensing from ground (AERONET ca 0.14) and space (MODIS-MISR composite ca 0.16). More detailed comparisons, however, reveal that larger differences in regional distribution and significant differences in compositional mixture have remained. Of particular concern is the large model diversity for contributions by dust and carbon, because it leads to significant uncertainty in aerosol absorption (aab). Since not only aot but also aab influence the aerosol impact on the radiative energy-balance, aerosol (direct) forcing uncertainty in modeling is larger than differences in aot might suggest. New diagnostic approaches are proposed to trace model differences in terms of aerosol processing and transport: These include the prescription of common input (e.g. amount, size and injection of aerosol component emissions) and the use of observational capabilities from ground (e.g. measurements networks) and space (e.g. correlations between retrieved aerosol and cloud properties).

  8. Giant nonlinear optical activity in a plasmonic metamaterial

    NASA Astrophysics Data System (ADS)

    Ren, Mengxin; Plum, Eric; Xu, Jingjun; Zheludev, Nikolay I.

    2012-05-01

    In 1950, a quarter of a century after his first-ever nonlinear optical experiment when intensity-dependent absorption was observed in uranium-doped glass, Sergey Vavilov predicted that birefringence, dichroism and polarization rotatory power should be dependent on light intensity. It required the invention of the laser to observe the barely detectable effect of light intensity on the polarization rotatory power of the optically active lithium iodate crystal, the phenomenon now known as the nonlinear optical activity, a high-intensity counterpart of the fundamental optical effect of polarization rotation in chiral media. Here we report that a plasmonic metamaterial exhibits nonlinear optical activity 30 million times stronger than lithium iodate crystals, thus transforming this fundamental phenomenon of polarization nonlinear optics from an esoteric phenomenon into a major effect of nonlinear plasmonics with potential for practical applications.

  9. Development of a graded index microlens based fiber optical trap and its characterization using principal component analysis.

    PubMed

    Nylk, J; Kristensen, M V G; Mazilu, M; Thayil, A K; Mitchell, C A; Campbell, E C; Powis, S J; Gunn-Moore, F J; Dholakia, K

    2015-04-01

    We demonstrate a miniaturized single beam fiber optical trapping probe based on a high numerical aperture graded index (GRIN) micro-objective lens. This enables optical trapping at a distance of 200μm from the probe tip. The fiber trapping probe is characterized experimentally using power spectral density analysis and an original approach based on principal component analysis for accurate particle tracking. Its use for biomedical microscopy is demonstrated through optically mediated immunological synapse formation.

  10. Lifecycle Prognostics Architecture for Selected High-Cost Active Components

    SciTech Connect

    N. Lybeck; B. Pham; M. Tawfik; J. B. Coble; R. M. Meyer; P. Ramuhalli; L. J. Bond

    2011-08-01

    There are an extensive body of knowledge and some commercial products available for calculating prognostics, remaining useful life, and damage index parameters. The application of these technologies within the nuclear power community is still in its infancy. Online monitoring and condition-based maintenance is seeing increasing acceptance and deployment, and these activities provide the technological bases for expanding to add predictive/prognostics capabilities. In looking to deploy prognostics there are three key aspects of systems that are presented and discussed: (1) component/system/structure selection, (2) prognostic algorithms, and (3) prognostics architectures. Criteria are presented for component selection: feasibility, failure probability, consequences of failure, and benefits of the prognostics and health management (PHM) system. The basis and methods commonly used for prognostics algorithms are reviewed and summarized. Criteria for evaluating PHM architectures are presented: open, modular architecture; platform independence; graphical user interface for system development and/or results viewing; web enabled tools; scalability; and standards compatibility. Thirteen software products were identified and discussed in the context of being potentially useful for deployment in a PHM program applied to systems in a nuclear power plant (NPP). These products were evaluated by using information available from company websites, product brochures, fact sheets, scholarly publications, and direct communication with vendors. The thirteen products were classified into four groups of software: (1) research tools, (2) PHM system development tools, (3) deployable architectures, and (4) peripheral tools. Eight software tools fell into the deployable architectures category. Of those eight, only two employ all six modules of a full PHM system. Five systems did not offer prognostic estimates, and one system employed the full health monitoring suite but lacked operations and

  11. Tumor necrosis factor-inducing activities of Cryptococcus neoformans components.

    PubMed Central

    Delfino, D; Cianci, L; Migliardo, M; Mancuso, G; Cusumano, V; Corradini, C; Teti, G

    1996-01-01

    Cryptococcus neoformans-induced tumor necrosis factor alpha (TNF-alpha) production may lead to increased human immunodeficiency virus replication in patients with AIDS. In order to identify cryptococcal components that are predominantly responsible for stimulating TNF production, various concentrations of glucuronoxylomannan (GXM), galactoxylomannan (GalXM), mannoproteins (MP), and alpha(1-3) [corrected] glucan were added to whole-blood cultures. All of the cryptococcal components tested, as well as whole heat-killed cryptococci, were capable of inducing TNF-alpha release in a dose-dependent manner. MP were significantly more potent than any of the other cryptococcal components tested or heat-killed cryptococci in stimulating TNF-alpha production (P < 0.05). GXM, in contrast, was significantly less potent in this activity than either GalXM or MP (P < 0.05). As little as 0.5 microg of MP per ml was sufficient to produce moderate but significant elevations of TNF-alpha release. Maximal MP-induced TNF-alpha levels were similar to those induced by Salmonella enteritidis lipopolysaccharide, our positive control. Further experiments using isolated leukocytes suggested that monocytes were the cell population mainly responsible for TNF-alpha production, although the participation of other cell types could not be excluded. The presence of complement-sufficient plasma was a necessary requirement for TNF-alpha induction by GXM, GalXM, and low doses of MP. High MP concentrations (100 microg/ml) were also capable of stimulating TNF-alpha production in the absence of plasma. These data indicate that soluble products released by C. neoformans are capable of inducing TNF-alpha secretion in human leukocytes. This may be clinically relevant, since high concentrations of such products are frequently found in the body fluids of AIDS patients infected with C. neoformans. PMID:8945566

  12. An Exploration of Professional Culture Differentials and Their Potential Impact on the Information Assurance Component of Optical Transmission Networks Design

    ERIC Educational Resources Information Center

    Cuthrell, Michael Gerard

    2011-01-01

    Optical transmission networks are an integral component of the critical infrastructures for many nations. Many people believe that optical transmission networks are impenetrable. In actuality, these networks possess weaknesses that can be exploited to bring about harm. An emerging Information Assurance (IA) industry has as its goals: to…

  13. Neuroprotective Activity of Hypericum perforatum and Its Major Components

    PubMed Central

    Oliveira, Ana I.; Pinho, Cláudia; Sarmento, Bruno; Dias, Alberto C. P.

    2016-01-01

    Hypericum perforatum is a perennial plant, with worldwide distribution, commonly known as St. John’s wort. It has been used for centuries in traditional medicine for the treatment of several disorders, such as minor burns, anxiety, and mild to moderate depression. In the past years, its antidepressant properties have been extensively studied. Despite that, other H. perforatum biological activities, as its neuroprotective properties have also been evaluated. The present review aims to provide a comprehensive summary of the main biologically active compounds of H. perforatum, as for its chemistry, pharmacological activities, drug interactions and adverse reactions and gather scattered information about its neuroprotective abilities. As for this, it has been demonstrated that H. perforatum extracts and several of its major molecular components have the ability to protect against toxic insults, either directly, through neuroprotective mechanisms, or indirectly, through is antioxidant properties. H. perforatum has therefore the potential to become an effective neuroprotective therapeutic agent, despite further studies that need to be carried out. PMID:27462333

  14. Neuroprotective Activity of Hypericum perforatum and Its Major Components.

    PubMed

    Oliveira, Ana I; Pinho, Cláudia; Sarmento, Bruno; Dias, Alberto C P

    2016-01-01

    Hypericum perforatum is a perennial plant, with worldwide distribution, commonly known as St. John's wort. It has been used for centuries in traditional medicine for the treatment of several disorders, such as minor burns, anxiety, and mild to moderate depression. In the past years, its antidepressant properties have been extensively studied. Despite that, other H. perforatum biological activities, as its neuroprotective properties have also been evaluated. The present review aims to provide a comprehensive summary of the main biologically active compounds of H. perforatum, as for its chemistry, pharmacological activities, drug interactions and adverse reactions and gather scattered information about its neuroprotective abilities. As for this, it has been demonstrated that H. perforatum extracts and several of its major molecular components have the ability to protect against toxic insults, either directly, through neuroprotective mechanisms, or indirectly, through is antioxidant properties. H. perforatum has therefore the potential to become an effective neuroprotective therapeutic agent, despite further studies that need to be carried out. PMID:27462333

  15. Embedded fiber optic sensors for monitoring processing, quality and structural health of resin transfer molded components

    NASA Astrophysics Data System (ADS)

    Keulen, C.; Rocha, B.; Yildiz, M.; Suleman, A.

    2011-07-01

    Due to their small size and flexibility fiber optics can be embedded into composite materials with little negative effect on strength and reliability of the host material. Fiber optic sensors such as Fiber Bragg Gratings (FBG) or Etched Fiber Sensors (EFS) can be used to detect a number of relevant parameters such as flow, degree of cure, quality and structural health throughout the life of a composite component. With a detection algorithm these embedded sensors can be used to detect damage in real time while the component remains in service. This paper presents the research being conducted on the use of fiber optic sensors for process and Structural Health Monitoring (SHM) of Resin Transfer Molded (RTM) composite structures. Fiber optic sensors are used at all life stages of an RTM composite panel. A laboratory scale RTM apparatus was developed with the capability of visually monitoring the resin filling process. A technique for embedding fiber optic sensors with this apparatus has also been developed. Both FBGs and EFSs have been embedded in composite panels using the apparatus. EFSs to monitor the fabrication process, specifically resin flow have been embedded and shown to be capable of detecting the presence of resin at various locations as it is injected into the mold. Simultaneously these sensors were multiplexed on the same fiber with FBGs, which have the ability to measure strain. Since multiple sensors can be multiplexed on a single fiber the number of ingress/egress locations required per sensor can be significantly reduced. To characterize the FBGs for strain detection tensile test specimens with embedded FBG sensors have been produced. These specimens have been instrumented with a resistive strain gauge for benchmarking. Both specimens and embedded sensors were characterized through tensile testing. Furthermore FBGs have been embedded into composite panels in a manner that is conducive to detection of Lamb waves generated with a centrally located PZT

  16. Reinvestigation of the proteolytically active components of Bromelia pinguin fruit.

    PubMed

    Payrol, Juan Abreu; Obregón, Walter D; Natalucci, Claudia L; Caffini, Néstor O

    2005-09-01

    Pinguinain is the name given to a proteolytic enzyme preparation obtained from Bromelia pinguin fruits that has been scarcely studied. The present paper deals on the reexamination of the proteases present in fruits of B. pinguin grown in Cienfuegos, Cuba. The preparation (partially purified pinguinain, PPP) showed the main characteristics of the cysteine proteases, i.e., optimum pH within alkaline range (pH 7.2-8.8), inhibition of proteolytic activity by thiol blocking reagents, which is usually reverted by addition of cysteine, a remarkable thermal stability and notable stability at high ionic strength values. Isoelectric focusing and zymogram of PPP revealed the presence of several proteolytic components between pI 4.6 and 8.1. Preliminary peptidase purification by cationic exchange chromatography showed the presence of two main proteolytic fractions with molecular masses of approximately 20.0 kDa, according to SDS-PAGE.

  17. Statistical Properties of Multiple Optical Emission Components in Gamma-Ray Bursts and Implications

    NASA Astrophysics Data System (ADS)

    Liang, En-Wei; Li, Liang; Tang, Qing-Wen; Chen, Jie-Min; Zhang, Bing

    2013-01-01

    Well-sampled optical lightcurves of 146 gamma-ray bursts (GRBs) are complied from the literature. Multiple optical emission components are extracted with power-law function fits to these lightcurves. We present a systematical analysis for statistical properties and their relations to prompt gamma-ray emission and X-ray afterglow for each component. We show that peak luminosity in the prompt and late flares are correlated and the evolution of the peak luminosity may signal the evolution of the accretion rate. No tight correlation between the shallow decay phase/plateau and prompt gamma-ray emission is found. Assuming that they are due to a long-lasting wind injected by a compact object, we show that the injected behavior favors the scenarios of a long-lasting wind powered by a Poynting flux from a black hole via the Blandford-Znajek mechanism fed by fall-back mass or by the spin-down energy release of a magnetar after the main burst episode. The peak luminosity of the afterglow onset is tightly correlated with Eγ,iso, and it is dimmer as peaking later. Assuming that the onset bump is due to the fireball deceleration by the external medium, we examine the Γ0 - Eγ,iso relation and find that it is confirmed with the current sample. Optical re-brightening is observed in 30 GRBs in our sample. It shares the same relation between the width and the peak time as found in the onset bump, but no clear correlation between LR,p and Eγ,iso similar to that observed for the onset bumps is found. Although its peak luminosity also decays with time, the slope is much shallower than that of the onset peak, as is the case for the onset bumps. We get L∝ t-1 p, being consistent with off-axis observations to an expanding external fireball in a wind-like circum medium. Therefore, the late re-brightening may signal another jet component. Mixing of different emission components may be the reason for the observed chromatic breaks of the shallow decay segment in different energy bands.

  18. Continuous angle steering of an optically- controlled phased array antenna based on differential true time delay constituted by micro-optical components.

    PubMed

    Wang, Jian; Hou, Peipei; Cai, Haiwen; Sun, Jianfeng; Wang, Shunan; Wang, Lijuan; Yang, Fei

    2015-04-01

    We propose an optically controlled phased array antenna (PAA) based on differential true time delay constructed optical beamforming network (OBFN). Differential true time delay is realized by stack integrated micro-optical components. Optically-controlled angle steering of radio frequency (RF) beams are realized and demonstrated by this configuration. Experimental results demonstrate that OBFN based PAA can accomplish RF-independent broadband beam steering without beam squint effect and can achieve continuous angle steering. In addition, multi-beams for different steering angles are acquired synchronously. PMID:25968773

  19. Continuous angle steering of an optically- controlled phased array antenna based on differential true time delay constituted by micro-optical components.

    PubMed

    Wang, Jian; Hou, Peipei; Cai, Haiwen; Sun, Jianfeng; Wang, Shunan; Wang, Lijuan; Yang, Fei

    2015-04-01

    We propose an optically controlled phased array antenna (PAA) based on differential true time delay constructed optical beamforming network (OBFN). Differential true time delay is realized by stack integrated micro-optical components. Optically-controlled angle steering of radio frequency (RF) beams are realized and demonstrated by this configuration. Experimental results demonstrate that OBFN based PAA can accomplish RF-independent broadband beam steering without beam squint effect and can achieve continuous angle steering. In addition, multi-beams for different steering angles are acquired synchronously.

  20. Radio Properties of Low Redshift Broad Line Active Galactic Nuclei Including Multiple Component Radio Sources

    NASA Astrophysics Data System (ADS)

    Rafter, Stephen E.

    2010-01-01

    We present results on the radio properties of a low redshift (z < 0.35) sample of 8434 broad line active galactic nuclei (AGNs) from the Sloan Digital Sky Survey after correlating the optical sources with radio sources in the Faint Images of the Radio Sky at Twenty-Centimeters survey. We find that 10% of our sample has radio emission < 4" away from the optical counterpart (core-only sources), and 1% has significant extended emission that must be taken into account when calculating the total radio luminosity (multi-component sources). Association of the extended radio emission is established by the proximity to the optical source, physical connection of jets and lobes, or large scale symmetry like in classic FRIIs. From these data we find an FRI/FRII luminosity dividing line like that found by Fanaroff & Riley (1974), where we use our core-only sources as proxies for FRIs, and our multi-component sources for the FRIIs. We find a bimodal distribution for the radio loudness (R = L(radio)/L(opt)) where the lower radio luminosity core-only sources appear as a population separate from the multi-component extended sources, compared with no evidence for bimodality when just the core-only sources are used. We also find that a log(R) value of 1.75 is well suited to separate the FRIs from the FRIIs, and that the R bimodality seen here is really a manifestation of the FRI/FRII break originally found by Fanaroff & Riley (1974). We find modest trends in the radio loud fraction as a function of Eddington ratio and black hole mass, where the fraction of RL AGNs decreases with increasing Eddington ratio, and increases when the black hole mass is above 2 x 108 solar masses.

  1. Direct writing of fiber optic components in photonic crystal fibers and other specialty fibers

    NASA Astrophysics Data System (ADS)

    Fernandes, Luis Andre; Sezerman, Omur; Best, Garland; Ng, Mi Li; Kane, Saidou

    2016-04-01

    Femtosecond direct laser writing has recently shown great potential for the fabrication of complex integrated devices in the cladding of optical fibers. Such devices have the advantage of requiring no bulk optical components and no breaks in the fiber path, thus reducing the need for complicated alignment, eliminating contamination, and increasing stability. This technology has already found applications using combinations of Bragg gratings, interferometers, and couplers for the fabrication of optical filters, sensors, and power monitors. The femtosecond laser writing method produces a local modification of refractive index through non-linear absorption of the ultrafast laser pulses inside the dielectric material of both the core and cladding of the fiber. However, fiber geometries that incorporate air or hollow structures, such as photonic crystal fibers (PCFs), still present a challenge since the index modification regions created by the writing process cannot be generated in the hollow regions of the fiber. In this work, the femtosecond laser method is used together with a pre-modification method that consists of partially collapsing the hollow holes using an electrical arc discharge. The partial collapse of the photonic band gap structure provides a path for femtosecond laser written waveguides to couple light from the core to the edge of the fiber for in-line power monitoring. This novel approach is expected to have applications in other specialty fibers such as suspended core fibers and can open the way for the integration of complex devices and facilitate miniaturization of optical circuits to take advantage of the particular characteristics of the PCFs.

  2. 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.

  3. Integrated optical components using hybrid organic-inorganic materials prepared by sol-gel technology

    NASA Astrophysics Data System (ADS)

    Mishechkin, Oleg Viktorovich

    2003-10-01

    A technological platform based on low-temperature hybrid sol-gel method for fabrication of optical waveguides and integrated optical components has been developed. The developed chemistry for doping incorporation in the host network provides a range of refractive indexes (1.444--1.51) critical for device optimization. A passivation method for improving long-term stability of organic-inorganic sol-gel material is reported. The degradation of waveguide loss over time due to moisture adsorption from the atmosphere is drastically suppressed by coating the material with a protective thin SiO2 film. The results indicate a long-term optical loss below 0.3 dB/cm for protected waveguides. The theory of multimode interference couplers employing self-imaging effect is described. A novel approach for design of high-performance MMI devices in low-contrast material is proposed. The design method is based on optimization of refractive index contrast and width of a multimode waveguide (the body of MMI couplers) to achieve a maximum number of constructively interfering modes resulting to the best self-imaging. This optimization is carried out using 3D BPM simulations. This method was applied to design 1 x 4, 1 x 12, and 4 x 4 MMI couplers and led to a superior performance in excess loss, power imbalance in output ports, and polarization sensitivity. Taking advantage of the inherent input-output phase relations in a 4 x 4 MMI coupler, an optical 90° hybrid is realized by incorporation a Y-junction to coherently excite two ports of the coupler. A series of MMI couplers were fabricated and characterized. The experimental results are in good agreement with the design. Measured performance of the sol-gel derived MMI components was compared to analogues fabricated by other technologies. The comparison demonstrates the superior performance of the sol-gel devices. The polarization sensitivity of all fabricated couplers is below 0.05 dB.

  4. Development of internal components for M38999 type connectors, for use in advanced photonic applications and with specialty optical fibers

    NASA Astrophysics Data System (ADS)

    Whitebook, Alan; Caloz, Francois

    2014-09-01

    This presentation outlines development work performed to produce internal components (connector insert assemblies & optical terminus assemblies) to be fit into MIL-DTL-38999, or commercial off the shelf (COTS) equivalent, connector housings. Connectors modified with these internal components are then suitable for optical termination and transmission through specialty fibers such as polarization maintaining, small core single-mode, and others, with the ability to achieve high levels of performance in the areas of insertion loss, return loss, polarization extinction ratio (as applicable) and power handling capability (as applicable.) Technical details are presented to illustrate features within the optical terminus, and its insert cavity, which serves to allow for fiber/ferrule polar orientation, concentricity of mated termini ferrules and fibers terminated within, and other attributes designed to support optical performance goals. Finally, optical performance data is given and discussed to illustrate results achieved by production of evaluation cable assemblies. emblies.

  5. Integration and alignment of ATLAS instrument engineering model components in Optical Development System Lab

    NASA Astrophysics Data System (ADS)

    Evans, Tyler

    2013-09-01

    The ATLAS Instrument for the ICESat-2 mission at NASA's Goddard Space Flight Center required a test-bed to prove out new concepts before the mission launches in 2016. The Optical Development System (ODS) laboratory was created to use breadboard, prototype, and engineering-model levels of hardware and software to model and evaluate the ATLAS alignment system. A one meter parabolic mirror was used to create a collimated light beam to align prototype and engineering model transmitter and receiver optics and test closed-loop alignment algorithms. To achieve an error of less than two micro-radians, an active deformable mirror was used to correct the wave front to subtract out the collimator mount error.

  6. 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.

  7. Asymmetric fishnet metamaterials with strong optical activity.

    PubMed

    Zhang, Yong-Liang; Jin, Wei; Dong, Xian-Zi; Zhao, Zhen-Sheng; Duan, Xuan-Ming

    2012-05-01

    We investigate the optical properties of mono- and double-layer asymmetric fishnet metamaterials with orientated elliptical holes, which exhibit exotic spectral and polarization rotating characteristics in the visible spectral range. Our results show that nontrivial orientations of the holes with respect to the reciprocal lattice vectors of the periodic lattice in both systems produce strong polarization rotation as well as additional enhanced optical transmission peaks. Analysis of the electromagnetic field distribution shows the unusual effect is produced by the spinning localized surface plasmon resonances due to the asymmetric geometry. High sensitivity of the hybridized mode on the dielectric spacing, the aspect ratio of the holes and the embedding media in double-layer structure is also observed. The dependence of spectral and polarization response on the orientation of the holes and the embedding media is useful for design of chiral metamaterials at optical frequencies and tailoring the polarization behavior of the metallic nano-structures.

  8. 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.

  9. Laser optical disk position encoder with active heads

    NASA Technical Reports Server (NTRS)

    Osborne, Eric P.

    1991-01-01

    An angular position encoder that minimizes the effects of eccentricity and other misalignments between the disk and the read stations by employing heads with beam steering optics that actively track the disk in directions along the disk radius and normal to its surface is discussed. The device adapts features prevalent in optical disk technology to the application of angular position sensing.

  10. Laser optical disk position encoder with active heads

    NASA Astrophysics Data System (ADS)

    Osborne, Eric P.

    An angular position encoder that minimizes the effects of eccentricity and other misalignments between the disk and the read stations by employing heads with beam steering optics that actively track the disk in directions along the disk radius and normal to its surface is discussed. The device adapts features prevalent in optical disk technology to the application of angular position sensing.

  11. The large-area hybrid-optics CLAS12 RICH detector: Tests of innovative components

    SciTech Connect

    Contalbrigo, M; Baltzell, N; Benmokhtar, F; Barion, L; Cisbani, E; El Alaoui, A; Hafidi, K; Hoek, M; Kubarovsky, V; Lagamba, L; Lucherini, V; Malaguti, R; Mirazita, M; Montgomery, R; Movsisyan, A; Musico, P; Orecchini, D; Orlandi, A; Pappalardo, L L; Pereira, S; Perrino, R; Phillips, J; Pisano, S; Rossi, P; Squerzanti, S; Tomassini, S; Turisini, M; Viticchiè, A

    2014-07-01

    A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator facility of Jefferson Lab to study the 3D nucleon structure in the yet poorly explored valence region by deep-inelastic scattering, and to perform precision measurements in hadronization and hadron spectroscopy. The adopted solution foresees a novel hybrid optics design based on an aerogel radiator, composite mirrors and densely packed and highly segmented photon detectors. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large angle tracks). The preliminary results of individual detector component tests and of the prototype performance at test-beams are reported here.

  12. [Active components of Ligustrum lucidum inhibiting hepatitis C virus replicase activity].

    PubMed

    Sun, Rui-na; Zhang, Yan-ni; Wang, Jun; Liu, Hao-ju; Kong, Ling-bao

    2013-09-01

    Based on previous report that the Chinese herb Ligustrum lucidum (LL) extract directly inhibited hepatitis C virus (HCV) replicase (NS5B) activity, the active components of LL extract to inhibit HCV NS5B activity and their inhibition mode were investigated in this study. LL extract was separated using ethyl acetate and thin layer chromatography (TLC). The inhibitory activity of separated fractions on HCV NS5B was analyzed by the inhibitory assay of NS5B activity. The results showed that only fractions 1 and 2 inhibited NS5B activity, and fraction 2 possessed higher inhibitory activity than fraction 1. HPLC analysis combined with inhibitory assays indicated that ursolic acid and oleanolic acid are the active components within fractions 1 and 2 to inhibit NS5B activity, separately. Moreover, oleanolic acid possessed higher inhibitory activity than ursolic acid. Further inhibition mode analysis found that both oleanolic acid and ursolic acid suppressed NS5B activity as noncompetitive inhibitors. The Ki values of ursolic acid and oleanolic acid were about 4.7 microg x mL(-1) (10 micromol x kg(-1)) and 2.5 microg x mL(-1) (5.5 micromol x kg(-1)), respectively. Taken together, these results demonstrated that oleanolic acid and ursolic acid suppressed NS5B activity as noncompetitive inhibitors, implying that the two natural products have potential value for HCV therapy. PMID:24358771

  13. 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

  14. Alternative technology for fabrication of nano- or microstructured mould inserts used for optical components

    NASA Astrophysics Data System (ADS)

    Wissmann, M.; Guttmann, M.; Hartmann, M.

    2010-02-01

    For mass production of multiscale-optical components, micro- and nanostructured moulding tools are needed. Metal tools are used for hot embossing or injection moulding of microcomponents in plastics. Tools are typically produced by classical forming processes such as mechanical manufacturing e.g. turning or milling, laser manufacturing or electrical discharge machining (EDM). Microstructures with extremely tight specifications, e.g. low side wall roughness and high aspect ratios are generally made by lithographic procedures such as LIGA or DPW technology. However, these processes are unsuitable for low-cost mass production. They are limited by the exposure area and structure design. In cooperation with international partners alternative manufacturing methods of moulding tools have been developed at the Institute of Microstructure Technology (IMT). In a new replication procedure, mould inserts are fabricated using micro- and nanoscale optics. The multiscale structured prototypes, either in plastics, glass, metal or material combinations are used as sacrificial parts. Using joining technology, electroforming and EDM technology, a negative copy of a prototype is transferred into metal to be used as a moulding tool. The benefits of this replication technique are rapid and economical production of moulding tools with extremely precise micro- and nanostructures, large structured area and long tool life. Low-cost mass replication is possible with these moulding tools. In this paper, an established manufacturing chain will be presented. Multiscale and multimaterial optical prototypes e.g. out-of-plane coupler or microinterferometer were made by DPW or laser technology. The mould insert fabrication of each individual manufacturing step will be shown. The process reliability and suitability for mass production was tested by hot embossing.

  15. Comparative activities of milk components in reversing chronic colitis.

    PubMed

    Kanwar, J R; Kanwar, R K; Stathopoulos, S; Haggarty, N W; MacGibbon, A K H; Palmano, K P; Roy, K; Rowan, A; Krissansen, G W

    2016-04-01

    Inflammatory bowel disease (IBD) is a poorly understood chronic immune disorder for which there is no medical cure. Milk and colostrum are rich sources of bioactives with immunomodulatory properties. Here we compared the therapeutic effects of oral delivery of bovine milk-derived iron-saturated lactoferrin (Fe-bLF), angiogenin, osteopontin (OPN), colostrum whey protein, Modulen IBD (Nestle Healthsciences, Rhodes, Australia), and cis-9,trans-11 conjugated linoleic acid (CLA)-enriched milk fat in a mouse model of dextran sulfate-induced colitis. The CLA-enriched milk fat significantly increased mouse body weights after 24d of treatment, reduced epithelium damage, and downregulated the expression of proinflammatory cytokines and nitrous oxide. Modulen IBD most effectively decreased the clinical score at d 12, and Modulen IBD and OPN most effectively lowered the inflammatory score. Myeloperoxidase activity that denotes neutrophil infiltration was significantly lower in mice fed Modulen IBD, OPN, angiogenin, and Fe-bLF. A significant decrease in the numbers of T cells, natural killer cells, dendritic cells, and a significant decrease in cytokine expression were observed in mice fed the treatment diets compared with dextran sulfate administered mice. The Fe-bLF, CLA-enriched milk fat, and Modulen IBD inhibited intestinal angiogenesis. In summary, each of the milk components attenuated IBD in mice, but with differing effectiveness against specific disease parameters. PMID:26805965

  16. Photonic muscle active optics for space telescopes (active optics with 1023 actuators)

    NASA Astrophysics Data System (ADS)

    Ritter, Joe

    2009-08-01

    Presented is a novel optical system using Cis-Trans photoisomerization where nearly every molecule of a mirror substrate is itself an optically powered actuator. Primary mirrors require sub-wavelength figure (shape) error in order to achieve acceptable Strehl ratios. Traditional telescopy methods require rigid and therefore heavy mirrors and reaction structures as well as proportionally heavy and expensive spacecraft busses and launch vehicles. Areal density can be reduced by increasing actuation density. Making every molecule of a substrate an actuator approaches the limit of the areal density vs actuation design trade space. Cis-Trans photoisomerization, a reversible reorganization of molecular structure induced by light, causes a change in the shape and volume of azobenzene based molecules. Induced strain in these "photonic muscles" can be over 40%. Forces are pico-newtons/molecule. Although this molecular limit is not typically multiplied in aggregate materials we have made, considering the large number of molecules in a mole, future optimized systems may approach this limit In some π-π* mixed valence azo-polymer membranes we have made photoisomerization causes a highly controllable change in macroscopic dimension with application of light. Using different wavelengths and polarizations provides the capability to actively reversibly and remotely control membrane mirror shape and dynamics using low power lasers, instead of bulky actuators and wires, thus allowing the substitution of optically induced control for rigidity and mass. Areal densities of our photonic muscle mirrors are approximately 100 g/m2. This includes the substrate and actuators (which are of course the same). These materials are thin and flexible (similar to saran wrap) so high packing ratios are possible, suggesting the possibility of deployable JWST size mirrors weighing 6 kilograms, and the possibility of ultralightweight space telescopes the size of a football field. Photons weigh nothing

  17. Studies of effects on optical components and sensors: LDEF experiments AO-147 (ERB components) and S-0014 (APEX)

    NASA Technical Reports Server (NTRS)

    Hickey, John R.; Brinker, David J.; Jenkins, Philip

    1993-01-01

    Some additional results of testing of optical filters and window materials and thermopile sensors of the two experiments are included. The Advanced Photovoltaic Experiment (APEX) interference filters exhibited much greater degradation in space than the ERB filters. The adhesion of the Indium washers to the APEX interference filters is reported.

  18. 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.

  19. Trifluoromethyl nitrones: from fluoral to optically active hydroxylamines.

    PubMed

    Milcent, Thierry; Hinks, Nathan; Bonnet-Delpon, Danièle; Crousse, Benoit

    2010-06-28

    Trifluoromethyl nitrones were obtained in high yields by condensation of various hydroxylamines with trifluoroacetaldehyde hydrate. The nucleophilic diastereoselective additions of organometallic reagents to these nitrones afforded the corresponding optically active trifluoroethyl hydroxylamines in good yields. PMID:20458418

  20. Study of a distributed feedback diode laser based hygrometer combined Herriot-gas cell and waterless optical components

    NASA Astrophysics Data System (ADS)

    Wei, Yubin; Chang, Jun; Lian, Jie; Wang, Qiang; Wei, Wei

    2016-09-01

    A distributed feedback diode laser (DFB-DL) based hygrometer combined with a long-path-length Herriot gas cell and waterless optical components was proposed and investigated. The main function of this sensor was to simultaneously improve the measurement reliability and resolution. A comparison test between a 10-cm normal transmission-type gas cell and a 3-m Herriot gas cell was carried out to demonstrate the improvement. Reliability improvement was achieved by influence suppression of water vapor inside optical components (WVOC) through combined action of the Herriot gas cell and waterless optical components. The influence of WVOC was suppressed from 726 ppmv to 25 ppmv using the Herriot gas cell. Moreover, combined with waterless optical components, the influence of WVOC was further suppressed to no more than 4 ppmv. Resolution improvement from 11.7 ppmv to 0.32 ppmv was achieved mainly due to the application of the long-path-length Herriot gas cell. The results show that the proposed sensor has a good performance and considerable potential application in gas sensing, especially when probed gas possibly permeates into optical components.

  1. Unmixing dynamic fluorescence diffuse optical tomography images with independent component analysis.

    PubMed

    Liu, Xin; Liu, Fei; Zhang, Yi; Bai, Jing

    2011-09-01

    Dynamic fluorescence diffuse optical tomography (D-FDOT) is important for drug delivery research. However, the low spatial resolution of FDOT and the complex kinetics of drug limit the ability of D-FDOT in resolving metabolic processes of drug throughout whole body of small animals. In this paper, we propose an independent component analysis (ICA)-based method to perform D-FDOT studies. When applied to D-FDOT images, ICA not only generates a set of independent components (ICs) which can illustrate functional structures with different kinetic behaviors, but also provides a set of associated time courses (TCs) which can represent normalized time courses of drug in corresponding functional structures. Further, the drug concentration in specific functional structure at different time points can be recovered by an inverse ICA transformation. To evaluate the performance of the proposed algorithm in the study of drug kinetics at whole-body level, simulation study and phantom experiment are both performed on a full-angle FDOT imaging system with line-shaped excitation pattern. In simulation study, the nanoparticle delivery of indocynaine green (ICG) throughout whole body of a digital mouse is simulated and imaged. In phantom experiment, four tubes containing different ICG concentrations are imaged and used to imitate the uptake and excretion of ICG in organs. The results suggest that we can not only illustrate ICG distributions in different functional structures, but also recover ICG concentrations in specific functional structure at different time points, when ICA is applied to D-FDOT images.

  2. Organic component vapor pressures and hygroscopicities of aqueous aerosol measured by optical tweezers.

    PubMed

    Cai, Chen; Stewart, David J; Reid, Jonathan P; Zhang, Yun-hong; Ohm, Peter; Dutcher, Cari S; Clegg, Simon L

    2015-01-29

    Measurements of the hygroscopic response of aerosol and the particle-to-gas partitioning of semivolatile organic compounds are crucial for providing more accurate descriptions of the compositional and size distributions of atmospheric aerosol. Concurrent measurements of particle size and composition (inferred from refractive index) are reported here using optical tweezers to isolate and probe individual aerosol droplets over extended timeframes. The measurements are shown to allow accurate retrievals of component vapor pressures and hygroscopic response through examining correlated variations in size and composition for binary droplets containing water and a single organic component. Measurements are reported for a homologous series of dicarboxylic acids, maleic acid, citric acid, glycerol, or 1,2,6-hexanetriol. An assessment of the inherent uncertainties in such measurements when measuring only particle size is provided to confirm the value of such a correlational approach. We also show that the method of molar refraction provides an accurate characterization of the compositional dependence of the refractive index of the solutions. In this method, the density of the pure liquid solute is the largest uncertainty and must be either known or inferred from subsaturated measurements with an error of <±2.5% to discriminate between different thermodynamic treatments.

  3. CONTRACTING AND ERUPTING COMPONENTS OF SIGMOIDAL ACTIVE REGIONS

    SciTech Connect

    Liu Rui; Wang Yuming; Liu Chang; Wang Haimin; Toeroek, Tibor

    2012-10-01

    It has recently been noted that solar eruptions can be associated with the contraction of coronal loops that are not involved in magnetic reconnection processes. In this paper, we investigate five coronal eruptions originating from four sigmoidal active regions, using high-cadence, high-resolution narrowband EUV images obtained by the Solar Dynamic Observatory (SDO). The magnitudes of the flares associated with the eruptions range from GOES class B to class X. Owing to the high-sensitivity and broad temperature coverage of the Atmospheric Imaging Assembly (AIA) on board SDO, we are able to identify both the contracting and erupting components of the eruptions: the former is observed in cold AIA channels as the contracting coronal loops overlying the elbows of the sigmoid, and the latter is preferentially observed in warm/hot AIA channels as an expanding bubble originating from the center of the sigmoid. The initiation of eruption always precedes the contraction, and in the energetically mild events (B- and C-flares), it also precedes the increase in GOES soft X-ray fluxes. In the more energetic events, the eruption is simultaneous with the impulsive phase of the nonthermal hard X-ray emission. These observations confirm that loop contraction is an integrated process in eruptions with partially opened arcades. The consequence of contraction is a new equilibrium with reduced magnetic energy, as the contracting loops never regain their original positions. The contracting process is a direct consequence of flare energy release, as evidenced by the strong correlation of the maximal contracting speed, and strong anti-correlation of the time delay of contraction relative to expansion, with the peak soft X-ray flux. This is also implied by the relationship between contraction and expansion, i.e., their timing and speed.

  4. [Fourier analysis of pattern visual evoked potentials and changes of the harmonic component in longstanding optic neuritis].

    PubMed

    Hasegawa, S; Abe, H

    1992-11-01

    To determine the clinical usefulness of Fast Fourier Transform (FFT) for the detection of abnormal pattern visual evoked potentials (P-VEPs), the P-VEPs were recorded using a checkerboard pattern (check size: 14.4') which was reversed ranging from 4 to 16 per second. Fourteen eyes of 7 patients with longstanding optic neuritis and 15 eyes of age-matched normal controls were examined. Means and the standard deviation of the square root of the FFT power as a function of spectral frequency (1.953 x fHz, f = 1-17) were calculated and statistically significant levels between the two groups were studied for each reversal rate. When the reversal rate was more than 8/sec, The 1st or 2nd harmonic components decreased significantly in optic neuritis and the significant levels (p) of the 1st harmonic component were lower than that (p) of 2nd or 3rd harmonic component. When the reversal rate was 6/sec, the 1st and 2nd harmonic components decreased significantly and 1st harmonic component had the same level of significance as the 2nd harmonic component. When the reversal rate was 4/sec, the 2nd, 3rd, 5th and 6th harmonic components decreased significantly but 1st harmonic component did not. The level of significance of the 3rd harmonic component was the lowest followed by that of 2nd harmonic component.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Advancement of Optical Component Control for an Imaging Fabry-Perot Interferometer

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Cook, William B.; Flood, Michael A.; Campbell, Joel F.; Boyer, Charles M.

    2009-01-01

    Risk mitigation activities associated with a prototype imaging Fabry-Perot Interferometer (FPI) system are continuing at the NASA Langley Research Center. The system concept and technology center about enabling and improving future space-based atmospheric composition missions, with a current focus on observing tropospheric ozone around 9.6 micron, while having applicability toward measurement in different spectral regions and other applications. Recent activities have focused on improving an optical element control subsystem to enable precise and accurate positioning and control of etalon plates; this is needed to provide high system spectral fidelity critical for enabling the required ability to spectrally-resolve atmospheric line structure. The latest results pertaining to methodology enhancements, system implementation, and laboratory characterization testing will be reported

  6. 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.

  7. The age-mass relation for chromospherically active binaries. III. Lithium depletion in giant components

    NASA Astrophysics Data System (ADS)

    Barrado y Navascues, D.; de Castro, E.; Fernandez-Figueroa, M. J.; Cornide, M.; Garcia Lopez, R. J.

    1998-09-01

    We present a study of the lithium abundances of a sample of evolved components of Chromospherically Active Binary Systems. We show that a significant part of them have lithium excesses, independently of their mass and evolutionary stage. Therefore, it can be concluded that Li abundance does not depend on age for giant components of CABS. These overabundances appear to be closely related to the stellar rotation, and we interpret them as a consequence of the transfer of angular momentum from the orbit to the rotation as the stars evolve in and off the Main Sequence, in a similar way as it happens in the dwarf components of the same systems and in the Tidally Locked Binaries belonging to the Hyades and M67. Based on observations collected with the 2.2\\,m telescope of the German-Spanish Observatorio de Calar Alto (Almeria, Spain), and with the 2.56\\,m Nordic Optical Telescope in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrof\\'\\i sica de Canarias (La Palma, Spain)

  8. On the characterization of ultra-precise X-ray optical components: advances and challenges in ex situ metrology.

    PubMed

    Siewert, F; Buchheim, J; Zeschke, T; Störmer, M; Falkenberg, G; Sankari, R

    2014-09-01

    To fully exploit the ultimate source properties of the next-generation light sources, such as free-electron lasers (FELs) and diffraction-limited storage rings (DLSRs), the quality requirements for gratings and reflective synchrotron optics, especially mirrors, have significantly increased. These coherence-preserving optical components for high-brightness sources will feature nanoscopic shape accuracies over macroscopic length scales up to 1000 mm. To enable high efficiency in terms of photon flux, such optics will be coated with application-tailored single or multilayer coatings. Advanced thin-film fabrication of today enables the synthesis of layers on the sub-nanometre precision level over a deposition length of up to 1500 mm. Specifically dedicated metrology instrumentation of comparable accuracy has been developed to characterize such optical elements. Second-generation slope-measuring profilers like the nanometre optical component measuring machine (NOM) at the BESSY-II Optics laboratory allow the inspection of up to 1500 mm-long reflective optical components with an accuracy better than 50 nrad r.m.s. Besides measuring the shape on top of the coated mirror, it is of particular interest to characterize the internal material properties of the mirror coating, which is the domain of X-rays. Layer thickness, density and interface roughness of single and multilayer coatings are investigated by means of X-ray reflectometry. In this publication recent achievements in the field of slope measuring metrology are shown and the characterization of different types of mirror coating demonstrated. Furthermore, upcoming challenges to the inspection of ultra-precise optical components designed to be used in future FEL and DLSR beamlines are discussed.

  9. Selection of independent components based on cortical mapping of electromagnetic activity

    NASA Astrophysics Data System (ADS)

    Chan, Hui-Ling; Chen, Yong-Sheng; Chen, Li-Fen

    2012-10-01

    Independent component analysis (ICA) has been widely used to attenuate interference caused by noise components from the electromagnetic recordings of brain activity. However, the scalp topographies and associated temporal waveforms provided by ICA may be insufficient to distinguish functional components from artifactual ones. In this work, we proposed two component selection methods, both of which first estimate the cortical distribution of the brain activity for each component, and then determine the functional components based on the parcellation of brain activity mapped onto the cortical surface. Among all independent components, the first method can identify the dominant components, which have strong activity in the selected dominant brain regions, whereas the second method can identify those inter-regional associating components, which have similar component spectra between a pair of regions. For a targeted region, its component spectrum enumerates the amplitudes of its parceled brain activity across all components. The selected functional components can be remixed to reconstruct the focused electromagnetic signals for further analysis, such as source estimation. Moreover, the inter-regional associating components can be used to estimate the functional brain network. The accuracy of the cortical activation estimation was evaluated on the data from simulation studies, whereas the usefulness and feasibility of the component selection methods were demonstrated on the magnetoencephalography data recorded from a gender discrimination study.

  10. Non-mechanical scanning laser Doppler velocimetry with sensitivity to direction of transverse velocity component using optical serrodyne frequency shifting

    NASA Astrophysics Data System (ADS)

    Maru, Koichi; Watanabe, Kento

    2014-05-01

    This paper proposes a non-mechanical axial scanning laser Doppler velocimeter (LDV) with sensitivity to the direction of the transverse velocity component using optical serrodyne frequency shifting. Serrodyne modulation via the electro-optic effect of a LiNbO3 (LN) phase shifter is employed to discriminate the direction of the transverse velocity component. The measurement position is scanned without any moving mechanism in the probe by changing the wavelength of the light input to the probe. The experimental results using a sensor probe setup indicate that both the scan of the measurement position and the introduction of directional sensitivity are successfully demonstrated.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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

  16. 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…

  17. 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%.

  18. Highly reproducible quasi-mosaic crystals as optical components for a Laue lens

    NASA Astrophysics Data System (ADS)

    Camattari, Riccardo; Battelli, Alessandro; Bellucci, Valerio; Guidi, Vincenzo

    2014-02-01

    The realization of a Laue lens for astronomical purposes involves the mass production of a series of crystalline tiles as optical components, allowing high-efficiency diffraction and high-resolution focusing of photons. Crystals with self-standing curved diffraction planes is a valid and promising solution. Exploiting the quasi-mosaic effect, it turns out to be possible to diffract radiation at higher resolution. In this paper we present the realization of 150 quasi-mosaic Ge samples, bent by grooving one of their largest surface. We show that grooving method is a viable technique to manufacture such crystals in a simple and very reproducible way, thus compatible with mass production. Realized samples present very homogenous curvature. Furthermore, with a specific chemical etch, it is possible to fine adjust one by one the radius of curvature of the grooved samples. Realized crystals was selected for the ASI's Laue project, that involves the implementation of a prototype of a Laue lens for hard X- and soft γ-ray astronomy.

  19. Optical coating performance for heat reflectors of JWST-ISIM electronic component

    NASA Astrophysics Data System (ADS)

    Quijada, Manuel A.; Bousquet, Robert; Garrison, Matt; Perrygo, Chuck; Threat, Felix; Rashford, Robert

    2008-07-01

    The James Webb Space Telescope (JWST) consists of an infrared-optimized Optical Telescope Element (OTE) that is cooled down to 40 degrees Kelvin. A second adjacent component to the OTE is the Integrated Science Instrument Module, or ISIM. This module includes the electronic compartment, which provides the mounting surfaces and ambient thermally controlled environment for the instrument control electronics. Dissipating the 200 watts generated from the ISIM structure away from the OTE is of paramount importance so that the spacecraft's own heat does not interfere with the infrared light detected from distant cosmic sources. This technical challenge is overcome by a thermal subsystem unit that provides passive cooling to the ISIM control electronics. The proposed design of this thermal radiator consists of a lightweight structure made out of composite materials and low-emittance metal coatings. In this paper, we will present characterizations of the coating emittance, bidirectional reflectance, and mechanical structure design that will affect the performance of this passive cooling reflector.

  20. Research on a simulation system for diamond turning of optical components with micro-structured surfaces

    NASA Astrophysics Data System (ADS)

    Zhou, Jingbo; Sun, Tao; Wang, Xiaohui

    2010-10-01

    Ultra-precision machine with a fast tool servo (FTS) can fabricate many kinds of optical components with complex micro-structured surfaces, achieving sub-micrometer form accuracy and nanometer surface finish without any subsequent processing. However, it is difficult to meet the ultimate processing requirements only by operators' experience due to the complicate numerical control (NC) programs and various machining parameters. To verify the NC programs, guarantee the processing quality and improve the efficiency, a simulation system is established according to the real micro-structured surface turning system. This system includes cutting force model, platform movement model, fast tool servo model, spindle movement model, vibration model and the surface topography model. Then some simulation results as the motion locus of the tool tip, three-dimensional microstructure morphology and the surface roughness are obtained. By comparing the simulated and actual results, it can be seen that this system can simulate the actual processing, predict the final machining results and has the guidance meaning for the machining of the microstructured surfaces.

  1. Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components.

    PubMed

    Malkov, Serghei; Shepherd, John

    2014-02-17

    We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed.

  2. Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components

    PubMed Central

    Malkov, Serghei; Shepherd, John

    2014-01-01

    We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed. PMID:25083118

  3. Combining 3D optical imaging and dual energy absorptiometry to measure three compositional components

    NASA Astrophysics Data System (ADS)

    Malkov, Serghei; Shepherd, John

    2014-02-01

    We report on the design of the technique combining 3D optical imaging and dual-energy absorptiometry body scanning to estimate local body area compositions of three compartments. Dual-energy attenuation and body shape measures are used together to solve for the three compositional tissue thicknesses: water, lipid, and protein. We designed phantoms with tissue-like properties as our reference standards for calibration purposes. The calibration was created by fitting phantom values using non-linear regression of quadratic and truncated polynomials. Dual-energy measurements were performed on tissue-mimicking phantoms using a bone densitometer unit. The phantoms were made of materials shown to have similar x-ray attenuation properties of the biological compositional compartments. The components for the solid phantom were tested and their high energy/low energy attenuation ratios are in good correspondent to water, lipid, and protein for the densitometer x-ray region. The three-dimensional body shape was reconstructed from the depth maps generated by Microsoft Kinect for Windows. We used open-source Point Cloud Library and freeware software to produce dense point clouds. Accuracy and precision of compositional and thickness measures were calculated. The error contributions due to two modalities were estimated. The preliminary phantom composition and shape measurements are found to demonstrate the feasibility of the method proposed.

  4. Application of independent component analysis method in real-time spectral analysis of gaseous mixtures for acousto-optical spectrometers based on differential optical absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Fadeyev, A. V.; Pozhar, V. E.

    2012-10-01

    It is discussed the reliability problem of time-optimized method for remote optical spectral analysis of gas-polluted ambient air. The method based on differential optical absorption spectroscopy (DOAS) enables fragmentary spectrum registration (FSR) and is suitable for random-spectral-access (RSA) optical spectrometers like acousto-optical (AO) ones. Here, it is proposed the algorithm based on statistical method of independent component analysis (ICA) for estimation of a correctness of absorption spectral lines selection for FSR-method. Implementations of ICA method for RSA-based real-time adaptive systems are considered. Numerical simulations are presented with use of real spectra detected by the trace gas monitoring system GAOS based on AO spectrometer.

  5. A Krebs Cycle Component Limits Caspase Activation Rate through Mitochondrial Surface Restriction of CRL Activation.

    PubMed

    Aram, Lior; Braun, Tslil; Braverman, Carmel; Kaplan, Yosef; Ravid, Liat; Levin-Zaidman, Smadar; Arama, Eli

    2016-04-01

    How cells avoid excessive caspase activity and unwanted cell death during apoptotic caspase-mediated removal of large cellular structures is poorly understood. We investigate caspase-mediated extrusion of spermatid cytoplasmic contents in Drosophila during spermatid individualization. We show that a Krebs cycle component, the ATP-specific form of the succinyl-CoA synthetase β subunit (A-Sβ), binds to and activates the Cullin-3-based ubiquitin ligase (CRL3) complex required for caspase activation in spermatids. In vitro and in vivo evidence suggests that this interaction occurs on the mitochondrial surface, thereby limiting the source of CRL3 complex activation to the vicinity of this organelle and reducing the potential rate of caspase activation by at least 60%. Domain swapping between A-Sβ and the GTP-specific SCSβ (G-Sβ), which functions redundantly in the Krebs cycle, show that the metabolic and structural roles of A-Sβ in spermatids can be uncoupled, highlighting a moonlighting function of this Krebs cycle component in CRL activation.

  6. A Krebs Cycle Component Limits Caspase Activation Rate through Mitochondrial Surface Restriction of CRL Activation.

    PubMed

    Aram, Lior; Braun, Tslil; Braverman, Carmel; Kaplan, Yosef; Ravid, Liat; Levin-Zaidman, Smadar; Arama, Eli

    2016-04-01

    How cells avoid excessive caspase activity and unwanted cell death during apoptotic caspase-mediated removal of large cellular structures is poorly understood. We investigate caspase-mediated extrusion of spermatid cytoplasmic contents in Drosophila during spermatid individualization. We show that a Krebs cycle component, the ATP-specific form of the succinyl-CoA synthetase β subunit (A-Sβ), binds to and activates the Cullin-3-based ubiquitin ligase (CRL3) complex required for caspase activation in spermatids. In vitro and in vivo evidence suggests that this interaction occurs on the mitochondrial surface, thereby limiting the source of CRL3 complex activation to the vicinity of this organelle and reducing the potential rate of caspase activation by at least 60%. Domain swapping between A-Sβ and the GTP-specific SCSβ (G-Sβ), which functions redundantly in the Krebs cycle, show that the metabolic and structural roles of A-Sβ in spermatids can be uncoupled, highlighting a moonlighting function of this Krebs cycle component in CRL activation. PMID:27052834

  7. Double-Knudsen-Cell Apparatus Measures Alloy-Component Activities

    NASA Technical Reports Server (NTRS)

    Jacobson, Nathan S.; Moore, Warren A.

    1995-01-01

    Double-Knudsen-cell apparatus provides molecular beam from selected one of two Knudsen cells. Both cells maintained at same temperature. Molecular beam directed into mass spectrometer for measurement of vapor pressure of selected material component. Designed to minimize undesired thermal gradients, provides appropriate translation to place selected cell in position for sampling, and minimizes mixing of molecular beams from cells.

  8. Pressure activated interconnection of micro transfer printed components

    NASA Astrophysics Data System (ADS)

    Prevatte, Carl; Guven, Ibrahim; Ghosal, Kanchan; Gomez, David; Moore, Tanya; Bonafede, Salvatore; Raymond, Brook; Trindade, António Jose; Fecioru, Alin; Kneeburg, David; Meitl, Matthew A.; Bower, Christopher A.

    2016-05-01

    Micro transfer printing and other forms of micro assembly deterministically produce heterogeneously integrated systems of miniaturized components on non-native substrates. Most micro assembled systems include electrical interconnections to the miniaturized components, typically accomplished by metal wires formed on the non-native substrate after the assembly operation. An alternative scheme establishing interconnections during the assembly operation is a cost-effective manufacturing method for producing heterogeneous microsystems, and facilitates the repair of integrated microsystems, such as displays, by ex post facto addition of components to correct defects after system-level tests. This letter describes pressure-concentrating conductor structures formed on silicon (1 0 0) wafers to establish connections to preexisting conductive traces on glass and plastic substrates during micro transfer printing with an elastomer stamp. The pressure concentrators penetrate a polymer layer to form the connection, and reflow of the polymer layer bonds the components securely to the target substrate. The experimental yield of series-connected test systems with >1000 electrical connections demonstrates the suitability of the process for manufacturing, and robustness of the test systems against exposure to thermal shock, damp heat, and mechanical flexure shows reliability of the resulting bonds.

  9. Deep Proton Writing for the rapid prototyping of polymer micro-components for optical interconnects and optofluidics

    NASA Astrophysics Data System (ADS)

    Van Erps, Jürgen; Vervaeke, Michael; Ottevaere, Heidi; Hermanne, Alex; Thienpont, Hugo

    2013-07-01

    The use of photonics in data communication and numerous other industrial applications brought plenty of prospects for innovation and opened up different unexplored market opportunities. This is a major driving force for the fabrication of micro-optical and micro-mechanical structures and their accurate alignment and integration into opto-mechanical modules and systems. To this end, we present Deep Proton Writing (DPW) as a powerful rapid prototyping technology for such micro-components. The DPW process consists of bombarding polymer samples (PMMA or SU-8) with swift protons, which results after chemical processing steps in high-quality micro-optical components. One of the strengths of the DPW micro-fabrication technology is the ability to fabricate monolithic building blocks that include micro-optical and mechanical functionalities which can be precisely integrated into more complex photonic systems. In this paper we comment on how we shifted from using 8.3 to 16.5 MeV protons for DPW and give some examples of micro-optical and micro-mechanical components recently fabricated through DPW, targeting applications in optical interconnections and in optofluidics.

  10. Low cost, small form factor, and integration as the key features for the optical component industry takeoff

    NASA Astrophysics Data System (ADS)

    Schiattone, Francesco; Bonino, Stefano; Gobbi, Luigi; Groppi, Angelamaria; Marazzi, Marco; Musio, Maurizio

    2003-04-01

    In the past the optical component market has been mainly driven by performances. Today, as the number of competitors has drastically increased, the system integrators have a wide range of possible suppliers and solutions giving them the possibility to be more focused on cost and also on footprint reduction. So, if performances are still essential, low cost and Small Form Factor issues are becoming more and more crucial in selecting components. Another evolution in the market is the current request of the optical system companies to simplify the supply chain in order to reduce the assembling and testing steps at system level. This corresponds to a growing demand in providing subassemblies, modules or hybrid integrated components: that means also Integration will be an issue in which all the optical component companies will compete to gain market shares. As we can see looking several examples offered by electronic market, to combine low cost and SFF is a very challenging task but Integration can help in achieving both features. In this work we present how these issues could be approached giving examples of some advanced solutions applied to LiNbO3 modulators. In particular we describe the progress made on automation, new materials and low cost fabrication methods for the parts. We also introduce an approach in integrating optical and electrical functionality on LiNbO3 modulators including RF driver, bias control loop, attenuator and photodiode integrated in a single device.

  11. High-power fiber optic cable with integrated active sensors for live process monitoring

    NASA Astrophysics Data System (ADS)

    Blomster, Ola; Blomqvist, Mats; Bergstrand, Hans; Pålsson, Magnus

    2012-03-01

    In industrial applications using high-brilliance lasers at power levels up to and exceeding 20 kW and similarly direct diode lasers of 10 kW, there is an increasing demand to continuously monitor component status even in passive components such as fiber-optic cables. With fiber-optic cables designed according to the European Automotive Industry fiber standard interface there is room for integrating active sensors inside the connectors. In this paper we present the integrated active sensors in the new Optoskand QD fiber-optic cable designed to handle extreme levels of power losses, and how these sensors can be employed in industrial manufacturing. The sensors include photo diodes for detection of scattered light inside the fiber connector, absolute temperature of the fiber connector, difference in temperature of incoming and outgoing cooling water, and humidity measurement inside the fiber connector. All these sensors are connected to the fiber interlock system, where interlock break enable functions can be activated when measured signals are higher than threshold levels. It is a very fast interlock break system as the control of the signals is integrated in the electronics inside the fiber connector. Also, since all signals can be logged it is possible to evaluate what happened inside the connector before the interlock break instance. The communication to the fiber-optic connectors is via a CAN interface. Thus it is straightforward to develop the existing laser host control to also control the CAN-messages from the QD sensors.

  12. High-density active optical cable: from a new concept to a prototype

    NASA Astrophysics Data System (ADS)

    Wohlfeld, Denis; Lemke, Frank; Froening, Holger; Schenk, Sven; Bruening, Ulrich

    2011-01-01

    Evolution in high performance computing (HPC) leads to increasing demands on bandwidth, connectivity and flexibility. Active optical cables (AOC) are of special interest, combining the benefits of electrical connectors and optical transmission. Optimization and development of AOC solutions requires enhancements concerning different technology barriers. Area and volume occupied by connectors is of special interest within HPC networks. This led to the development of a 12x AOC for the mini-HT connector creating the densest AOC available. In order to integrate electrical optical conversion into a module not higher than 3 mm, a new concept of coupling fibers to VCSELs or photodiodes had to be developed. This unique concept is based on a direct replication process of an integrated fiber coupler consisting of a 90° light deflecting and focusing mirror, a fiber guiding structure, and a fiber funnel. The integrated fiber coupler is directly replicated on top of active components, reducing the distance between active components and fibers to a minimum, thus providing a highly efficient light coupling. As AOC prototype, multi-chipmodules (MCM) including the complete electrical to optical conversion for send and receive connected by two 12x fiber ribbons have been developed. The paper presents the integrated fiber coupling technique and also design and measurement data of the prototype.

  13. Alignment of optical system components using an ADM beam through a null assembly

    NASA Technical Reports Server (NTRS)

    Hayden, Joseph E. (Inventor); Olczak, Eugene G. (Inventor)

    2010-01-01

    A system for testing an optical surface includes a rangefinder configured to emit a light beam and a null assembly located between the rangefinder and the optical surface. The null assembly is configured to receive and to reflect the emitted light beam toward the optical surface. The light beam reflected from the null assembly is further reflected back from the optical surface toward the null assembly as a return light beam. The rangefinder is configured to measure a distance to the optical surface using the return light beam.

  14. Study of passive and active optical waveguides: Synthesis, processing and characterization of materials

    NASA Astrophysics Data System (ADS)

    Yoshida, Makoto

    Photonics uses photons for information and image processing, and has been touted as the technology of the 21 st century. An optical waveguide is a key component of an optical integrated circuit which is the optical analog of an electrical integrated circuit (IC). Electrical transistor IC technology resulted in an enormous impact on society, and it changed our life styles from the age of the vacuum tube. The advent of the optical integrated circuit is expected to have the same impact on society as the electronic IC. Various optical circuit elements are interrelated to materials, therefore, the study and the better understanding of materials and processing have been receiving a great deal of attention. My research focuses on the study of optical waveguide materials and their processings in terms of passive and active optical waveguides. The first target was to establish a method for measuring the refractive index and optical propagation loss of optical waveguides. The second target was to develop passive waveguide materials which can route, split and combine optical signals on a substrate. There are several requirements for waveguiding, such as high optical transparency, proper refractive index, and proper thickness. The sol-gel technique was used to meet the requirements, and several types of organic: inorganic composite materials were developed. The third target involved the development of processing methods to fabricate channel waveguides using the above-mentioned passive and active waveguide materials. Selective laser densification was developed for sol-gel composite materials. Use of trenched substrates and photobleaching were also studied. The last target was to develop an active material which could process optical signals using the electrooptic effect. A crosslinked urethane polymer with a newly synthesized chromophore was used due to its high thermal stability and optical transparency. In order to obtain second order nonlinearity, macroscopic molecular

  15. Incident diagnoses of cancers in the active component and cancer-related deaths in the active and reserve components, U.S. Armed Forces, 2005-2014.

    PubMed

    Lee, Terrence; Williams, Valerie F; Clark, Leslie L

    2016-07-01

    Cancer is the second leading cause of death in the U.S., surpassed only by heart disease. It is estimated that approximately one of every four deaths in the U.S. is due to cancer. Between 2005 and 2014 among active component service members in the U.S. military, crude incidence rates of most cancer diagnoses have remained relatively stable. During this period, 8,973 active component members were diagnosed with at least one of the cancers of interest and no specific increasing or decreasing trends were evident. Cancers accounted for 1,054 deaths of service members on active duty during the 10-year surveillance period; this included 727 service members in the active component and 327 in the reserve component. PMID:27501939

  16. 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

  17. 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.

  18. Modeling injection molding of net-shape active ceramic components.

    SciTech Connect

    Baer, Tomas; Cote, Raymond O.; Grillet, Anne Mary; Yang, Pin; Hopkins, Matthew Morgan; Noble, David R.; Notz, Patrick K.; Rao, Rekha Ranjana; Halbleib, Laura L.; Castaneda, Jaime N.; Burns, George Robert; Mondy, Lisa Ann; Brooks, Carlton, F.

    2006-11-01

    To reduce costs and hazardous wastes associated with the production of lead-based active ceramic components, an injection molding process is being investigated to replace the current machining process. Here, lead zirconate titanate (PZT) ceramic particles are suspended in a thermoplastic resin and are injected into a mold and allowed to cool. The part is then bisque fired and sintered to complete the densification process. To help design this new process we use a finite element model to describe the injection molding of the ceramic paste. Flow solutions are obtained using a coupled, finite-element based, Newton-Raphson numerical method based on the GOMA/ARIA suite of Sandia flow solvers. The evolution of the free surface is solved with an advanced level set algorithm. This approach incorporates novel methods for representing surface tension and wetting forces that affect the evolution of the free surface. Thermal, rheological, and wetting properties of the PZT paste are measured for use as input to the model. The viscosity of the PZT is highly dependent both on temperature and shear rate. One challenge in modeling the injection process is coming up with appropriate constitutive equations that capture relevant phenomenology without being too computationally complex. For this reason we model the material as a Carreau fluid and a WLF temperature dependence. Two-dimensional (2D) modeling is performed to explore the effects of the shear in isothermal conditions. Results indicate that very low viscosity regions exist near walls and that these results look similar in terms of meniscus shape and fill times to a simple Newtonian constitutive equation at the shear-thinned viscosity for the paste. These results allow us to pick a representative viscosity to use in fully three-dimensional (3D) simulation, which because of numerical complexities are restricted to using a Newtonian constitutive equation. Further 2D modeling at nonisothermal conditions shows that the choice of

  19. The relationship between variable and polarized optical spectral components of luminous type 1 non-blazar quasars

    NASA Astrophysics Data System (ADS)

    Kokubo, Mitsuru

    2016-08-01

    Optical spectropolarimetry by Kishimoto et al. (2004, MNRAS, 354, 1065) has shown that several luminous type 1 quasars show a strong decrease of the polarized continuum flux in the rest-frame near-ultraviolet (UV) wavelengths of λ < 4000 Å. In the literature, this spectral feature is interpreted as evidence of the broadened hydrogen Balmer absorption edge imprinted on the accretion disk thermal emission due to the disk atmospheric opacity effect. On the other hand, quasar flux variability studies have shown that the variable continuum component in UV-optical spectra of quasars, which is considered to be a good indicator of the intrinsic spectral shape of the accretion disk emission, generally has a significantly flat spectral shape throughout the near-UV to optical spectral range. To examine whether the disk continuum spectral shapes revealed as the polarized flux and as the variable component spectra are consistent with each other, we carry out multi-band photometric monitoring observations for a sample of four polarization-decreasing quasars of Kishimoto et al.'s (4C 09.72, 3C 323.1, Ton 202, and B2 1208+32) to derive the variable component spectra and compare the spectral shape of them with that of the polarized flux spectra. Contrary to expectation, we confirm that the two spectral components of these quasars have totally different spectral shapes, in that the variable component spectra are significantly bluer compared to the polarized flux spectra. This discrepancy between two spectral shapes may imply either (1) the decrease of polarization degree in the rest-frame UV wavelengths is not indicating the Balmer absorption edge feature but is induced by some unknown (de)polarization mechanisms, or (2) the UV-optical flux variability is occurring preferentially at the hot inner radii of the accretion disk and thus the variable component spectra do not reflect the whole accretion disk emission.

  20. Spectral variability of the IR source IRAS 01005+7910 optical component

    NASA Astrophysics Data System (ADS)

    Klochkova, V. G.; Chentsov, E. L.; Panchuk, V. E.; Sendzikas, E. G.; Yushkin, M. V.

    2014-10-01

    High-resolution optical spectra of the IR source IRAS01005+7910 are used to determine the spectral type of its central star, B1.5±0.3, identify the spectral features, and analyze their profile and radial-velocity variations. The systemic velocity V sys = -50.5 km s-1 is determined from the positions of the symmetric and stable profiles of the forbidden [NI], [N II], [OI], [S II], and [Fe II] emission lines. The presence of the [NII] and [SII] forbidden emissions indicates the onset of the ionization of the circumstellar envelope and the fact that the star is very close to undergoing the planetary nebula stage. The broad range of radial velocity V r estimates based on the line cores, which amounts to about 34 km s-1, is partly due to the deformations of the profiles caused by variable emissions. The variations of the V r in the line wings are smaller, about 23 km s-1, and may be due to pulsations and/or hidden binarity of the star. The deformations of the profiles of absorption-emission lines may result from variations of their absorption components caused by the variations of the geometry and kinematics in the wind base. The H α lines exhibit PCyg III type wind profiles. Deviations of the wind from spherical symmetry are shown to be small. The relatively low wind velocity (27-74 km s-1 from different observations) and the strong intensity of the red emission (it exceeds the continuum level by up to a factor of seven) are typical for hypergiants rather than the classical supergiants. IRAS01005 is an example of spectral mimicry of a low-mass post-AGB star masquerading as a massive hypergiant.

  1. A new active solder for joining electronic components

    SciTech Connect

    SMITH,RONALD W.; VIANCO,PAUL T.; HERNANDEZ,CYNTHIA L.; LUGSCHEIDER,E.; RASS,I.; HILLEN,F.

    2000-05-11

    Electronic components and micro-sensors utilize ceramic substrates, copper and aluminum interconnect and silicon. The joining of these combinations require pre-metallization such that solders with fluxes can wet such combinations of metals and ceramics. The paper will present a new solder alloy that can bond metals, ceramics and composites. The alloy directly wets and bonds in air without the use flux or premetallized layers. The paper will present typical processing steps and joint microstructures in copper, aluminum, aluminum oxide, aluminum nitride, and silicon joints.

  2. 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.

  3. Biologically active components against Drosophila melanogaster from Podophyllum hexandrum.

    PubMed

    Miyazawa, M; Fukuyama, M; Yoshio, K; Kato, T; Ishikawa, Y

    1999-12-01

    In the course of screening for novel naturally occurring insecticides from Chinese crude drugs, a dichloromethane extract of Podophyllum hexandrum was found to give an insecticidal activity against larvae of Drosophila melanogaster Meigen. From the extract, an insecticidal compound was isolated by bioassay-guided fractionation. The compound was identified as podophyllotoxin (1) by comparison of its spectroscopic characteristics with literature data. In bioassays for insecticidal activity, 1 showed a LC(50) value of 0.24 micromol/mL diet against larvae of D. melanogaster and a LD(50) value of 22 microg/adult against adults. Acetylpodophyllotoxin (1A), however showed slight insecticidal activity in both assays, indicating that the 4-hydroxyl group was an important function for enhanced activity of 1.

  4. Improved Convergence for Two-Component Activity Expansions

    SciTech Connect

    DeWitt, H E; Rogers, F J; Sonnad, V

    2007-03-06

    It is well known that an activity expansion of the grand canonical partition function works well for attractive interactions, but works poorly for repulsive interactions, such as occur between atoms and molecules. The virial expansion of the canonical partition function shows just the opposite behavior. This poses a problem for applications that involve both types of interactions, such as occur in the outer layers of low-mass stars. We show that it is possible to obtain expansions for repulsive systems that convert the poorly performing Mayer activity expansion into a series of rational polynomials that converge uniformly to the virial expansion. In the current work we limit our discussion to the second virial approximation. In contrast to the Mayer activity expansion the activity expansion presented herein converges for both attractive and repulsive systems.

  5. The Triple Binary Star EQ Tau with an Active Component

    NASA Astrophysics Data System (ADS)

    Li, K.; Qian, S.-B.; Hu, S.-M.; He, J.-J.

    2014-05-01

    New photometric data of EQ Tau observed in 2010 and 2013 are presented. Light curves obtained in 2000 and 2004 by Yuan & Qian and 2001 by Yang & Liu, together with our two newly determined sets of light curves, were analyzed using the Wilson-Devinney code. The five sets of light curves exhibit very obvious variations, implying that the light curves of EQ Tau show a strong O'Connell effect. We found that EQ Tau is an A-type shallow contact binary with a contact degree of f = 11.8%; variable dark spots on the primary component of EQ Tau were also observed. Using 10 new times of minimum light, together with those collected from the literature, the orbital period change of EQ Tau was analyzed. We found that its orbital period includes a secular decrease (dP/dt = -3.63 × 10-8 days yr-1) and a cyclic oscillation (A 3 = 0.0058 days and P 3 = 22.7 yr). The secular increase of the period can be explained by mass transfer from the more massive component to the less massive one or/and angular momentum loss due to a magnetic stellar wind. The Applegate mechanism cannot explain the cyclic orbital period change. A probable transit-like event was observed in 2010. Therefore, the cyclic orbital period change of EQ Tau may be due to the light time effect of a third body.

  6. Do energy drinks contain active components other than caffeine?

    PubMed

    McLellan, Tom M; Lieberman, Harris R

    2012-12-01

    Energy drinks (EDs) contain caffeine and are a new, popular category of beverage. It has been suggested that EDs enhance physical and cognitive performance; however, it is unclear whether the claimed benefits are attributable to components other than caffeine. A typical 235 mL ED provides between 40 and 250 mg of caffeine, equating to doses that improve cognitive and, at the higher levels, physical performance. EDs often contain taurine, guaraná, ginseng, glucuronolactone, B-vitamins, and other compounds. A literature search using PubMed, Psych Info, and Google Scholar identified 32 articles that examined the effects of ED ingredients alone and/or in combination with caffeine on physical or cognitive performance. A systematic evaluation of the evidence-based findings in these articles was then conducted. With the exception of some weak evidence for glucose and guaraná extract, there is an overwhelming lack of evidence to substantiate claims that components of EDs, other than caffeine, contribute to the enhancement of physical or cognitive performance. Additional well-designed, randomized, placebo-controlled studies replicated across laboratories are needed in order to assess claims made for these products. PMID:23206286

  7. The triple binary star EQ Tau with an active component

    SciTech Connect

    Li, K.; Hu, S.-M.; Qian, S.-B.; He, J.-J. E-mail: likai@ynao.ac.cn

    2014-05-01

    New photometric data of EQ Tau observed in 2010 and 2013 are presented. Light curves obtained in 2000 and 2004 by Yuan and Qian and 2001 by Yang and Liu, together with our two newly determined sets of light curves, were analyzed using the Wilson-Devinney code. The five sets of light curves exhibit very obvious variations, implying that the light curves of EQ Tau show a strong O'Connell effect. We found that EQ Tau is an A-type shallow contact binary with a contact degree of f = 11.8%; variable dark spots on the primary component of EQ Tau were also observed. Using 10 new times of minimum light, together with those collected from the literature, the orbital period change of EQ Tau was analyzed. We found that its orbital period includes a secular decrease (dP/dt = –3.63 × 10{sup –8} days yr{sup –1}) and a cyclic oscillation (A {sub 3} = 0.0058 days and P {sub 3} = 22.7 yr). The secular increase of the period can be explained by mass transfer from the more massive component to the less massive one or/and angular momentum loss due to a magnetic stellar wind. The Applegate mechanism cannot explain the cyclic orbital period change. A probable transit-like event was observed in 2010. Therefore, the cyclic orbital period change of EQ Tau may be due to the light time effect of a third body.

  8. Do energy drinks contain active components other than caffeine?

    PubMed

    McLellan, Tom M; Lieberman, Harris R

    2012-12-01

    Energy drinks (EDs) contain caffeine and are a new, popular category of beverage. It has been suggested that EDs enhance physical and cognitive performance; however, it is unclear whether the claimed benefits are attributable to components other than caffeine. A typical 235 mL ED provides between 40 and 250 mg of caffeine, equating to doses that improve cognitive and, at the higher levels, physical performance. EDs often contain taurine, guaraná, ginseng, glucuronolactone, B-vitamins, and other compounds. A literature search using PubMed, Psych Info, and Google Scholar identified 32 articles that examined the effects of ED ingredients alone and/or in combination with caffeine on physical or cognitive performance. A systematic evaluation of the evidence-based findings in these articles was then conducted. With the exception of some weak evidence for glucose and guaraná extract, there is an overwhelming lack of evidence to substantiate claims that components of EDs, other than caffeine, contribute to the enhancement of physical or cognitive performance. Additional well-designed, randomized, placebo-controlled studies replicated across laboratories are needed in order to assess claims made for these products.

  9. Chemical Components and Cardiovascular Activities of Valeriana spp.

    PubMed Central

    Chen, Heng-Wen; Wei, Ben-Jun; He, Xuan-Hui; Liu, Yan; Wang, Jie

    2015-01-01

    Valeriana spp. is a flowering plant that is well known for its essential oils, iridoid compounds such as monoterpenes and sesquiterpenes, flavonoids, alkaloids, amino acids, and lignanoids. Valeriana spp. exhibits a wide range of biological activities such as lowering blood pressure and heart rate, antimyocardial ischemia reperfusion injury, antiarrhythmia, and regulation of blood lipid levels. This review focuses on the chemical constituents and cardiovascular activities of Valeriana spp. PMID:26788113

  10. Infrared optical activity: electric field approaches in time domain.

    PubMed

    Rhee, Hanju; Choi, Jun-Ho; Cho, Minhaeng

    2010-12-21

    Vibrational circular dichroism (VCD) spectroscopy provides detailed information about the absolute configurations of chiral molecules including biomolecules and synthetic drugs. This method is the infrared (IR) analogue of the more popular electronic CD spectroscopy that uses the ultraviolet and visible ranges of the electromagnetic spectrum. Because conventional electronic CD spectroscopy measures the difference in signal intensity, problems such as weak signal and low time-resolution can limit its utility. To overcome the difficulties associated with that approach, we have recently developed femtosecond IR optical activity (IOA) spectrometry, which directly measures the IOA free-induction-decay (FID), the impulsive chiroptical IR response that occurs over time. In this Account, we review the time-domain electric field measurement and calculation methods used to simultaneously characterize VCD and related vibrational optical rotatory dispersion (VORD) spectra. Although conventional methods measure the electric field intensity, this vibrational technique is based on a direct phase-and-amplitude measurement of the electric field of the chiroptical signal over time. This method uses a cross-polarization analyzer to carry out heterodyned spectral interferometry. The cross-polarization scheme enables us to selectively remove the achiral background signal, which is the dominant noise component present in differential intensity measurement techniques. Because we can detect the IOA FID signal in a phase-amplitude-sensitive manner, we can directly characterize the time-dependent electric dipole/magnetic dipole response function and the complex chiral susceptibility that contain information about the angular oscillations of charged particles. These parameters yield information about the VCD and VORD spectra. In parallel with such experimental developments, we have also calculated the IOA FID signal and the resulting VCD spectrum. These simulations use a quantum mechanical

  11. Infrared optical activity: electric field approaches in time domain.

    PubMed

    Rhee, Hanju; Choi, Jun-Ho; Cho, Minhaeng

    2010-12-21

    Vibrational circular dichroism (VCD) spectroscopy provides detailed information about the absolute configurations of chiral molecules including biomolecules and synthetic drugs. This method is the infrared (IR) analogue of the more popular electronic CD spectroscopy that uses the ultraviolet and visible ranges of the electromagnetic spectrum. Because conventional electronic CD spectroscopy measures the difference in signal intensity, problems such as weak signal and low time-resolution can limit its utility. To overcome the difficulties associated with that approach, we have recently developed femtosecond IR optical activity (IOA) spectrometry, which directly measures the IOA free-induction-decay (FID), the impulsive chiroptical IR response that occurs over time. In this Account, we review the time-domain electric field measurement and calculation methods used to simultaneously characterize VCD and related vibrational optical rotatory dispersion (VORD) spectra. Although conventional methods measure the electric field intensity, this vibrational technique is based on a direct phase-and-amplitude measurement of the electric field of the chiroptical signal over time. This method uses a cross-polarization analyzer to carry out heterodyned spectral interferometry. The cross-polarization scheme enables us to selectively remove the achiral background signal, which is the dominant noise component present in differential intensity measurement techniques. Because we can detect the IOA FID signal in a phase-amplitude-sensitive manner, we can directly characterize the time-dependent electric dipole/magnetic dipole response function and the complex chiral susceptibility that contain information about the angular oscillations of charged particles. These parameters yield information about the VCD and VORD spectra. In parallel with such experimental developments, we have also calculated the IOA FID signal and the resulting VCD spectrum. These simulations use a quantum mechanical

  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. Laser optical disk position encoder with active heads

    NASA Astrophysics Data System (ADS)

    Osborne, Eric P.

    1992-04-01

    An angular position encoder is provided that minimizes the effects of eccentricity and other misalignments between the disk and the read stations by employing heads which incorporate beam steering optics with the ability to actively track the disk in directions along the disk radius and normal to its surface. The device adapts features prevalent in optical disk technology toward the application of angular position sensing. A reflective disk and the principles of interferometry are employed. The servo-controlled steering optics move so as to acquire a track on the disk lying at a predetermined radius and distance below the head, and then adjust position and orientation in order to maintain the view of the disk track as required. Thus, the device is actively self-aligning.

  14. Laser optical disk position encoder with active heads

    NASA Astrophysics Data System (ADS)

    Osborne, Eric P.

    1990-03-01

    An angular position encoder is provided that minimizes the effects of eccentricity and other misalignments between the disk and the read stations by employing heads which incorporate beam steering optics with the ability to actively track the disk in directions along the disk radius and normal to its surface. The device adapts features prevalent in optical disk technology toward the application of angular position sensing. A reflective disk and the principles of interferometry are employed. The servo-controlled steering optics move so as to acquire a track on the disk lying at a predetermined radius and distance below the head, and then adjust position and orientation in order to maintain the view of the disk track as required. Thus, the device is actively self-aligning.

  15. Incorporation of small molecular weight active agents into polymeric components.

    PubMed

    Iconomopoulou, Sofia M; Kallitsis, Joannis K; Voyiatzis, George A

    2008-01-01

    The incorporation of small molecular weight active agents into polymeric matrixes bearing controlled release characteristics represents an interesting strategy with numerous useful applications. Antimicrobials, biocides, fungicides or drugs, encapsulated into erodible or non-erodible polymeric micro-spheres, micro-capsules and micro-shells or/and embedded into continuous polymeric matrixes, are controlled released either by particular degradation routes or/and by specific stimuli. Cross-linking, curing or micro-porosity generating agents acting during polymerization impart additional controlled encapsulation characteristics to the active substances. Release modulating agents, like retardants or carrier materials used as vehicles are often encapsulated into microspheres or dispersed within polymeric compositions for the controlled introduction of an active agent into a liquid-based medium. The aim of this review is to reveal relevant strategies reported in recent patents on the encapsulation or incorporation of low molecular weight active agents into the matrix of polymers bearing controlled release characteristics. The inventions described implicate the formation of both erodible and non erodible polymer microparticles that contain active ingredients. Modification of polymer matrix and inorganic porous carriers represent pertinent major strategies that have been also developed and patented.

  16. 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.

  17. 200-kV active optical fiber voltage transformer

    NASA Astrophysics Data System (ADS)

    Xu, Yan; Luo, Sunan; Ye, Miaoyuan

    1999-02-01

    The report describes a 220kV Active Optical Fiber Voltage Transformer (AOVT). The transformer is different from the passive optical fiber voltage transformer, for no optical crystal is used in the 220kV AOVT. Its principle is that a low voltage is divided for the 220kV high voltage by a capacitive divider and then is converted into a digital signal. The optical fiber is used to transfer the measured digital signal and control signal. The 220kV AOVT consists of an outdoors-high voltage measurement unit and an indoors low voltage metering and controlling unit. The optical fiber connects these units. The low voltage is effectively isolated from the high voltage by means of the optical fiber and a special power supply method which is specially designed for the outdoor high voltage unit. As a result, the safe protection is reliable for the indoor low voltage equipment and the operation staff. Compared to the conventional voltage transformer, the advantages of the 220kV AOVT are high accuracy, low cost, excellent dynamic characteristics and immunity from electromagnetic interference. The 220kV AOVT has been tested, and its accuracy could achieve +/- 0.2 percent.

  18. Optical materials for astronomy from SCHOTT: the quality of large components

    NASA Astrophysics Data System (ADS)

    Jedamzik, Ralf; Hengst, Joachim; Elsmann, Frank; Lemke, Christian; Döhring, Thorsten; Hartmann, Peter

    2008-07-01

    The new generation of survey telescopes and future giant observatories such as E-ELT or TMT do not only require very fast or very large mirrors, but also high sophisticated instruments with the need of large optical materials in outstanding quality. The huge variety of modern optical materials from SCHOTT covers almost all areas of specification needs of optical designers. Even if many interesting optical materials are restricted in size and/or quality, there is a variety of optical materials that can be produced in large sizes, with excellent optical homogeneity, and a low level of stress birefringence. Some actual examples are high homogeneous N-BK7 blanks with a diameter of up to 1000 mm, CaF2 blanks as large as 300 mm which are useable for IR applications, Fused Silica (LITHOSIL®) with dimensions up to 700 mm which are used for visible applications, and other optical glasses like FK5, LLF1 and F2 in large formats. In this presentation the latest inspection results of large optical materials will be presented, showing the advances in production and measurement technology.

  19. 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.

  20. 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

  1. 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

  2. A review of DOE HEPA filter component test activities

    SciTech Connect

    Slawski, J.W.; Bresson, J.F.; Scripsick, R.C.

    1997-08-01

    All HEPA filters purchased for installation in DOE nuclear facilities are required to be tested at a Filter Test Facility (FTF) prior to installation. The number of HEPA filters purchased by DOE has been reduced so much that the Hanford FTF was closed. From Fiscal Year (FY) 1992 to 1994, funding was not provided to the FTF Technical Support Group (TSG) at the Los Alamos National Laboratory. As a consequence, Round Robin Tests (RRTs), performed twice each year by the FTFs to assess constituency of test results among the FTFs, were not performed in FY 1992 and FY 1993. The Annual Reports of FTF test activities were not prepared for FY 1992 - 1995. Technical support provided to the FTFs was minimal. There is talk of closing a second FTF, and ongoing discussions as to whether DOE will continue to fund operation of the FTFs. In FY 1994, DOE Defense Programs commenced funding the TSG. RRT data for FY 1994 and 1995 have been entered into the database; the FY 1994 RRT report has been issued; and the FY 1995 RRT report is in progress. Data from semiannual reports have been retrieved and entered into the database. Standards related to HEPA filter test and procurement activities are now scheduled for issuance by FY 1996. Continuation of these activities depends on whether DOE will continue to support the HEPA filter test program. The history and activities of the FTFs and the TSG at Los Alamos have been reported at previous Air Cleaning Conferences. Data from the FY 1991 Annual Report of FTF activities was presented at the 1992 Air Cleaning Conference. Preparation of the Annual Reports was temporarily suspended in 1992. However, all of the FTF Semiannual report data have been retrieved and entered into the data base. This paper focuses primarily on the results of HEPA filter tests conducted by FTFs during FY 1992 - FY 1995, and the possible effects of the DOE program uncertainties on the quality of HEPA filters for installation at the DOE sites. 15 refs., 13 tabs.

  3. 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.

  4. Low-cost active optical system for fire surveillance

    NASA Astrophysics Data System (ADS)

    Utkin, A. B.; Lavrov, A. V.; Vilar, R. M.

    2009-06-01

    Detection of smoke plumes using active optical sensors provides many advantages with respect to passive methods of fire surveillance. However, the price of these sensors is often too high as compared to passive fire detection instruments, such as infrared and video cameras. This article describes robust and cost effective diode-laser optical sensor for automatic fire surveillance in industrial environment. Physical aspects of the sensing process allowing to simplify the hardware and software design, eventually leading to significant reduction of manufacturing and maintenance costs, are discussed.

  5. Pattern matching based active optical sorting of colloids/cells

    NASA Astrophysics Data System (ADS)

    Verma, R. S.; Dasgupta, R.; Ahlawat, S.; Kumar, N.; Uppal, A.; Gupta, P. K.

    2013-08-01

    We report active optical sorting of colloids/cells by employing a cross correlation based pattern matching technique for selection of the desired objects and thereafter sorting using dynamically controllable holographic optical traps. The problem of possible collision between the different sets of objects during sorting was avoided by raising one set of particles to a different plane. We also present the results obtained on using this approach for some representative applications such as sorting of silica particles of two different sizes, of closely packed colloids and of white blood cells and red blood cells from a mixture of the two.

  6. Use of component analyses to identify active variables in treatment packages for children with feeding disorders.

    PubMed Central

    Cooper, L J; Wacker, D P; McComas, J J; Brown, K; Peck, S M; Richman, D; Drew, J; Frischmeyer, P; Millard, T

    1995-01-01

    We evaluated the separate components in treatment packages for food refusal of 4 young children. First, treatment packages were implemented until food acceptance improved. Next, a component analysis was conducted within a multielement or reversal design to identify the active components that facilitated food acceptance. The results indicated that escape extinction was always identified as an active variable when assessed; however, other variables, including positive reinforcement and noncontingent play, were also identified as active variables for 2 of the children. The results suggest that the component analysis was useful for identifying variables that affected food acceptance. PMID:7601802

  7. Dynamical quantum phase transition of a two-component Bose-Einstein condensate in an optical lattice

    SciTech Connect

    Collin, Anssi; Martikainen, Jani-Petri; Larson, Jonas

    2010-01-15

    We study the dynamics of a two-component Bose-Einstein condensate where the two components are coupled via an optical lattice. In particular, we focus on the dynamics as one drives the system through a critical point of a first-order phase transition characterized by a jump in the internal populations. Solving the time-dependent Gross-Pitaevskii equation, we analyze the breakdown of adiabaticity, impact of nonlinear atom-atom scattering, and role of a harmonic trapping potential. Our findings demonstrate that the phase transition is resilient to both contact interaction between atoms and external trapping confinement.

  8. The orbit of Phi Cygni measured with long-baseline optical interferometry - Component masses and absolute magnitudes

    NASA Technical Reports Server (NTRS)

    Armstrong, J. T.; Hummel, C. A.; Quirrenbach, A.; Buscher, D. F.; Mozurkewich, D.; Vivekanand, M.; Simon, R. S.; Denison, C. S.; Johnston, K. J.; Pan, X.-P.

    1992-01-01

    The orbit of the double-lined spectroscopic binary Phi Cygni, the distance to the system, and the masses and absolute magnitudes of its components are presented via measurements with the Mar III Optical Interferometer. On the basis of a reexamination of the spectroscopic data of Rach & Herbig (1961), the values and uncertainties are adopted for the period and the projected semimajor axes from the present fit to the spectroscopic data and the values of the remaining elements from the present fit to the Mark III data. The elements of the true orbit are derived, and the masses and absolute magnitudes of the components, and the distance to the system are calculated.

  9. 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.

  10. Affordable Manufacturing Technologies Being Developed for Actively Cooled Ceramic Components

    NASA Technical Reports Server (NTRS)

    Bhatt, Ramakrishna T.

    1999-01-01

    Efforts to improve the performance of modern gas turbine engines have imposed increasing service temperature demands on structural materials. Through active cooling, the useful temperature range of nickel-base superalloys in current gas turbine engines has been extended, but the margin for further improvement appears modest. Because of their low density, high-temperature strength, and high thermal conductivity, in situ toughened silicon nitride ceramics have received a great deal of attention for cooled structures. However, high processing costs have proven to be a major obstacle to their widespread application. Advanced rapid prototyping technology, which is developing rapidly, offers the possibility of an affordable manufacturing approach.

  11. Identification of Optical Component of North Toroidal Source of Sporadic Meteors and its Origin

    NASA Technical Reports Server (NTRS)

    Hashimoto, T.; Watanabe, J.; Sato, M.; Ishiguro, M.

    2011-01-01

    We succeeded to identify the North Toroidal source by optical observations performed by the SonotaCo Network, which is a TV observation network coordinated by Japanese amateurs. This source has been known only for radar observations until now. The orbits of the optical meteors in the North Toroidal source are relatively large eccentricity and semi-major axis, compared with those of the radar meteors. In this paper, we report the characteristics of this North Toroidal source detected by optical observations, and discuss the possible origin and evolution of this source.

  12. Photopolarimetric Monitoring of the Blazar BL Lac in the Optical and Near-Infrared Bands: Decay of the Long-Lived Component

    NASA Astrophysics Data System (ADS)

    Sakimoto, Kiyoshi; Uemura, Makoto; Sasada, Mahito; Kawabata, Koji S.; Fukazawa, Yasushi; Yamanaka, Masayuki; Itoh, Ryosuke; Ohsugi, Takashi; Yoshida, Michitoshi; Akitaya, Hiroshi; Sato, Shuji; Kino, Masaru

    2013-04-01

    We report on the results of optical-near-infrared photopolarimetric observations of BL Lac conducted from 2008 to 2011. Our observations are consistent with past studies in which the behavior of the polarization of BL Lac could be understood with two components: short flares whose polarization angles randomly change, and a long-lived component. In addition, we detected a gradually decreasing trend in the total flux, the polarized flux, and the polarization degree without a large variation in the polarization angle from 2008 to mid-2009. These results suggest that the long-lived component decayed from 2008 to mid-2009. We propose that the long-lived component is not stationary, but is probably variable with a time-scale of years. We found no change in the activity of the short flares in 2008 and 2009, when the long-lived component was strong and weak, respectively. Furthermore, there were no clear differences in the mean color and the distribution of the polarization angle of the short flares from 2008 to 2009. These facts indicate that the emitting region of the long-term component was physically disconnected to that of the short flares. The color of the long-term component was bluer than that of the short flares, indicating a higher synchrotron peak-frequency. This could be due to a low efficiency of synchrotron and/or Compton cooling in the emitting region of the long-lived component. The long-term component is possibly originated from a relatively downstream region in the jet where the electron density is low, or the external radiation field is weak.

  13. Effect of cyclic third components on non-deoxygenated RTP and their potential in developing optical thermometer

    NASA Astrophysics Data System (ADS)

    Peng, Yun-Lin; Jin, Wei-Jun; Feng, Feng

    2005-10-01

    Effect of five cyclic third components, cyclohexane, methylcyclohexane, perfluorocyclohexane, perfluoromethylcyclohexane and adamantane, on cyclodextrin-induced room-temperature phosphorescence (CD-RTP) of 1-bromonaphthalene is studied. It is found that these five compounds can induce intensive RTP, and the enhancement order is as follows: cyclohexane > adamantane > methylcyclohexane > perfluorocyclohexane > perfluoromethylcyclohexane. Dependence of RTP intensity on temperature of these systems shows the potential application in developing optical thermometer.

  14. 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.

  15. 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.

  16. Distributed fiber optic chemical sensors for detection of corrosion in pipelines and structural components

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar A.; Lieberman, Robert A.; Prohaska, John D.; Robinson, Daniel P.

    1998-03-01

    Distributed fiber optic sensors for use in the prevention of catastrophic corrosion failure when embedded in key structures such as high pressure gas and hazardous fluid pipeline delivery systems, potable water distribution piping, steel reinforced concrete structures, and steel and aluminum access structures are reported here. Its principle of operation is based on the intrinsic optical properties of a distributed fiber optic corrosion sensor (DIFOCS) whose entire length is sensitive to corrosion progression indicators, such as moisture and pH. The sensors can be used to locate precisely with a 10-cm spatial resolution where the moisture infiltration or corrosions damage has occurred. A low-cost, light weight, optoelectronics package can be used to provide timely warnings of corrosion induced moisture and pH changes into these 'smart' structures, significantly reducing the cost and complexity of periodic inspections. Optical transmission through the fibers can be monitored either periodically or continuously to determine the extent of corrosion.

  17. Can a Double Component Outflow Explain the X-Ray and Optical Lightcurves of Swift Gamma-Ray Bursts?

    NASA Technical Reports Server (NTRS)

    De Pasquale, Massimiliano; Evans, P.; Oates, S.; Page, M.; Zane, S.; Schady, P.; Breeveld, A.; Holland, S.; Still, M.

    2011-01-01

    An increasing sample of Gamma-Ray Bursts (GRBs) observed by Swift show evidence of 'chromatic breaks', i.e. breaks that are present in the X-ray but not in the optical. We find that in a significant fraction of these GRB afterglows the X-ray and the optical emission cannot be produced by the same component. We propose that these afterglow lightcurves are the result of a two-component jet, in which both components undergo energy injection for the whole observation and the X-ray break is due to a jet break in the narrow outflow. Bursts with chromatic breaks also explain another surprising finding, the paucity of late achromatic breaks. We propose a model that may explain the behaviour of GRB emission in both X-ray and optical bands. This model can be a radical and noteworthy alternative to the current interpretation for the 'canonical' XRT and UVOT lightcurves, and it bears fundamental implications for GRB physics.

  18. Neural nets for aligning optical components in harsh environments: Beam smoothing spatial filter as an example

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.; Krasowski, Michael J.

    1991-01-01

    The goal is to develop an approach to automating the alignment and adjustment of optical measurement, visualization, inspection, and control systems. Classical controls, expert systems, and neural networks are three approaches to automating the alignment of an optical system. Neural networks were chosen for this project and the judgements that led to this decision are presented. Neural networks were used to automate the alignment of the ubiquitous laser-beam-smoothing spatial filter. The results and future plans of the project are presented.

  19. Thermal dissipation modeling in optical components modules for electrical power consumption optimization

    NASA Astrophysics Data System (ADS)

    Sabot, Germain; Chaudenson, Julien; Raulin, Franck; Jacquet, Jo"l.

    2010-02-01

    In a semi-conductor optical amplifier (SOA) as in any other optical devices, the performances that can be reached is strongly dependent on the chip temperature. For example, the optical output power of a laser or the optical gain in a SOA is reduced when the temperature of the junction increases. This latter can be controlled or monitored thanks to a thermo-electronic cooler (or a Peltier element) and a thermistor. In this paper, we first have calculated the thermal resistance of various semiconductor structures such as buried or ridge waveguides lasers. We then calculate the Peltier consumption necessary to maintain a given temperature. The influence of the thermistor position as well as the module conception have been investigated in these calculation. The size of the different mechanical elements, the nature and thermal properties of the material use for the module fabrication have been found to play an important role in the thermal performance of the optical modules. The Peltier size is defined by maximizing its efficiency. It depends on the power to be dissipated as well as the temperature operation of the device. The latter depends on the performance expected by the optical devices. We discussed the optimization of the device structure associated to its packaging to find the best compromise between performance and electrical consumption. The trade-off found depends on the temperature at which the device operates as well as on the thermal power to be dissipated.

  20. Continued education and experimental activities for optics education

    NASA Astrophysics Data System (ADS)

    Shinomiya, George K.; Muramatsu, Mikiya

    2001-08-01

    Of the evidence that the optics knowledge is practically unknown for the pupils who complete Basic Education, we initiate, in 1998, a project involving teachers of the Public Network and University teachers with the objective to change this situation. The main cause of this abandonment of optics is the bad understanding by the teachers of the optic phenomena, result of their bad initial formation. Based on this situation, we developed a series of simple experimental activities that demonstrate the main concepts of optics in the program. After that, we elaborate courses of university extension, destined to the teachers of Basic Education, giving emphasis to the experimentation, using kits and demonstrations, complemented by texts, videos and group works. From 98 until now, more than 200 teachers had participated of our course, and they made a sufficiently positive evaluation of these works pointing not only the including of the optics, but also a significant change in its strategies of education, going of meeting to the new parameters of our basic education.

  1. Differences in associations between active transportation and built environmental exposures when expressed using different components of individual activity spaces.

    PubMed

    van Heeswijck, Torbjorn; Paquet, Catherine; Kestens, Yan; Thierry, Benoit; Morency, Catherine; Daniel, Mark

    2015-05-01

    This study assessed relationships between built environmental exposures measured within components of individual activity spaces (i.e., travel origins, destinations and paths in-between), and use of active transportation in a metropolitan setting. Individuals (n=37,165) were categorised as using active or sedentary transportation based on travel survey data. Generalised Estimating Equations analysis was used to test relationships with active transportation. Strength and significance of relationships between exposures and active transportation varied for different components of the activity space. Associations were strongest when including travel paths in expression of the built environment. Land use mix and greenness were negatively related to active transportation.

  2. A laser electro-optic device for the orientation of mass-produced components

    NASA Astrophysics Data System (ADS)

    Dewhurst, R. J.; Swift, K. G.

    An experimental device is described which is used to orientate small industrial components being fed along conveyor belts or in bowl feeders. The component orientation is identified by laser light scattered from discrete regions of the component which moves through a field of view. Subsequent electronic signal processing leads to the control of a pneumatic system used to reject unwanted component modes. The device has been shown to be effective at feed rates up to above 100 components per minute. Flexibility of the device is demonstrated by a number of examples which include the orientation of grub-screws in either one of two stable orientations, and by the orientation of non-cylindrical-shaped components. In these examples, reliability of successful orientation has been found to be greater than 99%.

  3. Optical sensor based system to monitor caries activity

    NASA Astrophysics Data System (ADS)

    Shrestha, A.; Tahir, R.; Kishen, A.

    2007-07-01

    The aim of the study is to evaluate the ability of a visible light based spectroscopic sensor system to monitor caries activity in saliva. In this study an optical sensor is utilized to monitor the bacterial-mediated acidogenic profile of stimulated saliva using a photosensitive pH indicator. Microbiological assessment of the saliva samples were carried out using the conventional culture methods. In addition, the shifts in the pH of saliva-sucrose samples were recorded using a pH meter. The absorption spectra obtained from the optical sensor showed peak maxima at 595nm, which decreased as a function of time. The microbiological assessment showed increase in the bacterial count as a function of time. A strong positive correlation was also observed between the rates of decrease in the absorption intensity measured using the optical sensor and the decrease in pH measured using the pH meter. This study highlights the potential advantages of using the optical sensor as a sensitive and rapid chairside system for monitoring caries activity by quantification of the acidogenic profile of saliva.

  4. Transparent selective illumination means suitable for use in optically activated electrical switches and optically activated electrical switches constructed using same

    DOEpatents

    Wilcox, R.B.

    1991-09-10

    A planar transparent light conducting means and an improved optically activated electrical switch made using the novel light conducting means are disclosed. The light conducting means further comprise light scattering means on one or more opposite planar surfaces thereof to transmit light from the light conducting means into adjacent media and reflective means on other surfaces of the light conducting means not containing the light scattering means. The optically activated electrical switch comprises at least two stacked photoconductive wafers, each having electrodes formed on both surfaces thereof, and separated by the planar transparent light conducting means. The light scattering means on the light conducting means face surfaces of the wafers not covered by the electrodes to transmit light from the light conducting means into the photoconductive wafers to uniformly illuminate and activate the switch. 11 figures.

  5. Transparent selective illumination means suitable for use in optically activated electrical switches and optically activated electrical switches constructed using same

    DOEpatents

    Wilcox, Russell B.

    1991-01-01

    A planar transparent light conducting means and an improved optically activated electrical switch made using the novel light conducting means are disclosed. The light conducting means further comprise light scattering means on one or more opposite planar surfaces thereof to transmit light from the light conducting means into adjacent media and reflective means on other surfaces of the light conducting means not containing the light scattering means. The optically activated electrical switch comprises at least two stacked photoconductive wafers, each having electrodes formed on both surfaces thereof, and separated by the planar transparent light conducting means. The light scattering means on the light conducting means face surfaces of the wafers not covered by the electrodes to transmit light from the light conducting means into the photoconductive wafers to uniformly illuminate and activate the switch.

  6. Natural Silk as a Photonics Component: a Study on Its Light Guiding and Nonlinear Optical Properties

    NASA Astrophysics Data System (ADS)

    Kujala, Sami; Mannila, Anna; Karvonen, Lasse; Kieu, Khanh; Sun, Zhipei

    2016-03-01

    Silk fibers are expected to become a pathway to biocompatible and bioresorbable waveguides, which could be used to deliver localized optical power for various applications, e.g., optical therapy or imaging inside living tissue. Here, for the first time, the linear and nonlinear optical properties of natural silk fibers have been studied. The waveguiding properties of silk fibroin of largely unprocessed Bombyx mori silkworm silk are assessed using two complementary methods, and found to be on the average 2.8 dB mm-1. The waveguide losses of degummed silk are to a large extent due to scattering from debris on fiber surface and helical twisting of the fiber. Nonlinear optical microscopy reveals both configurational defects such as torsional twisting, and strong symmetry breaking at the center of the fiber, which provides potential for various nonlinear applications. Our results show that nonregenerated B. mori silk can be used for delivering optical power over short distances, when the waveguide needs to be biocompatible and bioresorbable, such as embedding the waveguide inside living tissue.

  7. Natural Silk as a Photonics Component: a Study on Its Light Guiding and Nonlinear Optical Properties

    PubMed Central

    Kujala, Sami; Mannila, Anna; Karvonen, Lasse; Kieu, Khanh; Sun, Zhipei

    2016-01-01

    Silk fibers are expected to become a pathway to biocompatible and bioresorbable waveguides, which could be used to deliver localized optical power for various applications, e.g., optical therapy or imaging inside living tissue. Here, for the first time, the linear and nonlinear optical properties of natural silk fibers have been studied. The waveguiding properties of silk fibroin of largely unprocessed Bombyx mori silkworm silk are assessed using two complementary methods, and found to be on the average 2.8 dB mm−1. The waveguide losses of degummed silk are to a large extent due to scattering from debris on fiber surface and helical twisting of the fiber. Nonlinear optical microscopy reveals both configurational defects such as torsional twisting, and strong symmetry breaking at the center of the fiber, which provides potential for various nonlinear applications. Our results show that nonregenerated B. mori silk can be used for delivering optical power over short distances, when the waveguide needs to be biocompatible and bioresorbable, such as embedding the waveguide inside living tissue. PMID:26926272

  8. The role of lanthanides in optical materials

    SciTech Connect

    Weber, M.J.

    1995-05-01

    A survey is presented of the use of the lanthanides as chemical components in transmitting optical materials and as activators in materials for luminescent, electro-optic, magneto-optic, and various photosensitive applications.

  9. Catalase activity as a potential indicator of the reducer component of small closed ecosystems.

    PubMed

    Sarangova, A B; Somova, L A; Pisman, T I

    1997-01-01

    Dynamics of catalase activity has been shown to reflect the growth curve of microorganisms in batch cultivation (celluloselythic bacteria Bacillus acidocaldarius and bacteria of the associated microflora Chlorella vulgaris). Gas and substrate closure of the three component ecosystems with spatially separated components "producer-consumer-reducer" (Chl. vulgaris-Paramecium caudatum-B. acidocaldarius, two bacterial strains isolated from the associated microflora Chl. vulgaris) demonstrated that the functioning of the reducer component can be estimated by the catalase activity of mciroorganisms of this component.

  10. Selectivity of the optical-absorption method based on an instrumental pick out of Fourier components in the absorption spectrum

    NASA Astrophysics Data System (ADS)

    Pisarevsky, Yu. V.; Kolesnikov, S. A.; Kolesnikova, E. S.; Turutin, Yu. A.; Konopelko, L. A.; Shor, N. B.

    2016-06-01

    The introduction of interference-polarization filters (IPFs) in the structure of an optical-absorption analyzer makes it possible to pick out a harmonic (a Fourier component of the absorption spectrum) providing measurement with the highest sensitivity. The selectivity of such a method of analysis is determined by overlapping the oscillations of the measured and interfering components. By the example of measurement in benzene in the presence of an interfering component (toluene), the possibility is considered for the optimization of selectivity due to the variation of the path-difference dispersion for ordinary and extraordinary interfering rays. The metrological characteristics of the interference-polarization analyzer of C6H6 confirming the results of calculations are given.

  11. Odour-evoked responses to queen pheromone components and to plant odours using optical imaging in the antennal lobe of the honey bee drone Apis mellifera L.

    PubMed

    Sandoz, Jean-Christophe

    2006-09-01

    The primordial functional role of honey bee males (drones) is to mate with virgin queens, a behaviour relying heavily on the olfactory detection of queen pheromone. In the present work I studied olfactory processing in the drone antennal lobe (AL), the primary olfactory centre of the insect brain. In drones, the AL consists of about 103 ordinary glomeruli and four enlarged glomeruli, the macroglomeruli (MG). Two macroglomeruli (MG1 and MG2) and approximately 20 ordinary glomeruli occupy the anterior surface of the antennal lobe and are thus accessible to optical recordings. Calcium imaging was used to measure odour-evoked responses to queen pheromonal components and plant odours. MG2 responded specifically to the main component of the queen mandibular pheromone, 9-ODA. The secondary components HOB and HVA each triggered activity in one, but not the same, ordinary glomerulus. MG1 did not respond to any of the tested stimuli. Plant odours induced signals only in ordinary glomeruli in a combinatorial manner, as in workers. This study thus shows that the major queen pheromonal component is processed in the most voluminous macroglomerulus of the drone antennal lobe, and that plant odours, as well as some queen pheromonal components, are processed in ordinary glomeruli.

  12. Odour-evoked responses to queen pheromone components and to plant odours using optical imaging in the antennal lobe of the honey bee drone Apis mellifera L.

    PubMed

    Sandoz, Jean-Christophe

    2006-09-01

    The primordial functional role of honey bee males (drones) is to mate with virgin queens, a behaviour relying heavily on the olfactory detection of queen pheromone. In the present work I studied olfactory processing in the drone antennal lobe (AL), the primary olfactory centre of the insect brain. In drones, the AL consists of about 103 ordinary glomeruli and four enlarged glomeruli, the macroglomeruli (MG). Two macroglomeruli (MG1 and MG2) and approximately 20 ordinary glomeruli occupy the anterior surface of the antennal lobe and are thus accessible to optical recordings. Calcium imaging was used to measure odour-evoked responses to queen pheromonal components and plant odours. MG2 responded specifically to the main component of the queen mandibular pheromone, 9-ODA. The secondary components HOB and HVA each triggered activity in one, but not the same, ordinary glomerulus. MG1 did not respond to any of the tested stimuli. Plant odours induced signals only in ordinary glomeruli in a combinatorial manner, as in workers. This study thus shows that the major queen pheromonal component is processed in the most voluminous macroglomerulus of the drone antennal lobe, and that plant odours, as well as some queen pheromonal components, are processed in ordinary glomeruli. PMID:16943499

  13. 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

  14. Dispersion of optical activity of magnesium sulfite hexahydrate single crystals

    NASA Astrophysics Data System (ADS)

    Dimov, T.; Bunzarov, Zh; Iliev, I.; Petkova, P.; Tzoukrovski, Y.

    2010-11-01

    The magnesium sulfite hexahydrate (MgSO3.6H2O) crystals are unique because they are the only representative (with sodium periodate) of the crystallographic class C3 (without a center of symmetry). The crystal symmetry suggests presence of nonlinearity, piezo- and pyro-electric properties and gyrotropy as well. Single crystals of MgSO3.6H2O (pure and doped with Ni, Co and Zn) for the time being are grown only by the original method developed in the Laboratory for Crystal growth at the Faculty of Physics in Sofia University. The first results of optical activity of pure MgSO3.6H2O and Zn doped MgSO3.6H2O crystals are described and analyzed in a wide spectral range. The optical activity manifests itself in the direction (0001) as a rotation of the polarization plane.

  15. Laser-heating-based active optics for synchrotron radiation applications.

    PubMed

    Yang, Fugui; Li, Ming; Gao, Lidan; Sheng, Weifan; Liu, Peng; Zhang, Xiaowei

    2016-06-15

    Active optics has attracted considerable interest from researchers in synchrotron radiation facilities because of its capacity for x-ray wavefront correction. Here, we report a novel and efficient technique for correcting or modulating a mirror surface profile based on laser-heating-induced thermal expansion. An experimental study of the characteristics of the surface thermal deformation response indicates that the power of a milliwatt laser yields a bump height as low as the subnanometer scale and that the variation of the spot size modulates the response function width effectively. In addition, the capacity of the laser-heating technique for free-form surface modulation is demonstrated via a one-dimensional surface correction experiment. The developed method is a promising new approach toward effective x-ray active optics coupled with at-wavelength metrology techniques.

  16. 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.

  17. Optical activity of transparent polymer layers characterized by spectral means

    NASA Astrophysics Data System (ADS)

    Cosutchi, Andreea Irina; Dimitriu, Dan Gheorghe; Zelinschi, Carmen Beatrice; Breaban, Iuliana; Dorohoi, Dana Ortansa

    2015-06-01

    The method based on the channeled spectrum, validated for inorganic optical active layers, is used now to determine the optical activity of some transparent polymer solutions in different solvents. The circular birefringence, the dispersion parameter and the specific rotation were estimated in the visible range by using the measurements of wavelengths in the channeled spectra of Hydroxypropyl cellulose in water, methanol and acetic acid. The experiments showed the specific rotation dependence on the polymer concentration and also on the solvent nature. The decrease of the specific rotation in the visible range with the increase in wavelength was evidenced. The method has some advantages as the rapidity of the experiments and the large spectral range in which it can be applied. One disadvantage is the fact that the channeled spectrum does not allow to establish the rotation sense of the electric field intensity.

  18. Subtractive 3D printing of optically active diamond structures.

    PubMed

    Martin, Aiden A; Toth, Milos; Aharonovich, Igor

    2014-05-21

    Controlled fabrication of semiconductor nanostructures is an essential step in engineering of high performance photonic and optoelectronic devices. Diamond in particular has recently attracted considerable attention as a promising platform for quantum technologies, photonics and high resolution sensing applications. Here we demonstrate the fabrication of optically active, functional diamond structures using gas-mediated electron beam induced etching (EBIE). The technique achieves dry chemical etching at room temperature through the dissociation of surface-adsorbed H2O molecules by energetic electrons in a water vapor environment. Parallel processing is possible by electron flood exposure and the use of an etch mask, while high resolution, mask-free, iterative editing is demonstrated by direct write etching of inclined facets of diamond microparticles. The realized structures demonstrate the potential of EBIE for the fabrication of optically active structures in diamond.

  19. Laser-heating-based active optics for synchrotron radiation applications.

    PubMed

    Yang, Fugui; Li, Ming; Gao, Lidan; Sheng, Weifan; Liu, Peng; Zhang, Xiaowei

    2016-06-15

    Active optics has attracted considerable interest from researchers in synchrotron radiation facilities because of its capacity for x-ray wavefront correction. Here, we report a novel and efficient technique for correcting or modulating a mirror surface profile based on laser-heating-induced thermal expansion. An experimental study of the characteristics of the surface thermal deformation response indicates that the power of a milliwatt laser yields a bump height as low as the subnanometer scale and that the variation of the spot size modulates the response function width effectively. In addition, the capacity of the laser-heating technique for free-form surface modulation is demonstrated via a one-dimensional surface correction experiment. The developed method is a promising new approach toward effective x-ray active optics coupled with at-wavelength metrology techniques. PMID:27304296

  20. COMPONENTS OF LASER SYSTEMS: Single-channel adaptive mirrors for laser optics

    NASA Astrophysics Data System (ADS)

    Safronov, A. G.

    1995-11-01

    Single-channel deformable mirrors for use in low-correction-order laser adaptive systems were developed and investigated. The structure of the mirrors is described and the results are given of experimental determinations of the initial shape of the optical surface, of the response functions, of the sensitivity, and of the electromechanical hysteresis. Calculations are reported of the thermal deformation of the mirrors subjected to the effects of heat under various conditions, and also of the frequency characteristics of these mirrors. It is shown that such adaptive mirrors are effective in compensation for large-scale axisymmetric distortions of the wavefront in laser optics operating at powers up to 1 kW. The operational range of these mirrors is approximately ±20 μm in respect of the amplitude of the optical surface displacements and up to 1 kHz in respect of the frequency.

  1. Characteristics of Noise and Photon Statistics of Fiber Components in Electro-Optical Systems

    NASA Astrophysics Data System (ADS)

    Zhao, Cheng

    This thesis presents a comprehensive study of the role of the fiber replicator in electro-optical systems. In the all fiber optical diagnostic system for the National Ignition Facility's DANTE data acquisition system running at 1550nm, the 8x fiber replicator was used to increase the SNR (Signal to Noise Ratio) of single-shot, electrical pulse measurements. In the system, Mach-Zehnder modulators were used to convert the electrical signals into optical signals. The fiber replicator was used to create identical copies of the optical signals. A High SNR was achieved through the averaging of these duplicated signals. Erbium-doped fiber amplifiers (EDFAs) were built to amplify the optical signals after the fiber replicator. The EDFAs applied in the DANTEEO system should have high gain, low noise, low background signals and high pulse-shape fidelity. In this thesis, we discussed the effect of different configurations and the type of Er-doped fibers on the gain and noise performance of EDFAs. We also used a simplified model for dynamic gain in EDFAs to explore the effect of the EDFA on the shape of the amplified pulse. Based on this model, the calculated pulse-shape distortions were found to be dependent on the EDFA configuration and the optical gain. We also investigated the photon statistics with the fiber replicator in a photon entanglement system. The entangled photons were created through the up-conversion and down-conversion of a Q-switch laser beam running at 1053nm. The different behavior between entangled photon and non-entangled single photons in the system with the fiber replicator are discussed.

  2. Synthesis of Optically Active Polystyrene Catalyzed by Monophosphine Pd Complexes.

    PubMed

    Jouffroy, Matthieu; Armspach, Dominique; Matt, Dominique; Osakada, Kohtaro; Takeuchi, Daisuke

    2016-07-11

    Cationic Pd(II) monophosphine complexes derived from α- and β-cyclodextrins (CDs) promote the homopolymerization of styrene under carbon monoxide pressure. Although reversible CO coordination takes place under catalytic conditions according to (13) C NMR studies with (13) C-enriched CO, both complexes catalyze the formation of CO-free styrene polymers. These macromolecules display optical activity as a result of the presence of stereoregular sequences within the overall atactic polymer.

  3. Final Report: Imaging of Buried Nanoscale Optically Active Materials

    SciTech Connect

    Appelbaum, Ian

    2011-07-05

    This is a final report covering work done at University of Maryland to develop a Ballistic Electron Emission Luminescence (BEEL) microscope. This technique was intended to examine the carrier transport and photon emission in deeply buried optically-active layers and thereby provide a means for materials science to unmask the detailed consequences of experimentally controllable growth parameters, such as quantum dot size, statistics and orientation, and defect density and charge recombination pathways.

  4. Demonstrating Optical Activity Using an iPad

    ERIC Educational Resources Information Center

    Schwartz, Pauline M.; Lepore, Dante M.; Morneau, Brandy N.; Barratt, Carl

    2011-01-01

    Optical activity using an iPad as a source of polarized light is demonstrated. A sample crystal or solution can be placed on the iPad running a white screen app. The sample is viewed through a polarized filter that can be rotated. This setup can be used in the laboratory or with a document camera to easily project in a large lecture hall.…

  5. Synthesis of Optically Active Polystyrene Catalyzed by Monophosphine Pd Complexes.

    PubMed

    Jouffroy, Matthieu; Armspach, Dominique; Matt, Dominique; Osakada, Kohtaro; Takeuchi, Daisuke

    2016-07-11

    Cationic Pd(II) monophosphine complexes derived from α- and β-cyclodextrins (CDs) promote the homopolymerization of styrene under carbon monoxide pressure. Although reversible CO coordination takes place under catalytic conditions according to (13) C NMR studies with (13) C-enriched CO, both complexes catalyze the formation of CO-free styrene polymers. These macromolecules display optical activity as a result of the presence of stereoregular sequences within the overall atactic polymer. PMID:27218801

  6. Active optics control of VST telescope secondary mirror.

    PubMed

    Schipani, Pietro; D'Orsi, Sergio; Fierro, Davide; Marty, Laurent

    2010-06-01

    In telescopes based on active optics, defocus and coma are usually compensated for by secondary mirror movements. They are performed at the Very Large Telescope Survey Telescope (VST) with a hexapod--a parallel robot with six degrees of freedom positioning capability. We describe the application of the two-mirror telescope theory to the VST case and the solutions adopted for the hexapod control. We present the results of performance and reliability tests performed both in the laboratory and at the telescope.

  7. The Fiber Optic Subsystem Components on Express Logistics Carrier for International Space Station

    NASA Technical Reports Server (NTRS)

    Ott, Melanie N.; Switzer, Robert; Thomes, William Joe; Chuska, Richard; LaRocca, Frank; Day, Lance

    2009-01-01

    ISS SSP 50184 HRDL optical fiber communication subsystem, has system level requirements that were changed to accommodate large loss optical fiber links previously installed. SSQ22680 design is difficult to implement, no metal shell over socket/pin combination to protect the weak part of the pin. Additions to ISS are planned for the future. AVIM still used for interconnection in space flight applications without incident. Thermal cycling resulted in less than 0.25 dB max change in Insertion Loss for all types during cycling, nominal as compared to the AVIM. Vibration testing results conclusion; no significant changes, nominal as compared to AVIM.

  8. COMPONENTS OF LASER SYSTEMS: Diffraction gratings with high optical strength for laser resonators

    NASA Astrophysics Data System (ADS)

    Svakhin, A. S.; Sychugov, V. A.; Tikhomirov, A. E.

    1994-03-01

    A new approach to the fabrication of efficient diffraction gratings of the reflection type with a high optical strength is proposed. A diffraction grating with an efficiency of 64% was made and used in a resonator of a Q-switched YAG : Nd3+ laser. Gratings of this type are capable of withstanding the action of pulsed optical radiation right up to a power density of 180 MW cm-2. Possible use of such gratings at high angles of incidence of radiation so as to improve the spectral selectivity is considered.

  9. Activities report of the Division of Optical Technology (FOA 33)

    NASA Astrophysics Data System (ADS)

    Letalick, Dietmar

    1988-11-01

    Research on hydro-optics; laser remote sensing; coherent CO2 laser radar; optical signatures; atmospheric transmission; ionizing radiation effects on electronics; fiber optics; optical processing; and terrain models is summarized.

  10. Incompressible states of a two-component Fermi gas in a double-well optical lattice

    SciTech Connect

    Crepin, Francois; Simon, Pascal; Citro, Roberta

    2010-07-15

    We propose a scheme to investigate the effect of frustration on the magnetic phase transitions of cold atoms confined in an optical lattice. We also demonstrate how to get two-leg spin ladders with frustrated spin-exchange coupling that display a phase transition from a spin liquid to a fully incompressible state. Further, various experimental quantities are analyzed for describing this phase.

  11. Gamma-radiation-induced degradation of actively pumped single-mode ytterbium-doped optical fibers

    NASA Astrophysics Data System (ADS)

    Singleton, B.; Petrosky, J.; Pochet, M.; Usechak, N. G.; Francis, S. A.

    2014-03-01

    The integration of optical components into the digital processing units of satellite subsystems has the potential to remove interconnect bottlenecks inherent to the volume, mass, complexity, reliability and crosstalk issues of copper-based interconnects. Assuming on-board high-bandwidth communications will utilize passive optical fibers as a communication channel, this work investigates the impact of gamma irradiation from a Co-60 source on both passive optical fibers and ytterbium-doped single-mode fibers operated as amplifiers for a 1060-nm light source. Standard optical patch cables were evaluated along with active Yb-doped double-clad fibers. Varied exposure times and signal transmission wavelengths were used to investigate the degradation of the fibers exposed to total doses above 100 krad (Si). The effect on the amplified signal gain was studied for the Yb-doped fibers. The increased attenuation in the fibers across a broad wavelength range in response to multiple levels of gamma radiation exposure along with the effect that the increased attenuation has on the actively pumped Yb-doped fiber amplifier performance, is discussed.

  12. Caffeic acid phenethyl ester (CAPE), an active component of propolis, inhibits Helicobacter pylori peptide deformylase activity.

    PubMed

    Cui, Kunqiang; Lu, Weiqiang; Zhu, Lili; Shen, Xu; Huang, Jin

    2013-05-31

    Helicobacter pylori (H. pylori) is a major causative factor for gastrointestinal illnesses, H. pylori peptide deformylase (HpPDF) catalyzes the removal of formyl group from the N-terminus of nascent polypeptide chains, which is essential for H. pylori survival and is considered as a promising drug target for anti-H. pylori therapy. Propolis, a natural antibiotic from honeybees, is reported to have an inhibitory effect on the growth of H. pylori in vitro. In addition, previous studies suggest that the main active constituents in the propolis are phenolic compounds. Therefore, we evaluated a collection of phenolic compounds derived from propolis for enzyme inhibition against HpPDF. Our study results show that Caffeic acid phenethyl ester (CAPE), one of the main medicinal components of propolis, is a competitive inhibitor against HpPDF, with an IC50 value of 4.02 μM. Furthermore, absorption spectra and crystal structural characterization revealed that different from most well known PDF inhibitors, CAPE block the substrate entrance, preventing substrate from approaching the active site, but CAPE does not have chelate interaction with HpPDF and does not disrupt the metal-dependent catalysis. Our study provides valuable information for understanding the potential anti-H. pylori mechanism of propolis, and CAPE could be served as a lead compound for further anti-H. pylori drug discovery. PMID:23611786

  13. Caffeic acid phenethyl ester (CAPE), an active component of propolis, inhibits Helicobacter pylori peptide deformylase activity.

    PubMed

    Cui, Kunqiang; Lu, Weiqiang; Zhu, Lili; Shen, Xu; Huang, Jin

    2013-05-31

    Helicobacter pylori (H. pylori) is a major causative factor for gastrointestinal illnesses, H. pylori peptide deformylase (HpPDF) catalyzes the removal of formyl group from the N-terminus of nascent polypeptide chains, which is essential for H. pylori survival and is considered as a promising drug target for anti-H. pylori therapy. Propolis, a natural antibiotic from honeybees, is reported to have an inhibitory effect on the growth of H. pylori in vitro. In addition, previous studies suggest that the main active constituents in the propolis are phenolic compounds. Therefore, we evaluated a collection of phenolic compounds derived from propolis for enzyme inhibition against HpPDF. Our study results show that Caffeic acid phenethyl ester (CAPE), one of the main medicinal components of propolis, is a competitive inhibitor against HpPDF, with an IC50 value of 4.02 μM. Furthermore, absorption spectra and crystal structural characterization revealed that different from most well known PDF inhibitors, CAPE block the substrate entrance, preventing substrate from approaching the active site, but CAPE does not have chelate interaction with HpPDF and does not disrupt the metal-dependent catalysis. Our study provides valuable information for understanding the potential anti-H. pylori mechanism of propolis, and CAPE could be served as a lead compound for further anti-H. pylori drug discovery.

  14. 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.

  15. Analysis and comparison of the active components and antioxidant activities of extracts from Abelmoschus esculentus L

    PubMed Central

    Liao, Haibing; Dong, Wenqi; Shi, Xiangjun; Liu, Hualiang; Yuan, Ke

    2012-01-01

    Background: Abelmoschus esculentus L. is a healthy vegetable belonging to the family Malvaceae. This article reports the contents of total phenolics (TP) and total flavonoids (TF) in 80% methanol extracts of the flower (FL), fruit (FR), leaf (L), and seed (S) of A. esculentus, and in 0, 10, 30, 50, and 70% methanol eluates (ME), through the HP-20 column chromatography of 80% of the methanol fruit extract after it is defatted with petroleum and extracted with ethyl acetate. All the names of the samples are shortened for AEE-FL, AEE-FR, AEE-L, AEE-S and 0% MEF-WE, 10% MEF-WE, 30% MEF-WE, 50% MEF-WE, 70% MEF-WE respectively. In addition, the effects of the aforementioned extracts on 1,1-Diphenyl-2-picryl-hydrazyl (DPPH) radical-scavenging and on ferric reducing antioxidant power (FRAP) have been evaluated. Materials and Methods: The antioxidant activity of the extracts and the enrichment fraction of A. esculentus were also evaluated by two assays, the DPPH radical-scavenging and ferric reducing antioxidant power (FRAP). The content measurement of TF and TP adopts the UV-2102 PCS method, and the measurement of the antioxidant activity adopts the Infinite M 200 method. Results: The experiment results show that all the different parts and different enrichment fractions of the water extracts of A. esculentus contain phenolics and flavonoids. Through the research of antioxidant activity we know that all the parts of the methanol extracts and different enrichment fractions of water extracts in the A. esculentus have the effect of scavenging free radicals, among which the antioxidant activity in the 50% MEF-WE part is the strongest. Here, the main components of antioxidant activity must be the flavonoids and phenolics, and furthermore, we know that there is a direct relationship between the contents of flavonoids and phenolics and the antioxidant activity. Conclusion: The study suggests that A. esculentus may be the potential rich source of natural antioxidant. The

  16. Photonic Component Qualification and Implementation Activities at NASA Goddard Space Flight Center

    NASA Technical Reports Server (NTRS)

    Ott, Melanie N.; Jin, Xiaodan Linda; Chuska, Richard F.; LaRocca, Frank V.; MacMurphy, Shawn L.; Matuszeski, Adam J.; Zellar, Ronald S.; Friedberg, Patricia R.; Malenab, Mary C.

    2006-01-01

    The photonics group in Code 562 at NASA Goddard Space Flight Center supports a variety of space flight programs at NASA including the: International Space Station (ISS), Shuttle Return to Flight Mission, Lunar Reconnaissance Orbiter (LRO), Express Logistics Carrier, and the NASA Electronic Parts and Packaging Program (NEPP). Through research, development, and testing of the photonic systems to support these missions much information has been gathered on practical implementations for space environments. Presented here are the highlights and lessons learned as a result of striving to satisfy the project requirements for high performance and reliable commercial optical fiber components for space flight systems. The approach of how to qualify optical fiber components for harsh environmental conditions, the physics of failure and development lessons learned will be discussed.

  17. Sparse matrix approximation method for an active optical control system

    NASA Astrophysics Data System (ADS)

    Murphy, Timothy P.; Lyon, Richard G.; Dorband, John E.; Hollis, Jan M.

    2001-12-01

    We develop a sparse matrix approximation method to decompose a wave front into a basis set of actuator influence functions for an active optical system consisting of a deformable mirror and a segmented primary mirror. The wave front used is constructed by Zernike polynomials to simulate the output of a phase-retrieval algorithm. Results of a Monte Carlo simulation of the optical control loop are compared with the standard, nonsparse approach in terms of accuracy and precision, as well as computational speed and memory. The sparse matrix approximation method can yield more than a 50-fold increase in the speed and a 20-fold-reduction in matrix size and a commensurate decrease in required memory, with less than 10% degradation in solution accuracy. Our method is also shown to be better than when elements are selected for the sparse matrix on a magnitude basis alone. We show that the method developed is a viable alternative to use of the full control matrix in a phase-retrieval-based active optical control system.

  18. Sparse matrix approximation method for an active optical control system.

    PubMed

    Murphy, T P; Lyon, R G; Dorband, J E; Hollis, J M

    2001-12-10

    We develop a sparse matrix approximation method to decompose a wave front into a basis set of actuator influence functions for an active optical system consisting of a deformable mirror and a segmented primary mirror. The wave front used is constructed by Zernike polynomials to simulate the output of a phase-retrieval algorithm. Results of a Monte Carlo simulation of the optical control loop are compared with the standard, nonsparse approach in terms of accuracy and precision, as well as computational speed and memory. The sparse matrix approximation method can yield more than a 50-fold increase in the speed and a 20-fold reduction in matrix size and a commensurate decrease in required memory, with less than 10% degradation in solution accuracy. Our method is also shown to be better than when elements are selected for the sparse matrix on a magnitude basis alone. We show that the method developed is a viable alternative to use of the full control matrix in a phase-retrieval-based active optical control system. PMID:18364958

  19. Chiral magnetic effect and natural optical activity in (Weyl) metals

    NASA Astrophysics Data System (ADS)

    Pesin, Dmytro; Ma, Jing

    We consider the phenomenon of natural optical activity, and related chiral magnetic effect in metals with low carrier concentration. To reveal the correspondence between the two phenomena, we compute the optical conductivity of a noncentrosymmetric metal to linear order in the wave vector of the light wave, specializing to the low-frequency regime. We show that it is the orbital magnetic moment of quasiparticles that is responsible for the natural optical activity, and thus the chiral magnetic effect. While for purely static magnetic fields the chiral magnetic effect is known to have a topological origin and to be related to the presence of Berry curvature monopoles (Weyl points) in the band structure, we show that the existence of Berry monopoles is not required for the dynamic chiral magnetic effect to appear; the latter is thus not unique to Weyl metals. The magnitude of the dynamic chiral magnetic effect in a material is related to the trace of its gyrotropic tensor. We discuss the conditions under which this trace is non-zero; in noncentrosymmetric Weyl metals it is found to be proportional to the energy-space dipole moment of Berry curvature monopoles. The calculations are done within both the semiclassical kinetic equation, and Kubo linear response formalisms. This work was supported by NSF Grant No. DMR-1409089.

  20. Nanoparticles as contrast-enhancing agents in optical coherence tomography imaging of the structural components of skin: Quantitative evaluation

    SciTech Connect

    Kirillin, M Yu; Agrba, P D; Kamenskii, V A; Sirotkina, M A; Shiryamova, M V; Zagainova, E V

    2010-08-27

    This work examines the effect of gold nanoshells and titania nanoparticles on the imaging contrast of structural components of skin in optical coherence tomography (OCT). Experimental data are compared to Monte Carlo (MC) simulation results. In experiments with pig skin in vivo, the epidermis - dermis contrast is improved from 0.78 {+-} 0.03 to 0.92 {+-} 0.04 by gold nanoshells applied to the skin surface and from 0.78 {+-} 0.03 to 0.86 {+-} 0.04 by titania nanoparticles. The contrast of glands is enhanced by titania from 0.68 {+-} 0.12 to 0.84 {+-} 0.07. The highest contrast is reached 120 - 150 min after applying gold nanoshells and 160 - 200 min after applying titania. According to the MC simulation results, the contrast of inclusions increases from zero to 0.85 and 0.65, respectively. (optical tomography)

  1. INHIBITION OF RETINOID ACTIVITY BY COMPONENTS OF A PAPER MILL EFFLUENT

    EPA Science Inventory

    A cell line stably transfected with reporter genes activated by retinoic acid was used to test a paper mill effluent for the presence of retinoids or components that interfere with retinoic acid-stimulated gene transcription.

  2. 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.

  3. Optical Assessment of Caries Lesion Structure and Activity

    NASA Astrophysics Data System (ADS)

    Lee, Robert Chulsung

    New, more sophisticated diagnostic tools are needed for the detection and characterization of caries lesions in the early stages of development. It is not sufficient to simply detect caries lesions, methods are needed to assess the activity of the lesion and determine if chemical or surgical intervention is needed. Previous studies have demonstrated that polarization sensitive optical coherence tomography (PS-OCT) can be used to nondestructively image the subsurface lesion structure and measure the thickness of the highly mineralized surface zone. Other studies have demonstrated that the rate of dehydration can be correlated with the lesion activity and that the rate can be measured using optical methods. The main objective of this work was to test the hypothesis that optical methods can be used to assess lesion activity on tooth coronal and root surfaces. Simulated caries models were used to develop and validate an algorithm for detecting and measuring the highly mineralized surface layer using PS-OCT. This work confirmed that the algorithm was capable of estimating the thickness of the highly mineralized surface layer with high accuracy. Near-infrared (NIR) reflectance and thermal imaging methods were used to assess activity of caries lesions by measuring the state of lesion hydration. NIR reflectance imaging performed the best for artificial enamel and natural coronal caries lesion samples, particularly at wavelengths coincident with the water absorption band at 1460-nm. However, thermal imaging performed the best for artificial dentin and natural root caries lesion samples. These novel optical methods outperformed the conventional methods (ICDAS II) in accurately assessing lesion activity of natural coronal and root caries lesions. Infrared-based imaging methods have shown potential for in-vivo applications to objectively assess caries lesion activity in a single examination. It is likely that if future clinical trials are a success, this novel imaging

  4. Optical impedance spectroscopy with single-mode electro-active-integrated optical waveguides.

    PubMed

    Han, Xue; Mendes, Sergio B

    2014-02-01

    An optical impedance spectroscopy (OIS) technique based on a single-mode electro-active-integrated optical waveguide (EA-IOW) was developed to investigate electron-transfer processes of redox adsorbates. A highly sensitive single-mode EA-IOW device was used to optically follow the time-dependent faradaic current originated from a submonolayer of cytochrome c undergoing redox exchanges driven by a harmonic modulation of the electric potential at several dc bias potentials and at several frequencies. To properly retrieve the faradaic current density from the ac-modulated optical signal, we introduce here a mathematical formalism that (i) accounts for intrinsic changes that invariably occur in the optical baseline of the EA-IOW device during potential modulation and (ii) provides accurate results for the electro-chemical parameters. We are able to optically reconstruct the faradaic current density profile against the dc bias potential in the working electrode, identify the formal potential, and determine the energy-width of the electron-transfer process. In addition, by combining the optically reconstructed faradaic signal with simple electrical measurements of impedance across the whole electrochemical cell and the capacitance of the electric double-layer, we are able to determine the time-constant connected to the redox reaction of the adsorbed protein assembly. For cytochrome c directly immobilized onto the indium tin oxide (ITO) surface, we measured a reaction rate constant of 26.5 s(-1). Finally, we calculate the charge-transfer resistance and pseudocapacitance associated with the electron-transfer process and show that the frequency dependence of the redox reaction of the protein submonolayer follows as expected the electrical equivalent of an RC-series admittance diagram. Above all, we show here that OIS with single-mode EA-IOW's provide strong analytical signals that can be readily monitored even for small surface-densities of species involved in the redox

  5. Geometry Effects on Multipole Components and Beam Optics in High-Velocity Multi-Spoke Cavities

    SciTech Connect

    Hopper, Christopher S.; Deitrick, Kirsten E.; Delayen, Jean R.

    2013-12-01

    Velocity-of-light, multi-spoke cavities are being proposed to accelerate electrons in a compact light-source. There are strict requirements on the beam quality which require that the linac have only small non-uniformities in the accelerating field. Beam dynamics simulations have uncovered varying levels of focusing and defocusing in the proposed cavities, which is dependent on the geometry of the spoke in the vicinity of the beam path. Here we present results for the influence different spoke geometries have on the multipole components of the accelerating field and how these components, in turn, impact the simulated beam properties.

  6. A COMPREHENSIVE STUDY OF GAMMA-RAY BURST OPTICAL EMISSION. II. AFTERGLOW ONSET AND LATE RE-BRIGHTENING COMPONENTS

    SciTech Connect

    Liang Enwei; Li Liang; Liang Yunfeng; Tang Qingwen; Chen Jiemin; Lu Ruijing; Lue Lianzhong; Gao He; Zhang, Bing; Lue Houjun; Wu Xuefeng; Yi Shuangxi; Dai Zigao; Zhang Jin; Wei Jianyan E-mail: zhang@physics.unlv.edu

    2013-09-01

    We continue our systematic statistical study of various components of gamma-ray burst (GRB) optical light curves. We decompose the early onset bump and the late re-brightening bump with empirical fits and analyze their statistical properties. Among the 146 GRBs that have well-sampled optical light curves, the onset and re-brightening bumps are observed in 38 and 26 GRBs, respectively. It is found that the typical rising and decaying slopes for both the onset and re-brightening bumps are {approx}1.5 and {approx} - 1.15, respectively. No early onset bumps in the X-ray band are detected to be associated with the optical onset bumps, while an X-ray re-brightening bump is detected for half of the re-brightening optical bumps. The peak luminosity is anti-correlated with the peak time L{sub p}{proportional_to}t{sub p}{sup -1.81{+-}0.32} for the onset bumps and L{sub p}{proportional_to}t{sub p}{sup -0.83{+-}0.17} for the re-brightening bumps. Both L{sub p} and the isotropic energy release of the onset bumps are correlated with E{sub {gamma},iso}, whereas no similar correlation is found for the re-brightening bumps. These results suggest that the afterglow onset bumps are likely due to the deceleration of the GRB fireballs. Taking the onset bumps as probes for the properties of the fireballs and their ambient medium, we find that the typical power-law index of the relativistic electrons is 2.5 and the medium density profile behaves as n{proportional_to}r {sup -1} within the framework of the synchrotron external shock models. With the medium density profile obtained from our analysis, we also confirm the correlation between the initial Lorentz factor ({Gamma}{sub 0}) and E{sub iso,{gamma}} in our previous work. The jet component that produces the re-brightening bump seems to be on-axis and independent of the prompt emission jet component. Its typical kinetic energy budget would be about one order of magnitude larger than the prompt emission component, but with a lower {Gamma

  7. Research strategy for the electro-optics sensors domain of the Materials and Components for Missiles Innovative Technology Partnership

    NASA Astrophysics Data System (ADS)

    Bray, Mark; Panella, Isabella

    2010-04-01

    We describe the Materials and Components for Missile (MCM) Innovation and Technology Partnership (ITP) programme. The MCM - ITP is an Anglo-French research programme started in 2007 to encourage early stage research in future weapons technology. SELEX Galileo leads the domain related to the Electro-Optic Sensor within future guided weapons. Our objective is to capture cutting edge ideas in the research community and develop them for exploitation in future missile generations. We provide a view of two areas where we believe development of enhanced seeker capability should be focussed. Examples of current research within and outside the ITP that may be harnessed to deliver these capabilities are provided.

  8. Active control for vibration suppression in a flexible beam using a modal domain optical fiber sensor

    NASA Technical Reports Server (NTRS)

    Cox, D. E.; Lindner, D. K.

    1991-01-01

    An account is given of the use of a modal-domain (MD) fiber-optic sensor as an active control system component for vibration suppression, whose output is proportional to the integral of the axial strain along the optical fiber. When an MD sensor is attached to, or embedded in, a flexible structure, it senses the strain in the structure along its gage length. On the basis of the present integration of the sensor model into a flexible-structure model, it becomes possible to design a control system with a dynamic compensator which adds damping to the low-order modes of the flexible structure. This modeling procedure has been experimentally validated.

  9. Three-dimensional display utilizing a diffractive optical element and an active matrix liquid crystal display

    NASA Astrophysics Data System (ADS)

    Nordin, Gregory P.; Jones, Michael W.; Kulick, Jeffrey H.; Lindquist, Robert G.; Kowel, Stephen T.

    1996-12-01

    We describe the design, construction, and performance of the first real-time autostereoscopic 3D display based on the partial pixel 3D display architecture. The primary optical components of the 3D display are an active-matrix liquid crystal display and a diffractive optical element (DOE). The display operates at video frame rates and is driven with a conventional VGA signal. 3D animations with horizontal motion parallax are readily viewable as sets of stereo images. Formation of the virtual viewing slits by diffraction from the partial pixel apertures is experimentally verified. The measured contrast and perceived brightness of the display are excellent, but there are minor flaws in image quality due to secondary images. The source of these images and how they may be eliminated is discussed. The effects of manufacturing-related systematic errors in the DOE are also analyzed.

  10. Integration of magneto-optical active bismuth iron garnet on nongarnet substrates

    NASA Astrophysics Data System (ADS)

    Körner, Timo; Heinrich, Andreas; Weckerle, Martin; Roocks, Patrick; Stritzker, Bernd

    2008-04-01

    For optical communication, high quality magneto-optical active iron garnet films such as Y3Fe5O12 are important ceramic systems with extensive applications, e.g., as optical isolators [H. Dötsch et al., J. Opt. Soc. Am. B 22, 240 (2005)], optical modulators, etc. Thereby, garnets stand out due to their high Faraday rotation and low optical losses in the near infrared. Currently, it is desirable to integrate such macroscopic optical components on a single chip (Si, SiO2, etc.) to build up optical circuits as in the case of microelectronics (integrated optics) or the use for magneto-optical imaging. Up to now, Bi3Fe5O12 shows the highest Faraday rotation over 20°/μm. Unfortunately, Bi3Fe5O12 forms in a nonthermodynamical way. Thus, it can only be grown on garnet substrates which prevent it from direct deposition on substrates such as Si or SiO2. In our present work, we studied the integration of Bi3Fe5O12 on different SiO2 substrates using the pulsed laser deposition method. Therefore, we deposited an Y3Fe5O12 buffer first which was optimized in a postannealing step above 900°C in order to form a polycrystalline garnet phase, which is needed for further Bi3Fe5O12 growth. We measured the Faraday rotation of the double layered films and intensely studied them with x-ray diffraction, Rutherford backscattering spectroscopy, environmental scanning electron microscopy, and high-resolution transmission electron microscopy. The attained Faraday rotation can be compared with epitaxial Bi3Fe5O12 films grown on Gd3Ga5O12 substrates or even overcome them due to interference effects in the double layer. So they are highly attractive for magneto-optical imaging. For the determination of the film thicknesses which is usually done by Rutherford backscattering or profilometry, we used another approach. We measured the transmission spectra of the stack which we also derived from a theoretical model that uses a transfer matrix formalism. The thickness of the multilayer can be

  11. Ship-borne rotating shadowband radiometer observations for determination of components of spectral irradiance and aerosol optical properties

    NASA Astrophysics Data System (ADS)

    Walther, Jonas; Deneke, Hartwig; Macke, Andreas; Bernhard, Germar

    2015-04-01

    The Maritime Aerosol Network (MAN) has been established as a sub-project of AERONET and a long-term program to collect ship-borne aerosol optical depth measurements over ocean. Its purpose is to serve as reliable reference database for the evaluation of models and satellite products. Data are currently collected by handheld Microtops II photometers, as the automated acquisition of data from sun photometers on stabilized platforms is so far too expensive for wide-spread use. A promising alternative to the sun photometer is the rotating shadowband radiometer, whose principle of operation allows the determination of the direct-beam component of solar radiation without stabilizing the instrument, if the orientation of the detector horizontal is known. OCEANET, a project to investigate the exchange fluxes of energy and matter between the atmosphere and ocean, has contributed aerosol observations to MAN on several of its cruises on RV Polarstern during the transit between the hemispheres. On the recent cruise (PS 83) from Cape Town to Bremerhaven, TROPOS has operated for the first time a 19 channel rotating shadowband radiometer (GUVis-3511) built by the company Biospherical, as a possible means to provide automated irradiance and aerosol optical depth measurements. Calibration and processing of the raw data will be described, and an initial evaluation of the instrumental performance will be given. Aerosol optical depths derived from Microtops II measurements and the rotating shadowband radiometer will be compared. We show that the standard deviation of Aerosol optical depths observed with Microtops II and the shadowband radiometer is about 0.02 for matching channels, and an aerosol type classification based on Angstrom exponent shows good agreement. Also the influence of ship smoke and ocean swell is studied. The suitability of the instrument to automate MAN observations is discussed, and an outlook to the use of the instrument to also derive cloud optical properties is

  12. Optical Emission Line Studies and the Warm, Ionized Component of the Local Interstellar Medium

    NASA Technical Reports Server (NTRS)

    Reynolds, R. J.

    1984-01-01

    Observations of diffuse, galactic H alpha, N2 lambda 6583, and S2 6716 emission lines provide evidence for a warm (10,000K), primarily ionized component of the interstellar medium distribution throughout the galactic disk. This component of the interstellar gas has an electron density approximately equals 0.1-0.2/cu cm and occupies about 10 to 30% of the interstellar volume. Interstellar H alpha emission near the galactic poles, the dispersion measure of a nearby pulsar, and observations of interstellar gas flowing into the solar system indicate that this ionized component is an important constituent of the interstellar medium in the solar neighborhood. The intensity of the H alpha background at high galactic latitudes implies that this component is maintained by an average hydrogen ionization rate in the vicinity of the Sun of (2-4) x 100,000 s(-1) per square cm of galactic disk. The emission measure is 1.3 to 2.3 cm (-6) pc toward the galactic poles. The sources of this ionization were not identified but may include escaping Lyman continuum radiation from planetary nebulae, hot white dwarfs, and early type stars.

  13. Bioactive Components of Chinese Propolis Water Extract on Antitumor Activity and Quality Control.

    PubMed

    Xuan, Hongzhuan; Wang, Yuehua; Li, Aifeng; Fu, Chongluo; Wang, Yuanjun; Peng, Wenjun

    2016-01-01

    To understand the material basis of antitumor activity of Chinese propolis water extract (CPWE), we developed a simple and efficient method using macroporous absorptive resin coupled with preparative high performance liquid chromatography and separated and purified eleven chemical components (caffeic acid, ferulic acid, isoferulic acid, 3,4-dimethoxycinnamic acid, pinobanksin, caffeic acid benzyl ester, caffeic acid phenethyl ester, apigenin, pinocembrin, chrysin, and galangin) from CPWE; then we tested the antitumor activities of these eleven components using different human tumor cell lines (MCF-7, MDA-MB-231, HeLa, and A549). Furthermore, cell migration, procaspase 3 level, and reactive oxygen species (ROS) of effective components from CPWE were investigated. Our data showed that antitumor activities of the eleven components from CPWE were different from each other. CPWE and its effective components induced apoptosis by inhibiting tumor cell migration, activating caspase 3, and promoting ROS production. It can be deduced that the antitumor effects of propolis did not depend on a single component, and there must exist "bioactive components," which also provides a new idea for Chinese propolis quality control. PMID:27123037

  14. Bioactive Components of Chinese Propolis Water Extract on Antitumor Activity and Quality Control

    PubMed Central

    Xuan, Hongzhuan; Wang, Yuehua; Li, Aifeng; Fu, Chongluo; Wang, Yuanjun; Peng, Wenjun

    2016-01-01

    To understand the material basis of antitumor activity of Chinese propolis water extract (CPWE), we developed a simple and efficient method using macroporous absorptive resin coupled with preparative high performance liquid chromatography and separated and purified eleven chemical components (caffeic acid, ferulic acid, isoferulic acid, 3,4-dimethoxycinnamic acid, pinobanksin, caffeic acid benzyl ester, caffeic acid phenethyl ester, apigenin, pinocembrin, chrysin, and galangin) from CPWE; then we tested the antitumor activities of these eleven components using different human tumor cell lines (MCF-7, MDA-MB-231, HeLa, and A549). Furthermore, cell migration, procaspase 3 level, and reactive oxygen species (ROS) of effective components from CPWE were investigated. Our data showed that antitumor activities of the eleven components from CPWE were different from each other. CPWE and its effective components induced apoptosis by inhibiting tumor cell migration, activating caspase 3, and promoting ROS production. It can be deduced that the antitumor effects of propolis did not depend on a single component, and there must exist “bioactive components,” which also provides a new idea for Chinese propolis quality control. PMID:27123037

  15. Use of rigorous vector coupled-wave theory for designing and tolerancing surface-relief diffractive components for magneto-optical heads

    NASA Technical Reports Server (NTRS)

    Haggans, Charles W.; Kostuk, Raymond K.

    1991-01-01

    A rigorous coupled wave model is presented, experimentally validated, and used for tolerancing surface relief diffractive elements. Applications of the model in the design and tolerancing of components for magneto optical (M-O) data storage heads are investigated.

  16. Fiber Optic Sensor Components and Systems for Smart Materials and Structures

    NASA Technical Reports Server (NTRS)

    Lyons, R.

    1999-01-01

    The general objective of the funded research effort has been the development of discrete and distributed fiber sensors and fiber optic centered opto-electronic networks for the intelligent monitoring of phenomena in various aerospace structures related to NASA Marshall specific applications. In particular, we have proposed and have been developing technologies that we believe to be readily transferrable and which involve new fabrication techniques. The associated sensors developed can be incorporated into the matrix or on the surfaces of structures for the purpose of sensing stress, strain, temperature-both low and high, pressure field variations, phase changes, and the presence of various chemical constituents.

  17. Pointing, acquisition and tracking (PAT) subsystems and components for optical space communication systems

    NASA Astrophysics Data System (ADS)

    Kern, R. H.; Kugel, U.

    1989-10-01

    The pointing, acquisition, and tracking (PAT) subsystem that will be incorporated by optical space communications transceivers must furnish very precise beam steering due to the highly collimated nature of the laser beams employed. The PAT subsystem must also be able to cover an angular rate of more than a full hemisphere, if it is intended for use on a LEO satellite which communicates with another in GEO. The present PAT is composed of a coarse-pointing assembly, a fine-pointing assembly, and a point-ahead assembly; their interactive operation is managed by a control law electronics unit. A CO2 laser is assumed to be the transmitter.

  18. Radiation hardness of optoelectronic components for the optical readout of the ATLAS inner detector

    NASA Astrophysics Data System (ADS)

    Hou, S.; Ishii, K.; Itoh, M.; Sakemi, Y.; Su, D. S.; Su, T. T.; Teng, P. K.; Yoshida, H. P.

    2011-04-01

    Optical links are used for data transmission of the ATLAS inner detector in a radiation hazard environment at the Large Hadron Collider (LHC). The radiation tolerance is studied for the opto-electronics of GaAs VCSEL and epitaxial Si PIN with 30 and 70 MeV protons at CYRIC. High speed Si and GaAs PIN photo-diodes are also investigated for upgrade to super-LHC. The annealing of GaAs VCSEL by charge injection is characterized. The GaAs devices show approximately linear degradations to fluence. The dependence on proton energy is compared to the Non-Ionizing Energy Loss calculations.

  19. Enzymatic aerobic ring rearrangement of optically active furylcarbinols.

    PubMed

    Thiel, Daniel; Doknić, Diana; Deska, Jan

    2014-01-01

    Biogenic furans are currently discussed as highly attractive alternative feedstock in a post-fossil society; thus, also the creation of sustainable furan valorization pathways appears of great importance. Here an artificial Achmatowicz monooxygenase activity for the aerobic ring expansion of furans is achieved by the combination of commercial glucose oxidase as oxygen-activating biocatalyst and wild-type chloroperoxidase as oxygen-transfer mediator, providing a biological ready-to-use solution for this truly synthetic furan rearrangement. In concert with enzymatic transformations for the enantioselective preparation of optically active furylcarbinols, purely biocatalytic reaction cascades for the stereocontrolled construction of complex pyranones are obtained, exhibiting high functional group tolerance even to oxidation-sensitive moieties. PMID:25335580

  20. Active Star Configured Fiber Optic CSMA/CD LANs

    NASA Astrophysics Data System (ADS)

    Truman, Alan K.; Smith, Robert W.; Schmidt, Ronald V.

    1987-01-01

    The widespread use of the IEEE 802.3 CSMA/CD (Ethernet) Local Area Network (LAN) has created demand for a fiber optic physical layer implementation to address security issues, hostile electromagnetic environments, modern structured wiring requirements and distance limitations of coaxial based implementations. Active Star CSMA/CD LANs will be described in this paper which consist of a central wiring Concentrator which supports point to point fiber links to Media Access Units (Transceivers) located at the Host computers. The fiber optic Active Star configured CSMA/CD LAN implementation provides a robust network which meets all the requirements imposed on an Ethernet Physical Layer. Collision detection is reliably performed in the electrical domain of the Concentrator. Network requirements included guaranteed collision detection, network reliability and easy addition and rearrangement of host connections. In addition, the Active Star implementation can provide an increased network diameter to 4.2 km and can support the four basic multimode fiber types, simultaneously, with substantial system margins.

  1. (Bio)hybrid materials based on optically active particles

    NASA Astrophysics Data System (ADS)

    Reitzig, Manuela; Härtling, Thomas; Opitz, Jörg

    2014-03-01

    In this contribution we provide an overview of current investigations on optically active particles (nanodiamonds, upconversion phospors) for biohybrid and sensing applications. Due to their outstanding properties nanodiamonds gain attention in various application elds such as microelectronics, optical monitoring, medicine, and biotechnology. Beyond the typical diamond properties such as high thermal conductivity and extreme hardness, the carbon surface and its various functional groups enable diverse chemical and biological surface functionalization. At Fraunhofer IKTS-MD we develop a customization of material surfaces via integration of chemically modi ed nanodiamonds at variable surfaces, e.g bone implants and pipelines. For the rst purpose, nanodiamonds are covalently modi ed at their surface with amino or phosphate functionalities that are known to increase adhesion to bone or titanium alloys. The second type of surface is approached via mechanical implementation into coatings. Besides nanodiamonds, we also investigate the properties of upconversion phosphors. In our contribution we show how upconversion phosphors are used to verify sterilization processes via a change of optical properties due to sterilizing electron beam exposure.

  2. Using DFT Methods to Study Activators in Optical Materials

    SciTech Connect

    Du, Mao-Hua

    2015-08-17

    Density functional theory (DFT) calculations of various activators (ranging from transition metal ions, rare-earth ions, ns2 ions, to self-trapped and dopant-bound excitons) in phosphors and scintillators are reviewed. As a single-particle ground-state theory, DFT calculations cannot reproduce the experimentally observed optical spectra, which involve transitions between multi-electronic states. However, DFT calculations can generally provide sufficiently accurate structural relaxation and distinguish different hybridization strengths between an activator and its ligands in different host compounds. This is important because the activator-ligand interaction often governs the trends in luminescence properties in phosphors and scintillators, and can be used to search for new materials. DFT calculations of the electronic structure of the host compound and the positions of the activator levels relative to the host band edges in scintillators are also important for finding optimal host-activator combinations for high light yields and fast scintillation response. Mn4+ activated red phosphors, scintillators activated by Ce3+, Eu2+, Tl+, and excitons are shown as examples of using DFT calculations in phosphor and scintillator research.

  3. Using DFT Methods to Study Activators in Optical Materials

    DOE PAGES

    Du, Mao-Hua

    2015-08-17

    Density functional theory (DFT) calculations of various activators (ranging from transition metal ions, rare-earth ions, ns2 ions, to self-trapped and dopant-bound excitons) in phosphors and scintillators are reviewed. As a single-particle ground-state theory, DFT calculations cannot reproduce the experimentally observed optical spectra, which involve transitions between multi-electronic states. However, DFT calculations can generally provide sufficiently accurate structural relaxation and distinguish different hybridization strengths between an activator and its ligands in different host compounds. This is important because the activator-ligand interaction often governs the trends in luminescence properties in phosphors and scintillators, and can be used to search for new materials.more » DFT calculations of the electronic structure of the host compound and the positions of the activator levels relative to the host band edges in scintillators are also important for finding optimal host-activator combinations for high light yields and fast scintillation response. Mn4+ activated red phosphors, scintillators activated by Ce3+, Eu2+, Tl+, and excitons are shown as examples of using DFT calculations in phosphor and scintillator research.« less

  4. All-optical video-image encryption with enforced security level using independent component analysis

    NASA Astrophysics Data System (ADS)

    Alfalou, A.; Mansour, A.

    2007-10-01

    In the last two decades, wireless communications have been introduced in various applications. However, the transmitted data can be, at any moment, intercepted by non-authorized people. That could explain why data encryption and secure transmission have gained enormous popularity. In order to secure data transmission, we should pay attention to two aspects: transmission rate and encryption security level. In this paper, we address these two aspects by proposing a new video-image transmission scheme. This new system consists in using the advantage of optical high transmission rate and some powerful signal processing tools to secure the transmitted data. The main idea of our approach is to secure transmitted information at two levels: at the classical level by using an adaptation of standard optical techniques and at a second level (spatial diversity) by using independent transmitters. In the second level, a hacker would need to intercept not only one channel but all of them in order to retrieve information. At the receiver, we can easily apply ICA algorithms to decrypt the received signals and retrieve information.

  5. Epitaxial superlattices with titanium nitride as a plasmonic component for optical hyperbolic metamaterials.

    PubMed

    Naik, Gururaj V; Saha, Bivas; Liu, Jing; Saber, Sammy M; Stach, Eric A; Irudayaraj, Joseph M K; Sands, Timothy D; Shalaev, Vladimir M; Boltasseva, Alexandra

    2014-05-27

    Titanium nitride (TiN) is a plasmonic material having optical properties resembling gold. Unlike gold, however, TiN is complementary metal oxide semiconductor-compatible, mechanically strong, and thermally stable at higher temperatures. Additionally, TiN exhibits low-index surfaces with surface energies that are lower than those of the noble metals which facilitates the growth of smooth, ultrathin crystalline films. Such films are crucial in constructing low-loss, high-performance plasmonic and metamaterial devices including hyperbolic metamaterials (HMMs). HMMs have been shown to exhibit exotic optical properties, including extremely high broadband photonic densities of states (PDOS), which are useful in quantum plasmonic applications. However, the extent to which the exotic properties of HMMs can be realized has been seriously limited by fabrication constraints and material properties. Here, we address these issues by realizing an epitaxial superlattice as an HMM. The superlattice consists of ultrasmooth layers as thin as 5 nm and exhibits sharp interfaces which are essential for high-quality HMM devices. Our study reveals that such a TiN-based superlattice HMM provides a higher PDOS enhancement than gold- or silver-based HMMs. PMID:24821762

  6. Epitaxial superlattices with titanium nitride as a plasmonic component for optical hyperbolic metamaterials

    PubMed Central

    Naik, Gururaj V.; Saha, Bivas; Liu, Jing; Saber, Sammy M.; Stach, Eric A.; Irudayaraj, Joseph M. K.; Sands, Timothy D.; Shalaev, Vladimir M.; Boltasseva, Alexandra

    2014-01-01

    Titanium nitride (TiN) is a plasmonic material having optical properties resembling gold. Unlike gold, however, TiN is complementary metal oxide semiconductor-compatible, mechanically strong, and thermally stable at higher temperatures. Additionally, TiN exhibits low-index surfaces with surface energies that are lower than those of the noble metals which facilitates the growth of smooth, ultrathin crystalline films. Such films are crucial in constructing low-loss, high-performance plasmonic and metamaterial devices including hyperbolic metamaterials (HMMs). HMMs have been shown to exhibit exotic optical properties, including extremely high broadband photonic densities of states (PDOS), which are useful in quantum plasmonic applications. However, the extent to which the exotic properties of HMMs can be realized has been seriously limited by fabrication constraints and material properties. Here, we address these issues by realizing an epitaxial superlattice as an HMM. The superlattice consists of ultrasmooth layers as thin as 5 nm and exhibits sharp interfaces which are essential for high-quality HMM devices. Our study reveals that such a TiN-based superlattice HMM provides a higher PDOS enhancement than gold- or silver-based HMMs. PMID:24821762

  7. Subsurface damage of optical components and the influence on scattering properties

    NASA Astrophysics Data System (ADS)

    Draheim, Falk; Harnisch, Bernd; Weigel, Thomas

    1994-09-01

    The influence ofsurface damage under smooth optical surfaces on the scattering properties was investigated. Usually thissurface damage is filled and covered by a polishing layer. Thereforesurface damage does not contribute to the micro roughness of the surface. Three glasses, SF3, BK7, and SUPRASIL, with different Knoop hardness and related differentsurface damage density were chosen for the measurements. Three samples of each glass were polished with increasing polishing time in order to reduce the layer which contains thesurface damage. Beside the extensive measurements of the scatter behavior the samples were also investigated by means of microscopy (Nomarski, darkfield, cross polarization) and optical profilometry. The stray light was detected in the case of reflection (back scatter), transmission (forward scatter) and total reflection. In the case of totalreflection the scattered light behind the reflection surface was investigated. The detected scatter light was integrated over the measurement range and the resulting value was compared with the polishing time. Additional investigations were carried out to determine the influence on the light polarization.

  8. Zeno inhibition of polarization rotation in an optically active medium

    NASA Astrophysics Data System (ADS)

    Gonzalo, Isabel; Porras, Miguel A.; Luis, Alfredo

    2015-07-01

    We describe an experiment in which the rotation of the polarization of light propagating in an optically active water solution of D-fructose tends to be inhibited by frequent monitoring whether the polarization remains unchanged. This is an example of the Zeno effect that has remarkable pedagogical interest because of its conceptual simplicity, easy implementation, low cost, and because the same the Zeno effect holds at classical and quantum levels. An added value is the demonstration of the Zeno effect beyond typical idealized assumptions in a practical setting with real polarizers.

  9. Heritability of ocular component dimensions in mice phenotyped using depth-enhanced swept source optical coherence tomography.

    PubMed

    Wang, Ling; Považay, Boris; Chen, Yen Po; Hofer, Bernd; Drexler, Wolfgang; Guggenheim, Jeremy A

    2011-10-01

    The range of genetic and genomic resources available makes the mouse a powerful model for the genetic dissection of complex traits. Because accurate, high-throughput phenotypic characterisation is crucial to the success of such endeavours, we recently developed an optical coherence tomography (OCT) system with extended depth range scanning capability for measuring ocular component dimensions in mice. In order to test whether the accuracy and reproducibility of our OCT system was sufficient for gene mapping studies, we carried out an experiment designed to estimate the heritability of mouse ocular component dimensions. High-resolution, two dimensional tomograms were obtained for both eyes of 11 pairs of 8 week-old outbred MF1 mice. Subsequently, images were obtained when their offspring were aged 8 weeks. Biometric data were extracted after image segmentation, reconstruction of the geometric shape of each surface, and calculation of intraocular distances. The repeatability of measurements was evaluated for 12 mice scanned on consecutive days. Heritability estimates were calculated using variance components analysis. Sets of tomograms took ∼2 s to acquire. Biometric data could be obtained for 98% of the 130 eyes scanned. The 95% limits of repeatability ranged from ±6 to ±16 μm for the axial ocular component dimensions. The heritability of the axial ocular components was 0.6-0.8, except for corneal thickness, which had a heritability not significantly different from zero. In conclusion, axial ocular component dimensions are highly heritable in mice, as they are in humans. OCT with extended depth range scanning can be used to rapidly phenotype individual mice with sufficient accuracy and precision to permit gene mapping studies.

  10. Calculation of optical second-harmonic susceptibilities and optical activity for crystals

    SciTech Connect

    Levine, Z.H.

    1994-12-31

    A new generation of nearly first-principles calculations predicts both the linear and second-harmonic susceptibilities for a variety of insulating crystals, including GaAs, GaP, AlAs, AlP, Se, {alpha}-quartz, and c-urea. The results are typically in agreement with experimental measurements. The calculations have been extended to optical activity, with somewhat less success to date. The theory, based on a simple self-energy correction to the local density approximation, and results are reviewed herein.

  11. Finite Temperature Properties of Three-Component Fermion Systems in Optical Lattice

    NASA Astrophysics Data System (ADS)

    Yanatori, Hiromasa; Koga, Akihisa

    2016-01-01

    We investigate finite temperature properties in the half-filled three-component (colors) fermion systems. It is clarified that a color density-wave (CDW) state is more stable than a color-selective "antiferromagnetic" (CSAF) state against thermal fluctuations. The reentrant behavior in the phase boundary for the CSAF state is found. We also address the maximum critical temperature of the translational symmetry breaking states in the multicomponent fermionic systems.

  12. 3(omega) damage threshold evaluation of final optics components using Beamlet mule and off-line testing

    SciTech Connect

    Kozlowski, M.F.; Maricle, S.; Mouser, R.; Schwartz, S.; Wegner, P.; Weiland, T.

    1998-07-27

    A statistics-based model is being developed to predict the laser-damage-limited lifetime of UV optical components on the NIF laser. In order to provide data for the model, laser damage experiments were performed on the Beamlet laser system at LLNL. An early prototype NIF focus lens was exposed to twenty 35 1 nm pulses at an average fluence of 5 J/cm{sup 2}, 3ns. Using a high resolution optic inspection system a total of 353 damage sites was detected within the 1160 cm{sup 2} beam aperture. Through inspections of the lens before, after and, in some cases, during the campaign, pulse to pulse damage growth rates were measured for damage initiating both on the surface and at bulk inclusions. Growth rates as high as 79 {micro}m/pulse (surface diameter) were observed for damage initiating at pre-existing scratches in the surface. For most damage sites on the optic, both surface and bulk, the damage growth rate was approximately l0{micro}m/pulse. The lens was also used in Beamlet for a subsequent 1053 {micro}m/526 {micro}m campaign. The 352 {micro}m-initiated damage continued to grow during that campaign although at generally lower growth rate.

  13. Active mode-locked lasers and other photonic devices using electro-optic whispering gallery mode resonators

    NASA Technical Reports Server (NTRS)

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

    2006-01-01

    Techniques and devices using whispering gallery mode (WGM) optical resonators, where the optical materials of the WGM resonators exhibit an electro-optical effect to perform optical modulation. Examples of actively mode-locked lasers and other devices are described.

  14. Interferon-mediated antiviral activities of Angelica tenuissima Nakai and its active components.

    PubMed

    Weeratunga, Prasanna; Uddin, Md Bashir; Kim, Myun Soo; Lee, Byeong-Hoon; Kim, Tae-Hwan; Yoon, Ji-Eun; Ma, Jin Yeul; Kim, Hongik; Lee, Jong-Soo

    2016-01-01

    Angelica tenuissima Nakai is a widely used commodity in traditional medicine. Nevertheless, no study has been conducted on the antiviral and immune-modulatory properties of an aqueous extract of Angelica tenuissima Nakai. In the present study, we evaluated the antiviral activities and the mechanism of action of an aqueous extract of Angelica tenuissima Nakai both in vitro and in vivo. In vitro, an effective dose of Angelica tenuissima Nakai markedly inhibited the replication of Influenza A virus (PR8), Vesicular stomatitis virus (VSV), Herpes simplex virus (HSV), Coxsackie virus, and Enterovirus (EV-71) on epithelial (HEK293T/HeLa) and immune (RAW264.7) cells. Such inhibition can be described by the induction of the antiviral state in cells by antiviral, IFNrelated gene induction and secretion of IFNs and pro-inflammatory cytokines. In vivo, Angelica tenuissima Nakai treated BALB/c mice displayed higher survivability and lower lung viral titers when challenged with lethal doses of highly pathogenic influenza A subtypes (H1N1, H5N2, H7N3, and H9N2). We also found that Angelica tenuissima Nakai can induce the secretion of IL-6, IFN-λ, and local IgA in bronchoalveolar lavage fluid (BALF) of Angelica tenuissima Nakai treated mice, which correlating with the observed prophylactic effects. In HPLC analysis, we found the presence of several compounds in the aqueous fraction and among them; we evaluated antiviral properties of ferulic acid. Therefore, an extract of Angelica tenuissima Nakai and its components, including ferulic acid, play roles as immunomodulators and may be potential candidates for novel anti-viral/anti-influenza agents.

  15. Using Indices of Fidelity to Intervention Core Components to Identify Program Active Ingredients

    ERIC Educational Resources Information Center

    Abry, Tashia; Hulleman, Chris S.; Rimm-Kaufman, Sara E.

    2015-01-01

    Identifying the active ingredients of an intervention--intervention-specific components serving as key levers of change--is crucial for unpacking the intervention black box. Measures of intervention fidelity can be used to identify specific active ingredients, yet such applications are rare. We illustrate how fidelity measures can be used to…

  16. The Connective Tissue Components of Optic Nerve Head Cupping in Monkey Experimental Glaucoma Part 1: Global Change

    PubMed Central

    Yang, Hongli; Ren, Ruojin; Lockwood, Howard; Williams, Galen; Libertiaux, Vincent; Downs, Crawford; Gardiner, Stuart K.; Burgoyne, Claude F.

    2015-01-01

    Purpose To characterize optic nerve head (ONH) connective tissue change within 21 monkey experimental glaucoma (EG) eyes, so as to identify its principal components. Methods Animals were imaged three to five times at baseline then every 2 weeks following chronic unilateral IOP elevation, and euthanized early through end-stage confocal scanning laser tomographic change. Optic nerve heads were serial-sectioned, three-dimensionally (3D) reconstructed, delineated, and quantified. Overall EG versus control eye differences were assessed by general estimating equations (GEE). Significant, animal-specific, EG eye change was required to exceed the maximum physiologic intereye differences in six healthy animals. Results Overall EG eye change was significant (P < 0.0026) and animal-specific EG eye change most frequent, for five phenomena (number of EG eyes and range of animal-specific change): posterior laminar deformation (21, −29 to −437 μm), laminar thickening (11, 20–73 μm) and thinning (3, −23 to −31 μm), scleral canal expansion (17, 20–139 μm), outward anterior (16, −16 to −124 μm) and posterior (17, −22 to −279 μm) laminar insertion migration, and peripapillary scleral bowing (11, 21–77 μm). Experimental glaucoma versus control eye laminar thickness differences were bimodal in behavior, being thickened in most EG eyes demonstrating the least deformation and less thickened or thinned in most EG eyes demonstrating the greatest deformation. Conclusions Our postmortem studies retrospectively identify five connective tissue components of ONH “cupping” in monkey EG which serve as targets for longitudinally staging and phenotyping ONH connective tissue alteration within all forms of monkey and human optic neuropathy. PMID:26641545

  17. Optical Measurement Techniques for Rocket Engine Testing and Component Applications: Digital Image Correlation and Dynamic Photogrammetry

    NASA Technical Reports Server (NTRS)

    Gradl, Paul

    2016-01-01

    NASA Marshall Space Flight Center (MSFC) has been advancing dynamic optical measurement systems, primarily Digital Image Correlation, for extreme environment rocket engine test applications. The Digital Image Correlation (DIC) technology is used to track local and full field deformations, displacement vectors and local and global strain measurements. This technology has been evaluated at MSFC through lab testing to full scale hotfire engine testing of the J-2X Upper Stage engine at Stennis Space Center. It has been shown to provide reliable measurement data and has replaced many traditional measurement techniques for NASA applications. NASA and AMRDEC have recently signed agreements for NASA to train and transition the technology to applications for missile and helicopter testing. This presentation will provide an overview and progression of the technology, various testing applications at NASA MSFC, overview of Army-NASA test collaborations and application lessons learned about Digital Image Correlation.

  18. Multilayer's birefringence and related optical components photo-induced by femtosecond laser in silica

    NASA Astrophysics Data System (ADS)

    Lancry, M.; Desmarchelier, R.; Cook, K.; Canning, J.; Poumellec, B.

    2014-10-01

    Recently, we showed that femtosecond laser induced "nanogratings" consist of thin regions with a low refractive index (Δn = -0.15) due to the formation of nanoporous silica surrounded by regions with a positive index change. In this paper, we investigate a wide range of laser parameters to achieve the highest retardance value within a single layer of such gratings; i.e. 350 nm at λ = 546 nm. We show that the total retardance depends on the number of layers present and can be accumulated in the direction of laser propagation to values higher than 1600 nm. This opens the door to using these nanostructures as refined building blocks for novel optical elements based on strong retardance. Rotating their orientation means properties such as the slow axis orientation can be spatially varied in the propagation direction to make interesting structures akin to, for example, a twisted nematic liquid crystals in fused silica.

  19. Optical test bench for high precision metrology and alignment of zoom sub-assembly components

    NASA Astrophysics Data System (ADS)

    Leprêtre, F.; Levillain, E.; Wattellier, B.; Delage, P.; Brahmi, D.; Gascon, A.

    2013-09-01

    Thales Angénieux (TAGX) designs and manufactures zoom lens assemblies for cinema applications. These objectives are made of mobile lens assemblies. These need to be precisely characterized to detect alignment, polishing or glass index homogeneity errors, which amplitude may range to a few hundreds of nanometers. However these assemblies are highly aberrated with mainly spherical aberration (>30 μm PV). PHASICS and TAGX developed a solution based on the use of a PHASICS SID4HR wave front sensor. This is based on quadri-wave lateral shearing interferometry, a technology known for its high dynamic range. A 100-mm diameter He:Ne source illuminates the lens assembly entrance pupil. The transmitted wave front is then directly measured by the SID4- HR. The measured wave front (WFmeas) is then compared to a simulation from the lens sub-assembly optical design (WFdesign). We obtain a residual wave front error (WFmanufactured), which reveals lens imperfections due to its manufacturing. WFmeas=WFdesign+(WFEradius+WFEglass+WFEpolish)=WF design + WFmanufactured The optical test bench was designed so that this residual wave front is measured with a precision below 100 nm PV. The measurement of fast F-Number lenses (F/2) with aberrations up to 30 μm, with a precision of 100 nm PV was demonstrated. This bench detects mismatches in sub-assemblies before the final integration step in the zoom. Pre-alignment is also performed in order to overpass the mechanical tolerances. This facilitates the completed zoom alignment. In final, productivity gains are expected due to alignment and mounting time savings.

  20. Design of software and hardware components for a six-degrees of freedom optical position sensor

    SciTech Connect

    Garcia, F.N.

    1997-06-01

    This report summarizes the evaluation of a fully compatible and operational data acquisition system for a six-degrees of freedom optical sensor (SixDOF). The SixDOF, developed at Lawrence Livermore National Laboratory by Charles Vann, is capable of tracking an object`s position in all its six degrees of freedom without any datum specification by means of two reflective surfaces mounted on the object. To make the SixDOF operational and thus validate its underlying physics, a signal processing system has been designed so that information from the sensor is transferred accurately and efficiently to a computer. In addition, a six-degrees of freedom positioning stage has been built in efforts to calibrate the sensor in real time. A crucial design constraint is the necessity to build the complete data acquisition system so that it be small and most importantly portable. The prototype of the SixDOF system proved to be capable of crudely detecting changes in the position of an object in all six spatial degrees of freedom. An accuracy of around 0.5 mm is estimated presently even though the position of the two reflectors on the object is seen to significantly influence the accuracy of the sensor. The resolution of the sensor is not quite understood yet because of uncertainties in the actual spot size of the laser, however, field of the view has been seen to increase as the resolution decreases. The decoupling (calibration) of the sensor data proved to be rather successful although some coupling still exists. This coupling, however, is almost certain to come from the crudeness in the alignment of the optics within the sensor.

  1. Active Learning Strategies for Introductory Light and Optics

    NASA Astrophysics Data System (ADS)

    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 the characteristics of these curricula are: (1) use of a learning cycle in which students are challenged to compare predictions—discussed with their peers in small groups—to observations of the physical world, (2) use of guided hands-on work to construct basic concepts from observations, and (3) use of computer-based tools. It has been possible to change the lecture and laboratory learning environments at a large number of universities, colleges, and high schools without changing the structure of the introductory course. For example, in the United States, nearly 200 physics departments have adopted RTP, and many others use pre-publication, open-source versions or have adopted the RTP approach to develop their own labs. Examples from RTP and ILDs (including optics magic tricks) are described in this paper.

  2. Progress on the development of active micro-structured optical arrays for x-ray optics

    NASA Astrophysics Data System (ADS)

    Rodriguez Sanmartin, Daniel; Zhang, Dou; Button, Tim; Atkins, Carolyn; Doel, Peter; Wang, Hongchang; Brooks, David; Feldman, Charlotte; Willingale, Richard; Michette, Alan; Pfauntsch, Slawka; Sahraei, Shahin; Shand, Matthew; James, Ady; Dunare, Camelia; Stevenson, Tom; Parkes, William; Smith, Andy

    2009-08-01

    The Smart X-Ray Optics (SXO) project comprises a U.K.-based consortium developing active/adaptive micro-structured optical arrays (MOAs). These devices are designed to focus X-rays using grazing incidence reflection through consecutive aligned arrays of microscopic channels etched in silicon. The silicon channels have been produced both by dry and wet etching, the latter providing smoother channel walls. Adaptability is achieved using piezoelectric actuators, which bend the device and therefore change its focal distance. We aim to achieve a 5 cm radius of curvature which can provide a suitable focal length using a tandem pair MOA configuration. Finite Element Analysis (FEA) modelling has been carried out for the optimization of the MOA device design, consider different types of actuators (unimorph, bimorph and active fibre composites), and different Si/piezoelectric absolute and relative thicknesses. Prototype devices have been manufactured using a Viscous Plastic Processing Process for the piezoelectric actuators and dry etched silicon channels, bonded together using a low shrinkage adhesive. Characterisation techniques have been developed in order to evaluate the device performance in terms of the bending of the MOA channels produced by the actuators. This paper evaluates the progress to date on the actuation of the MOAs, comparing FEA modelling with the results obtained for different prototype structures.

  3. Spatial Frequency Components of Images Modulate Neuronal Activity in Monkey Amygdala.

    PubMed

    Montes-Lourido, Pilar; Bermudez, M A; Romero, M C; Vicente, A F; Gonzalez, F

    2016-04-01

    Processing the spatial frequency components of an image is a crucial feature for visual perception, especially in recognition of faces. Here, we study the correlation between spatial frequency components of images of faces and neuronal activity in monkey amygdala while performing a visual recognition task. The frequency components of the images were analyzed using a fast Fourier transform for 40 spatial frequency ranges. We recorded 65 neurons showing statistically significant responses to at least one of the images used as a stimulus. A total of 37 of these neurons (n = 37) showed significant responses to at least three images, and in eight of them (8/37, 22%), we found a statistically significant correlation between neuron response and the modulus amplitude of at least one frequency range present in the images. Our results indicate that high spatial frequency and low spatial frequency components of images influence the activity of amygdala neurons.

  4. Default-Mode Network Activity Identified by Group Independent Component Analysis

    NASA Astrophysics Data System (ADS)

    Liu, Conghui; Zhuang, Jie; Peng, Danling; Yu, Guoliang; Yang, Yanhui

    Default-mode network activity refers to some regional increase in blood oxygenation level-dependent (BOLD) signal during baseline than cognitive tasks. Recent functional imaging studies have found co-activation in a distributed network of cortical regions, including ventral anterior cingulate cortex (vACC) and posterior cingulate cortex (PPC) that characterize the default mode of human brain. In this study, general linear model and group independent component analysis (ICA) were utilized to analyze the fMRI data obtained from two language tasks. Both methods yielded similar, but not identical results and detected a resting deactivation network at some midline regions including anterior and posterior cingulate cortex and precuneus. Particularly, the group ICA method segregated functional elements into two separate maps and identified ventral cingulate component and fronto-parietal component. These results suggest that these two components might be linked to different mental function during "resting" baseline.

  5. Assessment Of Mold-Design Dependent Textures In CIM-Components By Polarized Light Optical Texture Analysis (PLOTA)

    SciTech Connect

    Kern, Frank; Rauch, Johannes; Gadow, Rainer

    2007-04-07

    By thermoplastic ceramic injection moulding (CIM) ceramic components of high complexity can be produced in a large number of items at low dimensional tolerances. The cost advantage by the high degree of automation leads to an economical mass-production. The structure of injection-moulded components is determined by the form filling behaviour and viscosity of the feedstock, the machine parameters, the design of the mold and the gate design. With an adapted mold- and gate-design CIM-components without textures are possible. The ''Polarized Light Optical Texture analysis'' (PLOTA) makes it possible to inspect the components and detect and quantify the textures produced by a new mold. Based on the work of R. Fischer (2004) the PLOTA procedure was improved by including the possibility to measure the inclination angle and thus describe the orientation of the grains in three dimensions. Sampled thin sections of ceramic components are analysed under the polarization microscope and are brought in diagonal position. Pictures are taken with a digital camera. The pictures are converted in the L*a*b*- colour space and the crystals color values a* and b* in the picture are measured. The color values are compared with the values of a quartz wedge, which serves as universal standard. From the received values the inclination angle can be calculated relative to the microscope axis. It is possible to use the received data quantitatively e.g. for the FEM supported simulation of texture-conditioned divergences of mechanical values. Thus the injection molding parameters can be optimized to obtain improved mechanical properties.

  6. Assessment Of Mold-Design Dependent Textures In CIM-Components By Polarized Light Optical Texture Analysis (PLOTA)

    NASA Astrophysics Data System (ADS)

    Kern, Frank; Rauch, Johannes; Gadow, Rainer

    2007-04-01

    By thermoplastic ceramic injection moulding (CIM) ceramic components of high complexity can be produced in a large number of items at low dimensional tolerances. The cost advantage by the high degree of automation leads to an economical mass-production. The structure of injection-moulded components is determined by the form filling behaviour and viscosity of the feedstock, the machine parameters, the design of the mold and the gate design. With an adapted mold- and gate-design CIM-components without textures are possible. The "Polarized Light Optical Texture analysis" (PLOTA) makes it possible to inspect the components and detect and quantify the textures produced by a new mold. Based on the work of R. Fischer (2004) the PLOTA procedure was improved by including the possibility to measure the inclination angle and thus describe the orientation of the grains in three dimensions. Sampled thin sections of ceramic components are analysed under the polarization microscope and are brought in diagonal position. Pictures are taken with a digital camera. The pictures are converted in the L*a*b*- colour space and the crystals color values a* and b* in the picture are measured. The color values are compared with the values of a quartz wedge, which serves as universal standard. From the received values the inclination angle can be calculated relative to the microscope axis. It is possible to use the received data quantitatively e.g. for the FEM supported simulation of texture-conditioned divergences of mechanical values. Thus the injection molding parameters can be optimized to obtain improved mechanical properties.

  7. Physical Activity and Sedentary Behavior Associated with Components of Metabolic Syndrome among People in Rural China

    PubMed Central

    Xiao, Jing; Shen, Chong; Chu, Min J.; Gao, Yue X.; Xu, Guang F.; Huang, Jian P.; Xu, Qiong Q.; Cai, Hui

    2016-01-01

    Background Metabolic syndrome is prevalent worldwide and its prevalence is related to physical activity, race, and lifestyle. Little data is available for people living in rural areas of China. In this study we examined associations of physical activity and sedentary behaviors with metabolic syndrome components among people in rural China. Methods The Nantong Metabolic Syndrome Study recruited 13,505 female and 6,997 male participants between 2007 and 2008. Data of socio-demographic characteristics and lifestyle were collected. The associations of physical activity and sedentary behaviors with metabolic syndrome components were analyzed. Results Prevalence of metabolic syndrome was 21.6%. It was significantly lower in men than in women. Low risks of metabolic syndrome were observed in those who did less sitting and engaged in more vigorous physical activity. The highest tertile of vigorous physical activity was associated with 15–40% decreased odds of metabolic syndrome and all of its components, except for low high-density lipoprotein cholesterol in men. Women with the highest tertile of moderate physical activity had 15–30% lower odds of central obesity, high glucose, and high triglycerides compared with those in the lowest tertile. Sitting time >42 hours per week had a 4%-12% attributable risk of metabolic syndrome, central obesity, and high triglycerides in both genders, and abnormal glucose and diastolic blood pressure in women. Sleeping for more than 8 hours per day was associated with risk of high serum glucose and lipids. Conclusions Our data suggested that physical activity has a preventive effect against metabolic syndrome and all its abnormal components, and that longer sitting time and sleep duration are associated with an increased risk of metabolic syndrome components, including central obesity and high triglycerides, glucose, and diastolic blood pressure. This study could provide information for future investigation into these associations. Also

  8. Experience of handling beryllium, tritium and activated components from JET ITER like wall

    NASA Astrophysics Data System (ADS)

    Widdowson, A.; Baron-Wiechec, A.; Batistoni, P.; Belonohy, E.; Coad, J. P.; Dinca, P.; Flammini, D.; Fox, F.; Heinola, K.; Jepu, I.; Likonen, J.; Lilley, S.; Lungu, C. P.; Matthews, G. F.; Naish, J.; Pompilian, O.; Porosnicu, C.; Rubel, M.; Villari, R.; Contributors, JET

    2016-02-01

    JET components are removed periodically for surface analysis to assess material migration and fuel retention. This paper describes issues related to handling JET components and procedures for preparing samples for analysis; in particular a newly developed procedure for cutting beryllium tiles is presented. Consideration is also given to the hazards likely due to increased tritium inventory and material activation from 14 MeV neutrons following the planned TT and DT operations (DTE2) in 2017. Conclusions are drawn as to the feasibility of handling components from JET post DTE2.

  9. LONG-TERM OPTICAL CONTINUUM COLOR VARIABILITY OF NEARBY ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Sakata, Yu; Minezaki, Takeo; Yoshii, Yuzuru; Uchimoto, Yuka Katsuno; Sugawara, Shota; Kobayashi, Yukiyasu; Koshida, Shintaro; Aoki, Tsutomu; Tomita, Hiroyuki; Enya, Keigo; Suganuma, Masahiro

    2010-03-01

    We examine whether the spectral energy distribution of optical continuum emission of active galactic nuclei (AGNs) changes during flux variation, based on accurate and frequent monitoring observations of 11 nearby Seyfert galaxies and QSOs carried out in the B, V, and I bands for seven years by the MAGNUM telescope. The multi-epoch flux data in any two different bands obtained on the same night show a very tight linear flux-to-flux relationship for all target AGNs. The flux of the host galaxy within the photometric aperture is carefully estimated by surface brightness fitting to available high-resolution Hubble Space Telescope images and MAGNUM images. The flux of narrow emission lines in the photometric bands is also estimated from available spectroscopic data. We find that the non-variable component of the host galaxy plus narrow emission lines for all target AGNs is located on the fainter extension of the linear regression line of multi-epoch flux data in the flux-to-flux diagram. This result strongly indicates that the spectral shape of AGN continuum emission in the optical region ({approx}4400-7900 A) does not systematically change during flux variation. The trend of spectral hardening that optical continuum emission becomes bluer as it becomes brighter, which has been reported by many studies, is therefore interpreted as the domination of the variable component of the nearly constant spectral shape of an AGN as it brightens over the non-variable component of the host galaxy plus narrow lines, which is usually redder than AGN continuum emission.

  10. Spatial correspondence of brain alpha activity component in fMRI and EEG

    NASA Astrophysics Data System (ADS)

    Jeong, Jeong-Won; Kim, Sung-Heon; Singh, Manbir

    2005-04-01

    This paper presents a new approach to investigate the spatial correlation of brain alpha activity in functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). To avoid potential problems of simultaneous fMRI and EEG acquisitions in imaging brain alpha activity, data from each modality were acquired separately under a "three conditions" setup where one of the conditions involved closing eyes and relaxing, thus making it conducive to generation of alpha activity. The other two conditions -- eyes open in a lighted room or engaged in a mental arithmetic task, were designed to attenuate alpha activity. Using the Mixture Density Independent Component Analysis (MD-ICA) that incorporates flexible non-linearity functions into the conventional ICA framework, we could identify the spatiotemporal components of fMRI activations and EEG activities associated with the alpha rhythm. The sources of the individual EEG alpha activity component were localized by a Maximum Entropy (ME) method that solves an inverse problem in the framework of a classical four-sphere head model. The resulting dipole sources of EEG alpha activity were spatially transformed to 3D MRIs of the subject and compared to fMRI ICA-determined alpha activity maps.

  11. Resolving the spatial relationship between intracellular components by dual color super resolution optical fluctuations imaging (SOFI)

    PubMed Central

    Gallina, Maria Elena; Xu, Jianmin; Dertinger, Thomas; Aizer, Adva; Shav-Tal, Yaron; Weiss, Shimon

    2013-01-01

    Background Multi-color super-resolution (SR) imaging microscopy techniques can resolve ultrastructura relationships between- and provide co-localization information of- different proteins inside the cell or even within organelles at a higher resolution than afforded by conventional diffraction-limited imaging. While still very challenging, important SR colocalization results have been reported in recent years using STED, PALM and STORM techniques. Results In this work, we demonstrate dual-color Super Resolution Optical Fluctuations Imaging (SOFI) using a standard far-field fluorescence microscope and different color blinking quantum dots. We define the spatial relationship between hDcp1a, a processing body (P-body, PB) protein, and the tubulin cytoskeletal network. Our finding could open up new perspectives on the role of the cytoskeleton in PB formation and assembly. Further insights into PB internal organization are also reported and discussed. Conclusions Our results demonstrate the suitability and facile use of multi-color SOFI for the investigation of intracellular ultrastructures. PMID:24324919

  12. Joint representation of translational and rotational components of optic flow in parietal cortex.

    PubMed

    Sunkara, Adhira; DeAngelis, Gregory C; Angelaki, Dora E

    2016-05-01

    Terrestrial navigation naturally involves translations within the horizontal plane and eye rotations about a vertical (yaw) axis to track and fixate targets of interest. Neurons in the macaque ventral intraparietal (VIP) area are known to represent heading (the direction of self-translation) from optic flow in a manner that is tolerant to rotational visual cues generated during pursuit eye movements. Previous studies have also reported that eye rotations modulate the response gain of heading tuning curves in VIP neurons. We tested the hypothesis that VIP neurons simultaneously represent both heading and horizontal (yaw) eye rotation velocity by measuring heading tuning curves for a range of rotational velocities of either real or simulated eye movements. Three findings support the hypothesis of a joint representation. First, we show that rotation velocity selectivity based on gain modulations of visual heading tuning is similar to that measured during pure rotations. Second, gain modulations of heading tuning are similar for self-generated eye rotations and visually simulated rotations, indicating that the representation of rotation velocity in VIP is multimodal, driven by both visual and extraretinal signals. Third, we show that roughly one-half of VIP neurons jointly represent heading and rotation velocity in a multiplicatively separable manner. These results provide the first evidence, to our knowledge, for a joint representation of translation direction and rotation velocity in parietal cortex and show that rotation velocity can be represented based on visual cues, even in the absence of efference copy signals. PMID:27095846

  13. Direct measurements of mass-specific optical cross sections of single-component aerosol mixtures.

    PubMed

    Radney, James G; Ma, Xiaofei; Gillis, Keith A; Zachariah, Michael R; Hodges, Joseph T; Zangmeister, Christopher D

    2013-09-01

    The optical properties of atmospheric aerosols vary widely, being dependent upon particle composition, morphology, and mixing state. This diversity and complexity of aerosols motivates measurement techniques that can discriminate and quantify a variety of single- and multicomponent aerosols that are both internally and externally mixed. Here, we present a new combination of techniques to directly measure the mass-specific extinction and absorption cross sections of laboratory-generated aerosols that are relevant to atmospheric studies. Our approach employs a tandem differential mobility analyzer, an aerosol particle mass analyzer, cavity ring-down and photoacoustic spectrometers, and a condensation particle counter. This suite of instruments enables measurement of aerosol particle size, mass, extinction and absorption coefficients, and aerosol number density, respectively. Taken together, these observables yield the mass-specific extinction and absorption cross sections without the need to model particle morphology or account for sample collection artifacts. Here we demonstrate the technique in a set of case studies which involve complete separation of aerosol by charge, separation of an external mixture by mass, and discrimination between particle types by effective density and single-scattering albedo. PMID:23875772

  14. Optical Characterization of Component Wear and Near-Field Plasma of the Hermes Thruster

    NASA Technical Reports Server (NTRS)

    Williams, George J., Jr.; Kamhawi, Hani

    2015-01-01

    Optical emission spectral (OES) data are presented which correlate trends in sputtered species and the near-field plasma with the Hall-Effect Rocket with Magnetic Shielding (HERMeS) thruster operating condition. The relative density of singly-ionized xenon (Xe II) is estimated using a collisional-radiative model. OES data were collected at three radial and several axial locations downstream of the thruster's exit plane. These data were deconvolved to show the structure for the near-field plasma as a function of thruster operating condition. The magnetic field is shown to have a much greater affect on plasma structure than the discharge voltage with the primary ionization/acceleration zone boundary being similar for all nominal operating voltages at constant power. OES measurement of sputtered boron shows that the HERMeS thruster is magnetically shielded across its operating envelope. Preliminary assessment of carbon sputtered from the keeper face suggest it increases significantly with operating voltage, but the uncertainty associated with these measurements is very high.

  15. Multi-function optical characterization and inspection of MEMS components using stroboscopic coherence scanning interferometry

    NASA Astrophysics Data System (ADS)

    Tapilouw, Abraham Mario; Chen, Liang-Chia; Xuan-Loc, Nguyen; Chen, Jin-Liang

    2014-08-01

    A Micro-electro-mechanical-system (MEMS) is a widely used component in many industries, including energy, biotechnology, medical, communications, and automotive industries. However, effective inspection systems are also needed to ensure the functional reliability of MEMS. This study developed a stroboscopic coherence scanning Interferometry (SCSI) technique for measuring key characteristics typically used as criteria in MEMS inspections. Surface profiles of MEMS both static and dynamic conditions were measured by means of coherence scanning Interferometry (CSI). Resonant frequencies of vibrating MEMS were measured by deformation of interferogram fringes for out-of-plane vibration and by image correlation for in-plane vibration. The measurement bandwidth of the developed system can be tuned up to three megahertz or higher for both in-plane and out-of-plane measurement of MEMS.

  16. Optical quantal analysis reveals a presynaptic component of LTP at hippocampal Schaffer-associational synapses.

    PubMed

    Emptage, Nigel J; Reid, Christopher A; Fine, Alan; Bliss, Timothy V P

    2003-06-01

    The mechanisms by which long-term potentiation (LTP) is expressed are controversial, with evidence for both presynaptic and postsynaptic involvement. We have used confocal microscopy and Ca(2+)-sensitive dyes to study LTP at individual visualized synapses. Synaptically evoked Ca(2+) transients were imaged in distal dendritic spines of pyramidal cells in cultured hippocampal slices, before and after the induction of LTP. At most synapses, from as early as 10 min to at least 60 min after induction, LTP was associated with an increase in the probability of a single stimulus evoking a postsynaptic Ca(2+) response. These observations provide compelling evidence of a presynaptic component to the expression of early LTP at Schaffer-associational synapses. In most cases, the store-dependent evoked Ca(2+) transient in the spine was also increased after induction, a novel postsynaptic aspect of LTP.

  17. Optical Coating Performance for Heat Reflectors of the JWST-ISIM Electronic Component

    NASA Technical Reports Server (NTRS)

    Rashford, Robert A.; Perrygo, Charles M.; Garrison, Matthew B.; White, Bryant K.; Threat, Felix T.; Quijada, Manuel A.; Jeans, James W.; Huber, Frank K.; Bousquet, Robert R.; Shaw, Dave

    2011-01-01

    A document discusses a thermal radiator design consisting of lightweight composite materials and low-emittance metal coatings for use on the James Webb Space Telescope (JWST) structure. The structure will have a Thermal Subsystem unit to provide passive cooling to the Integrated Science Instrument Module (ISIM) control electronics. The ISIM, in the JWST observatory, is the platform that provides the mounting surfaces for the instrument control electronics. Dissipating the control electronic generated-heat away from JWST is of paramount importance so that the spacecraft s own heat does not interfere with the infrared-light gathering of distant cosmic sources. The need to have lateral control in the emission direction of the IEC (ISIM Electronics Compartment) radiators led to the development of a directional baffle design that uses multiple curved mirrorlike surfaces. This concept started out from the so-called Winston non-imaging optical concentrators that use opposing parabolic reflector surfaces, where each parabola has its focus at the opposite edge of the exit aperture. For this reason they are often known as compound parabolic concentrators or CPCs. This radiator system with the circular section was chosen for the IEC reflectors because it offers two advantages over other designs. The first is that the area of the reflector strips for a given radiator area is less, which results in a lower mass baffle assembly. Secondly, the fraction of energy emitted by the radiator strips and subsequently reflected by the baffle is less. These fewer reflections reduced the amount of energy that is absorbed and eventually re-emitted, typically in a direction outside the design emission range angle. A baffle frame holds the mirrors in position above a radiator panel on the IEC. Together, these will direct the majority of the heat from the IEC above the sunshield away towards empty space.

  18. Polyazomethine as a component of solar cells-theoretical and optical study

    NASA Astrophysics Data System (ADS)

    Korona, K. P.; Korona, T.; Rutkowska-Zbik, D.; Grankowska-Ciechanowicz, S.; Iwan, A.; Kamińska, M.

    2015-11-01

    A recently synthesized 25Th-cardo polyazomethine (PAZ) and its photocurrent generating junction with [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) have been examined as possible materials for construction of new-generation solar cells. Properties of a 25Th-cardo/PCBM system, where PAZ and PCBM act as donor and acceptor materials, respectively, have been studied theoretically by time-dependent density-functional theory (TD-DFT) and experimentally by means of optical absorption, photocurrent spectroscopy (PCS), and time-resolved luminescence (TRPL). Theoretical calculations show that highest occupied molecular orbital (HOMO) energy levels of PAZ and PCBM are almost equal (values of -6.01 and -5.98 eV were obtained with the B3LYP functional and the def2-TZVP orbital basis for PAZ and PCBM, respectively), what suggests a possibility of charge transfer in both directions for this system. The shape of the calculated absorption spectrum is in a qualitative agreement with the experiment. The PCS measurements of the new material show that the external quantum efficiency is the highest (about 0.3%) in the near UV range. The TRPL studies reveal a fast decay of a Langevin type (in picosecond range) of the PAZ-related photoluminescence, which accelerates in presence of PCBM, probably due to the charge transfer to PCBM. In addition, our measurements document a usually neglected process of the hole transfer from a donor to an acceptor. A leakage of holes from PAZ to PCBM is supported by a small energy difference of the HOMO energies, as predicted by theory.

  19. Tea and human health: biomedical functions of tea active components and current issues*

    PubMed Central

    Chen, Zong-mao; Lin, Zhi

    2015-01-01

    Originating in China, tea and tea planting have spread throughout the world since the middle of the Tang dynasty. Now people from 160 countries in the world are accustomed to tea drinking. A brief history of tea’s medicinal role in China and its spread to the world are introduced. The effectiveness of tea active components and tea drinking on major human diseases, including cancer, metabolic syndrome, cardiovascular disease, and neurodegenerative diseases, is discussed. Also presented are some related issues, such as the bioavailability of tea active components, the new formulations of tea polyphenols, and the safety for consumers of dietary supplements containing tea polyphenols. PMID:25644464

  20. Thermal properties of ration components as affected by moisture content and water activity during freezing.

    PubMed

    Li, J; Chinachoti, P; Wang, D; Hallberg, L M; Sun, X S

    2008-11-01

    Beef roast with vegetables is an example of a meal, ready-to-eat (MRE) ration entrée. It is a mixture of meat, potato, mushroom, and carrot with a gravy sauce. The thermal properties of each component were characterized in terms of freezing point, latent heat, freezable and unfreezable water contents, and enthalpy during freezing using differential scanning calorimetry. Freezing and thawing curves and the effect of freezing and thawing cycles on thermal properties were also evaluated. The freezing points of beef, potato, mushroom, and sauce were all in the range of -5.1 to -5.6 degrees C, but moisture content, water activity, latent heat, freezable and unfreezable water contents, and enthalpy varied among these components. Freezing temperature greatly affected the unfrozen water fraction. The unfreezable water content (unfrozen water fraction at -50 degrees C) of ration components was in the range of 8.2% to 9.7%. The freezing and thawing curves of vegetables with sauce differed from those of beef but took similar time to freeze or thaw. Freezing and thawing cycles did not greatly affect the thermal properties of each component. Freezing point and latent heat were reduced by decreasing moisture content and water activity of each component. Water activity was proportionally linear to freezing point at a(w) > 0.88, and moisture content was proportionally linear to freezable water content in all ration components. Water was not available for freezing when moisture content was reduced to 28.8% or less. This study indicates that moisture content and water activity are critical factors affecting thermal behavior of ration components during freezing.

  1. Optical Properties of Anisotropic Polycrystalline Ce+3 activated LSO

    PubMed Central

    Roy, Sudesna; Lingertat, Helmut; Brecher, Charles; Sarin, Vinod

    2012-01-01

    Polycrystalline cerium activated lutetium oxyorthosilicate (LSO:Ce) is highly desirable technique to make cost effective and highly reproducible radiation detectors for medical imaging. In this article methods to improve transparency in polycrystalline LSO:Ce were explored. Two commercially available powders of different particulate sizes (average particle size 30 and 1500 nm) were evaluated for producing dense LSO:Ce by pressure assisted densification routes, such as hot pressing and hot isostatic pressing. Consolidation of the powders at optimum conditions produced three polycrystalline ceramics with average grain sizes of 500 nm, 700 and 2000 nm. Microstructural evolution studies showed that for grain sizes larger than 1 µm, anisotropy in thermal expansion coefficient and elastic constants of LSO, resulted in residual stress at grain boundaries and triple points that led to intragranular microcracking. However, reducing the grain size below 1 µm effectively avoids microcracking, leading to more favorable optical properties. The optical scattering profiles generated by a Stover scatterometer, measured by a He-Ne laser of wavelength 633 nm, showed that by reducing the grain size from 2 µm to 500 nm, the in-line transmission increased by a factor of 103. Although these values were encouraging and showed that small changes in grain size could increase transmission by almost 3 orders of magnitude, even smaller grain sizes need to be achieved in order to get truly transparent material with high in-line transmission. PMID:23505329

  2. 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.

  3. Fluence Thresholds for Laser-Induced Damage of Optical Components in the Injector Laser of the SSRL Gun Test Facility

    SciTech Connect

    Boton, P

    2005-01-31

    Damage threshold fluences for several optical components were measured at three wavelengths using the injector laser at SSRL's Gun Test Facility. Measurements were conducted using the fundamental ir wavelength at 1053 nanometers and harmonics at 526 nm and 263 nm with 3.4ps pulses (1/e{sup 2} full width intensity); ir measurements were also conducted with 850 ps pulses. Practical surfaces relevant to the laser system performance are emphasized. Damage onset was evidenced by an alteration of the specular reflection of a cw probe laser (650 nm) from the irradiated region of the target surface. For the case of stretched ir pulses, damage to a Nd:glass rod was observed to begin at a site within the bulk material and to progress back toward the incident surface.

  4. [In vitro transdermal delivery of the active fraction of xiangfusiwu decoction based on principal component analysis].

    PubMed

    Li, Zhen-Hao; Liu, Pei; Qian, Da-Wei; Li, Wei; Shang, Er-Xin; Duan, Jin-Ao

    2013-06-01

    The objective of the present study was to establish a method based on principal component analysis (PCA) for the study of transdermal delivery of multiple components in Chinese medicine, and to choose the best penetration enhancers for the active fraction of Xiangfusiwu decoction (BW) with this method. Improved Franz diffusion cells with isolated rat abdomen skins were carried out to experiment on the transdermal delivery of six active components, including ferulic acid, paeoniflorin, albiflorin, protopine, tetrahydropalmatine and tetrahydrocolumbamine. The concentrations of these components were determined by LC-MS/MS, then the total factor scores of the concentrations at different times were calculated using PCA and were employed instead of the concentrations to compute the cumulative amounts and steady fluxes, the latter of which were considered as the indexes for optimizing penetration enhancers. The results showed that compared to the control group, the steady fluxes of the other groups increased significantly and furthermore, 4% azone with 1% propylene glycol manifested the best effect. The six components could penetrate through skin well under the action of penetration enhancers. The method established in this study has been proved to be suitable for the study of transdermal delivery of multiple components, and it provided a scientific basis for preparation research of Xiangfusiwu decoction and moreover, it could be a reference for Chinese medicine research. PMID:23984531

  5. CMOS Imaging Device for Optical Imaging of Biological Activities

    NASA Astrophysics Data System (ADS)

    Shishido, Sanshiro; Oguro, Yasuhiro; Noda, Toshihiko; Sasagawa, Kiyotaka; Tokuda, Takashi; Ohta, Jun

    In this paper, we propose a CMOS image sensor device placed on the brain surface or cerebral sulcus (Fig. 1). The device has a photo detector array where a single optical detector is usually used. The proposed imaging device enables the analysis which reflects a surface blood pattern in the observed area. It is also possible to improve effective sensitivity by image processing and to simplify the measurement system by the CMOS sensor device with on-chip light source. We describe the design details and characterization of proposed device. We also demonstrate detection of hemoglobin oxygenation level with external light source, imaging capability of biological activities, and image processing for sensitivity improvement is also realized.

  6. Optically Active Hybrid Materials Constructed from Helically Substituted Polyacetylenes.

    PubMed

    Zhang, Huanyu; Zhao, Biao; Deng, Jianping

    2016-04-01

    Functional materials derived from synthetic helical polymers are attracting increasing interest. Helically substituted polyacetylenes (HSPAs) are especially interesting as typical artificial helical polymers. In recent years, we designed and prepared a series of functional materials based on HSPAs and inorganic materials. The target is to establish some novel hybrid materials that combine the superior properties of both. The examined inorganic materials include silica, graphene, and magnetic Fe3 O4 nanoparticles. Such new functional materials hold great promise and are expected to find practical applications, for instance, as chiral absorbents, chiral sensors, chiral selectors for inducing enantioselective crystallization, chiral catalysts towards asymmetric catalysis, and chiral carriers for enantioselective release. The Personal Account summarizes our major achievements in preparing optically active hybrid materials. We hope it will speed up progress in chiral-related research areas.

  7. Sensor data fusion of optical and active radar data

    NASA Astrophysics Data System (ADS)

    Schultz, Johan; Gustafsson, Ulf; Crona, Torbjorn

    2004-08-01

    In this paper two different methods for fusing data from optical and active radar sensors are studied. The first method fuses data prior to feature extraction and the second method fuses data, in a more traditional way, after feature extraction. The advantage of fusing before feature extraction is that no information is lost prior to the fusion. The sensor data share one common dimension, namely azimuth, but the radar suffers from lower resolution. The algorithms are tested on real measurements from Ku- and millimeter wave radar combined with infrared or TV-camera. The study is in its initial phase and the two methods studied are simple in nature. The study aims to reveal differences between a raw data method and a feature-based method and should later result in a more complex and robust method.

  8. Aluminum: a requirement for activation of the regulatory component of adenylate cyclase by fluoride.

    PubMed Central

    Sternweis, P C; Gilman, A G

    1982-01-01

    Activation of the purified guanine nucleotide-binding regulatory component (G/F) of adenylate cyclase by F- requires the presence of Mg2+ and another factor. This factor, which contaminates commercial preparations of various nucleotides and disposable glass test tubes, has been identified as Al3+. In the presence of 10 mM Mg2+ and 5 mM F-, AlCl3 causes activation of G/F with an apparent activation constant of approximately 1-5 muM. The requirement for Al3+ is highly specific; of 28 other metals tested, only Be2+ promoted activation of G/F by F-. PMID:6289322

  9. Design, Analysis, and Characterization of Metamaterial Quasi-Optical Components for Millimeter-Wave Automotive Radar

    NASA Astrophysics Data System (ADS)

    Nguyen, Vinh Ngoc

    Since their introduction by Mercedes Benz in the late 1990s, W-band radars operating at 76-77 GHz have found their way into more and more passenger cars. These automotive radars are typically used in adaptive cruise control, pre-collision sensing, and other driver assistance systems. While these systems are usually only about the size of two stacked cigarette packs, system size, and weight remains a concern for many automotive manufacturers. In this dissertation, I discuss how artificially structured metamaterials can be used to improve lens-based automotive radar systems. Metamaterials allow the fabrication of smaller and lighter systems, while still meeting the frequency, high gain, and cost requirements of this application. In particular, I focus on the development of planar artificial dielectric lenses suitable for use in place of the injection-molded lenses now used in many automotive radar systems. I begin by using analytic and numerical ray-tracing to compare the performance of planar metamaterial GRIN lenses to equivalent aspheric refractive lenses. I do this to determine whether metamaterials are best employed in GRIN or refractive automotive radar lenses. Through this study I find that planar GRIN lenses with the large refractive index ranges enabled by metamaterials have approximately optically equivalent performance to equivalent refractive lenses for fields of view approaching +/-20°. I also find that the uniaxial nature of most planar metamaterials does not negatively impact planar GRIN lens performance. I then turn my attention to implementing these planar GRIN lenses at W-band automotive radar frequencies. I begin by designing uniform sheets of W-band electrically-coupled LC resonator-based metamaterials. These metamaterial samples were fabricated by the Jokerst research group on glass and liquid crystal polymer (LCP) substrates and tested at Toyota Research Institute- North America (TRI-NA). When characterized at W-band frequencies, these

  10. 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.

  11. Electrosprayed core-shell polymer-lipid nanoparticles for active component delivery

    NASA Astrophysics Data System (ADS)

    Eltayeb, Megdi; Stride, Eleanor; Edirisinghe, Mohan

    2013-11-01

    A key challenge in the production of multicomponent nanoparticles for healthcare applications is obtaining reproducible monodisperse nanoparticles with the minimum number of preparation steps. This paper focus on the use of electrohydrodynamic (EHD) techniques to produce core-shell polymer-lipid structures with a narrow size distribution in a single step process. These nanoparticles are composed of a hydrophilic core for active component encapsulation and a lipid shell. It was found that core-shell nanoparticles with a tunable size range between 30 and 90 nm and a narrow size distribution could be reproducibly manufactured. The results indicate that the lipid component (stearic acid) stabilizes the nanoparticles against collapse and aggregation and improves entrapment of active components, in this case vanillin, ethylmaltol and maltol. The overall structure of the nanoparticles produced was examined by multiple methods, including transmission electron microscopy and differential scanning calorimetry, to confirm that they were of core-shell form.

  12. Meaningful Components of Exercise and Active Recreation for Spinal Cord Injuries.

    PubMed

    Luchauer, Bryna; Shurtleff, Timothy

    2015-10-01

    This qualitative study used focus groups to identify meaningful components of exercise and active recreation (E/AR) related to consistent participation for those with spinal cord injury (SCI). Transcripts from each focus group were analyzed with classical content analysis, grounded theory coding, and meaning condensation using the International Classification of Function, Disability and Health (ICF). Variables within each of the ICF domains (body structures and functions, activities/participation, and environment) were indicated as meaningful components leading to increased participation, independence, and reasons why people consistently participated in E/AR. Occupational therapists can utilize these components to implement therapeutic intervisions, which provide clients with a sense of purpose and being, thus improving outcomes in meaningful occupations. PMID:27505903

  13. Spectroscopic sensing of reflection optical activity in achiral AgGaS₂.

    PubMed

    Arteaga, Oriol

    2015-09-15

    Optical activity is a fundamental effect of electrodynamics that was discovered more than 200 years ago. While optical activity is typically recognized by the rotation of the polarization of light as it propagates through a bulk medium, in certain configurations, the specular reflection of light on the surface of a material is also sensitive to its optical activity. Here, we show that the ellipsometric analysis of the light reflected at the surface of a gyrotropic but achiral crystal of AgGaS(2) allows the spectroscopic determination of its optical activity above the bandgap, where transmission methods are not applicable. This is the first clear spectroscopic determination of reflection optical activity in a crystal, and the values obtained are, to the best of our knowledge, the largest ever reported for a natural material. We also demonstrate that normal incidence transmission and reflection measurements probe different aspects of optical activity.

  14. Spectroscopic sensing of reflection optical activity in achiral AgGaS₂.

    PubMed

    Arteaga, Oriol

    2015-09-15

    Optical activity is a fundamental effect of electrodynamics that was discovered more than 200 years ago. While optical activity is typically recognized by the rotation of the polarization of light as it propagates through a bulk medium, in certain configurations, the specular reflection of light on the surface of a material is also sensitive to its optical activity. Here, we show that the ellipsometric analysis of the light reflected at the surface of a gyrotropic but achiral crystal of AgGaS(2) allows the spectroscopic determination of its optical activity above the bandgap, where transmission methods are not applicable. This is the first clear spectroscopic determination of reflection optical activity in a crystal, and the values obtained are, to the best of our knowledge, the largest ever reported for a natural material. We also demonstrate that normal incidence transmission and reflection measurements probe different aspects of optical activity. PMID:26371915

  15. Optical observations of comet 67P/Churyumov-Gerasimenko with the Nordic Optical Telescope. Comet activity before the solar conjunction

    NASA Astrophysics Data System (ADS)

    Zaprudin, B.; Lehto, H. J.; Nilsson, K.; Pursimo, T.; Somero, A.; Snodgrass, C.; Schulz, R.

    2015-11-01

    Context. 67P/Churyumov-Gerasimenko (67P) is a short-period Jupiter-family comet that was chosen as a target for the Rosetta mission by the European Space Agency (ESA). Monitoring of 67P with the Nordic Optical Telescope (NOT; La Palma, Spain) intends to aid this mission by providing ground-based reference information about the overall activity of the target and its astrometric position before the rendezvous. One motivation for our observations was to monitor sudden major increases in activity because they might have affected the Rosetta mission planning. None were observed. Ground-based photometric observations register the global activity of the comet, while the Rosetta spacecraft mostly measures local events. These data combined can lead to new insights into the comet behavior. Aims: The aim of this work is to perform the photometric and the astrometric monitoring of comet 67P with the NOT and to compare the results with the latest predictions for its position and activity. A new method of fitting extended-source components to the target surface brightness distribution was developed and applied to the data to estimate the size and contribution of the coma to the total brightness of the target. Methods: Comet 67P was monitored by the NOT in service mode during the period between 12.5.2013 and 11.11.2014. The very first observations were performed in the V band alone, but in the latest observations, the R band was used as well to estimate the color and nature of activity of the target. We applied a new method for estimating the coma size by deconvolving the point spread function profile from the image, which used Markov chain Monte Carlo and Bayesian statistics. This method will also be used for coma size estimations in further observations after the solar conjunction of 67P. Results: Photometric magnitudes in two colors were monitored during the period of observations. At the end of April 2014, the beginning of activity was observed. In late September 2014, a

  16. Rapid optical determination of β-lactamase and antibiotic activity

    PubMed Central

    2014-01-01

    Background The absence of rapid tests evaluating antibiotic susceptibility results in the empirical prescription of antibiotics. This can lead to treatment failures due to escalating antibiotic resistance, and also furthers the emergence of drug-resistant bacteria. This study reports a rapid optical method to detect β-lactamase and thereby assess activity of β-lactam antibiotics, which could provide an approach for targeted prescription of antibiotics. The methodology is centred on a fluorescence quenching based probe (β-LEAF – β-Lactamase Enzyme Activated Fluorophore) that mimics the structure of β-lactam antibiotics. Results The β-LEAF assay was performed for rapid determination of β-lactamase production and activity of β-lactam antibiotic (cefazolin) on a panel of Staphylococcus aureus ATCC strains and clinical isolates. Four of the clinical isolates were determined to be lactamase producers, with the capacity to inactivate cefazolin, out of the twenty-five isolates tested. These results were compared against gold standard methods, nitrocefin disk test for β-lactamase detection and disk diffusion for antibiotic susceptibility, showing results to be largely consistent. Furthermore, in the sub-set of β-lactamase producers, it was demonstrated and validated that multiple antibiotics (cefazolin, cefoxitin, cefepime) could be assessed simultaneously to predict the antibiotic that would be most active for a given bacterial isolate. Conclusions The study establishes the rapid β-LEAF assay for β-lactamase detection and prediction of antibiotic activity using S. aureus clinical isolates. Although the focus in the current study is β-lactamase-based resistance, the overall approach represents a broad diagnostic platform. In the long-term, these studies form the basis for the development of assays utilizing a broader variety of targets, pathogens and drugs. PMID:24708478

  17. Aerosol Optical Properties and Component Extinction from Measurements on the Ronald H. Brown During ACE-Asia

    NASA Astrophysics Data System (ADS)

    Quinn, P. K.; Bates, T. S.; Coffman, D.; Miller, T.; Anderson, J.

    2002-12-01

    Measurements of aerosol chemical, physical, and optical properties were made onboard the NOAA R/V Ronald H. Brown during the ACE-Asia Intensive Field Program to characterize Asian aerosol as it was transported across the Pacific Ocean. The ship traveled across the Pacific from Hawaii to Japan and into the East China Sea and the Sea of Japan. Based on trajectory analysis, the aerosol has been categorized as remote marine, volcanic from the Miyakejima volcano, polluted from Korea and Japan, polluted from Beijing, polluted mixed with dust during post frontal conditions, and polluted mixed with dust from Shanghai and Korea. Presented here, for these different categories, are aerosol optical properties (scattering and absorption coefficients, single scattering albedo (SSA), Angstrom Exponent, and aerosol optical depth), mass fractions of the major chemical components, and mass extinction efficiencies and extinction coefficients for individual aerosol components. Lowest scattering and absorption coefficients and highest single scattering albedos were measured in marine air masses encountered as the ship transited from Hawaii toward Japan (mean SSA = 0.97). Lowest SSA were measured in polluted air masses from Korea and Japan (mean SSA = 0.90). With dust mixed into the polluted air masses, SSA increased due to the high scattering levels associated with the dust (mean SSA ranged from 0.92 to 0.96 for different pollution/dust mixtures). These SSA are for the sub-10 micron aerosol at 55 percent RH. They were 1 to 4 percent lower for the sub-1 micron aerosol. Unique to the ACE Asia aerosol was the observation of significant absorption at 550 nm by supermicron aerosol. A correlation between supermicron elemental carbon concentrations and the ratio of absorption by sub-1 um aerosol to absorption by sub-10 um aerosol suggests that supermicron EC is responsible. As the mean concentration of supermicron EC increased from the marine to polluted to polluted with dust cases, the ratio

  18. Suicide Risk by Military Occupation in the DoD Active Component Population

    ERIC Educational Resources Information Center

    Trofimovich, Lily; Reger, Mark A.; Luxton, David D.; Oetjen-Gerdes, Lynne A.

    2013-01-01

    Suicide risk based on occupational cohorts within the U.S. military was investigated. Rates of suicide based on military occupational categories were computed for the Department of Defense (DoD) active component population between 2001 and 2010. The combined infantry, gun crews, and seamanship specialist group was at increased risk of suicide…

  19. The Components of Effective Professional Development Activities in Terms of Teachers' Perspective

    ERIC Educational Resources Information Center

    Bayar, Adem

    2014-01-01

    Teacher preparedness is linked to student achievement, yet regularly teachers are entering the profession unprepared. In-service training, or professional development activities, are increasingly being used to remedy this situation. There is little agreement regarding exactly what key components should be included in an effective professional…

  20. ALTERATION OF CARDIAC ELECTRICAL ACTIVITY BY WATER-LEACHABLE COMPONENTS OF RESIDUAL OIL FLY ASH (ROFA)

    EPA Science Inventory

    Alteration of cardiac electrical activity by water-leachable components
    of residual oil fly ash (ROFA)

    Desuo Wang, Yuh-Chin T. Huang*, An Xie, Ting Wang

    *Human Studies Division, NHEERL, US EPA
    104 Mason Farm Road, Chapel Hill, NC 27599
    Department of Basic ...

  1. Superfluidity and solid order in a two-component Bose gas with dipolar interactions in an optical lattice

    NASA Astrophysics Data System (ADS)

    Kuno, Yoshihito; Suzuki, Keita; Ichinose, Ikuo

    2014-12-01

    In this paper, we study an extended bosonic t-J model in an optical lattice, which describes two-component hard-core bosons with nearest-neighbor pseudospin interactions and, also, inter- and intraspecies dipole-dipole interactions. In particular, we focus on the case in which two-component hard-core bosons have antiparallel polarized dipoles with each other. The global phase diagram is studied by means of the Gutzwiller variational method and also quantum Monte Carlo (QMC) simulations. Both calculations show that a striped solid order, besides a checkerboard one, appears as a result of the dipole-dipole interactions. By QMC, we find that two kinds of supersolids (SSs) form, i.e., checkerboard SS and striped SS, and we also verify the existence of an exotic phase between the striped solid and the checkerboard SS. Finally, by QMC, we study the t-J-like model, which was recently realized experimentally by A. de Paz et al. [Phys. Rev. Lett. 111, 185305 (2013), 10.1103/PhysRevLett.111.185305].

  2. Complement Component C3 Binds to Activated Normal Platelets without Preceding Proteolytic Activation and Promotes Binding to Complement Receptor 1

    PubMed Central

    Hamad, Osama A.; Nilsson, Per H.; Wouters, Diana; Lambris, John D.; Ekdahl, Kristina N.; Nilsson, Bo

    2010-01-01

    It has been reported that complement is activated on the surface of activated platelets, despite the presence of multiple regulators of complement activation. To reinvestigate the mechanisms by which activated platelets bind to complement components, the presence of complement proteins on the surfaces of nonactivated and thrombin receptor-activating peptide-activated platelets was analyzed by flow cytometry and Western blot analyses. C1q, C4, C3, and C9 were found to bind to thrombin receptor-activating peptide-activated platelets in lepirudin-anticoagulated platelet-rich plasma (PRP) and whole blood. However, inhibiting complement activation at the C1q or C3 level did not block the binding of C3 to activated platelets. Diluting PRP and chelating divalent cations also had no effect, further indicating that the deposition of complement components was independent of complement activation. Furthermore, washed, activated platelets bound added C1q and C3 to the same extent as platelets in PRP. The use of mAbs against different forms of C3 demonstrated that the bound C3 consisted of C3(H2O). Furthermore, exogenously added soluble complement receptor 1 was shown to bind to this form of platelet-bound C3. These observations indicate that there is no complement activation on the surface of platelets under physiological conditions. This situation is in direct contrast to a number of pathological conditions in which regulators of complement activation are lacking and thrombocytopenia and thrombotic disease are the ultimate result. However, the generation of C3(H2O) represents nonproteolytic activation of C3 and after factor I cleavage may act as a ligand for receptor binding. PMID:20139276

  3. Antioxidative activity of Rosmarinus officinalis L. essential oil compared to its main components.

    PubMed

    Wang, W; Wu, N; Zu, Y G; Fu, Y J

    2008-06-01

    This study was designed to examine the in vitro antioxidant activities of Rosmarinus officinalis L. essential oil compared to three of its main components (1,8-cineole, α-pinene, β-pinene). GC-MS analysis of the essential oil resulted in the identification of 19 compounds, representing 97.97% of the oil, the major constituents of the oil were described as 1,8-cineole (27.23%), α-pinene (19.43%), camphor (14.26%), camphene (11.52%) and β-pinene (6.71%). The oil and the components were subjected to screening for their possible antioxidant activity by means of 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and β-carotene bleaching test. In the DPPH test system, free radical-scavenging activity of R. officinalis L. essential oil, 1,8-cineole, α-pinene and β-pinene were determined to be 62.45%±3.42%, 42.7%±2.5%, 45.61%±4.23% and 46.21%±2.24% (v/v), respectively. In the β-carotene bleaching test system, we tested series concentration of samples to show the antioxidant activities of the oil and its main components, whereas the concentrations providing 50% inhibition (IC50) values of R. officinalis L. essential oil, 1,8-cineole, α-pinene and β-pinene were 2.04%±0.42%, 4.05%±0.65%, 2.28%±0.23% and 2.56%±0.16% (v/v), respectively. In general, R. officinalis L. essential oil showed greater activity than its components in both systems, and the antioxidant activities of all the tested samples were mostly related to their concentrations. Antioxidant activities of the synthetic antioxidant, ascorbic acid and BHT, were also determined in parallel experiments as positive control.

  4. Male pheromone protein components activate female vomeronasal neurons in the salamander Plethodon shermani

    PubMed Central

    Wirsig-Wiechmann, Celeste R; Houck, Lynne D; Wood, Jessica M; Feldhoff, Pamela W; Feldhoff, Richard C

    2006-01-01

    Background The mental gland pheromone of male Plethodon salamanders contains two main protein components: a 22 kDa protein named Plethodon Receptivity Factor (PRF) and a 7 kDa protein named Plethodon Modulating Factor (PMF), respectively. Each protein component individually has opposing effects on female courtship behavior, with PRF shortening and PMF lengthening courtship. In this study, we test the hypothesis that PRF or PMF individually activate vomeronasal neurons. The agmatine-uptake technique was used to visualize chemosensory neurons that were activated by each protein component individually. Results Vomeronasal neurons exposed to agmatine in saline did not demonstrate significant labeling. However, a population of vomeronasal neurons was labeled following exposure to either PRF or PMF. When expressed as a percent of control level labeled cells, PRF labeled more neurons than did PMF. These percentages for PRF and PMF, added together, parallel the percentage of labeled vomeronasal neurons when females are exposed to the whole pheromone. Conclusion This study suggests that two specific populations of female vomeronasal neurons are responsible for responding to each of the two components of the male pheromone mixture. These two neural populations, therefore, could express different receptors which, in turn, transmit different information to the brain, thus accounting for the different female behavior elicited by each pheromone component. PMID:16553953

  5. Field-dependent magneto-optical Kerr effect spectroscopy applied to the magnetic component diagnosis of a rubrene/Ni system.

    PubMed

    Li, Wen; Fronk, Michael; Albrecht, Manfred; Franke, Mechthild; Zahn, Dietrich R T; Salvan, Georgeta

    2014-07-28

    Polar magneto-optical Kerr effect (MOKE) spectroscopy in the energy range from 1.75 eV to 5 eV at different magnetic field strength was applied to study Ni nanostructures formed on rubrene nanoislands. The magnetic hysteresis curves measured by MOKE change the shape depending on the photon energy and therefore deviate from those measured by superconducting quantum interference device (SQUID) magnetometry. Similar optical effects were previously observed in inorganic heterostructures. Our observations show that it correlates to the change in lineshape of the MOKE rotation and ellipticity spectra as a function of magnetic field strength. We show that this spectral dependence on magnetic field can be exploited to separate the contributions of two magnetic components to the magneto-optical spectra and hysteresis. The proposed model does not require the a priori knowledge of the (magneto-)optical constants of the heterostructure and its components. PMID:25089464

  6. Water Extract of Ashwagandha Leaves Has Anticancer Activity: Identification of an Active Component and Its Mechanism of Action

    PubMed Central

    Gao, Ran; Shah, Navjot; Widodo, Nashi; Nakamoto, Tomoko; Ishida, Yoshiyuki; Terao, Keiji; Kaul, Sunil C.

    2013-01-01

    Background Cancer is a leading cause of death accounting for 15-20% of global mortality. Although advancements in diagnostic and therapeutic technologies have improved cancer survival statistics, 75% of the world population live in underdeveloped regions and have poor access to the advanced medical remedies. Natural therapies hence become an alternative choice of treatment. Ashwagandha, a tropical herb used in Indian Ayurvedic medicine, has a long history of its health promoting and therapeutic effects. In the present study, we have investigated an anticancer activity in the water extract of Ashwagandha leaves (ASH-WEX). Methodology/Principal Findings Anticancer activity in the water extract of Ashwagandha leaves (ASH-WEX) was detected by in vitro and in vivo assays. Bioactivity-based size fractionation and NMR analysis were performed to identify the active anticancer component(s). Mechanism of anticancer activity in the extract and its purified component was investigated by biochemical assays. We report that the ASH-WEX is cytotoxic to cancer cells selectively, and causes tumor suppression in vivo. Its active anticancer component was identified as triethylene glycol (TEG). Molecular analysis revealed activation of tumor suppressor proteins p53 and pRB by ASH-WEX and TEG in cancer cells. In contrast to the hypophosphorylation of pRB, decrease in cyclin B1 and increase in cyclin D1 in ASH-WEX and TEG-treated cancer cells (undergoing growth arrest), normal cells showed increase in pRB phosphorylation and cyclin B1, and decrease in cyclin D1 (signifying their cell cycle progression). We also found that the MMP-3 and MMP-9 that regulate metastasis were down regulated in ASH-WEX and TEG-treated cancer cells; normal cells remained unaffected. Conclusion We provide the first molecular evidence that the ASH-WEX and TEG have selective cancer cell growth arrest activity and hence may offer natural and economic resources for anticancer medicine. PMID:24130852

  7. Peptide-modified optical filters for detecting protease activity.

    PubMed

    Kilian, Kristopher A; Böcking, Till; Gaus, Katharina; Gal, Michael; Gooding, J Justin

    2007-11-01

    The organic derivatization of silicon-based nanoporous photonic crystals is presented as a method to immobilize peptides for the detection of protease enzymes in solution. A narrow-line-width rugate filter, a one-dimensional photonic crystal, is fabricated that exhibits a high-reflectivity optical resonance that is sensitive to small changes in the refractive index at the pore walls. To immobilize peptide in the pore of the photonic crystal, the hydrogen-terminated silicon surface was first modified with the alkene 10-succinimidyl undecenoate via hydrosilylation. The monolayer with the succinimide ester moiety at the distal end served the dual function of protecting the underlying silicon from oxidation as well as providing a surface suitable for subsequent derivatization with amines. The surface was further modified with 1-aminohexa(ethylene glycol) (EG(6)) to resist nonspecific adsorption of proteins common in complex biological samples. The distal hydroxyl of the EG(6) is activated using the solid-phase coupling reagent disuccinimidyl carbonate for selective immobilization of peptides as protease recognition elements. X-ray photoelectron spectroscopy analysis reveals high activation and coupling efficiency at each stage of the functionalization. Exposure of the peptide-modified crystals to the protease subtilisin in solution causes a change in the refractive index, resulting in a shift of the resonance to shorter wavelengths, indicating cleavage of organic material within the pores. The lowest detected concentration of enzyme was 37 nM (7.4 pmol in 200 microL).

  8. Ciliary motility activity measurement using a dense optical flow algorithm.

    PubMed

    Parrilla, Eduardo; Armengot, Miguel; Mata, Manuel; Cortijo, Julio; Riera, Jaime; Hueso, José L; Moratal, David

    2013-01-01

    Persistent respiratory syncytial virus (RSV) infections have been associated with the exacerbation of chronic inflammatory diseases, including chronic obstructive pulmonary disease (COPD). This virus infects the respiratory epithelium, leading to chronic inflammation, and induces the release of mucins and the loss of cilia activity, two factors that determine mucus clearance and the increase in sputum volume. In this study, an automatic method has been established to determine the ciliary motility activity from cell cultures by means of optical flow computation, and has been applied to 136 control cultures and to 144 RSV-infected cultures. The control group presented an average of cell surface with cilia motility per field of 41 ± 15 % (mean ± standard deviation), while the infected group presented a 11 ± 5 %, t-Student p<0.001. The cutoff value to classify a infected specimen was <17.89 % (sensitivity 0.94, specificity 0.93). This methodology has proved to be a robust technique to evaluate cilia motility in cell cultures. PMID:24110720

  9. Drug target identification using network analysis: Taking active components in Sini decoction as an example

    PubMed Central

    Chen, Si; Jiang, Hailong; Cao, Yan; Wang, Yun; Hu, Ziheng; Zhu, Zhenyu; Chai, Yifeng

    2016-01-01

    Identifying the molecular targets for the beneficial effects of active small-molecule compounds simultaneously is an important and currently unmet challenge. In this study, we firstly proposed network analysis by integrating data from network pharmacology and metabolomics to identify targets of active components in sini decoction (SND) simultaneously against heart failure. To begin with, 48 potential active components in SND against heart failure were predicted by serum pharmacochemistry, text mining and similarity match. Then, we employed network pharmacology including text mining and molecular docking to identify the potential targets of these components. The key enriched processes, pathways and related diseases of these target proteins were analyzed by STRING database. At last, network analysis was conducted to identify most possible targets of components in SND. Among the 25 targets predicted by network analysis, tumor necrosis factor α (TNF-α) was firstly experimentally validated in molecular and cellular level. Results indicated that hypaconitine, mesaconitine, higenamine and quercetin in SND can directly bind to TNF-α, reduce the TNF-α-mediated cytotoxicity on L929 cells and exert anti-myocardial cell apoptosis effects. We envisage that network analysis will also be useful in target identification of a bioactive compound. PMID:27095146

  10. On the characterization of ultra-precise X-ray optical components: advances and challenges in ex situ metrology

    PubMed Central

    Siewert, F.; Buchheim, J.; Zeschke, T.; Störmer, M.; Falkenberg, G.; Sankari, R.

    2014-01-01

    To fully exploit the ultimate source properties of the next-generation light sources, such as free-electron lasers (FELs) and diffraction-limited storage rings (DLSRs), the quality requirements for gratings and reflective synchrotron optics, especially mirrors, have significantly increased. These coherence-preserving optical components for high-brightness sources will feature nanoscopic shape accuracies over macroscopic length scales up to 1000 mm. To enable high efficiency in terms of photon flux, such optics will be coated with application-tailored single or multilayer coatings. Advanced thin-film fabrication of today enables the synthesis of layers on the sub-nanometre precision level over a deposition length of up to 1500 mm. Specifically dedicated metrology instrumentation of comparable accuracy has been developed to characterize such optical elements. Second-generation slope-measuring profilers like the nanometre optical component measuring machine (NOM) at the BESSY-II Optics laboratory allow the inspection of up to 1500 mm-long reflective optical components with an accuracy better than 50 nrad r.m.s. Besides measuring the shape on top of the coated mirror, it is of particular interest to characterize the internal material properties of the mirror coating, which is the domain of X-rays. Layer thickness, density and interface roughness of single and multilayer coatings are investigated by means of X-ray reflectometry. In this publication recent achievements in the field of slope measuring metrology are shown and the characterization of different types of mirror coating demonstrated. Furthermore, upcoming challenges to the inspection of ultra-precise optical components designed to be used in future FEL and DLSR beamlines are discussed. PMID:25177985

  11. Microbiological activity of whole and fractionated crude extracts of tea (Camellia sinensis), and of tea components.

    PubMed

    Yam, T S; Shah, S; Hamilton-Miller, J M

    1997-07-01

    Aqueous extracts of teas (Camellia sinensis) of different types and from various sources inhibited a wide range of pathogenic bacteria, including methicillin-resistant Staphylococcus aureus. Tea extracts were bactericidal to staphylococci and Yersinia enterocolitica at well below 'cup of tea' concentrations. Activity was confined to one of four fractions obtained from a green tea extract by partition chromatography. Testing of pure tea compounds and closely related chemicals suggested that the antibacterial activity of extracts of green tea can be explained by its content of epigallocatechin, epigallocatechin gallate and epicatechin gallate. In black tea extracts, theaflavin and its gallates are additional antibacterially active components. PMID:9228784

  12. Anticancer activity of essential oils and their chemical components - a review

    PubMed Central

    Bayala, Bagora; Bassole, Imaël HN; Scifo, Riccardo; Gnoula, Charlemagne; Morel, Laurent; Lobaccaro, Jean-Marc A; Simpore, Jacques

    2014-01-01

    Essential oils are widely used in pharmaceutical, sanitary, cosmetic, agriculture and food industries for their bactericidal, virucidal, fungicidal, antiparasitical and insecticidal properties. Their anticancer activity is well documented. Over a hundred essential oils from more than twenty plant families have been tested on more than twenty types of cancers in last past ten years. This review is focused on the activity of essential oils and their components on various types of cancers. For some of them the mechanisms involved in their anticancer activities have been carried out. PMID:25520854

  13. Phase matching of four-wave interactions of SRS components in birefringent SRS-active crystals

    NASA Astrophysics Data System (ADS)

    Smetanin, Sergei N.; Basiev, Tasoltan T.

    2012-03-01

    A new method has been proposed for achieving wave vector matching in four-wave interactions of frequency components upon SRS in birefringent SRS-active crystals. The method ensures anti-Stokes wave generation and enables a substantial reduction in higher order Stokes SRS generation thresholds. Phase matching directions in BaWO4 SRS-active negative uniaxial crystals and SrWO4 SRS-active positive uniaxial crystals have been found in the wavelength range 0.4 — 0.7 μm.

  14. Multipolar Effects in the Optical Active Second Harmonic Generation from Sawtooth Chiral Metamaterials

    PubMed Central

    Su, Huimin; Guo, Yuxiang; Gao, Wensheng; Ma, Jie; Zhong, Yongchun; Tam, Wing Yim; Chan, C. T.; Wong, Kam Sing

    2016-01-01

    Based on the facts that chiral molecules response differently to left- and right-handed circular polarized light, chiroptical effects are widely employed for determining structure chirality, detecting enantiomeric excess, or controlling chemical reactions of molecules. Compared to those in natural materials, chiroptical behaviors can be significantly amplified in chiral plasmonic metamaterials due to the concentrated local fields in the structure. The on-going research towards giant chiroptical effects in metamaterial generally focus on optimizing the field-enhancement effects. However, the observed chiroptical effects in metamaterials rely on more complicated factors and various possibilities towards giant chiroptical effects remains unexplored. Here we study the optical-active second harmonic generation (SHG) behaviors in a pair of planar sawtooth gratings with mirror-imaged patterns. Significant multipolar effects were observed in the polarization-dependent SHG curves. We show that the chirality of the nanostructure not only give rise to nonzero chiral susceptibility tensor components within the electric-dipole approximation, but also lead to different levels of multipolar interactions for the two orthogonal circular polarizations that further enhance the nonlinear optical activity of the material. Our results thus indicate novel ways to optimize nonlinear plasmonic structures and achieve giant chiroptical response via multipolar interactions. PMID:26911449

  15. Multipolar Effects in the Optical Active Second Harmonic Generation from Sawtooth Chiral Metamaterials.

    PubMed

    Su, Huimin; Guo, Yuxiang; Gao, Wensheng; Ma, Jie; Zhong, Yongchun; Tam, Wing Yim; Chan, C T; Wong, Kam Sing

    2016-02-25

    Based on the facts that chiral molecules response differently to left- and right-handed circular polarized light, chiroptical effects are widely employed for determining structure chirality, detecting enantiomeric excess, or controlling chemical reactions of molecules. Compared to those in natural materials, chiroptical behaviors can be significantly amplified in chiral plasmonic metamaterials due to the concentrated local fields in the structure. The on-going research towards giant chiroptical effects in metamaterial generally focus on optimizing the field-enhancement effects. However, the observed chiroptical effects in metamaterials rely on more complicated factors and various possibilities towards giant chiroptical effects remains unexplored. Here we study the optical-active second harmonic generation (SHG) behaviors in a pair of planar sawtooth gratings with mirror-imaged patterns. Significant multipolar effects were observed in the polarization-dependent SHG curves. We show that the chirality of the nanostructure not only give rise to nonzero chiral susceptibility tensor components within the electric-dipole approximation, but also lead to different levels of multipolar interactions for the two orthogonal circular polarizations that further enhance the nonlinear optical activity of the material. Our results thus indicate novel ways to optimize nonlinear plasmonic structures and achieve giant chiroptical response via multipolar interactions.

  16. Essential oil from Chenopodium ambrosioides and main components: activity against Leishmania, their mitochondria and other microorganisms.

    PubMed

    Monzote, Lianet; García, Marley; Pastor, Jacinta; Gil, Lizette; Scull, Ramón; Maes, Louis; Cos, Paul; Gille, Lars

    2014-01-01

    Chenopodium ambrosioides is an aromatic herb used by native people to treat parasitic diseases. The aim of this work is to compare the in vitro anti-leishmanial activity of the essential oil (EO) from C. ambrosioides and its major components (ascaridole, carvacrol and caryophyllene oxide) and study their mechanism of action and activity against a panel of microorganism. Antileishmanial activity and cytotoxicity of the EO and major components was study. In addition, experiments to elucidate the mechanism of action were perform and activities against other microorganisms (bacteria, fungi and protozoa) were evaluate. All products were active against promastigote and amastigote forms of Leishmania. Ascaridole exhibited the better antileishmanial activity and the EO the highest selectivity index. The exploration of the mechanism suggests that the products cause a breakdown of mitochondrial membrane potential and a modification of redox indexes. Only EO showed antiprotozoal effect against Plasmodium falciparum and Trypanosoma brucei; while no activity against bacteria and fungi was observed. Our results demonstrate the potentialities of EO in cellular and molecular system, which could be consider in future studies to develop new antileishmanial drugs with a wide anti-parasitic spectrum.

  17. High-aperture binary axicons for the formation of the longitudinal electric field component on the optical axis for linear and circular polarizations of the illuminating beam

    SciTech Connect

    Khonina, S. N. Savelyev, D. A.

    2013-10-15

    Diffraction of uniformly polarized laser beams with vortex phase singularity is theoretically analyzed using the plane wave expansion. It is shown that for a high numerical aperture, an intense longitudinal electric field component is formed on the optical axis in this case. It is numerically demonstrated that an analogous effect is ensured for diffraction of a conventional Gaussian beam from asymmetric binary axicons. The field intensity on the optical axis can be varied either by rotating the optical element or by changing the direction of polarization of radiation.

  18. Antibacterial properties and major bioactive components of cinnamon stick (Cinnamomum burmannii): activity against foodborne pathogenic bacteria.

    PubMed

    Shan, Bin; Cai, Yi-Zhong; Brooks, John D; Corke, Harold

    2007-07-11

    Cinnamomum burmannii Blume (cinnamon stick) from Indonesia is a little-investigated spice. In this study, the antibacterial activity, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) of cinnamon stick extract were evaluated against five common foodborne pathogenic bacteria (Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella anatum). Cinnamon stick extract exhibited significant antibacterial properties. Major compounds in cinnamon stick were tentatively identified by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography (LC-MS) as a predominant volatile oil component ((E)-cinnamaldehyde) and several polyphenols (mainly proanthocyanidins and (epi)catechins). Both (E)-cinnamaldehyde and proanthocyanidins significantly contributed to the antibacterial properties. Additionally, scanning electron microscopy was used to observe morphological changes of bacteria treated with the crude extract of cinnamon stick and its major components. This study suggests that cinnamon stick and its bioactive components have potential for application as natural food preservatives.

  19. [Analysis of the informational and activating components of reinforcement in a conditioned reflex experiment].

    PubMed

    Menitskiĭ, D N

    1983-01-01

    The reinforcement in adaptive behaviour performs at least two functions: satisfaction of specific need (activational component) and estimation of signal significance of the conditioned stimulus while comparing the nervous model of the stimulus with current afferentation (informational component). In usual conditioning experiments with permanent reinforcement these components concide and therefore do not differ. However, they may be separated in the case of probabilistic reinforcement by changing stimuli contingency and shifting motivational level. With this aim the diagrams of probabilistic stimuli and reactions space, semantic and pragmatic matrices are worked out, allowing to estimate correlations of these parameters of conditioning experiments. Comparative psychophysiological investigations showed the possibility of determination of species peculiarities in behavioural choice strategies among various animals under above mentioned conditions.

  20. The Effects of Training on the Time Components of the Left Ventricle, and Cardiac Time Components: Sedentary versus Active Individuals.

    ERIC Educational Resources Information Center

    Plowman, Sharon Ann

    A review of previous research was completed to determine (a) the response of the cardiac time components of the left ventricle to varying types and intensities of training programs, (b) the probable physiological explanations for these responses, and (c) the significance of the changes which did or did not occur. It was found that, at rest,…

  1. Two kinetically distinct components of hyperpolarization-activated current in rat superior colliculus-projecting neurons.

    PubMed Central

    Solomon, J S; Nerbonne, J M

    1993-01-01

    1. Whole-cell and perforated patch recording techniques were used to examine the activation, deactivation and inactivation of the time-dependent hyperpolarization-activated inward currents (Ih) in isolated superior colliculus-projecting (SCP) neurons from rat primary visual cortex. 2. Examination of inward current waveforms revealed the presence of two kinetically distinct components of Ih: one that activates with a time constant of the order of hundreds of milliseconds, and one that activates with a time constant of the order of seconds. We have termed these Ih,f and Ih,s, to denote the fast and slow components, respectively, of current activation. The time constants of activation of both Ih,f and Ih,s decrease with increasing membrane hyperpolarization. 3. Following the onset of hyperpolarizing voltage steps, a delay is evident prior to time-dependent inward current activation. This delay is voltage dependent and decreases with increasing membrane hyperpolarization. 4. The sigmoidal inward current waveforms are well fitted by the sum of two exponentials in which the faster term, corresponding to the activation of Ih,f, is raised to the power 1.34 +/- 0.26 (mean +/- S.D.). The non-integral exponent suggests that Ih,f activation involves at least two energetically non-equivalent gating transitions prior to channel opening. 5. Over a limited voltage range, tail currents could also be resolved into two distinct components. The faster component, which corresponds to the deactivation of Ih,f, decayed over a single exponential time course with a mean (+/- S.D.) time constant of 355 +/- 161 ms at -70 mV. Ih,s decay also followed a single exponential time course with a mean (+/- S.D.) time constant of 2428 +/- 1285 ms at -70 mV. Both deactivation time constants decreased with increasing depolarization. 6. The separation of inward current activation and deactivation into two distinct components and the lack of correlation between the relative amplitudes of these components

  2. Antiadhesion and antibiofilm activities of high molecular weight coffee components against Streptococcus mutans.

    PubMed

    Stauder, Monica; Papetti, Adele; Mascherpa, Dora; Schito, Anna Maria; Gazzani, Gabriella; Pruzzo, Carla; Daglia, Maria

    2010-11-24

    In previous studies we demonstrated that green and roasted coffee contains low molecular weight (LMW) compounds capable of inhibiting the ability of Streptococcus mutans, the major causative agent of human dental caries, to adhere to hydroxyapatite (HA) beads. This study addressed the ability of the whole high molecular weight coffee fraction (cHMW) and of its melanoidin and non-melanoidin components (GFC1-5), applied at concentrations that occur in coffee beverages, to (i) inhibit S. mutans growth; (ii) affect S. mutans sucrose-dependent adhesion to and detachment from saliva-coated HA beads (sHA); and (iii) inhibit biofilm development on microtiter plates. The results indicated that only cHMW is endowed with antimicrobial activity. The cHMW fraction and each of the five GFC components inhibited S. mutans adhesion, the strongest effect being exerted by cHMW (91%) and GFC1 (88%). S. mutans detachment from sHA was four times greater (∼20%) with cHMW and the GFC1 and GFC4 melanoidins than with controls. Finally, biofilm production by S. mutans was completely abolished by cHMW and was reduced by 20% by the melanoidin components GFC2 and GFC4 and by the non-melanoidin component GFC5 compared with controls. Altogether these findings show that coffee beverage contains both LMW compounds and HMW melanoidin and non-melanoidin components with a strong ability to interfere in vitro with the S. mutans traits relevant for cariogenesis. PMID:21038921

  3. Ulysses observations of electron and proton components in a magnetic cloud and related wave activity

    NASA Technical Reports Server (NTRS)

    Osherovich, V. A.; Fainberg, J.; Stone, R. G.; MacDowall, R. J.; Phillips, J. L.; Balogh, A.

    1995-01-01

    In addition to a smooth rotation of the magnetic field vector, magnetic clouds have a low proton temperature T(sub p). Their expansion in the solar wind leads to depletion and therefore the ion component cools down. It has been shown recently that the electron component in magnetic clouds behaves differently: when the cloud expands, electron temperature Te anti correlates with density and therefore Te increases in the cloud, creating favorable conditions for the rise of ion-acoustic waves. For the magnetic cloud observed by Ulysses on June 10 - 12, 1993 at 4.64 AU at S 32.5 deg, we present observations for both electron and proton components and related plasma wave activity. Our results confirm the anti correlation between T(sub e) and electron density and also exhibit a high ratio of T(sub e)/T(sub P) in the cloud. Since Landau damping is not effective for T(sub e)/T(sub p) much greater than 1, Doppler shifted ion acoustic waves are expected in the cloud. Calculation of ion acoustic wave frequencies in the cloud and comparison with observed wave activity confirm this expectation. As in our previous work, we show that the electron component in the cloud obeys a polytropic law with gamma is less than 1 (gamma approximately equals 0.3-0.4). The dynamics of the magnetic cloud are determined to a large degree by the dominating electron pressure.

  4. Temperamental Traits Versus Individual Physical Fitness Components and a Physical Activity Level.

    PubMed

    Bernatowicz, Dominik; Izdebski, Paweł; Boraczyński, Tomasz; Boraczyński, Michał

    2015-06-27

    The main aim of the study was to examine whether relationships exist between particular temperamental traits within the concept of Regulative Theory of Temperament and components of physical fitness, that are most crucial for success in sport. The research involved 108 individuals including 63 men (age 21.1 ± 1.6 yrs) and 45 women (age 20.7 ± 1.3 yrs). None of the respondents were professionally engaged in sport. Components of physical fitness included: aerobic capacity, strength, agility, static-dynamic balance and reaction time. The respondents also completed two questionnaires: the Formal Characteristics of Behaviour - Temperament Inventory and the International Physical Activity Questionnaire. The results indicate that the temperamental traits had average to poor correlations with the components of physical fitness, whereas more statistically significant correlations were observed in women. Negative correlations were obtained between emotional reactivity and agility, which was a result confirmed by previous research. All temperamental traits related with the energetic aspects of behaviour correlated with simple reaction time in women. Physical activity and aerobic capacity did not correlate with any of the studied traits. The results do not allow for any general conclusions to be drawn, but can serve as a reference point for future research on temperamental traits as delineated by Regulative Theory of Temperament and their relationship with the components of physical fitness.

  5. Temperamental Traits Versus Individual Physical Fitness Components and a Physical Activity Level

    PubMed Central

    Bernatowicz, Dominik; Izdebski, Paweł; Boraczyński, Tomasz; Boraczyński, Michał

    2015-01-01

    The main aim of the study was to examine whether relationships exist between particular temperamental traits within the concept of Regulative Theory of Temperament and components of physical fitness, that are most crucial for success in sport. The research involved 108 individuals including 63 men (age 21.1 ± 1.6 yrs) and 45 women (age 20.7 ± 1.3 yrs). None of the respondents were professionally engaged in sport. Components of physical fitness included: aerobic capacity, strength, agility, static-dynamic balance and reaction time. The respondents also completed two questionnaires: the Formal Characteristics of Behaviour – Temperament Inventory and the International Physical Activity Questionnaire. The results indicate that the temperamental traits had average to poor correlations with the components of physical fitness, whereas more statistically significant correlations were observed in women. Negative correlations were obtained between emotional reactivity and agility, which was a result confirmed by previous research. All temperamental traits related with the energetic aspects of behaviour correlated with simple reaction time in women. Physical activity and aerobic capacity did not correlate with any of the studied traits. The results do not allow for any general conclusions to be drawn, but can serve as a reference point for future research on temperamental traits as delineated by Regulative Theory of Temperament and their relationship with the components of physical fitness. PMID:26240664

  6. The alteration of components in the fermented Hwangryunhaedok-tang and its neuroprotective activity

    PubMed Central

    Yang, Hye Jin; Weon, Jin Bae; Lee, Bohyoung; Ma, Choong Je

    2011-01-01

    Background: Hwangryunhaedok-tang is a traditional herbal prescription that has sedative activity, hypotensive and anti-bacterial effects. Objective: In this study, we investigated the alteration of contents of components in Hwangryunhaedok-tang, antioxidant activity and neuroprotective activity by fermentation with Lactobacillus acidophilus KFRI 128. Materials and Methods: Contents of three marker compounds (geniposide, berberine and palmatine) and unknown compounds in the Hwangryunhaedok-tang (HR) and the fermented Hwangryunhaedok-tang (FHR) were measured and compared using the established high-performance liqued chromatograph coupled with a photodiode (HPLC-DAD) method. The antioxidant activity of HR and FHR were determined by DPPH free radical and hydrogen peroxide (H2O2) scavenging assay. Also, the neuroprotective activities of HR and FHR against glutamate-induced oxidative stress in a mouse hippocampal cell line (HT22) were evaluated by MTT assay. Results: The contents of geniposide and palmatine were decreased but the content of berberine was increased in the FHR. And the contents of unknown compounds (1), (2), (3), (4) and (5) in the HR were altered by fermentation. Electron donating activity (EDA, %) value of FHR was higher than HR for DPPH radical scavenging activity and H2O2 scavenging activity, respectively. In the MTT assay, FHR showed more potent neuroprotective activity than HR by 513.90%. Conclusion: The FHR using microorganism could convert compounds in HR and enhance the antioxidant and neuroprotective activity. PMID:21969791

  7. Nanowires and nanoribbons as subwavelength optical waveguides and their use as components in photonic circuits and devices

    DOEpatents

    Yang, Peidong; Law, Matt; Sirbuly, Donald J.; Johnson, Justin C.; Saykally, Richard; Fan, Rong; Tao, Andrea

    2012-10-02

    Nanoribbons and nanowires having diameters less than the wavelength of light are used in the formation and operation of optical circuits and devices. Such nanostructures function as subwavelength optical waveguides which form a fundamental building block for optical integration. The extraordinary length, flexibility and strength of these structures enable their manipulation on surfaces, including the precise positioning and optical linking of nanoribbon/wire waveguides and other nanoribbon/wire elements to form optical networks and devices. In addition, such structures provide for waveguiding in liquids, enabling them to further be used in other applications such as optical probes and sensors.

  8. Quinic acid is a biologically active component of the Uncaria tomentosa extract C-Med 100.

    PubMed

    Akesson, Christina; Lindgren, Hanna; Pero, Ronald W; Leanderson, Tomas; Ivars, Fredrik

    2005-01-01

    We have previously reported that the C-Med 100 extract of the plant Uncaria tomentosa induces prolonged lymphocyte half life and hence increased spleen cell number in mice receiving the extract in their drinking water. Further, the extract induces cell proliferation arrest and inhibits activation of the transcriptional regulator nuclear factor kappaB (NF-kappaB) in vitro. We now report that mice exposed to quinic acid (QA), a component of this extract, had significantly increased number of spleen cells, thus recapitulating the in vivo biological effect of C-Med 100 exposure. Commercially supplied QA (H(+) form) did not, however, inhibit cell proliferation in vitro, while the ammonia-treated QA (QAA) was a potent inhibitor. Both QA and QAA inhibited NF-kappaB activity in exposed cells at similar concentrations. Thus, our present data identify QA as a candidate component for both in vivo and in vitro biological effects of the C-Med 100 extract.

  9. Update: Diagnoses of overweight and obesity, active component, U.S. Armed Forces, 2011-2015.

    PubMed

    Clark, Leslie L; Taubman, Stephen B

    2016-09-01

    Excessive weight and body fat among currently serving active component members have a detrimental effect on operational effectiveness and increase the risk of both acute and chronic health effects related to overweight and obesity. During 2011-2015, the number and prevalence of active component members who received at least one clinical overweight diagnosis increased steadily (2011: n=71,168; 4.5%; 2015: n=113,958; 7.8%). Annual prevalences of clinical overweight increased most rapidly between 2011 and 2013, then remained relatively stable for the remainder of the surveillance period. Continued emphasis on improving "nutritional fitness" as well as physical fitness should continue as a priority of military medical and line leaders at every level. PMID:27682628

  10. Principal component analysis of Birkeland currents determined by the Active Magnetosphere and Planetary Electrodynamics Response Experiment

    NASA Astrophysics Data System (ADS)

    Milan, S. E.; Carter, J. A.; Korth, H.; Anderson, B. J.

    2015-12-01

    Principal component analysis is performed on Birkeland or field-aligned current (FAC) measurements from the Active Magnetosphere and Planetary Electrodynamics Response Experiment. Principal component analysis (PCA) identifies the patterns in the FACs that respond coherently to different aspects of geomagnetic activity. The regions 1 and 2 current system is shown to be the most reproducible feature of the currents, followed by cusp currents associated with magnetic tension forces on newly reconnected field lines. The cusp currents are strongly modulated by season, indicating that their strength is regulated by the ionospheric conductance at the foot of the field lines. PCA does not identify a pattern that is clearly characteristic of a substorm current wedge. Rather, a superposed epoch analysis of the currents associated with substorms demonstrates that there is not a single mode of response, but a complicated and subtle mixture of different patterns.

  11. 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.

  12. Calculation of Raman optical activity spectra for vibrational analysis.

    PubMed

    Mutter, Shaun T; Zielinski, François; Popelier, Paul L A; Blanch, Ewan W

    2015-05-01

    By looking back on the history of Raman Optical Activity (ROA), the present article shows that the success of this analytical technique was for a long time hindered, paradoxically, by the deep level of detail and wealth of structural information it can provide. Basic principles of the underlying theory are discussed, to illustrate the technique's sensitivity due to its physical origins in the delicate response of molecular vibrations to electromagnetic properties. Following a short review of significant advances in the application of ROA by UK researchers, we dedicate two extensive sections to the technical and theoretical difficulties that were overcome to eventually provide predictive power to computational simulations in terms of ROA spectral calculation. In the last sections, we focus on a new modelling strategy that has been successful in coping with the dramatic impact of solvent effects on ROA analyses. This work emphasises the role of complementarity between experiment and theory for analysing the conformations and dynamics of biomolecules, so providing new perspectives for methodological improvements and molecular modelling development. For the latter, an example of a next-generation force-field for more accurate simulations and analysis of molecular behaviour is presented. By improving the accuracy of computational modelling, the analytical capabilities of ROA spectroscopy will be further developed so generating new insights into the complex behaviour of molecules.

  13. Origin invariance in vibrational resonance Raman optical activity

    SciTech Connect

    Vidal, Luciano N. Cappelli, Chiara; Egidi, Franco; Barone, Vincenzo

    2015-05-07

    A theoretical investigation on the origin dependence of the vibronic polarizabilities, isotropic and anisotropic rotational invariants, and scattering cross sections in Resonance Raman Optical Activity (RROA) spectroscopy is presented. Expressions showing the origin dependence of these polarizabilities were written in the resonance regime using the Franck-Condon (FC) and Herzberg-Teller (HT) approximations for the electronic transition moments. Differently from the far-from-resonance scattering regime, where the origin dependent terms cancel out when the rotational invariants are calculated, RROA spectrum can exhibit some origin dependence even for eigenfunctions of the electronic Hamiltonian. At the FC level, the RROA spectrum is completely origin invariant if the polarizabilities are calculated using a single excited state or for a set of degenerate states. Otherwise, some origin effects can be observed in the spectrum. At the HT level, RROA spectrum is origin dependent even when the polarizabilities are evaluated from a single excited state but the origin effect is expected to be small in this case. Numerical calculations performed for (S)-methyloxirane, (2R,3R)-dimethyloxirane, and (R)-4-F-2-azetidinone at both FC and HT levels using the velocity representation of the electric dipole and quadrupole transition moments confirm the predictions of the theory and show the extent of origin effects and the effectiveness of suggested ways to remove them.

  14. 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.

  15. 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

  16. Automated optic disk boundary detection by modified active contour model.

    PubMed

    Xu, Juan; Chutatape, Opas; Chew, Paul

    2007-03-01

    This paper presents a novel deformable-model-based algorithm for fully automated detection of optic disk boundary in fundus images. The proposed method improves and extends the original snake (deforming-only technique) in two aspects: clustering and smoothing update. The contour points are first self-separated into edge-point group or uncertain-point group by clustering after each deformation, and these contour points are then updated by different criteria based on different groups. The updating process combines both the local and global information of the contour to achieve the balance of contour stability and accuracy. The modifications make the proposed algorithm more accurate and robust to blood vessel occlusions, noises, ill-defined edges and fuzzy contour shapes. The comparative results show that the proposed method can estimate the disk boundaries of 100 test images closer to the groundtruth, as measured by mean distance to closest point (MDCP) <3 pixels, with the better success rate when compared to those obtained by gradient vector flow snake (GVF-snake) and modified active shape models (ASM).

  17. Resonance Raman Optical Activity of Single Walled Chiral Carbon Nanotubes.

    PubMed

    Nagy, Péter R; Koltai, János; Surján, Péter R; Kürti, Jenő; Szabados, Ágnes

    2016-07-21

    Resonance (vibrational) Raman Optical Activity (ROA) spectra of six chiral single-walled carbon nanotubes (SWCNTs) are studied by theoretical means. Calculations are performed imposing line group symmetry. Polarizability tensors, computed at the π-electron level, are differentiated with respect to DFT normal modes to generate spectral intensities. This computational protocol yields a ROA spectrum in good agreement with the only experiment on SWCNT, available at present. In addition to the conventional periodic electric dipole operator we introduce magnetic dipole and electric quadrupole operators, suitable for conventional k-space calculations. Consequences of the complex nature of the wave function on the scattering cross section are discussed in detail. The resonance phenomenon is accounted for by the short time approximation. Involvement of fundamental vibrations in the region of the intermediate frequency modes is found to be more notable in ROA than in Raman spectra. Calculations indicate exceptionally strong resonance enhancement of SWCNT ROA signals. Resonance ROA profile of the (6,5) tube shows an interesting sign change that may be exploited experimentally for SWCNT identification. PMID:27315548

  18. Informal Activities with Lasers, Lights, and Lenses: The Hands-On Optics Project

    NASA Astrophysics Data System (ADS)

    Pompea, S. M.; Sparks, C. E.; Sparks, R. T.

    2005-12-01

    The Hands-On Optics project began as a follow-up to the 2001 NSF planning grant "Optics Education -- A Blueprint for the 21st Century", which described the value of informal science programs in addressing the disconnect between the ubiquity of optics in everyday life and the noticeable absence of optics education in K-12 curricula and in informal science education programs. Key partners in the project are NOAO, SPIE-The International Society for Optical Engineering, and the Optical Society of America (OSA). The informal instructional materials created by the project are distributed through science centers nationwide and through the Mathematics, Engineering, Science Achievement Program (MESA) in a number of states, including Arizona, California, Washington, and Maryland. A key part of the project is the involvement, modeled after Project ASTRO, of optics professionals currently engaged in outreach activities and programs. Optics professionals (termed optics resource volunteers) are teamed with MESA and science center educators in implementing the program. These hands-on, high-interest, standards-connected activities and materials provide 6, three-hour-long optics activity modules that can be used in a variety of informal settings. We will describe the techniques used at NOAO to train educators, parents, and optics professionals who will work with the HOO activities as well as the different approaches needed for different informal education programs, ranging from Saturday programs, after-school programs, and science center programs. NOAO is developing the six modules and associated kits as well as competitions that have broad appeal to 12-year olds. Hands-On Optics: Making an Impact with Light (HOO) is a collaborative NSF-funded four-year informal science education program to excite students about science by actively engaging them in optics activities. NOAO is operated by the Association of Universities for Research in Astronomy (AURA), Inc. under cooperative

  19. [Study on extraction methods of activity components from Podophyllum emodi wall].

    PubMed

    Shen, Guang-yuan; Tian, Xuan

    2006-05-01

    Supercritical fluid Extraction (SFE) with subsequent HPLC analysis was utilized to extract activity components such as podophyllotoxin, deoxypodophyllotoxin, kaempferol and quercetin from the roots and stems of Podophyllum emodi Wall. The extraction yields obtained by SFE were compared to those obtained by organic solvent extraction and were found to be comparable or lower. In addition, we used the orthogonal experiment which conducts with 3 factors and 4 levers in order to find the best dynamic extraction conditions.

  20. Active Components of Fungus Shiraia bambusiscola Can Specifically Induce BGC823 Gastric Cancer Cell Apoptosis

    PubMed Central

    Zhang, Shubing; Qiu, Dewen; Liu, Jingjiang; Li, Zhijian

    2016-01-01

    Objective Gastric cancer is a major health issue worldwide. Using a therapeutic approach, with minor side-effects, is very essential for the treatment of the gastric cancer. Shiraia bambusicola is a parasitic fungus which is widely used in China for curing several diseases with little side-effects. However, the mechanisms are not well understood yet. The aim of this study was to further understand the pharmacological mechanisms of Shiraia bambusicola and investigate whether it can be used for curing gastric cancer. Materials and Methods In this experimental study, we mainly tested the effect of active components extracted from Shiraia bambusicola on BGC823, A549 and HepG2 cells. We used MTT assay to test cell viability. We also analyzed morphologic changes caused by apoptosis using Hoechst 33342 fluorescence staining, as well as cell cycle status and apoptosis ratio using flow-cytometer. In addition, protein expression level was tested by Western-blotting assay. Results BGC-823 cell proliferation was specifically inhibited by active components of Shiraia bambusicola. Meanwhile, these active components could induce BGC-823 cells apoptosis and retard the cell cycle in S/G2 phase. We also determined that two critical protein markers cleaved Poly(ADP-ribose) polymerase-1 (PARP-1) and FLICE-inhibitory protein (FLIP), involved in apoptosis process, were regulated by these active components. Conclusion These data shed light on the treatment of human gastric cancer and conclude that Shiraia bambusicola can be a good therapeutic candidate for treatment of this malignancy. PMID:27540519