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Sample records for high-speed optical quantum

  1. High Speed Quantum Key Distribution Over Optical Fiber Network System.

    PubMed

    Ma, Lijun; Mink, Alan; Tang, Xiao

    2009-01-01

    The National Institute of Standards and Technology (NIST) has developed a number of complete fiber-based high-speed quantum key distribution (QKD) systems that includes an 850 nm QKD system for a local area network (LAN), a 1310 nm QKD system for a metropolitan area network (MAN), and a 3-node quantum network controlled by a network manager. This paper discusses the key techniques used to implement these systems, which include polarization recovery, noise reduction, frequency up-conversion detection based on a periodically polled lithium nitrate (PPLN) waveguide, custom high-speed data handling boards and quantum network management. Using our quantum network, a QKD secured video surveillance application has been demonstrated. Our intention is to show the feasibility and sophistication of QKD systems based on current technology. PMID:27504218

  2. High-speed linear optics quantum computing using active feed-forward.

    PubMed

    Prevedel, Robert; Walther, Philip; Tiefenbacher, Felix; Böhi, Pascal; Kaltenbaek, Rainer; Jennewein, Thomas; Zeilinger, Anton

    2007-01-01

    As information carriers in quantum computing, photonic qubits have the advantage of undergoing negligible decoherence. However, the absence of any significant photon-photon interaction is problematic for the realization of non-trivial two-qubit gates. One solution is to introduce an effective nonlinearity by measurements resulting in probabilistic gate operations. In one-way quantum computation, the random quantum measurement error can be overcome by applying a feed-forward technique, such that the future measurement basis depends on earlier measurement results. This technique is crucial for achieving deterministic quantum computation once a cluster state (the highly entangled multiparticle state on which one-way quantum computation is based) is prepared. Here we realize a concatenated scheme of measurement and active feed-forward in a one-way quantum computing experiment. We demonstrate that, for a perfect cluster state and no photon loss, our quantum computation scheme would operate with good fidelity and that our feed-forward components function with very high speed and low error for detected photons. With present technology, the individual computational step (in our case the individual feed-forward cycle) can be operated in less than 150 ns using electro-optical modulators. This is an important result for the future development of one-way quantum computers, whose large-scale implementation will depend on advances in the production and detection of the required highly entangled cluster states.

  3. High Speed Quantum Key Distribution Over Optical Fiber Network System1

    PubMed Central

    Ma, Lijun; Mink, Alan; Tang, Xiao

    2009-01-01

    The National Institute of Standards and Technology (NIST) has developed a number of complete fiber-based high-speed quantum key distribution (QKD) systems that includes an 850 nm QKD system for a local area network (LAN), a 1310 nm QKD system for a metropolitan area network (MAN), and a 3-node quantum network controlled by a network manager. This paper discusses the key techniques used to implement these systems, which include polarization recovery, noise reduction, frequency up-conversion detection based on a periodically polled lithium nitrate (PPLN) waveguide, custom high-speed data handling boards and quantum network management. Using our quantum network, a QKD secured video surveillance application has been demonstrated. Our intention is to show the feasibility and sophistication of QKD systems based on current technology. PMID:27504218

  4. High speed optical networks

    NASA Astrophysics Data System (ADS)

    Frankel, Michael Y.; Livas, Jeff

    2005-02-01

    This overview will discuss core network technology and cost trade-offs inherent in choosing between "analog" architectures with high optical transparency, and ones heavily dependent on frequent "digital" signal regeneration. The exact balance will be related to the specific technology choices in each area outlined above, as well as the network needs such as node geographic spread, physical connectivity patterns, and demand loading. Over the course of a decade, optical networks have evolved from simple single-channel SONET regenerator-based links to multi-span multi-channel optically amplified ultra-long haul systems, fueled by high demand for bandwidth at reduced cost. In general, the cost of a well-designed high capacity system is dominated by the number of optical to electrical (OE) and electrical to optical (EO) conversions required. As the reach and channel capacity of the transport systems continued to increase, it became necessary to improve the granularity of the demand connections by introducing (optical add/drop multiplexers) OADMs. Thus, if a node requires only small demand connectivity, most of the optical channels are expressed through without regeneration (OEO). The network costs are correspondingly reduced, partially balanced by the increased cost of the OADM nodes. Lately, the industry has been aggressively pursuing a natural extension of this philosophy towards all-optical "analog" core networks, with each demand touching electrical digital circuitry only at the in/egress nodes. This is expected to produce a substantial elimination of OEO costs, increase in network capacity, and a notionally simpler operation and service turn-up. At the same time, such optical "analog" network requires a large amount of complicated hardware and software for monitoring and manipulating high bit rate optical signals. New and more complex modulation formats that provide resiliency to both optical noise and nonlinear propagation effects are important for extended

  5. Gated high speed optical detector

    NASA Technical Reports Server (NTRS)

    Green, S. I.; Carson, L. M.; Neal, G. W.

    1973-01-01

    The design, fabrication, and test of two gated, high speed optical detectors for use in high speed digital laser communication links are discussed. The optical detectors used a dynamic crossed field photomultiplier and electronics including dc bias and RF drive circuits, automatic remote synchronization circuits, automatic gain control circuits, and threshold detection circuits. The equipment is used to detect binary encoded signals from a mode locked neodynium laser.

  6. High speed quantum communication testbed

    NASA Astrophysics Data System (ADS)

    Williams, Carl J.; Tang, Xiao; Heikkero, Mikko; Rouzaud, Julie; Lu, Richang; Goedecke, Andreas; Migdall, Alan L.; Mink, Alan; Nakassis, Anastase; Pibida, Leticia S.; Wen, Jesse; Hagley, Edward; Clark, Charles W.

    2002-12-01

    We describe the status of the NIST Quantum Communication Testbed (QCT) facility. QCT is a facility for exploring quantum communication in an environment similar to that projected for early commercial implementations: quantum cryptographic key exchange on a gigabit/second free-space optical (FSO) channel. Its purpose is to provide an open platform for testing and validating performance in the application, network, and physical layers of quantum communications systems. The channel uses modified commercial FSO equipment to link two buildings on the Gaithersburg, MD campus of the National Institute of Standards and Technology (NIST), separated by approximately 600 meters. At the time of writing, QCT is under construction; it will eventually be made available to the research community as a user facility. This paper presents the basic design considerations underlying QCT, and reports the status of the project.

  7. Quantum dot semiconductor optical amplifier/silicon external cavity laser for O-band high-speed optical communications

    NASA Astrophysics Data System (ADS)

    Yang, Shuyu; Zhang, Yi; Li, Qi; Zhu, Xiaoliang; Bergman, Keren; Magill, Peter; Baehr-Jones, Thomas; Hochberg, Michael

    2015-02-01

    We report a hybrid integrated external cavity laser by butt coupling a quantum dot reflective semiconductor optical amplifier and a silicon-on-insulator chip. The device lasers at 1302 nm in the O-band, a wavelength regime critical to data communication systems. We measured 18 mW on-chip output power and over 50-dB side-mode suppression ratio. We also demonstrated open eye diagrams at 10 and 40 Gb/s.

  8. Optical receiver for high-speed communication

    NASA Astrophysics Data System (ADS)

    Mitchell, Paul A.; Grib, Valerie J.

    2010-04-01

    For through-the-air optical communication applications, we present a high speed detector module with high bandwidth and large active area. The detector has achieved a rise time of 220 pS with a full-width-half-max of 420 pS. Data rates are expected to approach 2 GHz. The active area of the input window is 12 mm, giving a large collection surface for through-the-air applications. The detector module includes an integrated power supply having low power consumption. In comparison with other detector technologies, this new detector exceeds the speed of conventional photomultiplier designs by 3 to 5 times. In comparison with microchannel plate detectors, the speed is comparable, but the throughput of the new detector is much higher - tens of microamperes of signal current can be obtained indefinitely. Optical communication applications can be served by two different designs. In the first case, the module utilizes gain based on ordinary secondary emission materials to achieve current gains of 1500. This design is suitable for applications at the limit of the detector's bandwidth where light power is relatively high. In another design, the secondary emission material was changed to diamond film which allows five times higher gain. While the current design uses an ordinary, blue sensitive input light conversion material, higher efficiency materials are in development for signals at longer wavelength.

  9. High-speed wireless optical LANs

    NASA Astrophysics Data System (ADS)

    Oe, Kunishige; Sato, Syuichi; Okayama, Motoyuki; Kubota, Toshihiro

    2001-11-01

    Study on high speed indoor wireless optical LAN system enabling 100Mbps signal transmission with low bit error rate (10-9) is presented. To realize the optical LAN system handling 100 Mbps signal, a directed line of sight (LOS) system is adopted as the optical receiver sensitivity for a bit error rate of 10-9 for 100 Mbps signals is fairly large. In the system, new approaches are introduced: WDM technology which enables bi-directional transmission in full duplex manner is applied using a 1.3 micrometers laser diode for down-link and 0.65 micrometers red laser diode for up-link light sources. As the wavelengths of the two lasers are quite separated from each other, this WDM technology brings an advantage that two kind of semiconductor materials can be used for detectors; GaInAs is used for down-link while Si is applied for up-link. GaInAs PD cannot detect the up-link laser light of 0.65 micrometers and Si PD or APD cannot detect the down-link laser light of 1.3micrometers . Therefore full duplex transmission can be achieved in this configuration. In the indoor wireless optical LAN system, one of the critical points is the transmitter configuration for down- link which enables to deliver optical power enough for 100 Mbps transmission to user areas as wide as possible with inexpensive prices. To realize the point, a special 1.3micrometers laser diode, a spot-size converter integrated laser (SS-LD), is introduced in company with convex lens and an object lens to deliver optical power to areas as wide as possible. As the far-field patterns of the SS-LD are fairly narrow, most of the output power of the LD could be collected to and spread wide by the object lens of 40 magnifications. Using the device, 3m diameter circle area in the plane 2m apart from the 1.3micrometers SS-LD emitting 20 mW optical power, could receive optical power above the receiver sensitivity for a bit error rate of 10-9 for 100 Mbps signals. The visible red light is convenient for not only position

  10. High speed demodulation systems for fiber optic grating sensors

    NASA Technical Reports Server (NTRS)

    Udd, Eric (Inventor); Weisshaar, Andreas (Inventor)

    2002-01-01

    Fiber optic grating sensor demodulation systems are described that offer high speed and multiplexing options for both single and multiple parameter fiber optic grating sensors. To attain very high speeds for single parameter fiber grating sensors ratio techniques are used that allow a series of sensors to be placed in a single fiber while retaining high speed capability. These methods can be extended to multiparameter fiber grating sensors. Optimization of speeds can be obtained by minimizing the number of spectral peaks that must be processed and it is shown that two or three spectral peak measurements may in specific multiparameter applications offer comparable or better performance than processing four spectral peaks. Combining the ratio methods with minimization of peak measurements allows very high speed measurement of such important environmental effects as transverse strain and pressure.

  11. Magneto-optical system for high speed real time imaging.

    PubMed

    Baziljevich, M; Barness, D; Sinvani, M; Perel, E; Shaulov, A; Yeshurun, Y

    2012-08-01

    A new magneto-optical system has been developed to expand the range of high speed real time magneto-optical imaging. A special source for the external magnetic field has also been designed, using a pump solenoid to rapidly excite the field coil. Together with careful modifications of the cryostat, to reduce eddy currents, ramping rates reaching 3000 T/s have been achieved. Using a powerful laser as the light source, a custom designed optical assembly, and a high speed digital camera, real time imaging rates up to 30 000 frames per seconds have been demonstrated.

  12. Magneto-optical system for high speed real time imaging.

    PubMed

    Baziljevich, M; Barness, D; Sinvani, M; Perel, E; Shaulov, A; Yeshurun, Y

    2012-08-01

    A new magneto-optical system has been developed to expand the range of high speed real time magneto-optical imaging. A special source for the external magnetic field has also been designed, using a pump solenoid to rapidly excite the field coil. Together with careful modifications of the cryostat, to reduce eddy currents, ramping rates reaching 3000 T/s have been achieved. Using a powerful laser as the light source, a custom designed optical assembly, and a high speed digital camera, real time imaging rates up to 30 000 frames per seconds have been demonstrated. PMID:22938303

  13. Review of High-Speed Fiber Optic Grating Sensors Systems

    SciTech Connect

    Udd, E; Benterou, J; May, C; Mihailov, S J; Lu, P

    2010-03-24

    Fiber grating sensors can be used to support a wide variety of high speed measurement applications. This includes measurements of vibrations on bridges, traffic monitoring on freeways, ultrasonic detection to support non-destructive tests on metal plates and providing details of detonation events. This paper provides a brief overview of some of the techniques that have been used to support high speed measurements using fiber grating sensors over frequency ranges from 10s of kHz, to MHZ and finally toward frequencies approaching the GHz regime. Very early in the development of fiber grating sensor systems it was realized that a high speed fiber grating sensor system could be realized by placing an optical filter that might be a fiber grating in front of a detector so that spectral changes in the reflection from a fiber grating were amplitude modulated. In principal the only limitation on this type of system involved the speed of the output detector which with the development of high speed communication links moved from the regime of 10s of MHz toward 10s of GHz. The earliest deployed systems involved civil structures including measurements of the strain fields on composite utility poles and missile bodies during break tests, bridges and freeways. This was followed by a series of developments that included high speed fiber grating sensors to support nondestructive testing via ultrasonic wave detection, high speed machining and monitoring ship hulls. Each of these applications involved monitoring mechanical motion of structures and thus interest was in speeds up to a few 10s of MHz. Most recently there has been interest in using fiber grating to monitor the very high speed events such as detonations and this has led to utilization of fiber gratings that are consumed during an event that may require detection speeds of hundreds of MHz and in the future multiple GHz.

  14. Ultra-high-speed optical and electronic distributed devices

    SciTech Connect

    Hietala, V.M.; Plut, T.A.; Kravitz, S.H.; Vawter, G.A.; Wendt, J.R.; Armendariz, M.G.

    1995-08-01

    This report summarizes work on the development of ultra-high-speed semiconductor optical and electronic devices. High-speed operation is achieved by velocity matching the input stimulus to the output signal along the device`s length. Electronic devices such as field-effect transistors (FET`s), should experience significant speed increases by velocity matching the electrical input and output signals along the device. Likewise, optical devices, which are typically large, can obtain significant bandwidths by velocity matching the light being generated, detected or modulated with the electrical signal on the device`s electrodes. The devices discussed in this report utilize truly distributed electrical design based on slow-wave propagation to achieve velocity matching.

  15. Bufferless Ultra-High Speed All-Optical Packet Routing

    NASA Astrophysics Data System (ADS)

    Muttagi, Shrihari; Prince, Shanthi

    2011-10-01

    All-Optical network is still in adolescence to cope up with steep rise in data traffic at the backbone network. Routing of packets in optical network depends on the processing speed of the All-Optical routers, thus there is a need to enhance optical processing to curb the delay in packet forwarding unit. In the proposed scheme, the header processing takes place on fly, therefore processing delay is at its lower limit. The objective is to propose a framework which establishes high data rate transmission with least latency in data routing from source to destination. The Routing table and optical header pulses are converted into Pulse Position (PP) format, thus reducing the complexity and in turn the processing delay. Optical pulse matching is exercised which results in multi-output transmission. This results in ultra-high speed packet forwarding unit. In addition, this proposed scheme includes dispersion compensation unit, which makes the data reliable.

  16. Multiplexed communication over a high-speed quantum channel

    NASA Astrophysics Data System (ADS)

    Heurs, M.; Webb, J. G.; Dunlop, A. E.; Harb, C. C.; Ralph, T. C.; Huntington, E. H.

    2010-03-01

    In quantum information systems it is of particular interest to consider the best way in which to use the nonclassical resources consumed by that system. Quantum communication protocols are integral to quantum information systems and are among the most promising near-term applications of quantum information science. Here we show that a multiplexed, digital quantum communications system supported by a comb of vacuum squeezing has a greater channel capacity per photon than a source of broadband squeezing with the same analog band width. We report on the time-resolved, simultaneous observation of the first dozen teeth in a 2.4-GHz comb of vacuum squeezing produced by a subthreshold optical parametric oscillator, as required for such a quantum communications channel. We also demonstrate multiplexed communication on that channel.

  17. Multiplexed communication over a high-speed quantum channel

    SciTech Connect

    Heurs, M.; Webb, J. G.; Dunlop, A. E.; Harb, C. C.; Huntington, E. H.; Ralph, T. C.

    2010-03-15

    In quantum information systems it is of particular interest to consider the best way in which to use the nonclassical resources consumed by that system. Quantum communication protocols are integral to quantum information systems and are among the most promising near-term applications of quantum information science. Here we show that a multiplexed, digital quantum communications system supported by a comb of vacuum squeezing has a greater channel capacity per photon than a source of broadband squeezing with the same analog band width. We report on the time-resolved, simultaneous observation of the first dozen teeth in a 2.4-GHz comb of vacuum squeezing produced by a subthreshold optical parametric oscillator, as required for such a quantum communications channel. We also demonstrate multiplexed communication on that channel.

  18. High Speed Optical Tomography System for Imaging Dynamic Transparent Media

    NASA Astrophysics Data System (ADS)

    McMackin, Lenore; Hugo, Ronald J.; Pierson, R. E.; Truman, C. R.

    1997-11-01

    We describe the design and operation of a high speed optical tomography system for measuring two-dimensional images of a dynamic phase object at a rate of 5 kHz. Data from a set of eight Hartmann wavefront sensors is back-projected to produce phase images showing the details of the inner structure of a heated air flow. The tomographic reconstructions have a spatial resolution of approximately 2.0 mm and can measure temperature variations across the flow with an accuracy of about 0.7 C. Series of animated reconstructions at different downstream locations illustrate the development of flow structure and the effect of acoustic flow forcing.

  19. High speed optical links between LLNL and Berkeley

    SciTech Connect

    Lennon, W.J.; Thombley, R.L.

    1994-08-08

    The Advanced Telecommunications Program at Lawrence Livermore National Laboratory, in collaboration with Pacific Bell, is developing an experimental high speed, four wavelength, protocol independent optical link for evaluating wide area networking interconnection schemes and the use of fiber amplifiers. Lawrence Livermore National Laboratory, as a super-user, supercomputer, and super-application site, is anticipating the future bandwidth and protocol requirements to connect to other such sites as well as to connect to remote sited control centers and experiments. In this paper we discuss our vision of the future of Wide Area Networking and describe the plans for the wavelength division multiplexed link between Livermore and the University of California at Berkeley.

  20. Reflectively Coupled Waveguide Photodetector for High Speed Optical Interconnection

    PubMed Central

    Hsu*, Shih-Hsiang

    2010-01-01

    To fully utilize GaAs high drift mobility, techniques to monolithically integrate In0.53Ga0.47As p-i-n photodetectors with GaAs based optical waveguides using total internal reflection coupling are reviewed. Metal coplanar waveguides, deposited on top of the polyimide layer for the photodetector’s planarization and passivation, were then uniquely connected as a bridge between the photonics and electronics to illustrate the high-speed monitoring function. The photodetectors were efficiently implemented and imposed on the echelle grating circle for wavelength division multiplexing monitoring. In optical filtering performance, the monolithically integrated photodetector channel spacing was 2 nm over the 1,520–1,550 nm wavelength range and the pass band was 1 nm at the −1 dB level. For high-speed applications the full-width half-maximum of the temporal response and 3-dB bandwidth for the reflectively coupled waveguide photodetectors were demonstrated to be 30 ps and 11 GHz, respectively. The bit error rate performance of this integrated photodetector at 10 Gbit/s with 27-1 long pseudo-random bit sequence non-return to zero input data also showed error-free operation. PMID:22163502

  1. Coherent DWDM technology for high speed optical communications

    NASA Astrophysics Data System (ADS)

    Saunders, Ross

    2011-10-01

    The introduction of coherent digital optical transmission enables a new generation of high speed optical data transport and fiber impairment mitigation. An initial implementation of 40 Gb/s coherent systems using Dual Polarization Quadrature Phase Shift Keying (DP-QPSK) is already being installed in carrier networks. New systems running at 100 Gb/s DP-QPSK data rate are in development and early technology lab and field trial phase. Significant investment in the 100 Gb/s ecosystem (optical components, ASICs, transponders and systems) bodes well for commercial application in 2012 and beyond. Following in the footsteps of other telecommunications fields such as wireless and DSL, we can expect coherent optical transmission to evolve from QPSK to higher order modulations schemes such as Mary PSK and/or QAM. This will be an interesting area of research in coming years and poses significant challenges in terms of electro-optic, DSP, ADC/DAC design and fiber nonlinearity mitigation to reach practical implementation ready for real network deployments.

  2. Corneal Pachymetry Mapping with High-speed Optical Coherence Tomography

    PubMed Central

    Li, Yan; Shekhar, Raj; Huang, David

    2006-01-01

    Objective To map corneal thickness before and after LASIK with optical coherence tomography (OCT). Design Cross-sectional observational study. Participants Forty-two eyes of 21 normal subjects undergoing LASIK. Methods A high-speed (2000 axial scans/second) 1.3-μm-wavelength corneal and anterior segment OCT prototype was used for corneal scanning. The scan pattern consisted of 10-mm radial lines on 8 meridians centered on the vertex reflection. The entire scan pattern of 1024 a-scans was acquired in 0.5 seconds. We developed automated computer processing for 3-dimensional corneal reconstruction and measurement. Corneal thickness was measured normal to the anterior surface and presented as color pachymetry maps and zonal statistics. The maps were divided into a central zone (<2 mm) and 3 annular areas (pericentral, 2–5 mm; transitional, 5–7 mm; peripheral, 7–10 mm), which were further divided into quadrantal zones. The average, minimum, and maximum corneal thicknesses were computed for zones within the 7-mm diameter. Optical coherence tomography and ultrasound pachymetry were measured 3 times at the preoperative and 3-month postoperative visits. Reproducibility was assessed by the pooled standard deviations (SDs) of the repeated measurements. Main Outcome Measures Optical coherence tomography pachymetric map and zonal statistic, and ultrasound pachymetry. Results Before LASIK, central corneal thicknesses (CCTs) were 546.9±29.4 μm (mean ± SD) for OCT and 553.3±33.0 μm for ultrasound. After LASIK, CCTs were 513.7±44.5 μm for OCT and 498±46.6 μm for ultrasound. Optical coherence tomography and ultrasound CCT were highly correlated (Pearson correlation r = 0.97 before LASIK and 0.98 afterwards). Optical coherence tomography CCT was slightly less than ultrasound CCT before surgery (mean difference, −6.4 μm; 95% limits of agreement, −23.2 to 10.4 μm) but slightly greater after LASIK (15.7 μm; −1.6 to 33 μm). These differences were statistically

  3. Data security in high-speed optical links

    NASA Astrophysics Data System (ADS)

    Kartalopoulos, Stamatios V.

    2005-05-01

    Wavelength Division Multiplexing (WDM) is a photonic technology capable to transport over a single fiber more than a Tbit/s aggregate traffic. Currently, WDM is the only deployed method in transcontinental and transoceanic applications. In the optical network, each fiber link consists of segments, each several kilometers long, the connecting points of which are amenable to tapping. When a small amount of optical signal is extracted from a tap, when the signal is properly amplified it can be monitored by unauthorized personnel thus threatening communications and land-security. Since each WDM channel carries traffic from one customer, it is not difficult for the connoisseur to demultiplex a specific channel, isolate a specific payload and break the encrypted datagram. Therefore, in addition to data encryption, high-speed communications security should also rely on securing the optical links. In this paper, we present a WDM link security method that, even if fiber is tapped, constitutes channel monitoring and information decrypting by an eavesdropper or unauthorized personnel virtually impossible. In addition, we describe the circuit building blocks behind the method that makes eavesdropping impossible.

  4. High Speed Measurements using Fiber-optic Bragg Grating Sensors

    SciTech Connect

    Benterou, J J; May, C A; Udd, E; Mihailov, S J; Lu, P

    2011-03-26

    Fiber grating sensors may be used to monitor high-speed events that include catastrophic failure of structures, ultrasonic testing and detonations. This paper provides insights into the utility of fiber grating sensors to measure structural changes under extreme conditions. An emphasis is placed on situations where there is a structural discontinuity. Embedded chirped fiber Bragg grating (CFBG) sensors can track the very high-speed progress of detonation waves (6-9 km/sec) inside energetic materials. This paper discusses diagnostic instrumentation and analysis techniques used to measure these high-speed events.

  5. High-speed data encryption over 25 km of fiber by two-mode coherent-state quantum cryptography.

    PubMed

    Corndorf, Eric; Barbosa, Geraldo; Liang, Chuang; Yuen, Horace P; Kumar, Prem

    2003-11-01

    We demonstrate high-speed (250 Mbps) data encryption over 25 km of telecommunication fiber by use of coherent states. For the parameter values used in the experiment, the demonstration is secure against individual ciphertext-only eavesdropping attacks near the transmitter with ideal detection equipment. Whereas other quantum-cryptographic schemes require the use of fragile quantum states and ultrasensitive detection equipment, our protocol is loss tolerant, uses off-the-shelf components, and is optically amplifiable.

  6. Atomic thermal motion effect on efficiency of a high-speed quantum memory

    NASA Astrophysics Data System (ADS)

    Tikhonov, Kirill; Golubeva, Tania; Golubev, Yuri

    2015-11-01

    We discuss the influence of atomic thermal motion on the efficiency of multimode quantum memory in two configurations: over the free expand of atoms cooled beforehand in a magneto-optical trap, and over complete mixing of atoms in a closed cell at room temperature. We consider the high-speed quantum memory, and assume that writing and retrieval are short enough, and the displacements of atoms during these stages are negligibly small. At the same time we take in account thermal motion during the storage time, which, as well known, must be much longer than durations of all the other memory processes for successful application of memory cell in communication and computation. We will analyze this influence in terms of eigenmodes of the full memory cycle and show that distortion of the eigenmodes, caused by thermal motion, leads to the efficiency reduction. We will demonstrate, that in the multimode memory this interconnection has complicated character.

  7. High-speed red RCLEDs and VCSELs for plastic optical fiber application

    NASA Astrophysics Data System (ADS)

    Chiou, Shu-Woei; Lee, Yea-Chen; Chang, Chih-Sung; Chen, Tzer-Peng

    2005-03-01

    To investigate the high performance light source for high-speed plastic optical fiber (POF) communication application is important as high-speed short distance communication for the home networks becomes popular. It is straightforward to reduce the size of RCLEDs to increase the small-signal modulation bandwidth (f-3dB). But reduce the size of RCLEDs not only reduce the output power but also decrease lifetime because higher current density flowed through active region. In this paper, we improve. f-3dB of RCLEDs with the aperture of 84μm by reducing the number of quantum wells (QWs) in active region. We found the speed of RCLED inverse proportional to the number of QWs. By reducing the number of QWs to one, the device with standard aperture size exhibits high f-3dB as 235MHz at bias current of 20mA without sacrificing the other performance like maximum output power, high temperature performance, etc. These devices can transmit data rate as high as 500Mb/sec through graded-index POF over 50 meters. Beyond 1Gbits/sec, we have investigated red VCSELs as suitable high-speed light sources. The structure of red VCSELs is similar to RCLEDs except more pairs of DBR yield high reflectivity. Our red VCSEL can have output power as high as 1.5mW at 5mA and transmission data rate up to 2.5Gbits/sec.

  8. Visible high-speed optical transmission over photonic crystal fiber.

    PubMed

    Kurokawa, K; Ieda, K; Tajima, K; Nakajima, K; Shiraki, K; Sankawa, I

    2007-01-22

    We demonstrated high-speed transmission at visible wavelengths over a 1 km photonic crystal fiber (PCF). We achieved a 1 Gbit/s transmission at 783 nm by using the direct modulation of a cost-effective Fabry-Perot laser diode (FP-LD). By employing the external modulation of the longitudinally single-mode grating-stabilized LD, we obtained the first penalty free 10 Gbit/s transmission at 780 nm. PMID:19532256

  9. High-speed quantum-random number generation by continuous measurement of arrival time of photons

    SciTech Connect

    Yan, Qiurong; Zhao, Baosheng; Hua, Zhang; Liao, Qinghong; Yang, Hao

    2015-07-15

    We demonstrate a novel high speed and multi-bit optical quantum random number generator by continuously measuring arrival time of photons with a common starting point. To obtain the unbiased and post-processing free random bits, the measured photon arrival time is converted into the sum of integral multiple of a fixed period and a phase time. Theoretical and experimental results show that the phase time is an independent and uniform random variable. A random bit extraction method by encoding the phase time is proposed. An experimental setup has been built and the unbiased random bit generation rate could reach 128 Mb/s, with random bit generation efficiency of 8 bits per detected photon. The random numbers passed all tests in the statistical test suite.

  10. High-Speed Characterizatin of Optical Telecommunication Signals

    SciTech Connect

    Dorrer, C.

    2007-05-17

    Optical telecommunication systems constantly evolve toward higher bit rates, requiring the modulation and detection of higher-bandwidth optical waves. Commercial systems operating at 40 Gb/s are now available and research and development efforts are targeting higher bit rates for which optical pulses with picosecond-range duration are used. Chromatic dispersion, nonlinearities and amplified spontaneous emission from optical amplifiers are sources of transmission impairments that must be characterized and mitigated. Advanced modulation formats rely on the modulation of not only the amplitude of an optical wave (e.g., on/off keying), but also its phase (e.g., phase-shift keying) in order to optimize the transmission capabilities. The importance of the characterization of the properties of optical sources and components and the specificities of the optical telecommunication environment with respect to ultrafast optics are emphasized. Various diagnostics measuring the electric field of optical sources in the telecommunication environment are described. Sampling diagnostics capable of measuring eye diagrams and constellation diagrams of high-bit-rate, data-encoded sources are presented. Various optical pulse characterization techniques that meet the sensitivity requirements imposed by the telecommunication environment are also described.

  11. A high-speed GaAs MESFET optical controller

    NASA Technical Reports Server (NTRS)

    Claspy, P. C.; Bhasin, K. B.; Richard, M.; Bendett, M.; Gustafson, G.

    1989-01-01

    Optical interconnects are being considered for control signal distribution in phased array antennas. A packaged hybrid GaAs optical controller with a 1:16 demultiplexed output that is suitable for this application is described. The controller, which was fabricated using enhancement/depletion mode MESFET technology, operates at demultiplexer-limited input data rates up to 305 Mb/s and requires less than 200 microW optical input power.

  12. High-speed adaptive optics for imaging of the living human eye

    PubMed Central

    Yu, Yongxin; Zhang, Tianjiao; Meadway, Alexander; Wang, Xiaolin; Zhang, Yuhua

    2015-01-01

    The discovery of high frequency temporal fluctuation of human ocular wave aberration dictates the necessity of high speed adaptive optics (AO) correction for high resolution retinal imaging. We present a high speed AO system for an experimental adaptive optics scanning laser ophthalmoscope (AOSLO). We developed a custom high speed Shack-Hartmann wavefront sensor and maximized the wavefront detection speed based upon a trade-off among the wavefront spatial sampling density, the dynamic range, and the measurement sensitivity. We examined the temporal dynamic property of the ocular wavefront under the AOSLO imaging condition and improved the dual-thread AO control strategy. The high speed AO can be operated with a closed-loop frequency up to 110 Hz. Experiment results demonstrated that the high speed AO system can provide improved compensation for the wave aberration up to 30 Hz in the living human eye. PMID:26368408

  13. Electro-optical time marker for high-speed cameras

    NASA Technical Reports Server (NTRS)

    Copeland, J. T., Jr.

    1970-01-01

    Electro-optical device converts high-frequency electrical pulses into permanent optical records on film. Accurate, well defined images are formed of electronic pulses having repetition rates greater than 10,000 pulses/sec and pulse widths of 20 microseconds or less. Small electronic switch drives a silicon carbide electroluminescent diode.

  14. High-speed image matching with coaxial holographic optical correlator

    NASA Astrophysics Data System (ADS)

    Ikeda, Kanami; Watanabe, Eriko

    2016-09-01

    A computation speed of more than 100 Gbps is experimentally demonstrated using our developed ultrahigh-speed optical correlator. To verify this high computation speed practically, the computation speeds of our optical correlator and conventional digital image matching are quantitatively compared. We use a population count function that achieves the fastest calculation speed when calculating binary matching by a central processing unit (CPU). The calculation speed of the optical correlator is dramatically faster than that using a CPU (2.40 GHz × 4) and 16 GB of random access memory, especially when the calculation data are large-scale.

  15. Radiation-hard/high-speed parallel optical links

    NASA Astrophysics Data System (ADS)

    Gan, K. K.; Buchholz, P.; Heidbrink, S.; Kagan, H. P.; Kass, R. D.; Moore, J.; Smith, D. S.; Vogt, M.; Ziolkowski, M.

    2016-09-01

    We have designed and fabricated a compact parallel optical engine for transmitting data at 5 Gb/s. The device consists of a 4-channel ASIC driving a VCSEL (Vertical Cavity Surface Emitting Laser) array in an optical package. The ASIC is designed using only core transistors in a 65 nm CMOS process to enhance the radiation-hardness. The ASIC contains an 8-bit DAC to control the bias and modulation currents of the individual channels in the VCSEL array. The performance of the optical engine up at 5 Gb/s is satisfactory.

  16. Optical Peaking Enhancement in High-Speed Ring Modulators

    PubMed Central

    Müller, J.; Merget, F.; Azadeh, S. Sharif; Hauck, J.; García, S. Romero; Shen, B.; Witzens, J.

    2014-01-01

    Ring resonator modulators (RRM) combine extreme compactness, low power consumption and wavelength division multiplexing functionality, making them a frontrunner for addressing the scalability requirements of short distance optical links. To extend data rates beyond the classically assumed bandwidth capability, we derive and experimentally verify closed form equations of the electro-optic response and asymmetric side band generation resulting from inherent transient time dynamics and leverage these to significantly improve device performance. An equivalent circuit description with a commonly used peaking amplifier model allows straightforward assessment of the effect on existing communication system architectures. A small signal analytical expression of peaking in the electro-optic response of RRMs is derived and used to extend the electro-optic bandwidth of the device above 40 GHz as well as to open eye diagrams penalized by intersymbol interference at 32, 40 and 44 Gbps. Predicted peaking and asymmetric side band generation are in excellent agreement with experiments. PMID:25209255

  17. Ultra-high-speed pumping of an optical parametric oscillator (OPO) for high-speed laser-induced fluorescence measurements

    NASA Astrophysics Data System (ADS)

    Sjöholm, Johan; Kristensson, Elias; Richter, Mattias; Aldén, Marcus; Göritz, Guido; Knebel, Kai

    2009-02-01

    The feasibility of pumping an optical parametric oscillator (OPO) with an ultra-high repetition rate multi:YAG laser system, producing a burst of up to eight high-energy pulses, has been investigated. For this investigation an OPO with a bandwidth around 5 cm-1, together with a frequency doubling crystal, was selected. In some laser-induced fluorescence measurements the large linewidth from the OPO can be advantageous as several lines can be excited simultaneously avoiding the saturation effects of individual lines. The energy output from the OPO as a function of pulse separation was measured down to pulse separations of 400 ns and was found to be completely independent of the pulse separation. The efficiency of the OPO unit, when optimized for single-pulse operation, was measured to be around 25% for all pulses, giving over 80 mJ at 585 nm output when pumped with ~350 mJ at 355 nm. This is similar to the specified efficiency for the OPO. The system was found to give a slightly lower efficiency when double pulsing the Nd:YAG lasers. This is attributed to a somewhat elongated pulse length from the Nd:YAG lasers giving a lower pump energy density. The system was applied for measuring high-speed planar laser-induced fluorescence images of OH radicals in a Bunsen burner.

  18. Multiserver switch scheduling for high speed optical switches

    NASA Astrophysics Data System (ADS)

    Golla, Prasad; Blanton, John; Damm, Gerard

    2003-10-01

    A switch matrix implemented as an optical crossbar using semiconductor optical amplifiers is able to accommodate extreme concentrations of data traffic. Due to the need to reduce optical guard band overhead it is beneficial to switch fixed size bursts of data cells on a time slot basis. The high capacity of the optical matrix supports multiple optical ports per burst card, and the implementation of multiple queue servers per burst card helps make better use of the multiplicity of ports. Problems associated with arbitrating multiple ports and multiple servers per burst card have been resolved by extending the operation of existing iterative, single server scheduling algorithms. The multiserver arbitration time will be in proportion to the number of servers -- corresponding to the channels of DWDM link -- unless a reconciliation stage is used after each iteration when an arbiter per server is used. The reconciliation stage sets the problem of broken data dependencies between server arbitrations in this case. Further, to address the time limitations for computing the scheduling solution, parallel arbiter implementations have been developed and tested against single arbiter designs. Again, the broken dependencies between iterations of an arbitration are addressed through the use of a grant reconciliation stage. The use of multiple queue servers per burst card also resolves some of the data loss problems related to polarized traffic. Simulations of the multiple server and parallel arbiter implementations have demonstrated their efficiency compared to previous implementations. Compounded to this problem is maintaining high throughput of the switch matrix while observing data transit time limits. This involves balancing two contradictory requirements; switch or line card efficiency and data transit times. To improve efficiency it is desirable to transmit only full packets. However, to prevent loss of data due to timeout it will be necessary to transmit some incomplete

  19. Radiation-hard/high-speed data transmission using optical links

    NASA Astrophysics Data System (ADS)

    Gan, K. K.; Abi, B.; Fernando, W.; Kagan, H. P.; Kass, R. D.; Lebbai, M. R. M.; Moore, J. R.; Rizatdinova, F.; Skubic, P. L.; Smith, D. S.

    2009-12-01

    The silicon trackers of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN (Geneva) use optical links for data transmission. An upgrade of the trackers is planned for the Super LHC (SLHC), an upgraded LHC with ten times higher luminosity. We investigate the radiation-hardness of various components for possible application in the data transmission upgrade. We study the radiation-hardness of VCSELs (Vertical-Cavity Surface-Emitting Laser) and GaAs and silicon PINs from various sources using 24 GeV/c protons at CERN. The optical power of VCSEL arrays decreases significantly after the irradiation but can be partially annealed with high drive currents. The responsivities of the PIN diodes also decrease significantly after irradiation, especially for the GaAs devices. We have designed the ASICs for the opto-link applications and find that the degradation with radiation is acceptable.

  20. A prototype high-speed optically-steered X-band phased array antenna.

    PubMed

    Wu, Pengfei; Tang, Suning; Raible, Daniel E

    2013-12-30

    We develop a prototype of optically-steered X-band phased array antenna with capabilities of multi-band and multi-beam operations. It exploits high-speed wavelength tunable lasers for optical true-time delays over a dispersive optical fiber link, enabling agile, broadband and vibration-free RF beam steering with large angle.

  1. High speed infrared optical wireless for home access networks

    NASA Astrophysics Data System (ADS)

    O'Brien, Dominic C.

    2013-12-01

    The availability of high-bandwidth internet connections to home gateways will place increasing demands on the home access network that provides connections to computers and other devices. In this paper the use of infrared optical wireless to provide connections to user appliances and terminals is discussed. The design and implementation of two demonstration systems operating at hundreds of Mbit/s and above are detailed. Future challenges are also discussed.

  2. High speed OFDM-CDMA optical access network.

    PubMed

    Guo, X; Wang, Q; Zhou, L; Fang, L; Wonfor, A; Penty, R V; White, I H

    2016-04-15

    We demonstrate the feasibility of a 16 × 3.75 Gb/s (60 Gb/s aggregate) Orthogonal frequency division multiplexing-code division multiple access passive optical network for next-generation access applications. 3.75 Gb/s PON channel transmission over 25 km single-mode fiber shows 0.1 dB dispersion and 0.9 dB crosstalk penalties. Advantages of the system include high capacity, enhanced spectral efficiency, coding gain, and networking functions such as increased security and single-wavelength operation.

  3. High-Speed Flexible Optical Disk for Broadcast Archival Storage

    NASA Astrophysics Data System (ADS)

    Koide, Daiichi; Kajiyama, Takeshi; Tokumaru, Haruki; Takano, Yoshimichi; Onagi, Nobuaki; Aman, Yasutomo; Ohishi, Kiyoshi

    2010-08-01

    We developed a prototype of a flexible optical disk (FOD) drive with a mechanical stabilizer. We prepared the FOD that had a high recording sensitivity of a recording layer and had low byte error rates below 2 ×10-4 at speeds from 36 to 252 Mbps, and examined the recording of video data on the FOD and the drive. We could record and play a high-definition television (HDTV) video (MPEG-2, 422P@HL) seamlessly at 144 Mbps over the entire area of the FOD and the FOD drive with broadcast video systems. We confirmed that the FOD and the FOD drive can record and play HDTV signals for professional broadcast use.

  4. Nanocomposites for high-speed optical modulators and plasmonic thermal mid-infrared emitters

    NASA Astrophysics Data System (ADS)

    Demir, Veysi

    Demand for high-speed optical modulators and narrow-bandwidth infrared thermal emitters for numerous applications continues to rise and new optical devices are needed to deal with massive data flows, processing powers, and fabrication costs. Conventional techniques are usually hindered by material limitations or electronic interconnects and advances in organic nanocomposite materials and their integration into photonic integrated circuits (PICs) have been acknowledged as a promising alternative to single crystal techniques. The work presented in this thesis uses plasmonic and magneto-optic effects towards the development of novel optical devices for harnessing light and generating high bandwidth signals (>40GHz) at room and cryogenic temperatures (4.2°K). Several publications have resulted from these efforts and are listed at the end of the abstract. In our first published research we developed a narrow-bandwidth mid-infrared thermal emitter using an Ag/dielectric/Ag thin film structure arranged in hexagonal planar lattice structures. PECVD produced nanoamorphous carbon (NAC) is used as a dielectric layer. Spectrally tunable (>2 mum) and narrow bandwidth (<0.5 mum) emission peaks in the range of 4-7 mum were demonstrated by decreasing the resistivity of NAC from 1012 and 109 O.cm with an MoSi2 dopant and increasing the emitter lattice constant from 4 to 7 mum. This technique offers excellent flexibility for developing cost-effective mid-IR sources as compared to costly fiber and quantum cascade lasers (QCLs). Next, the effect of temperature on the Verdet constant for cobalt-ferrite polymer nanocomposites was measured for a series of temperatures ranging from 40 to 200°K with a Faraday rotation polarimeter. No visual change was observed in the films during thermal cycling, and ˜4x improvement was achieved at 40°K. The results are promising and further analysis is merited at 4.2°K to assess the performance of this material for cryogenic magneto-optic modulators

  5. Absorption Filter Based Optical Diagnostics in High Speed Flows

    NASA Technical Reports Server (NTRS)

    Samimy, Mo; Elliott, Gregory; Arnette, Stephen

    1996-01-01

    Two major regimes where laser light scattered by molecules or particles in a flow contains significant information about the flow are Mie scattering and Rayleigh scattering. Mie scattering is used to obtain only velocity information, while Rayleigh scattering can be used to measure both the velocity and the thermodynamic properties of the flow. Now, recently introduced (1990, 1991) absorption filter based diagnostic techniques have started a new era in flow visualization, simultaneous velocity and thermodynamic measurements, and planar velocity measurements. Using a filtered planar velocimetry (FPV) technique, we have modified the optically thick iodine filter profile of Miles, et al., and used it in the pressure-broaden regime which accommodates measurements in a wide range of velocity applications. Measuring velocity and thermodynamic properties simultaneously, using absorption filtered based Rayleigh scattering, involves not only the measurement of the Doppler shift, but also the spectral profile of the Rayleigh scattering signal. Using multiple observation angles, simultaneous measurement of one component velocity and thermodynamic properties in a supersonic jet were measured. Presently, the technique is being extended for simultaneous measurements of all three components of velocity and thermodynamic properties.

  6. Quantum Optics

    NASA Astrophysics Data System (ADS)

    Orvil Scully, Marlan; Zubairy, Muhammad Suhail

    1997-09-01

    Quantum optics has witnessed significant theoretical and experimental developments in recent years. This book provides an in-depth and wide-ranging introduction to the subject, emphasizing throughout the basic principles and their applications. The book begins by developing the basic tools of quantum optics, and goes on to show the application of these tools in a variety of quantum optical systems, including lasing without inversion, squeezed states, and atom optics. The final four chapters discuss quantum optical tests of the foundations of quantum mechanics, and particular aspects of measurement theory. Assuming only a background of standard quantum mechanics and electromagnetic theory, and containing many problems and references, this book will be invaluable to graduate students of quantum optics, as well as to researchers in this field.

  7. High Speed All Optical Nyquist Signal Generation and Full-band Coherent Detection

    PubMed Central

    Zhang, Junwen; Yu, Jianjun; Fang, Yuan; Chi, Nan

    2014-01-01

    Spectrum efficient data transmission is of key interest for high capacity optical communication systems considering the limited available bandwidth. Transmission of the high speed signal with higher-order modulation formats within the Nyquist bandwidth using coherent detection brings attractive performance advantages. However, high speed Nyquist signal generation with high order modulation formats is challenging. Electrical Nyquist pulse generation is restricted by the limited sampling rate and processor capacities of digital-to-analog convertor devices, while the optical Nyquist signals can provide a much higher symbol rate using time domain multiplexing method. However, most optical Nyquist signals are based on direct detection with simple modulation formats. Here we report the first experimental demonstration of high speed all optical Nyquist signal generation based on Sinc-shaped pulse generation and time-division multiplexing with high level modulation format and full-band coherent detection. Our experiments demonstrate a highly flexible and compatible all optical high speed Nyquist signal generation and detection scheme for future fiber communication systems. PMID:25142269

  8. High speed all optical Nyquist signal generation and full-band coherent detection.

    PubMed

    Zhang, Junwen; Yu, Jianjun; Fang, Yuan; Chi, Nan

    2014-08-21

    Spectrum efficient data transmission is of key interest for high capacity optical communication systems considering the limited available bandwidth. Transmission of the high speed signal with higher-order modulation formats within the Nyquist bandwidth using coherent detection brings attractive performance advantages. However, high speed Nyquist signal generation with high order modulation formats is challenging. Electrical Nyquist pulse generation is restricted by the limited sampling rate and processor capacities of digital-to-analog convertor devices, while the optical Nyquist signals can provide a much higher symbol rate using time domain multiplexing method. However, most optical Nyquist signals are based on direct detection with simple modulation formats. Here we report the first experimental demonstration of high speed all optical Nyquist signal generation based on Sinc-shaped pulse generation and time-division multiplexing with high level modulation format and full-band coherent detection. Our experiments demonstrate a highly flexible and compatible all optical high speed Nyquist signal generation and detection scheme for future fiber communication systems.

  9. Nonlinear optical signal processing for high-speed, spectrally efficient fiber optic systems and networks

    NASA Astrophysics Data System (ADS)

    Zhang, Bo

    The past decade has witnessed astounding boom in telecommunication network traffic. With the emergence of multimedia over Internet, the high-capacity optical transport systems have started to shift focus from the core network towards the end users. This trend leads to diverse optical networks with transparency and reconfigurability requirement. As single channel data rate continues to increase and channel spacing continues to shrink for high capacity, high spectral efficiency, the workload on conventional electronic signal processing elements in the router nodes continues to build up. Performing signal processing functions in the optical domain can potentially alleviate the speed bottleneck if the unique optical properties are efficiently leveraged to assist electronic processing methodologies. Ultra-high bandwidth capability along with the promise for multi-channel and format-transparent operation make optical signal processing an attractive technology which is expected to have great impact on future optical networks. For optical signal processing applications in fiber-optic network and systems, a laudable goal would be to explore the unique nonlinear optical processes in novel photonic devices. This dissertation investigates novel optical signal processing techniques through simulations and experimental demonstrations, analyzes limitations of these nonlinear processing elements and proposes techniques to enhance the system performance or designs for functional photonic modules. Two key signal-processing building blocks for future optical networks, namely slow-light-based tunable optical delay lines and SOA-based high-speed wavelength converters, are presented in the first part of the dissertation. Phase preserving and spectrally efficient slow light are experimentally demonstrated using advanced modulation formats. Functional and novel photonic modules, such as multi-channel synchronizer and variable-bit-rate optical time division multiplexer are designed and

  10. New High Speed File Format for High Definition Television Optical Disks

    NASA Astrophysics Data System (ADS)

    Ishikawa, Kiyohiko; Koide, Daiichi; Kishida, Masahiko; Tokumaru, Haruki; Nakamura, Shoich

    2004-07-01

    Optical disk systems have advantages over video cassette recorders for broadcasting because they provide excellent random access, reliability and archiving performance. However, the transfer data rates of optical disks are inadequate for use in broadcasting applications. An optical disk medium, a servo system and signal processing techniques were developed for a 200 Mbps read/write system with two optical heads that was aimed at application to high definition television (HDTV) news gathering. We also developed an original disk format (ODF) that features a new high speed file format which has two new characteristics for HDTV. One is a guaranteed minimum extent length and the other is separation of the recording areas for files and directories. Our high-speed optical disk emulator proved that ODF is requiered to achieve a consecutive data transfer rate of more than 200 Mbps per head.

  11. Design of spectrometer for high-speed line field optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Kamal, Mohammad; Narayanswamy, Sivakumar; Packirisamy, Muthukumaran

    2011-08-01

    The quality of the spectrometer affects the sensitivity fall-off, axial resolution, and depth scan range, therefore overall performance of the spectral domain optical coherence tomography (SD-OCT) imaging. Chromatic aberration, optical resolution, and detector array resolution are the key design consideration for high-quality OCT spectrometer. Traditionally refractive optics spectrometer is used in SD-OCT. In the present work, the optical design of the reflective optics spectrometer and of the refractive optics spectrometers is reported for high-speed line field optical coherence tomography imaging. The performance of the spectrometers was compared by using the ZEMAX optical design software. The ZEMAX optical modeling analysis shows that the reflective optics spectrometer provides better performance by comparison with the refractive optics spectrometer.

  12. Low loss and high speed silicon optical modulator based on a lateral carrier depletion structure.

    PubMed

    Marris-Morini, Delphine; Vivien, Laurent; Fédéli, Jean Marc; Cassan, Eric; Lyan, Philippe; Laval, Suzanne

    2008-01-01

    A high speed and low loss silicon optical modulator based on carrier depletion has been made using an original structure consisting of a p-doped slit embedded in the intrinsic region of a lateral pin diode. This design allows a good overlap between the optical mode and carrier density variations. Insertion loss of 5 dB has been measured with a contrast ratio of 14 dB for a 3 dB bandwidth of 10 GHz.

  13. Rad-Tolerant, Thermally Stable, High-Speed Fiber-Optic Network for Harsh Environments

    NASA Technical Reports Server (NTRS)

    Leftwich, Matt; Hull, Tony; Leary, Michael; Leftwich, Marcus

    2013-01-01

    Future NASA destinations will be challenging to get to, have extreme environmental conditions, and may present difficulty in retrieving a spacecraft or its data. Space Photonics is developing a radiation-tolerant (rad-tolerant), high-speed, multi-channel fiber-optic transceiver, associated reconfigurable intelligent node communications architecture, and supporting hardware for intravehicular and ground-based optical networking applications. Data rates approaching 3.2 Gbps per channel will be achieved.

  14. Low loss and high speed silicon optical modulator based on a lateral carrier depletion structure.

    PubMed

    Marris-Morini, Delphine; Vivien, Laurent; Fédéli, Jean Marc; Cassan, Eric; Lyan, Philippe; Laval, Suzanne

    2008-01-01

    A high speed and low loss silicon optical modulator based on carrier depletion has been made using an original structure consisting of a p-doped slit embedded in the intrinsic region of a lateral pin diode. This design allows a good overlap between the optical mode and carrier density variations. Insertion loss of 5 dB has been measured with a contrast ratio of 14 dB for a 3 dB bandwidth of 10 GHz. PMID:18521165

  15. An optical system for detecting 3D high-speed oscillation of a single ultrasound microbubble

    PubMed Central

    Liu, Yuan; Yuan, Baohong

    2013-01-01

    As contrast agents, microbubbles have been playing significant roles in ultrasound imaging. Investigation of microbubble oscillation is crucial for microbubble characterization and detection. Unfortunately, 3-dimensional (3D) observation of microbubble oscillation is challenging and costly because of the bubble size—a few microns in diameter—and the high-speed dynamics under MHz ultrasound pressure waves. In this study, a cost-efficient optical confocal microscopic system combined with a gated and intensified charge-coupled device (ICCD) camera were developed to detect 3D microbubble oscillation. The capability of imaging microbubble high-speed oscillation with much lower costs than with an ultra-fast framing or streak camera system was demonstrated. In addition, microbubble oscillations along both lateral (x and y) and axial (z) directions were demonstrated. Accordingly, this system is an excellent alternative for 3D investigation of microbubble high-speed oscillation, especially when budgets are limited. PMID:24049677

  16. An optical system for detecting 3D high-speed oscillation of a single ultrasound microbubble.

    PubMed

    Liu, Yuan; Yuan, Baohong

    2013-01-01

    As contrast agents, microbubbles have been playing significant roles in ultrasound imaging. Investigation of microbubble oscillation is crucial for microbubble characterization and detection. Unfortunately, 3-dimensional (3D) observation of microbubble oscillation is challenging and costly because of the bubble size-a few microns in diameter-and the high-speed dynamics under MHz ultrasound pressure waves. In this study, a cost-efficient optical confocal microscopic system combined with a gated and intensified charge-coupled device (ICCD) camera were developed to detect 3D microbubble oscillation. The capability of imaging microbubble high-speed oscillation with much lower costs than with an ultra-fast framing or streak camera system was demonstrated. In addition, microbubble oscillations along both lateral (x and y) and axial (z) directions were demonstrated. Accordingly, this system is an excellent alternative for 3D investigation of microbubble high-speed oscillation, especially when budgets are limited. PMID:24049677

  17. High speed all optical shear wave imaging optical coherence elastography (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Song, Shaozhen; Hsieh, Bao-Yu; Wei, Wei; Shen, Tueng; O'Donnell, Matthew; Wang, Ruikang K.

    2016-03-01

    Optical Coherence Elastography (OCE) is a non-invasive testing modality that maps the mechanical property of soft tissues with high sensitivity and spatial resolution using phase-sensitive optical coherence tomography (PhS-OCT). Shear wave OCE (SW-OCE) is a leading technique that relies on the speed of propagating shear waves to provide a quantitative elastography. Previous shear wave imaging OCT techniques are based on repeated M-B scans, which have several drawbacks such as long acquisition time and repeated wave stimulations. Recent developments of Fourier domain mode-locked high-speed swept-source OCT system has enabled enough speed to perform KHz B-scan rate OCT imaging. Here we propose ultra-high speed, single shot shear wave imaging to capture single-shot transient shear wave propagation to perform SW-OCE. The frame rate of shear wave imaging is 16 kHz, at A-line rate of ~1.62 MHz, which allows the detection of high-frequency shear wave of up to 8 kHz. The shear wave is generated photothermal-acoustically, by ultra-violet pulsed laser, which requires no contact to OCE subjects, while launching high frequency shear waves that carries rich localized elasticity information. The image acquisition and processing can be performed at video-rate, which enables real-time 3D elastography. SW-OCE measurements are demonstrated on tissue-mimicking phantoms and porcine ocular tissue. This approach opens up the feasibility to perform real-time 3D SW-OCE in clinical applications, to obtain high-resolution localized quantitative measurement of tissue biomechanical property.

  18. NASA Langley and AF RADC high-speed fiber optic transceiver program

    NASA Technical Reports Server (NTRS)

    Hendricks, Herbert D.; Cook, Anthony L.; Mack, Terry L.; Hunter, James R.

    1990-01-01

    NASA-Langley and the USAF Rome Air Development Center have been pursuing the development of military- and space-qualified fiber optic transceivers for a variety of ground-based, space-based, and general avionic applications. An initial development pursued a design called the multipurpose fiber optic transceiver (MFOX) and provided a family of fiber optic transceivers which operated up to 1 Gb/s. Currently, a second generation of high-speed fiber optic transceivers (HSFOX) is being developed. This design will utilize an all-integrated-circuits approach in order to develop a lighter-weight, smaller-size, and more efficient transceiver. The high-speed fiber optic transceiver will be military-and-space-operating in the 0.05-5 Gb/s data rate range. The initial results of tests, performance, and availability of commercial high-speed all-integrated-circuit chipsets for fiber-optic transceivers are discussed, as well as the performance of transceivers fabricated from these chipsets.

  19. High-speed, room-temperature quantum cascade detectors at 4.3 μm

    NASA Astrophysics Data System (ADS)

    Zhou, Yuhong; Zhai, Shenqiang; Wang, Fengjiao; Liu, Junqi; Liu, Fengqi; Liu, Shuman; Zhang, Jinchuan; Zhuo, Ning; Wang, Lijun; Wang, ZhanGuo

    2016-03-01

    We present high-speed, room-temperature operated 4.3 μm quantum cascade detectors. The devices are processed as square mesas with 50 Ω coplanar access line and air-bridge connector. The high frequency features are explored using microwave rectification technique and a RLC circuit model. The -3 dB cutoff frequency is experimentally 9 GHz and 4 GHz for 20×20 μm2 and 50×50 μm2 detectors, respectively. The equivalent circuit analysis shows that a second order filter feature governs the devices. Higher cutoff frequency can be achieved by eliminate the parasitics further.

  20. Fiber Fabry-Perot tunable filter for high-speed optical packet switching

    SciTech Connect

    Taranenko, N.L.; Tenbrink, S.C.; Hsu, K.; Miller, C.M.

    1997-01-01

    Tunable optical filters are important building blocks for All-Optical systems and networks. Fast optical tuning in several microseconds is necessary to perform high-speed optical packet switching. Multi- Gigabit/sec packet-switching will provide flexibility and higher network throughput when large numbers of users communicate simultaneously. One approach to achieve fast wavelength tuning is to use high-speed piezoelectrically-driven Fiber Fabry-Perot tunable filters (FFP-TFs). The requirement for tuning in microseconds raises a whole new set of challenges, such as ringing, thermostability and mechanical inertia control. It was shown that correlation between the mechanical resonance and optical response of the filter is important for the filter`s speed and for mounting hardware and control circuitry optimization. These features together with the FFP-TF`s high capacitance (approximately 0.25-0.5 microfarad) are being folded into building a special controller to substantially improve the shape of the driving signal and the response of the filter. The resultant controller enables tuning the high-speed FFP-TF three-orders-of- magnitude faster than that possible with standard commercial FFP-TFS. The fastest switching time achieved is 2.5 microseconds. As the result, a new packet-switched media access control protocol is being designed to minimize the searching time. The filter scans only once through the entire optical region and then tunes to all the required channels one after another in a few microseconds. It can help update Rainbow-2 Broadcast-and-Select High-Speed Wavelength Division Multiplexing All-Optical network that currently has a circuit- switched protocol using standard FFP-TFS.

  1. High-speed dual-wavelength optical polarimetry for glucose sensing

    NASA Astrophysics Data System (ADS)

    Grunden, Daniel T.; Pirnstill, Casey W.; Coté, Gerard L.

    2014-02-01

    Optical polarimetry in the anterior chamber of the eye has emerged as a potential technique to non-invasively measure glucose levels for diabetes. Time varying corneal birefringence due to eye motion artifact confounds the optical signal ultimately limiting the polarimetric technique from accurately predicting glucose concentrations. In this study, a high speed dual-wavelength optical polarimetric approach was developed and in vitro phantom studies were performed with and without motion. The glucose concentrations ranged from 0-600 mg/dL at 100 mg/dL increments. The polarimeter produced glucose measurements with less than a 10 msec stabilization time and yielding standard errors of less than 10 mg/dL without motion and standard errors less than 26 mg/dL with motion. The results indicate a high speed dual-wavelength polarimetric approach has the potential to be used for non-invasive glucose measurements.

  2. Thermal/structural/optical integrated design for optical window of a high-speed aerial optical camera

    NASA Astrophysics Data System (ADS)

    Zhang, Gaopeng; Yang, Hongtao; Mei, Chao; Shi, Kui; Wu, Dengshan; Qiao, Mingrui

    2015-10-01

    In order to obtain high quality image of the aero optical remote sensor, it is important to analysis its thermal-optical performance on the condition of high speed and high altitude. Especially for the key imaging assembly, such as optical window, the temperature variation and temperature gradient can result in defocus and aberrations in optical system, which will lead to the poor quality image. In order to improve the optical performance of a high speed aerial camera optical window, the thermal/structural/optical integrated design method is developed. Firstly, the flight environment of optical window is analyzed. Based on the theory of aerodynamics and heat transfer, the convection heat transfer coefficient is calculated. The temperature distributing of optical window is simulated by the finite element analysis software. The maximum difference in temperature of the inside and outside of optical window is obtained. Then the deformation of optical window under the boundary condition of the maximum difference in temperature is calculated. The optical window surface deformation is fitted in Zernike polynomial as the interface, the calculated Zernike fitting coefficients is brought in and analyzed by CodeV Optical Software. At last, the transfer function diagrams of the optical system on temperature field are comparatively analyzed. By comparing and analyzing the result, it can be obtained that the optical path difference caused by thermal deformation of the optical window is 149.6 nm, which is under PV <=1 4λ .The simulation result meets the requirements of optical design very well. The above study can be used as an important reference for other optical window designs.

  3. Optical performance monitoring in high-speed optical fiber communication systems

    NASA Astrophysics Data System (ADS)

    Yu, Changyuan; Yang, Jing; Hu, Junhao; Zhang, Banghong

    2011-11-01

    Optical performance monitoring (OPM) becomes an attractive topic as the rapid growth of data rate in optical communication networks. It provides improved operation of the high capacity optical transmission systems. Among the various impairments, chromatic dispersion (CD) is one of major factors limiting the transmission distance in high-speed communication systems. Polarization-mode dispersion (PMD) also becomes a degrading effect in the system with data rate larger than 40 Gbit/s. In this paper, we summarize several CD and PMD monitoring methods based on RF spectrum analysis and delay-tap sampling. By using a narrow band fiber Bragg grating (FBG) notch filter, centered at 10 GHz away from the optical carrier, 10-GHz RF power can be used as a CD-insensitive PMD monitoring signal. By taking the 10-GHz RF power ratio of non-filtered and filtered signal, PMD-insensitive CD monitoring can be achieved. If the FBG notch filter is placed at optical carrier, the RF clock power ratio between non-filtered and filtered signal is also a PMDinsensitive CD monitoring parameter, which has larger RF power dynamic range and better measurement resolution. Both simulation and experiment results show that the proposed methods are efficient on measuring CD and PMD values in 57-Gbit/s D8PSK systems. Delay-tap sampling is another efficient method of measuring residual CD. Amplitude ratio of asynchronous delay-tap sampling plot decreases with CD monotonously, and the amplitude ratio can be obtained by using low bandwidth balanced receiver. The simulated results show that our method is efficient on residual CD measurement in 50-Gbit/s 50% RZ DQPSK systems with a 12-GHz balanced receiver. Since no modification on the transmitter or receiver is required, the proposed scheme is simple and cost effective.

  4. Design of a novel high-speed magneto-optic modulator

    NASA Astrophysics Data System (ADS)

    Wan, Jin; Huang, Yuanqing; Weng, Zihua; Yan, Huangping; Wang, Yiju; Wu, Zhaoxi; Ye, Ruifang

    2007-11-01

    A novel high-speed magneto-optic (MO) modulator which consists of an integrated wire grid polarizer (WGP), Bi-YIG waveguide with cladding layer and conducting micro-strip line is proposed. With the integrated WGP, this MO modulator is faster, more accurate and more stable because it is not only completely driven by electric signals but also has no mechanically moving parts. Moreover, it is compact-structured and low-cost. Large Faraday rotation is obtained with specific arrangement of the directions of the bias magnetic field and the modulation RF magnetic field. Optical route and optic-electrical detect circuit are also designed and analyzed.

  5. High-speed Light Peak optical link for high energy applications

    NASA Astrophysics Data System (ADS)

    Chang, F. X.; Chiang, F.; Deng, B.; Hou, J.; Hou, S.; Liu, C.; Liu, T.; Teng, P. K.; Wang, C. H.; Xu, T.; Ye, J.

    2014-11-01

    Optical links provide high speed data transmission with low mass fibers favorable for applications in high energy experiments. We report investigation of a compact Light Peak optical engine designed for data transmission at 4.8 Gbps. The module is assembled with bare die VCSEL, PIN diodes and a control IC aligned within a prism receptacle for light coupling to fiber ferrule. Radiation damage in the receptacle was examined with 60Co gamma ray. Radiation induced single event effects in the optical engine were studied with protons, neutrons and X-ray tests.

  6. A novel high-speed magneto-optic switch design and analysis

    NASA Astrophysics Data System (ADS)

    Zhu, Yun; Weng, Zihua; Huang, Yuanqing; Chen, Zhimin

    2006-01-01

    A novel type of 2×2 polarization independent magneto-optic switch with low Insertion Loss, nanosecond order switching time is designed and analyzed. The study of the magneto-optic switch involves two main parts: Faraday rotator assembly and optical route design. In faraday rotator design, magneto-optic crystal comparison and selection, two types of Faraday rotator assembly schemes design and analysis; high speed magnetic field simulation and generation; nanosecond trigger signal generator design, simulation and experiment are involved. Within optical router design, a simple but effective optical router with 2×2 mode is introduced. The nanosecond trigger signal supply to the Faraday rotator assembly is 12ns. The key characteristics, insertion loss, far-end crosstalk, switching time of magneto-optic switch that developed at a wavelength of 1550nm have been tested and root causes analyzed.

  7. System and method that suppresses intensity fluctuations for free space high-speed optical communication

    DOEpatents

    Berman, Gennady P.; Bishop, Alan R.; Nguyen, Dinh C.; Chernobrod, Boris M.; Gorshkov, Vacheslav N.

    2009-10-13

    A high-speed (Gbps), free space optical communication system is based on spectral encoding of radiation from a wide band light source, such as a laser. By using partially coherent laser beams in combination with a relatively slow photosensor, scintillations can be suppressed by orders of magnitude for distances of more than 10 km. To suppress the intensity fluctuations due to atmospheric turbulence, a source with partial transverse coherence in combination with slow response time photodetector is used. Information is encoded in the spectral domain of a wideband optical source by modulation of spectral amplitudes. A non-coherent light source with wide spectrum (an LED, for example) may be used for high-speed communication over short (less than about a mile) distances.

  8. High-Speed Recording up to 15,000 rpm Using Thin Optical Disks

    NASA Astrophysics Data System (ADS)

    Koide, Daiichi; Takano, Yoshimichi; Tokumaru, Haruki; Onagi, Nobuaki; Aman, Yasutomo; Murata, Shozo; Sugimoto, Yasunori; Ohishi, Kiyoshi

    2008-07-01

    We propose a high-speed optical disk system using thin flexible optical disks (HS-FOD) recording up to 15,000 rpm. The thin optical disk system is composed of three technical elements: media employing a thin and flexible substrate 0.1 mm thick, a mechanical stabilizer, and a high-speed tracking servo employing a feed-forward control with zero phase error tracking (ZPET-FF control). The HS-FOD system has an optical head with numerical aperture (NA) of 0.85 and is compatible with the optical system of a Blu-ray disc or a broadcast-use optical disk. We have successfully performed disk rotation stably and have performed precisely a focus servo and a tracking servo at 15,000 rpm. We also achieved writing and reading data at 15,000 rpm and recording 252 Mbps of random pattern data and could get small values of jitter below the tolerance. These results are enough to record professional high-definition television (HDTV) video signals in formats such as HD-D5 for broadcast-use.

  9. High speed optical phased array using high contrast grating all-pass filters.

    PubMed

    Yang, Weijian; Sun, Tianbo; Rao, Yi; Megens, Mischa; Chan, Trevor; Yoo, Byung-Wook; Horsley, David A; Wu, Ming C; Chang-Hasnain, Connie J

    2014-08-25

    We report a high speed 8x8 optical phased array using tunable 1550 nm all-pass filters with ultrathin high contrast gratings (HCGs) as the microelectromechanical-actuated top reflectors. The all-pass filter design enables a highly efficient phase tuning (1.7 π) with a small actuation voltage (10 V) and actuation displacement of the HCG (50 nm). The microelectromechanical HCG structure facilitates a high phase tuning speed >0.5 MHz. Beam steering is experimentally demonstrated with the optical phased array.

  10. Dynamic Observation of Sweat Glands of Human Finger Tip Using All-Optical-Fiber High-Speed Optical Coherence Tomography

    NASA Astrophysics Data System (ADS)

    Ohmi, Masato; Nohara, Kenji; Ueda, Yoshihiro; Fuji, Toshie; Haruna, Masamitsu

    2005-06-01

    High-speed optical coherence tomography (OCT) makes it possible to perform a time-sequential imaging of biological tissue and small organs. In this paper, we demonstrate in vivo observation of dynamics of sweat glands of human finger tip using high-speed OCT with push-pull driven fiber-optic PZT phase modulators. Movement of a sweat droplet through a micro spiral duct can be tracked clearly. An interesting function of sweat glands is found out in time-sequential OCT imaging.

  11. Large motion high cycle high speed optical fibers for space based applications.

    SciTech Connect

    Stromberg, Peter G.; Tandon, Rajan; Gibson, Cory S; Reedlunn, Benjamin; Rasberry, Roger David; Rohr, Garth David

    2014-10-01

    Future remote sensing applications will require higher resolution and therefore higher data rates (up to perhaps 100 gigabits per second) while achieving lower mass and cost. A current limitation to the design space is high speed high bandwidth data does not cross movable gimbals because of cabling issues. This requires the detectors to be off gimbal. The ability to get data across the gimbal would open up efficiencies in designs where the detectors and the electronics can be placed anywhere on the system. Fiber optic cables provide light weight high speed high bandwidth connections. Current options are limited to 20,000 cycles as opposed to the 1,000,000 cycles needed for future space based applications. To extend this to the million+ regime, requires a thorough understanding of the failure mechanisms and the materials, proper selection of materials (e.g., glass and jacket material) allowable geometry changes to the cable, radiation hardness, etc.

  12. Perfect Optical Compensator With 1:1 Shutter Ratio Used For High Speed Camera

    NASA Astrophysics Data System (ADS)

    Zhihong, Rong

    1983-03-01

    An optical compensator used for high speed camera is described. The method of compensation, the analysis of the imaging quality and the result of experiment are introduced. The compensator consists of pairs of parallel mirrors. It can perform perfect compensation even at 1:1 shutter ratio. Using this compensator a high speed camera can be operated with no shutter and can obtain the same image sharpness as that of the intermittent camera. The advantages of this compensator are summarized as follows: . While compensating, the aberration correction of the objective would not be damaged. . There is no displacement and defocussing between the scanning image and the film in frame center during compensation. Increasing the exposure angle doesn't reduce the resolving power. . The compensator can also be used in the projector in place of the intermittent mechanism to practise continuous (non-intermittent) projection without shutter.

  13. Optical knife-edge displacement sensor for high-speed atomic force microscopy

    SciTech Connect

    Braunsmann, Christoph; Schäffer, Tilman E.; Prucker, Veronika

    2014-03-10

    We show that an optical knife-edge technique can be used to detect the parallel shift of an object with sub-nanometer resolution over a wide bandwidth. This allows to design simple, contact-free, and high-speed displacement sensors that can be implemented in high-speed atomic force microscope scanners. In an experimental setup, we achieved a root-mean-square sensor noise of 0.8 nm within a bandwidth from 1 Hz to 1.1 MHz. We used this sensor to detect and correct the nonlinear z-piezo displacement during force curves acquired with rates of up to 5 kHz. We discuss the fundamental resolution limit and the linearity of the sensor.

  14. Design and implementation of interface units for high speed fiber optics local area networks and broadband integrated services digital networks

    NASA Technical Reports Server (NTRS)

    Tobagi, Fouad A.; Dalgic, Ismail; Pang, Joseph

    1990-01-01

    The design and implementation of interface units for high speed Fiber Optic Local Area Networks and Broadband Integrated Services Digital Networks are discussed. During the last years, a number of network adapters that are designed to support high speed communications have emerged. This approach to the design of a high speed network interface unit was to implement package processing functions in hardware, using VLSI technology. The VLSI hardware implementation of a buffer management unit, which is required in such architectures, is described.

  15. Computed optical interferometric tomography for high-speed volumetric cellular imaging

    PubMed Central

    Liu, Yuan-Zhi; Shemonski, Nathan D.; Adie, Steven G.; Ahmad, Adeel; Bower, Andrew J.; Carney, P. Scott; Boppart, Stephen A.

    2014-01-01

    Three-dimensional high-resolution imaging methods are important for cellular-level research. Optical coherence microscopy (OCM) is a low-coherence-based interferometry technology for cellular imaging with both high axial and lateral resolution. Using a high-numerical-aperture objective, OCM normally has a shallow depth of field and requires scanning the focus through the entire region of interest to perform volumetric imaging. With a higher-numerical-aperture objective, the image quality of OCM is affected by and more sensitive to aberrations. Interferometric synthetic aperture microscopy (ISAM) and computational adaptive optics (CAO) are computed imaging techniques that overcome the depth-of-field limitation and the effect of optical aberrations in optical coherence tomography (OCT), respectively. In this work we combine OCM with ISAM and CAO to achieve high-speed volumetric cellular imaging. Experimental imaging results of ex vivo human breast tissue, ex vivo mouse brain tissue, in vitro fibroblast cells in 3D scaffolds, and in vivo human skin demonstrate the significant potential of this technique for high-speed volumetric cellular imaging. PMID:25401012

  16. 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.

  17. A hybrid high-speed atomic force-optical microscope for visualizing single membrane proteins on eukaryotic cells.

    PubMed

    Colom, Adai; Casuso, Ignacio; Rico, Felix; Scheuring, Simon

    2013-01-01

    High-speed atomic force microscopy is a powerful tool for studying structure and dynamics of proteins. So far, however, high-speed atomic force microscopy was restricted to well-controlled molecular systems of purified proteins. Here we integrate an optical microscopy path into high-speed atomic force microscopy, allowing bright field and fluorescence microscopy, without loss of high-speed atomic force microscopy performance. This hybrid high-speed atomic force microscopy/optical microscopy setup allows positioning of the high-speed atomic force microscopy tip with high spatial precision on an optically identified zone of interest on cells. We present movies at 960 ms per frame displaying aquaporin-0 array and single molecule dynamics in the plasma membrane of intact eye lens cells. This hybrid setup allows high-speed atomic force microscopy imaging on cells about 1,000 times faster than conventional atomic force microscopy/optical microscopy setups, and allows first time visualization of unlabelled membrane proteins on a eukaryotic cell under physiological conditions. This development advances high-speed atomic force microscopy from molecular to cell biology to analyse cellular processes at the membrane such as signalling, infection, transport and diffusion.

  18. Optical signal processing for enabling high-speed, highly spectrally efficient and high capacity optical systems

    NASA Astrophysics Data System (ADS)

    Fazal, Muhammad Irfan

    may be possible. Recently, interest has increased in exploring the spatial dimension of light to increase capacity, both in fiber as well as free-space communication channels. The orbital angular momentum (OAM) of light, carried by Laguerre-Gaussian (LG) beams have the interesting property that, in theory, an infinite number of OAMs can be transmitted; which due to its inherent orthogonality will not affect each other. Thus, in theory, one can increase the channel capacity arbitrarily. However, in practice, the device dimensions will reduce the number of OAMs used. In addition to advanced modulation formats, it is expected that optical signal processing may play a role in the future development of more efficient optical transmission systems. The hope is that performing signal processing in the optical domain may reduce optical-to-electronic conversion inefficiencies, eliminate bottlenecks and take advantage of the ultrahigh bandwidth inherent in optics. While 40 to 50 Gbit/s electronic components are the peak of commercial technology and 100 Gbit/s capable RF components are still in their infancy, optical signal processing of these high-speed data signals may provide a potential solution. Furthermore, any optical processing system or sub-system must be capable of handling the wide array of data formats and data rates that networks may employ. The work presented in this Ph.D. dissertation attempts at addressing the issue of optical processing for advanced optical modulation formats, and particularly explores the state of the art in increasing the capacity of an optical link by a combination of wavelength/phase/polarization/OAM dimensions of light. Spatial multiplexing and demultiplexing of both coherently and directly detected signals at the 100 Gbit/s Ethernet standard is addressed. The application of a continuously tunable all-optical delay for all-optical functionality like time-slot interchange at high data-rates is presented. Moreover the interplay of chirp

  19. Optical fiber imaging for high speed plasma motion diagnostics: Applied to low voltage circuit breakers

    SciTech Connect

    McBride, J. W.; Balestrero, A.; Tribulato, G.; Ghezzi, L.; Cross, K. J.

    2010-05-15

    An integrated portable measurement system is described for the study of high speed and high temperature unsteady plasma flows such as those found in the vicinity of high current switching arcs. An array of optical fibers allows the formation of low spatial resolution images, with a maximum capture rate of 1x10{sup 6} images per second (1 MHz), with 8 bit intensity resolution. Novel software techniques are reported to allow imaging of the arc; and to measure arc trajectories. Results are presented on high current (2 kA) discharge events in a model test fixture and on the application to a commercial low voltage circuit breaker.

  20. High Speed Optical Observations of Cataclysmic Variables: FL Ceti, BY Cam, and DQ Her

    NASA Astrophysics Data System (ADS)

    Mason, Paul A.; Gomez, S.; Robinson, E. L.; Andronov, I. L.; Gonzalez, R. I.

    2013-01-01

    We present photometric data on three cataclysmic variables. Broad-band CCD observations of FL Ceti, BY Cam, and DQ Her were obtained with 1-3s integrations at the Otto Struve, 2.1m, Telescope of McDonald Observatory. High speed optical photometry reveals details in these cataclysmic variables not possible using longer time integrations. In FL Ceti, the shortest period eclipsing polar known, the eclipse of two separate well localized accretion regions is resolved. In BY Cam and DQ Her, the spin period of the white dwarf is revealed. We discuss model constrains provided by these observations.

  1. A frequency and sensitivity tunable microresonator array for high-speed quantum processor readout

    NASA Astrophysics Data System (ADS)

    Whittaker, J. D.; Swenson, L. J.; Volkmann, M. H.; Spear, P.; Altomare, F.; Berkley, A. J.; Bumble, B.; Bunyk, P.; Day, P. K.; Eom, B. H.; Harris, R.; Hilton, J. P.; Hoskinson, E.; Johnson, M. W.; Kleinsasser, A.; Ladizinsky, E.; Lanting, T.; Oh, T.; Perminov, I.; Tolkacheva, E.; Yao, J.

    2016-01-01

    Superconducting microresonators have been successfully utilized as detection elements for a wide variety of applications. With multiplexing factors exceeding 1000 detectors per transmission line, they are the most scalable low-temperature detector technology demonstrated to date. For high-throughput applications, fewer detectors can be coupled to a single wire but utilize a larger per-detector bandwidth. For all existing designs, fluctuations in fabrication tolerances result in a non-uniform shift in resonance frequency and sensitivity, which ultimately limits the efficiency of bandwidth utilization. Here, we present the design, implementation, and initial characterization of a superconducting microresonator readout integrating two tunable inductances per detector. We demonstrate that these tuning elements provide independent control of both the detector frequency and sensitivity, allowing us to maximize the transmission line bandwidth utilization. Finally, we discuss the integration of these detectors in a multilayer fabrication stack for high-speed readout of the D-Wave quantum processor, highlighting the use of control and routing circuitry composed of single-flux-quantum loops to minimize the number of control wires at the lowest temperature stage.

  2. FOCEX: A fiber-optic extender for a high speed parallel RS485 data cable

    SciTech Connect

    Meadows, J.T.; Anderson, J.T.; Cooper, P.S.; Engelfried, J.; Franzen, J.W.; Forster, B.G.; Levinson, F.; Rawls, J.; Haber, S.

    1995-05-01

    For longer-distant, high speed data links, optical fibre becomes most cost-effective than copper or other hard wire cable systems. Fermilab supplied to Finisar Corp. of Menlo Park, CA., a set of specifications for card functions, sizes and interconnector pin assignments. Finisar designed and assembled a set of fiber optical P.C. cards using 100 megabyte/sec commercial optoelectronics and a serialization and deserialization HOT-ROD chipset designed by GAZELLE Microcircuits, Inc. (A Tri Quint Semiconductors company). The cooperative effort between Fermilab and Finisar has allowed Fermilab to created a reliable 50 Megabytes/sec (40 bit parallel RS485 DART data bus) cable to cable extender using a virtually invisible Fiber Channel point-to-point(FC-0) fiber optical single-simplex system. The system is easily capable of sustaining a 50 megabytes/sec of data, control and status line throughput at distances of 1625 feet (500 meters) using standard multi-mode fiber.

  3. High speed QPPM direct detection optical communication receivers for FSDD intersatellite links

    NASA Technical Reports Server (NTRS)

    Davidson, Frederic M.; Sun, Xiaoli

    1993-01-01

    This final report consists of four separate reports, one for each project involved in this contract. The first report is entitled '325 Mbps QPPM (quaternary pulse position modulation) Direct Detection Free Space Optical Communication Encoder and Receiver,' which was our primary work. The second report is entitled 'Test Results of the 325 Mbps QPPM High Speed Data Transmission GaAs ASICs,' which describes our work in connection with Galaxy Microsystems, Inc. who produced these ASICs for NASA. The third report, 'Receiver Performance Analysis of BPPM Optical Communication Systems Using 1.3 micron Wavelength Transmitter and InGaAs PIN Photodiodes,' was prepared at the request of the NASA/Photonics Branch for their efforts in upgrading the 1773 optical fiber data bus. The fourth report, 'Photomultiplier Tubes for Use at 1.064 micron Wavelength,' was also prepared at the request of the NASA/Photonics Branch as a research project.

  4. FOCEX: A fiber-optic extender for a high speed parallel RS485 data cable

    NASA Astrophysics Data System (ADS)

    Meadows, J. T.; Anderson, J. T.; Cooper, P. S.; Engelfried, J.; Franzen, J. W.; Forster, B. G.; Levinson, F.; Rawls, J.; Haber, S.

    1995-05-01

    For longer-distant, high speed data links, optical fiber becomes most cost-effective than copper or other hard wire cable systems. Fermilab supplied to Finisar Corp. of Menlo Park, CA, a set of specifications for card functions, sizes and interconnector pin assignments. Finisar designed and assembled a set of fiber optical P.C. cards using 100 megabyte/sec commercial optoelectronics and a serialization and deserialization HOT-ROD chipset designed by GAZELLE Microcircuits, Inc. (A Tri Quint Semiconductors company). The cooperative effort between Fermilab and Finisar has allowed Fermilab to created a reliable 50 Megabytes/sec (40 bit parallel RS485 DART data bus) cable to cable extender using a virtually invisible Fiber Channel point-to-point(FC-0) fiber optical single-simplex system. The system is easily capable of sustaining a 50 megabytes/sec of data, control and status line throughput at distances of 1625 feet (500 meters) using standard multi-mode fiber.

  5. 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.

  6. Modeling simulation of the thermal radiation for high-speed flight vehicles' aero-optical windows

    NASA Astrophysics Data System (ADS)

    Chen, Lei; Zhang, Liqin; Guo, Mingjiang

    2015-10-01

    When high-speed flight vehicles fly in the atmosphere, they can generate serious aero-optical effect. The optical window temperature rises sharply because of aerodynamic heating. It will form radiation interference that can lead infrared detectors to producing non-uniform radiation backgrounds, decreasing system SNR and detection range. Besides, there exits temperature difference due to uneven heating. Under the thermo-optical and elastic-optical effects, optical windows change into inhomogeneous mediums which influence the ray propagation. In this paper, a model of thermal radiation effect was built by a finite element analysis method. Firstly, the optical window was divided into uniform grids. Then, radiation distribution on the focal planes at different angles of the window's normal line and optical axis was obtained by tracing light rays of each grid. Finally, simulation results indicate that radiation distribution reflects the two directions-the length and width-of temperature distribution, and the change of angle causes the center of radiation distribution to shift to one direction of the image surface under the same window temperature.

  7. High-Power, High-Speed Electro-Optic Pockels Cell Modulator

    NASA Technical Reports Server (NTRS)

    Hawthorne, Justin; Battle, Philip

    2013-01-01

    Electro-optic modulators rely on a change in the index of refraction for the optical wave as a function of an applied voltage. The corresponding change in index acts to delay the wavefront in the waveguide. The goal of this work was to develop a high-speed, high-power waveguide- based modulator (phase and amplitude) and investigate its use as a pulse slicer. The key innovation in this effort is the use of potassium titanyl phosphate (KTP) waveguides, making the highpower, polarization-based waveguide amplitude modulator possible. Furthermore, because it is fabricated in KTP, the waveguide component will withstand high optical power and have a significantly higher RF modulation figure of merit (FOM) relative to lithium niobate. KTP waveguides support high-power TE and TM modes - a necessary requirement for polarization-based modulation as with a Pockels cell. High-power fiber laser development has greatly outpaced fiber-based modulators in terms of its maturity and specifications. The demand for high-performance nonlinear optical (NLO) devices in terms of power handling, efficiency, bandwidth, and useful wavelength range has driven the development of bulk NLO options, which are limited in their bandwidth, as well as waveguide based LN modulators, which are limited by their low optical damage threshold. Today, commercially available lithium niobate (LN) modulators are used for laser formatting; however, because of photorefractive damage that can reduce transmission and increase requirements on bias control, LN modulators cannot be used with powers over several mW, dependent on wavelength. The high-power, high-speed modulators proposed for development under this effort will enable advancements in several exciting fields including lidarbased remote sensing, atomic interferometry, free-space laser communications, and others.

  8. High speed miniature motorized endoscopic probe for 3D optical frequency domain imaging

    NASA Astrophysics Data System (ADS)

    Li, Jianan; Feroldi, Fabio; Mo, Jianhua; Helderman, Frank; de Groot, Mattijs; de Boer, Johannes F.

    2013-03-01

    We present a miniature motorized endoscopic probe for Optical Frequency Domain Imaging with an outer diameter of 1.65 mm and a rotation speed of 3,000 - 12,500 rpm. This is the smallest motorized high speed OCT probe to our knowledge. The probe has a motorized distal end which provides a significant advantage over proximally driven probes since it does not require a drive shaft to transfer the rotational torque to the distal end of the probe and functions without a fiber rotary junction. The probe has a focal Full Width at Half Maximum of 9.6 μm and a working distance of 0.47 mm. We analyzed the non-uniform rotation distortion and found a location fluctuation of only 1.87° in repeated measurements of the same object. The probe was integrated in a high-speed Optical Frequency Domain Imaging setup at 1310 nm We demonstrated its performance with imaging ex vivo pig bronchial and in vivo goat lung.

  9. High-speed Optical Coherence Tomography for Management after Laser in Situ Keratomileusis

    PubMed Central

    Avila, Mariana; Li, Yan; Song, Jonathan C.; Huang, David

    2007-01-01

    PURPOSE: To report applications of optical coherence tomography (OCT) in the management of laser in situ keratomileusis (LASIK) related problems. SETTING: Doheny Eye Institute and Department of Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, California, USA. METHODS: Five patients referred for LASIK-related problems were enrolled in a prospective observational study. Clinical examination, ultrasound (US) pachymetry, Placido ring slit-scanning corneal topography (Orbscan II, Bausch & Lomb), and high-speed corneal OCT were performed. RESULTS: In cases of regression and keratectasia, OCT provided thickness measurements of the cornea, flap, and posterior stromal bed. Locations of tissue loss and flap interface planes were identified in a case with a recut enhancement complication. The information was used to determine whether further laser ablation was safe, confirm keratectasia, and manage complications. Optical coherence tomography measurements of central corneal thickness agreed well with US pachymetry measurements (difference 6.4 mm G 11.7 [SD]) (P Z .026), while Orbscan significantly underestimated corneal thickness (-67.5 ± 72.5 μm) (P = .17). CONCLUSIONS: High-speed OCT provided noncontact imaging and measurement of LASIK anatomy. It was useful in monitoring LASIK results and evaluating complications. PMID:17081866

  10. In-plane deeply-etched optical MEMS notch filter with high-speed tunability

    NASA Astrophysics Data System (ADS)

    Sabry, Yasser M.; Eltagoury, Yomna M.; Shebl, Ahmed; Soliman, Mostafa; Sadek, Mohamed; Khalil, Diaa

    2015-12-01

    Notch filters are used in spectroscopy, multi-photon microscopy, fluorescence instrumentation, optical sensors and other life science applications. One type of notch filter is based on a fiber-coupled Fabry-Pérot cavity, which is formed by a reflector (external mirror) facing a dielectric-coated end of an optical fiber. Tailoring this kind of optical filter for different applications is possible because the external mirror has fewer mechanical and optical constraints. In this paper we present optical modeling and implementation of a fiber-coupled Fabry-Pérot filter based on dielectric-coated optical fiber inserted into a micromachined fiber groove facing a metallized micromirror, which is driven by a high-speed MEMS actuator. The optical MEMS chip is fabricated using deep reactive ion etching (DRIE) technology on a silicon on insulator wafer, where the optical axis is parallel to the substrate (in-plane) and the optical/mechanical components are self-aligned by the photolithographic process. The DRIE etching depth is 150 μm, chosen to increase the micromirror optical throughput and improving the out-of-plane stiffness of the MEMS actuator. The MEMS actuator type is closing-gap, while its quality factor is almost doubled by slotting the fixed plate. A low-finesse Fabry-Pérot interferometer is formed by the metallized surface of the micromirror and a cleaved end of a standard single-mode fiber, for characterization of the MEMS actuator stroke and resonance frequency. The actuator achieves a travel distance of 800 nm at a resonance frequency of 89.9 kHz. The notch filter characteristics were measured using an optical spectrum analyzer, and the filter exhibits a free spectral range up to 100 nm and a notch rejection ratio up to 20 dB around a wavelength of 1300 nm. The presented device provides batch processing and low-cost production of the filter.

  11. Molecular-Based Optical Measurement Techniques for Transition and Turbulence in High-Speed Flow

    NASA Technical Reports Server (NTRS)

    Bathel, Brett F.; Danehy, Paul M.; Cutler, Andrew D.

    2013-01-01

    photogrammetry (for model attitude and deformation measurement) are excluded to limit the scope of this report. Other physical probes such as heat flux gauges, total temperature probes are also excluded. We further exclude measurement techniques that require particle seeding though particle based methods may still be useful in many high speed flow applications. This manuscript details some of the more widely used molecular-based measurement techniques for studying transition and turbulence: laser-induced fluorescence (LIF), Rayleigh and Raman Scattering and coherent anti-Stokes Raman scattering (CARS). These techniques are emphasized, in part, because of the prior experience of the authors. Additional molecular based techniques are described, albeit in less detail. Where possible, an effort is made to compare the relative advantages and disadvantages of the various measurement techniques, although these comparisons can be subjective views of the authors. Finally, the manuscript concludes by evaluating the different measurement techniques in view of the precision requirements described in this chapter. Additional requirements and considerations are discussed to assist with choosing an optical measurement technique for a given application.

  12. High speed 3D endoscopic optical frequency domain imaging probe for lung cancer diagnosis

    NASA Astrophysics Data System (ADS)

    Li, Jianan; Feroldi, Fabio; Mo, Jianhua; Helderman, Frank; de Groot, Mattijs; de Boer, Johannes F.

    2013-06-01

    We present a miniature motorized endoscopic probe for Optical Frequency Domain Imaging with an outer diameter of 1.65 mm and a rotation speed of 3,000 - 12,500 rpm. The probe has a motorized distal end which provides a significant advantage over proximally driven probes since it does not require a drive shaft to transfer the rotational torque to the distal end of the probe and functions without a fiber rotary junction. The probe has a focal Full Width at Half Maximum of 9.6 μm and a working distance of 0.47 mm. We analyzed the non-uniform rotation distortion and found a location fluctuation of only 1.87° in repeated measurements of the same object. The probe was integrated in a high-speed Optical Frequency Domain Imaging setup at 1310 nm. We demonstrated its performance with imaging ex vivo pig bronchial and in vivo goat lung.

  13. Fault-tolerance techniques for high-speed fiber-optic networks

    NASA Technical Reports Server (NTRS)

    Deruiter, John

    1991-01-01

    Four fiber optic network topologies (linear bus, ring, central star, and distributed star) are discussed relative to their application to high data throughput, fault tolerant networks. The topologies are also examined in terms of redundancy and the need to provide for single point, failure free (or better) system operation. Linear bus topology, although traditionally the method of choice for wire systems, presents implementation problems when larger fiber optic systems are considered. Ring topology works well for high speed systems when coupled with a token passing protocol, but it requires a significant increase in protocol complexity to manage system reconfiguration due to ring and node failures. Star topologies offer a natural fault tolerance, without added protocol complexity, while still providing high data throughput capability.

  14. Secure Communications in High Speed Fiber Optical Networks Using Code Division Multiple Access (CDMA) Transmission

    SciTech Connect

    Han, I; Bond, S; Welty, R; Du, Y; Yoo, S; Reinhardt, C; Behymer, E; Sperry, V; Kobayashi, N

    2004-02-12

    This project is focused on the development of advanced components and system technologies for secure data transmission on high-speed fiber optic data systems. This work capitalizes on (1) a strong relationship with outstanding faculty at the University of California-Davis who are experts in high speed fiber-optic networks, (2) the realization that code division multiple access (CDMA) is emerging as a bandwidth enhancing technique for fiber optic networks, (3) the realization that CDMA of sufficient complexity forms the basis for almost unbreakable one-time key transmissions, (4) our concepts for superior components for implementing CDMA, (5) our expertise in semiconductor device processing and (6) our Center for Nano and Microtechnology, which is where the majority of the experimental work was done. Here we present a novel device concept, which will push the limits of current technology, and will simultaneously solve system implementation issues by investigating new state-of-the-art fiber technologies. This will enable the development of secure communication systems for the transmission and reception of messages on deployed commercial fiber optic networks, through the CDMA phase encoding of broad bandwidth pulses. CDMA technology has been developed as a multiplexing technology, much like wavelength division multiplexing (WDM) or time division multiplexing (TDM), to increase the potential number of users on a given communication link. A novel application of the techniques created for CDMA is to generate secure communication through physical layer encoding. Physical layer encoding devices are developed which utilize semiconductor waveguides with fast carrier response times to phase encode spectral components of a secure signal. Current commercial technology, most commonly a spatial light modulator, allows phase codes to be changed at rates of only 10's of Hertz ({approx}25ms response). The use of fast (picosecond to nanosecond) carrier dynamics of semiconductors, as

  15. Invited Article: Polarization diversity and modulation for high-speed optical communications: architectures and capacity

    NASA Astrophysics Data System (ADS)

    Shieh, William; Khodakarami, Hamid; Che, Di

    2016-07-01

    Polarization is one of the fundamental properties of optical waves. To cope with the exponential growth of the Internet traffic, optical communications has advanced by leaps and bounds within the last decade. For the first time, the polarization domain has been extensively explored for high-speed optical communications. In this paper, we discuss the general principle of polarization modulation in both Jones and Stokes spaces. We show that there is no linear optical device capable of transforming an arbitrary input polarization into one that is orthogonal to itself. This excludes the receiver self-polarization diversity architecture by splitting the signal into two branches, and then transferring one of the branches into orthogonal polarization. We next propose a novel Stokes vector (SV) detection architecture using four single-ended photodiodes (PD) that can recover a full set of SV. We then derive a closed-form expression for the information capacity of different SV detection architectures and compare the capacity of our proposed architectures with that of intensity-modulated directly-detected (IM/DD) method. We next study the 3-PD SV detection architecture where a subset of SV is detected, and devise a novel modulation algorithm that can achieve 2-dimensional modulation with the 3-PD detection. By using cost-effective SV receivers, polarization modulation and multiplexing offers a powerful solution for short-reach optical networks where the wavelength domain is quickly exhausted.

  16. High speed, high performance, portable, dual-channel, optical fiber Bragg grating (FBG) demodulator

    NASA Astrophysics Data System (ADS)

    Zhang, Hongtao; Wei, Zhanxiong; Fan, Lingling; Wang, Pengfei; Zhao, Xilin; Wang, Zhenhua; Yang, Shangming; Cui, Hong-Liang

    2009-10-01

    A high speed, high performance, portable, dual-channel, optical Fiber Bragg Grating demodulator based on fiber Fabry- Pérot tunable filter (FFP-FT) is reported in this paper. The high speed demodulation can be achieved to detect the dynamical loads of vehicles with speed of 15 mph. However, the drifts of piezoelectric transducer (PZT) in the cavity of FFP-FT dramatically degrade the stability of system. Two schemes are implemented to improve the stability of system. Firstly, a temperature control system is installed to effectively remove the thermal drifts of PZT. Secondly, a scheme of changing the bias voltage of FFP-FT to restrain non-thermal drifts has been realized at lab and will be further developed to an automatic control system based on microcontroller. Although this demodulator is originally used in Weight-In- Motion (WIM) sensing system, it can be extended into other aspects and the schemes presented in this paper will be useful in many applications.

  17. Modeling and characteristic of the SMT Board Plug connector in high speed optical communication system

    NASA Astrophysics Data System (ADS)

    Wu, Haoran; Dong, Zhenzhen; Wang, Tanglin; Zhao, Heng; Feng, Junbo; Cui, Naidi; Teng, Jie; Guo, Jin

    2015-04-01

    Modeling and characteristic of the SMT Board Plug connector, which is used to connect micro optical transceiver to the main board, are proposed and analyzed in this paper. When the high speed signal transfers from the PCB of transceiver to main board through SMT Board Plug connector, the structure and material discontinuity of the connector causes insertion losses and impedance mismatches. This makes the performance of high speed digital system exacerbated. So it is essential to analyze the signal transfer characteristics of the connector and find out what factors affected the signal quality at the design stage of the digital system. To solve this problem, Ansoft's High Frequency Structure Simulator (HFSS), based on the finite element method, was employed to build accurate 3D models, analyze the effects of various structure parameters, and obtain the full-wave characteristics of the SMT Board Plug connectors in this paper. Then an equivalent circuit model was developed. The circuit parameters were extracted precisely in the frequency range of interests by using the curve fitting method in ADS software, and the result was in good agreement with HFSS simulations up to 8GHz with different structure parameters. At last, the measurement results of S-parameter and eye diagram were given and the S-parameters showed good coincidence between the measurement and HFSS simulation up to 4GHz.

  18. Dense all-optical WDM-SCM technology for high-speed computer interconnects

    NASA Astrophysics Data System (ADS)

    Ih, Charles S.; Tian, Rongsheng; Zhou, H. X.; Xia, Xiang-Gen

    1993-07-01

    We describe a dense and flexible all optical multi-channel communication system for high speed computer interconnects. The system can provide 10 Gb/s for each individual node with a total system capacity to 250 Gb/s using currently available technologies. The system capacity can be scaled to 1 Tb/s using optical amplifiers with a broader bandwidth and higher modulations. The system is based on the multi-beam (heterodyne) modulator (MBM) recently demonstrated in our laboratory and other current technologies in tunable laser arrays and acousto-optical tunable filter (AOTF). Each MBM automatically forms a high frequency microwave sub-carrier multiplexing (SCM) with sub-carrier frequency to tens of GHz. A MBM with sub-carriers at 17 and 21 GHz has already been demonstrated and can be scaled to higher frequencies by using a higher frequency detector. Each SCM group may consist of up to 10 one-Gb/s channels and occupies only 1 nm spectral width. Therefore we can form a conventional WDM with 25 divisions within the bandwidth of commercially available optical amplifiers.

  19. High-speed polarization sensitive optical frequency domain imaging with frequency multiplexing.

    PubMed

    Oh, W Y; Yun, S H; Vakoc, B J; Shishkov, M; Desjardins, A E; Park, B H; de Boer, J F; Tearney, G J; Bouma, B E

    2008-01-21

    Polarization sensitive optical coherence tomography (PS-OCT) provides a cross-sectional image of birefringence in biological samples that is complementary in many applications to the standard reflectance-based image. Recent ex vivo studies have demonstrated that birefringence mapping enables the characterization of collagen and smooth muscle concentration and distribution in vascular tissues. Instruments capable of applying these measurements percutaneously in vivo may provide new insights into coronary atherosclerosis and acute myocardial infarction. We have developed a polarization sensitive optical frequency domain imaging (PS-OFDI) system that enables high-speed intravascular birefringence imaging through a fiber-optic catheter. The novel design of this system utilizes frequency multiplexing to simultaneously measure reflectance of two incident polarization states, overcoming concerns regarding temporal variations of the catheter fiber birefringence and spatial variations in the birefringence of the sample. We demonstrate circular cross-sectional birefringence imaging of a human coronary artery ex vivo through a flexible fiber-optic catheter with an A-line rate of 62 kHz and a ranging depth of 6.2 mm.

  20. High speed optical wireless data transmission system for particle sensors in high energy physics

    NASA Astrophysics Data System (ADS)

    Ali, W.; Corsini, R.; Ciaramella, E.; Dell'Orso, R.; Messineo, A.; Palla, F.

    2015-08-01

    High speed optical fiber or copper wire communication systems are frequently deployed for readout data links used in particle physics detectors. Future detector upgrades will need more bandwidth for data transfer, but routing requirements for new cables or optical fiber will be challenging due to space limitations. Optical wireless communication (OWC) can provide high bandwidth connectivity with an advantage of reduced material budget and complexity of cable installation and management. In a collaborative effort, Scuola Superiore Sant'Anna and INFN Pisa are pursuing the development of a free-space optical link that could be installed in a future particle physics detector or upgrade. We describe initial studies of an OWC link using the inner tracker of the Compact Muon Solenoid (CMS) detector as a reference architecture. The results of two experiments are described: the first to verify that the laser source transmission wavelength of 1550 nm will not introduce fake signals in silicon strip sensors while the second was to study the source beam diameter and its tolerance to misalignment. For data rates of 2.5 Gb/s and 10 Gb/s over a 10 cm working distance it was observed that a tolerance limit of ±0.25 mm to ±0.8 mm can be obtained for misaligned systems with source beam diameters of 0.38 mm to 3.5 mm, respectively.

  1. High-speed measurement of rotational anisotropy nonlinear optical harmonic generation using position-sensitive detection.

    PubMed

    Harter, J W; Niu, L; Woss, A J; Hsieh, D

    2015-10-15

    We present a method of performing high-speed rotational anisotropy nonlinear optical harmonic generation experiments at rotational frequencies of several hertz by projecting the harmonic light reflected at different angles from a sample onto a stationary position-sensitive detector. The high rotational speed of the technique, 10(3) to 10(4) times larger than existing methods, permits precise measurements of the crystallographic and electronic symmetries of samples by averaging over low frequency laser-power, beam-pointing, and pulse-width fluctuations. We demonstrate the sensitivity of our technique by resolving the bulk fourfold rotational symmetry of GaAs about its [001] axis using second-harmonic generation. PMID:26469591

  2. High-speed asynchronous optical sampling with sub-50fs time resolution.

    PubMed

    Gebs, R; Klatt, G; Janke, C; Dekorsy, T; Bartels, A

    2010-03-15

    We report an ultrafast time-domain spectroscopy system based on high-speed asynchronous optical sampling operating without mechanical scanner. The system uses two 1 GHz femtosecond oscillators that are offset-stabilized using high-bandwidth feedback electronics operating at the tenth repetition rate harmonics. Definition of the offset frequency, i.e. the time-delay scan rate, in the range of a few kilohertz is accomplished using direct-digital-synthesis electronics for the first time. The time-resolution of the system over the full available 1 ns time-delay window is determined by the laser pulse duration and is 45 fs. This represents a three-fold improvement compared to previous approaches where timing jitter was the limiting factor. Two showcase experiments are presented to verify the high time-resolution and sensitivity of the system.

  3. Large-scale IP router using a high-speed optical switch element [Invited

    NASA Astrophysics Data System (ADS)

    McDermott, Tom; Brewer, Tony

    2003-07-01

    The system design and architectural considerations for a large, high-performance IP packet router that uses a nonblocking optical switching fabric are presented. The objective of the router is to provide fully network-compatible routing of IP, multiprotocol label switching (MPLS), and Ethernet packets in a router with a very large number of high speed ports while maintaining the low-delay, low-jitter, low-packet-loss, and line-rate throughput characteristics of today's small port-count routers over a large scale. Such a large router is useful for the core of a packetized transport network capable of supporting various classes of real-time and best-effort service in a reliable and efficient manner.

  4. High-speed upper-airway imaging using full-range optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Jing, Joseph; Zhang, Jun; Loy, Anthony Chin; Wong, Brian J. F.; Chen, Zhongping

    2012-11-01

    Obstruction in the upper airway can often cause reductions in breathing or gas exchange efficiency and lead to rest disorders such as sleep apnea. Imaging diagnosis of the obstruction region has been accomplished using computed tomography (CT) and magnetic resonance imaging (MRI). However CT requires the use of ionizing radiation, and MRI typically requires sedation of the patient to prevent motion artifacts. Long-range optical coherence tomography (OCT) has the potential to provide high-speed three-dimensional tomographic images with high resolution and without the use of ionizing radiation. In this paper, we present work on the development of a long-range OCT endoscopic probe with 1.2 mm OD and 20 mm working distance used in conjunction with a modified Fourier domain swept source OCT system to acquire structural and anatomical datasets of the human airway. Imaging from the bottom of the larynx to the end of the nasal cavity is completed within 40 s.

  5. High Speed Optical Photometry of V1055 Orionis (=4U 0614+091)

    NASA Astrophysics Data System (ADS)

    Lopez, Isaac; Mason, P. A.; Robinson, E. L.

    2013-01-01

    V1055 Orionis (=4U 0614+091) is thought to be an ultra-compact binary containing a neutron star primary with a white dwarf companion. High-speed (10s) broad-band optical observations using the McDonald Observatory, 2.1m, Otto Struve Telescope were obtained on 13 nights in 2010, 2011, and 2012. The nightly mean brightness remained quite stable over the dataset. The light curve is dominated by complex oscillatory behavior reminiscent of the beating of hidden frequencies. A variety of photometric periods have been previously reported and none are found to be coherent periods in our dataset. Rather, a given night exhibits short lived quasi-periodic variations covering a variety of timescales, especially 10-40 min and even as long as two hours. This short period variability combined with recent spectroscopic abundance studies suggests that the likely donor in this binary is a white dwarf.

  6. High-speed optical shutter coupled to fast-readout CCD camera

    NASA Astrophysics Data System (ADS)

    Yates, George J.; Pena, Claudine R.; McDonald, Thomas E., Jr.; Gallegos, Robert A.; Numkena, Dustin M.; Turko, Bojan T.; Ziska, George; Millaud, Jacques E.; Diaz, Rick; Buckley, John; Anthony, Glen; Araki, Takae; Larson, Eric D.

    1999-04-01

    A high frame rate optically shuttered CCD camera for radiometric imaging of transient optical phenomena has been designed and several prototypes fabricated, which are now in evaluation phase. the camera design incorporates stripline geometry image intensifiers for ultra fast image shutters capable of 200ps exposures. The intensifiers are fiber optically coupled to a multiport CCD capable of 75 MHz pixel clocking to achieve 4KHz frame rate for 512 X 512 pixels from simultaneous readout of 16 individual segments of the CCD array. The intensifier, Philips XX1412MH/E03 is generically a Generation II proximity-focused micro channel plate intensifier (MCPII) redesigned for high speed gating by Los Alamos National Laboratory and manufactured by Philips Components. The CCD is a Reticon HSO512 split storage with bi-direcitonal vertical readout architecture. The camera main frame is designed utilizing a multilayer motherboard for transporting CCD video signals and clocks via imbedded stripline buses designed for 100MHz operation. The MCPII gate duration and gain variables are controlled and measured in real time and up-dated for data logging each frame, with 10-bit resolution, selectable either locally or by computer. The camera provides both analog and 10-bit digital video. The camera's architecture, salient design characteristics, and current test data depicting resolution, dynamic range, shutter sequences, and image reconstruction will be presented and discussed.

  7. Optical transceiver frontend for high speed bus STANAG 3910 with one fiber only

    NASA Astrophysics Data System (ADS)

    Tilly, Bodo

    The 200/280 micron glass fiber bus system is planned to be installed into the European Fighter Aircraft (EFA). Hybrid integration includes an optical fiber bidirectional T-coupler for aeronautical use. This mode of acting saves 50 percent of the cost intensive glass fiber installation, one reflective star coupler included, and therefore doubles the reliability of the new system. Significant transceiver frontend requirements had to be considered due to the concept of high speed bus STANAG 3910. In particular it is the intertransmission dynamic range on the receiver side: control of 23 dB signal level swing within the short time of 2 microseconds. And the optical power output of 0.5 dBm at the wavelength of 830 nm with the rise and fall times of 10 ns, using a surface emitting light emitting diode on the transmitter side. The data rate is 20 Mbit/s encoded in Manchester 2 format. That requires a wide receiver bandwidth (greater than 30 MHz) and a wide dynamic range (greater than 25 dB) to guarantee a bit error rate less than or equal to 10 (exp -10). The minimum optical power obtained is -37 dBm. Further details with values near to theoretical limits are given.

  8. Triggering of high-speed neurite outgrowth using an optical microheater

    PubMed Central

    Oyama, Kotaro; Zeeb, Vadim; Kawamura, Yuki; Arai, Tomomi; Gotoh, Mizuho; Itoh, Hideki; Itabashi, Takeshi; Suzuki, Madoka; Ishiwata, Shin’ichi

    2015-01-01

    Optical microheating is a powerful non-invasive method for manipulating biological functions such as gene expression, muscle contraction, and cell excitation. Here, we demonstrate its potential usage for regulating neurite outgrowth. We found that optical microheating with a water-absorbable 1,455-nm laser beam triggers directional and explosive neurite outgrowth and branching in rat hippocampal neurons. The focused laser beam under a microscope rapidly increases the local temperature from 36 °C to 41 °C (stabilized within 2 s), resulting in the elongation of neurites by more than 10 μm within 1 min. This high-speed, persistent elongation of neurites was suppressed by inhibitors of both microtubule and actin polymerization, indicating that the thermosensitive dynamics of these cytoskeletons play crucial roles in this heat-induced neurite outgrowth. Furthermore, we showed that microheating induced the regrowth of injured neurites and the interconnection of neurites. These results demonstrate the efficacy of optical microheating methods for the construction of arbitrary neural networks. PMID:26568288

  9. An FPGA-based High Speed Parallel Signal Processing System for Adaptive Optics Testbed

    NASA Astrophysics Data System (ADS)

    Kim, H.; Choi, Y.; Yang, Y.

    In this paper a state-of-the-art FPGA (Field Programmable Gate Array) based high speed parallel signal processing system (SPS) for adaptive optics (AO) testbed with 1 kHz wavefront error (WFE) correction frequency is reported. The AO system consists of Shack-Hartmann sensor (SHS) and deformable mirror (DM), tip-tilt sensor (TTS), tip-tilt mirror (TTM) and an FPGA-based high performance SPS to correct wavefront aberrations. The SHS is composed of 400 subapertures and the DM 277 actuators with Fried geometry, requiring high speed parallel computing capability SPS. In this study, the target WFE correction speed is 1 kHz; therefore, it requires massive parallel computing capabilities as well as strict hard real time constraints on measurements from sensors, matrix computation latency for correction algorithms, and output of control signals for actuators. In order to meet them, an FPGA based real-time SPS with parallel computing capabilities is proposed. In particular, the SPS is made up of a National Instrument's (NI's) real time computer and five FPGA boards based on state-of-the-art Xilinx Kintex 7 FPGA. Programming is done with NI's LabView environment, providing flexibility when applying different algorithms for WFE correction. It also facilitates faster programming and debugging environment as compared to conventional ones. One of the five FPGA's is assigned to measure TTS and calculate control signals for TTM, while the rest four are used to receive SHS signal, calculate slops for each subaperture and correction signal for DM. With this parallel processing capabilities of the SPS the overall closed-loop WFE correction speed of 1 kHz has been achieved. System requirements, architecture and implementation issues are described; furthermore, experimental results are also given.

  10. High-Speed Microscale Optical Tracking Using Digital Frequency-Domain Multiplexing.

    PubMed

    Maclachlan, Robert A; Riviere, Cameron N

    2009-06-01

    Position-sensitive detectors (PSDs), or lateral-effect photodiodes, are commonly used for high-speed, high-resolution optical position measurement. This paper describes the instrument design for multidimensional position and orientation measurement based on the simultaneous position measurement of multiple modulated sources using frequency-domain-multiplexed (FDM) PSDs. The important advantages of this optical configuration in comparison with laser/mirror combinations are that it has a large angular measurement range and allows the use of a probe that is small in comparison with the measurement volume. We review PSD characteristics and quantitative resolution limits, consider the lock-in amplifier measurement system as a communication link, discuss the application of FDM to PSDs, and make comparisons with time-domain techniques. We consider the phase-sensitive detector as a multirate DSP problem, explore parallels with Fourier spectral estimation and filter banks, discuss how to choose the modulation frequencies and sample rates that maximize channel isolation under design constraints, and describe efficient digital implementation. We also discuss hardware design considerations, sensor calibration, probe construction and calibration, and 3-D measurement by triangulation using two sensors. As an example, we characterize the resolution, speed, and accuracy of an instrument that measures the position and orientation of a 10 mm × 5 mm probe in 5 degrees of freedom (DOF) over a 30-mm cube with 4-μm peak-to-peak resolution at 1-kHz sampling.

  11. Investigations of high-speed optical transmission systems employing Absolute Added Correlative Coding (AACC)

    NASA Astrophysics Data System (ADS)

    Dong-Nhat, Nguyen; Elsherif, Mohamed A.; Malekmohammadi, Amin

    2016-07-01

    A novel multilevel modulation format based on partial-response signaling called Absolute Added Correlative Coding (AACC) is proposed and numerically demonstrated for high-speed fiber-optic communication systems. A bit error rate (BER) estimation model for the proposed multilevel format has also been developed. The performance of AACC is examined and compared against other prevailing On-Off-Keying and multilevel modulation formats e.g. non-return-to-zero (NRZ), 50% return-to-zero (RZ), 67% carrier-suppressed return-to-zero (CS-RZ), duobinary and four-level pulse-amplitude modulation (4-PAM) in terms of receiver sensitivity, spectral efficiency and dispersion tolerance. Calculated receiver sensitivity at a BER of 10-9 and chromatic dispersion tolerance of the proposed system are ∼-28.3 dBm and ∼336 ps/nm, respectively. The performance of AACC is delineated to be improved by 7.8 dB in terms of receiver sensitivity compared to 4-PAM in back-to-back scenario. The comparison results also show a clear advantage of AACC in achieving longer fiber transmission distance due to the higher dispersion tolerance in optical access networks.

  12. Investigations of high-speed optical transmission systems employing Absolute Added Correlative Coding (AACC)

    NASA Astrophysics Data System (ADS)

    Dong-Nhat, Nguyen; Elsherif, Mohamed A.; Malekmohammadi, Amin

    2016-07-01

    A novel multilevel modulation format based on partial-response signaling called Absolute Added Correlative Coding (AACC) is proposed and numerically demonstrated for high-speed fiber-optic communication systems. A bit error rate (BER) estimation model for the proposed multilevel format has also been developed. The performance of AACC is examined and compared against other prevailing On-Off-Keying and multilevel modulation formats e.g. non-return-to-zero (NRZ), 50% return-to-zero (RZ), 67% carrier-suppressed return-to-zero (CS-RZ), duobinary and four-level pulse-amplitude modulation (4-PAM) in terms of receiver sensitivity, spectral efficiency and dispersion tolerance. Calculated receiver sensitivity at a BER of 10-9 and chromatic dispersion tolerance of the proposed system are ˜-28.3 dBm and ˜336 ps/nm, respectively. The performance of AACC is delineated to be improved by 7.8 dB in terms of receiver sensitivity compared to 4-PAM in back-to-back scenario. The comparison results also show a clear advantage of AACC in achieving longer fiber transmission distance due to the higher dispersion tolerance in optical access networks.

  13. High-Speed Microscale Optical Tracking Using Digital Frequency-Domain Multiplexing.

    PubMed

    Maclachlan, Robert A; Riviere, Cameron N

    2009-06-01

    Position-sensitive detectors (PSDs), or lateral-effect photodiodes, are commonly used for high-speed, high-resolution optical position measurement. This paper describes the instrument design for multidimensional position and orientation measurement based on the simultaneous position measurement of multiple modulated sources using frequency-domain-multiplexed (FDM) PSDs. The important advantages of this optical configuration in comparison with laser/mirror combinations are that it has a large angular measurement range and allows the use of a probe that is small in comparison with the measurement volume. We review PSD characteristics and quantitative resolution limits, consider the lock-in amplifier measurement system as a communication link, discuss the application of FDM to PSDs, and make comparisons with time-domain techniques. We consider the phase-sensitive detector as a multirate DSP problem, explore parallels with Fourier spectral estimation and filter banks, discuss how to choose the modulation frequencies and sample rates that maximize channel isolation under design constraints, and describe efficient digital implementation. We also discuss hardware design considerations, sensor calibration, probe construction and calibration, and 3-D measurement by triangulation using two sensors. As an example, we characterize the resolution, speed, and accuracy of an instrument that measures the position and orientation of a 10 mm × 5 mm probe in 5 degrees of freedom (DOF) over a 30-mm cube with 4-μm peak-to-peak resolution at 1-kHz sampling. PMID:20428484

  14. Adaptive software-defined coded modulation for ultra-high-speed optical transport

    NASA Astrophysics Data System (ADS)

    Djordjevic, Ivan B.; Zhang, Yequn

    2013-10-01

    In optically-routed networks, different wavelength channels carrying the traffic to different destinations can have quite different optical signal-to-noise ratios (OSNRs) and signal is differently impacted by various channel impairments. Regardless of the data destination, an optical transport system (OTS) must provide the target bit-error rate (BER) performance. To provide target BER regardless of the data destination we adjust the forward error correction (FEC) strength. Depending on the information obtained from the monitoring channels, we select the appropriate code rate matching to the OSNR range that current channel OSNR falls into. To avoid frame synchronization issues, we keep the codeword length fixed independent of the FEC code being employed. The common denominator is the employment of quasi-cyclic (QC-) LDPC codes in FEC. For high-speed implementation, low-complexity LDPC decoding algorithms are needed, and some of them will be described in this invited paper. Instead of conventional QAM based modulation schemes, we employ the signal constellations obtained by optimum signal constellation design (OSCD) algorithm. To improve the spectral efficiency, we perform the simultaneous rate adaptation and signal constellation size selection so that the product of number of bits per symbol × code rate is closest to the channel capacity. Further, we describe the advantages of using 4D signaling instead of polarization-division multiplexed (PDM) QAM, by using the 4D MAP detection, combined with LDPC coding, in a turbo equalization fashion. Finally, to solve the problems related to the limited bandwidth of information infrastructure, high energy consumption, and heterogeneity of optical networks, we describe an adaptive energy-efficient hybrid coded-modulation scheme, which in addition to amplitude, phase, and polarization state employs the spatial modes as additional basis functions for multidimensional coded-modulation.

  15. A reciprocating optical in situ tribometer with high-speed data acquisition.

    PubMed

    Becker, S; Popp, U; Greiner, C

    2016-08-01

    Tribology is the science of interacting surfaces in relative motion. Processes like the transition from static to dynamic friction are fast and complex, especially as the contacting interface is buried. A direct view at the interface, in order to gain a deeper understanding of the interaction between the materials, is therefore of great interest. The reciprocating optical in situ tribometer introduced here observes the interface of two contacting materials (one of them being optical transparent) with a high-speed camera, taking up to 230 000 frames per second. The camera is attached to an optical microscope with a magnification of up to 2500 times. Friction forces are measured by an analog laser detection setup, with a maximum sampling rate of 500 kHz. The sliding motion of the materials is realized by two displacement units. A linear positioning stage allows velocities between 500 nm/s and 100 mm/s for a maximum distance of 200 mm. For smaller velocities, and to exclude breakaway torque, a piezo actuator can be used. The maximum displacement distance of the piezo actuator is 120 μm. The smallest applicable normal load on the samples is 0.5 N which is applied by the dead weights. Tribological experiments to investigate the transition from static to dynamic friction have been performed with morphologically textured brass hemispheres in contact with the sapphire discs. Sapphire was chosen for its high hardness and optical transparency. These experiments revealed, due to the high data acquisition possible with the new setup, a so far unobserved effect during the transition from static to dynamic friction. PMID:27587154

  16. Proven high-reliability assembly methods applied to avionics fiber-optics high-speed transceivers

    NASA Astrophysics Data System (ADS)

    Lauzon, Jocelyn; Leduc, Lorrain; Bessette, Daniel; Bélanger, Nicolas; Larose, Robert; Dion, Bruno

    2012-06-01

    Harsh environment avionics applications require operating temperature ranges that can extend to, and exceed -50 to 115°C. For obvious maintenance, management and cost arguments, product lifetimes as long as 20 years are also sought. This leads to mandatory long-term hermeticity that cannot be obtained with epoxy or silicone sealing; but only with glass seal or metal solder or brazing. A hermetic design can indirectly result in the required RF shielding of the component. For fiber-optics products, these specifications need to be compatible with the smallest possible size, weight and power consumption. The products also need to offer the best possible high-speed performances added to the known EMI immunity in the transmission lines. Fiber-optics transceivers with data rates per fiber channel up to 10Gbps are now starting to be offered on the market for avionics applications. Some of them are being developed by companies involved in the "normal environment" telecommunications market that are trying to ruggedize their products packaging in order to diversify their customer base. Another approach, for which we will present detailed results, is to go back to the drawing boards and design a new product that is adapted to proven MIL-PRF-38534 high-reliability packaging assembly methods. These methods will lead to the introduction of additional requirements at the components level; such as long-term high-temperature resistance for the fiber-optic cables. We will compare both approaches and demonstrate the latter, associated with the redesign, is the preferable one. The performance of the fiber-optic transceiver we have developed, in terms of qualification tests such as temperature cycling, constant acceleration, hermeticity, residual gaz analysis, operation under random vibration and mechanical shocks and accelerated lifetime tests will be presented. The tests are still under way, but so far, we have observed no performance degradation of such a product after more than

  17. A reciprocating optical in situ tribometer with high-speed data acquisition

    NASA Astrophysics Data System (ADS)

    Becker, S.; Popp, U.; Greiner, C.

    2016-08-01

    Tribology is the science of interacting surfaces in relative motion. Processes like the transition from static to dynamic friction are fast and complex, especially as the contacting interface is buried. A direct view at the interface, in order to gain a deeper understanding of the interaction between the materials, is therefore of great interest. The reciprocating optical in situ tribometer introduced here observes the interface of two contacting materials (one of them being optical transparent) with a high-speed camera, taking up to 230 000 frames per second. The camera is attached to an optical microscope with a magnification of up to 2500 times. Friction forces are measured by an analog laser detection setup, with a maximum sampling rate of 500 kHz. The sliding motion of the materials is realized by two displacement units. A linear positioning stage allows velocities between 500 nm/s and 100 mm/s for a maximum distance of 200 mm. For smaller velocities, and to exclude breakaway torque, a piezo actuator can be used. The maximum displacement distance of the piezo actuator is 120 μm. The smallest applicable normal load on the samples is 0.5 N which is applied by the dead weights. Tribological experiments to investigate the transition from static to dynamic friction have been performed with morphologically textured brass hemispheres in contact with the sapphire discs. Sapphire was chosen for its high hardness and optical transparency. These experiments revealed, due to the high data acquisition possible with the new setup, a so far unobserved effect during the transition from static to dynamic friction.

  18. Improved optical performance monitoring technique based on nonlinear optics for high-speed WDM Nyquist systems

    NASA Astrophysics Data System (ADS)

    Guesmi, Latifa; Menif, Mourad

    2016-04-01

    The field of fiber optics nonlinearity is more discussed last years due to such remarkable enhancement in the nonlinear processes efficiency. In this paper, and for optical performance monitoring (OPM), a new achievement of nonlinear effects has been investigated. The use of cross-phase modulation (XPM) and four-wave mixing (FWM) effects between input optical signal and inserted continuous-wave probe has proposed for impairments monitoring. Indeed, transmitting a multi-channels phase modulated signal at high data rate (1 Tbps WDM Nyquist NRZ- DP-QPSK) improves the sensitivity and the dynamic range monitoring. It was observed by simulation results that various optical parameters including optical power, wavelength, chromatic dispersion (CD), polarization mode dispersion (PMD), optical signal-to-noise ratio (OSNR), Q-factor and so on, can be monitored. Also, the effect of increasing the channel spacing between WDM signals is studied and proved its use for FWM power monitoring.

  19. Monolithic, High-Speed Fiber-Optic Switching Array for Lidar

    NASA Technical Reports Server (NTRS)

    Suckow, Will; Roberts, Tony; Switzer, Gregg; Terwilliger, Chelle

    2011-01-01

    Current fiber switch technologies use mechanical means to redirect light beams, resulting in slow switch time, as well as poor reliability due to moving parts wearing out quickly at high speeds. A non-mechanical ability to switch laser output into one of multiple fibers within a fiber array can provide significant power, weight, and costs savings to an all-fiber system. This invention uses an array of crystals that act as miniature prisms to redirect light as an electric voltage changes the prism s properties. At the heart of the electro-optic fiber-optic switch is an electro- optic crystal patterned with tiny prisms that can deflect the beam from the input fiber into any one of the receiving fibers arranged in a linear array when a voltage is applied across the crystal. Prism boundaries are defined by a net dipole moment in the crystal lattice that has been poled opposite to the surrounding lattice fabricated using patterned, removable microelectrodes. When a voltage is applied across the crystal, the resulting electric field changes the index of refraction within the prism boundaries relative to the surrounding substrate, causing light to deflect slightly according to Snell s Law. There are several materials that can host the necessary monolithic poled pattern (including, but not limited to, SLT, KTP, LiNbO3, and Mg:LiNbO3). Be cause this is a solid-state system without moving parts, it is very fast, and does not wear down easily. This invention is applicable to all fiber networks, as well as industries that use such networks. The unit comes in a compact package, can handle both low and high voltages, and has a high reliability (100,000 hours without maintenance).

  20. Dynamical hologram generation for high speed optical trapping of smart droplet microtools.

    PubMed

    Lanigan, P M P; Munro, I; Grace, E J; Casey, D R; Phillips, J; Klug, D R; Ces, O; Neil, M A A

    2012-07-01

    This paper demonstrates spatially selective sampling of the plasma membrane by the implementation of time-multiplexed holographic optical tweezers for Smart Droplet Microtools (SDMs). High speed (>1000fps) dynamical hologram generation was computed on the graphics processing unit of a standard display card and controlled by a user friendly LabView interface. Time multiplexed binary holograms were displayed in real time and mirrored to a ferroelectric Spatial Light Modulator. SDMs were manufactured with both liquid cores (as previously described) and solid cores, which confer significant advantages in terms of stability, polydispersity and ease of use. These were coated with a number of detergents, the most successful based upon lipids doped with transfection reagents. In order to validate these, trapped SDMs were maneuvered up to the plasma membrane of giant vesicles containing Nile Red and human biliary epithelial (BE) colon cancer cells with green fluorescent labeled protein (GFP)-labeled CAAX (a motif belonging to the Ras protein). Bright field and fluorescence images showed that successful trapping and manipulation of multiple SDMs in x, y, z was achieved with success rates of 30-50% and that subsequent membrane-SDM interactions led to the uptake of Nile Red or GFP-CAAX into the SDM.

  1. Microscopic feature extraction from optical sections of contracting cardiac muscle cells recorded at high speed

    NASA Astrophysics Data System (ADS)

    Roos, Kenneth P.; Lake, David S.; Lubell, Bradford A.

    1991-05-01

    The rapid motion of microscopic features such as the cross-striations of contracting cardiac muscle cells are difficult to capture with conventional RS-170 video systems and image processing approaches. In this report, efforts to extract, enhance and analyze striation data from widefield optical sections of single contracting cells recorded with a charge-coupled device (CCD) video camera modified for high-speed RS-170 compatible operation are described. Each video field from the camera provides four 1/4 height images separated by 4 ms in time for a 240 Hz image acquisition rate. Data are continuously recorded on S-VHS video tape during each experiment. Selected image sequences are digitized field by field and stored in a computer system under automated software control. The four individual images in each video field are separated, geometrically corrected for time base error, and reassembled as a single sequence of images for interpretable visualization. The images are then processed with digital filters and gray scale expansion to preferentially enhance the cross-striations and minimize out of focus features. Regions within each image containing striations are identified and their positions determined and followed during the contraction cycle to obtain individual, regional and cellular sarcomere dynamics. This approach permits the critical evaluation of the magnitude, time course and uniformity of contractile function throughout the volume of a single cell with higher temporal and spatial resolutions than previously possible.

  2. High-Speed GPU-Based Fully Three-Dimensional Diffuse Optical Tomographic System

    PubMed Central

    Saikia, Manob Jyoti; Kanhirodan, Rajan; Mohan Vasu, Ram

    2014-01-01

    We have developed a graphics processor unit (GPU-) based high-speed fully 3D system for diffuse optical tomography (DOT). The reduction in execution time of 3D DOT algorithm, a severely ill-posed problem, is made possible through the use of (1) an algorithmic improvement that uses Broyden approach for updating the Jacobian matrix and thereby updating the parameter matrix and (2) the multinode multithreaded GPU and CUDA (Compute Unified Device Architecture) software architecture. Two different GPU implementations of DOT programs are developed in this study: (1) conventional C language program augmented by GPU CUDA and CULA routines (C GPU), (2) MATLAB program supported by MATLAB parallel computing toolkit for GPU (MATLAB GPU). The computation time of the algorithm on host CPU and the GPU system is presented for C and Matlab implementations. The forward computation uses finite element method (FEM) and the problem domain is discretized into 14610, 30823, and 66514 tetrahedral elements. The reconstruction time, so achieved for one iteration of the DOT reconstruction for 14610 elements, is 0.52 seconds for a C based GPU program for 2-plane measurements. The corresponding MATLAB based GPU program took 0.86 seconds. The maximum number of reconstructed frames so achieved is 2 frames per second. PMID:24891848

  3. High-Speed Imaging Optical Pyrometry for Study of Boron Nitride Nanotube Generation

    NASA Technical Reports Server (NTRS)

    Inman, Jennifer A.; Danehy, Paul M.; Jones, Stephen B.; Lee, Joseph W.

    2014-01-01

    A high-speed imaging optical pyrometry system is designed for making in-situ measurements of boron temperature during the boron nitride nanotube synthesis process. Spectrometer measurements show molten boron emission to be essentially graybody in nature, lacking spectral emission fine structure over the visible range of the electromagnetic spectrum. Camera calibration experiments are performed and compared with theoretical calculations to quantitatively establish the relationship between observed signal intensity and temperature. The one-color pyrometry technique described herein involves measuring temperature based upon the absolute signal intensity observed through a narrowband spectral filter, while the two-color technique uses the ratio of the signals through two spectrally separated filters. The present study calibrated both the one- and two-color techniques at temperatures between 1,173 K and 1,591 K using a pco.dimax HD CMOS-based camera along with three such filters having transmission peaks near 550 nm, 632.8 nm, and 800 nm.

  4. Evaluation of hypoxic swelling of human cornea with high speed ultrahigh resolution optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Bizheva, Kostadinka; Hyun, Chulho; Eichel, Justin; Hariri, Sepideh; Mishra, Akshaya; Clausi, David; Fieguth, Paul; Simpson, Trefford; Hutchings, Natalie

    2009-02-01

    Hypoxia induced corneal swelling was observed and evaluated in healthy human volunteers by use of high speed, ultrahigh resolution optical coherence tomography (UHROCT). Two dimensional corneal images were acquired at a speed of 47,000 A-scans/s with 3µm x 10µm (axial x lateral) resolution in corneal tissue. The UHROCT tomograms showed clear visualization of all corneal layers, including the Bowman's layer and the Descemet's membrane - Endothelium complex. A segmentation algorithm was developed and used for automatic detection of the boundaries of the different corneal layers and evaluation the individual layer thickness as a function of location. Corneal hypoxia was induced by wear of a soft contact lens (SCL) and an eye patch by 2 healthy volunteers for duration of 3 hours. The thickness of all corneal layers was measured as a function of time, prior to, with and after removal of the SCL. Results from the hypoxia study showed different rates of swelling and de-swelling of the individual corneal layers. About 10% increase in the total cornea thickness was observed, similar to the changes in the stroma, the Bowman's membrane swelled by 20%, while no significant change in the thickness was observed in the Descemet's - Endothelium complex.

  5. Dynamical hologram generation for high speed optical trapping of smart droplet microtools.

    PubMed

    Lanigan, P M P; Munro, I; Grace, E J; Casey, D R; Phillips, J; Klug, D R; Ces, O; Neil, M A A

    2012-07-01

    This paper demonstrates spatially selective sampling of the plasma membrane by the implementation of time-multiplexed holographic optical tweezers for Smart Droplet Microtools (SDMs). High speed (>1000fps) dynamical hologram generation was computed on the graphics processing unit of a standard display card and controlled by a user friendly LabView interface. Time multiplexed binary holograms were displayed in real time and mirrored to a ferroelectric Spatial Light Modulator. SDMs were manufactured with both liquid cores (as previously described) and solid cores, which confer significant advantages in terms of stability, polydispersity and ease of use. These were coated with a number of detergents, the most successful based upon lipids doped with transfection reagents. In order to validate these, trapped SDMs were maneuvered up to the plasma membrane of giant vesicles containing Nile Red and human biliary epithelial (BE) colon cancer cells with green fluorescent labeled protein (GFP)-labeled CAAX (a motif belonging to the Ras protein). Bright field and fluorescence images showed that successful trapping and manipulation of multiple SDMs in x, y, z was achieved with success rates of 30-50% and that subsequent membrane-SDM interactions led to the uptake of Nile Red or GFP-CAAX into the SDM. PMID:22808432

  6. Assessing trophic linkages in and around offshore wind farms using two high-speed optical sensors

    NASA Astrophysics Data System (ADS)

    Dudeck, Tim; Hufnagl, Marc; Auch, Dominik; Eckhardt, André; Möller, Klas-Ove; van Beusekom, Justus; Walter, Bettina; Möllmann, Christian; Floeter, Jens

    2016-04-01

    In search for clean, renewable energy sources European countries have built and planned numerous Offshore Wind Farms (OWF) in the North Sea region. While some research has been carried out on their influence on marine mammals and bottom-dwelling organisms, less is known about fish and lower trophic levels in these areas. Yet, marine mammals purposely seek these structures and there are indications that there are higher chances of fish encounters. However, the local bottom-up effects probably driving these aggregations of higher trophic level organisms are poorly understood. In this study we show preliminary results of primary and secondary production in and around German OWFs in the North Sea using a Laser Optical Particle Counter and a Video Plankton Recorder. With the two sensors working simultaneously on the TRIAXUS system at high speed, we were able to investigate and ground-truth size-spectrum changes on a very high spatial resolution making it possible to detect OWF effects from local to larger scales. Our results show new possibilities in OWF research and the necessity to collect highly resolved field data for meaningful results in these dynamic environments. Furthermore, the use of size spectra simplifies the integration of energy flow through low and medium trophic levels into biogeochemical models by using only a single automatically measurable variable such as size.

  7. OPTICAL COMMUNICATION: Simulation of autosoliton optical pulses in high-speed fibreoptic communication systems

    NASA Astrophysics Data System (ADS)

    Latkin, A. I.

    2005-03-01

    The propagation of a pulse in a fibreoptic communication link with periodically included regenerators — nonlinear optical loop mirrors, is studied. The autosoliton propagation regime of the optical pulse is revealed. It is shown that the inclusion of a ring mirror to the communication link leads to a substantial increase in the transmission distance of the pulse at a small negative average dispersion in the link.

  8. Final Report and Documentation for the Optical Backplane/Interconnect for High Speed Communication LDRD

    SciTech Connect

    ROBERTSON, PERRY J.; CHEN, HELEN Y.; BRANDT, JAMES M.; SULLIVAN, CHARLES T.; PIERSON, LYNDON G.; WITZKE, EDWARD L.; GASS, KARL

    2001-03-01

    Current copper backplane technology has reached the technical limits of clock speed and width for systems requiring multiple boards. Currently, bus technology such as VME and PCI (types of buses) will face severe limitations are the bus speed approaches 100 MHz. At this speed, the physical length limit of an unterminated bus is barely three inches. Terminating the bus enables much higher clock rates but at drastically higher power cost. Sandia has developed high bandwidth parallel optical interconnects that can provide over 40 Gbps throughput between circuit boards in a system. Based on Sandia's unique VCSEL (Vertical Cavity Surface Emitting Laser) technology, these devices are compatible with CMOS (Complementary Metal Oxide Semiconductor) chips and have single channel bandwidth in excess of 20 GHz. In this project, we are researching the use of this interconnect scheme as the physical layer of a greater ATM (Asynchronous Transfer Mode) based backplane. There are several advantages to this technology including small board space, lower power and non-contact communication. This technology is also easily expandable to meet future bandwidth requirements in excess of 160 Gbps sometimes referred to as UTOPIA 6. ATM over optical backplane will enable automatic switching of wide high-speed circuits between boards in a system. In the first year we developed integrated VCSELs and receivers, identified fiber ribbon based interconnect scheme and a high level architecture. In the second year, we implemented the physical layer in the form of a PCI computer peripheral card. A description of future work including super computer networking deployment and protocol processing is included.

  9. Development of novel high-speed en face optical coherence tomography system using KTN optical beam deflector

    NASA Astrophysics Data System (ADS)

    Ohmi, Masato; Fukuda, Akihiro; Miyazu, Jun; Ueno, Masahiro; Toyoda, Seiji; Kobayashi, Junya

    2015-02-01

    We developed a novel high-speed en face optical coherence tomography (OCT) system using a KTa1-xNbxO3 (KTN) optical beam deflector. Using the imaging system, fast scanning was performed at 200 kHz by the KTN beam deflector, while slow scanning was performed at 400 Hz by the galvanometer mirror. In a preliminary experiment, we obtained en face OCT images of a human fingerprint at 400 fps. This is the highest speed reported in time-domain en face OCT imaging and is comparable to the speed of swept-source OCT. A 3D-OCT image of a sweat gland was also obtained by our imaging system.

  10. Intrinsic imperfection of self-differencing single-photon detectors harms the security of high-speed quantum cryptography systems

    NASA Astrophysics Data System (ADS)

    Jiang, Mu-Sheng; Sun, Shi-Hai; Tang, Guang-Zhao; Ma, Xiang-Chun; Li, Chun-Yan; Liang, Lin-Mei

    2013-12-01

    Thanks to the high-speed self-differencing single-photon detector (SD-SPD), the secret key rate of quantum key distribution (QKD), which can, in principle, offer unconditionally secure private communications between two users (Alice and Bob), can exceed 1 Mbit/s. However, the SD-SPD may contain loopholes, which can be exploited by an eavesdropper (Eve) to hack into the unconditional security of the high-speed QKD systems. In this paper, we analyze the fact that the SD-SPD can be remotely controlled by Eve in order to spy on full information without being discovered, then proof-of-principle experiments are demonstrated. Here, we point out that this loophole is introduced directly by the operating principle of the SD-SPD, thus, it cannot be removed, except for the fact that some active countermeasures are applied by the legitimate parties.

  11. Is blue optical filter necessary in high speed phosphor-based white light LED visible light communications?

    PubMed

    Sung, Jiun-Yu; Chow, Chi-Wai; Yeh, Chien-Hung

    2014-08-25

    Optical blue filter is usually regarded as a critical optical component for high speed phosphor-based white light emitting diode (LED) visible-light-communication (VLC). However, the optical blue filter plays different roles in VLC when using modulations of on-off keying (OOK) or discrete multi-tone (DMT). We show that in the DMT VLC system, the blue optical filter may be unnecessary, and even degrade the transmission performance (by reducing the optical signal-to-noise ratio (SNR)). Analyses and verifications by experiments are performed. To the best of our knowledge, this is the first time the function of blue filters in VLC is explicitly analyzed.

  12. Proposed new approach to design all optical AND gate using plasmonic based Mach-Zehnder interferometer for high speed communication

    NASA Astrophysics Data System (ADS)

    Kumar, Santosh; Singh, Lokendra

    2016-04-01

    The limitation of conventional electronics is mitigated by all optical integrated circuits which have potential of high speed computing and information processing. In this work, an all optical AND gate using optical Kerr effect and optical bistability of a plasmonic based Mach-Zehnder interferometer (MZI) is proposed. An MZI is capable for switching of light according to the intensities of optical input signal. The paper constitutes with mathematical formulation of device and its study is verified using finite difference time domain (FDTD) method.

  13. A High-Speed Optical Modem Communication System for CORK Seafloor Observatories

    NASA Astrophysics Data System (ADS)

    Farr, N.; Tivey, M.; Ware, J.; Pontbriand, C.; Pelletier, L. P.

    2014-12-01

    High-speed communications underwater is an increasing requirement for data intensive seafloor sensors. Acoustic modems provide dependable long-range communications underwater, but data rates are limited to <57Kbps. Free-water optical modems (OMs) offer high data rate, 10Mbps communications over a range of 200 m - a distance for ROVs, AUVs or wire-lowered packages to communicate without the need to directly plug-in or retrieve the instrument. Over the past 4 years, we have demonstrated the functionality and utility of OM technology using a CORK borehole observatory as a test case. A CORK represents all of the basic components required for a seafloor observatory: a stable environment for long-term continuous measurements of earth and ocean phenomena, access to a unique environment below the seafloor and a standard communication interface. The CORK-OM features a high-bandwidth, low-latency optical system based on LED emitters and PMT receivers and an acoustic command and control system. OM tests established a communication link from 20 to 200 meters range at rates of 1, 5 and 10 Mbps with no bit errors. The seafloor OM was plugged into the CORK's existing underwater wet mateable connector and provided additional power to the CORK to boost the data rate to 1 Hz from the normal 1 minute sample period. To communicate with the seafloor CORK-OM, a number of different modalities were used. One method was an OM mounted to a CTD frame on a lowered wire from a ship with an SDSL link over the conducting wire. Other methods utilized OMs mounted to both ROV Jason and submersible Alvin. We deployed OMs at two CORKs in 2012 in the northeast pacific at sites 857D and 1025C. The CORKs were visited in 2013 by a vessel of opportunity to download data and were put into sleep mode. The CORKs were revisited in 2014, woken up and successfully interrogated for data. ALVIN retrieved the CORK-OMs for corrosion, biofouling and battery performance assessment. We also performed tests of a next

  14. Optical Flow-Field Techniques Used for Measurements in High-Speed Centrifugal Compressors

    NASA Technical Reports Server (NTRS)

    Skoch, Gary J.

    1999-01-01

    The overall performance of a centrifugal compressor depends on the performance of the impeller and diffuser as well as on the interactions occurring between these components. Accurate measurements of the flow fields in each component are needed to develop computational models that can be used in compressor design codes. These measurements must be made simultaneously over an area that covers both components so that researchers can understand the interactions occurring between the two components. Optical measurement techniques are being used at the NASA Lewis Research Center to measure the velocity fields present in both the impeller and diffuser of a 4:1 pressure ratio centrifugal compressor operating at several conditions ranging from design flow to surge. Laser Doppler Velocimetry (LDV) was used to measure the intrablade flows present in the impeller, and the results were compared with analyses obtained from two three-dimensional viscous codes. The development of a region of low throughflow velocity fluid within this high-speed impeller was examined and compared with a similar region first observed in a large low-speed centrifugal impeller at Lewis. Particle Image Velocimetry (PIV) is a relatively new technique that has been applied to measuring the diffuser flow fields. PIV can collect data rapidly in the diffuser while avoiding the light-reflection problems that are often encountered when LDV is used. The Particle Image Velocimeter employs a sheet of pulsed laser light that is introduced into the diffuser in a quasi-radial direction through an optical probe inserted near the diffuser discharge. The light sheet is positioned such that its centerline is parallel to the hub and shroud surfaces and such that it is parallel to the diffuser vane, thereby avoiding reflections from the solid surfaces. Seed particles small enough to follow the diffuser flow are introduced into the compressor at an upstream location. A high-speed charge-coupled discharge (CCD) camera is

  15. High-speed spectral calibration by complex FIR filter in phase-sensitive optical coherence tomography.

    PubMed

    Kim, Sangmin; Raphael, Patrick D; Oghalai, John S; Applegate, Brian E

    2016-04-01

    Swept-laser sources offer a number of advantages for Phase-sensitive Optical Coherence Tomography (PhOCT). However, inter- and intra-sweep variability leads to calibration errors that adversely affect phase sensitivity. While there are several approaches to overcoming this problem, our preferred method is to simply calibrate every sweep of the laser. This approach offers high accuracy and phase stability at the expense of a substantial processing burden. In this approach, the Hilbert phase of the interferogram from a reference interferometer provides the instantaneous wavenumber of the laser, but is computationally expensive. Fortunately, the Hilbert transform may be approximated by a Finite Impulse-Response (FIR) filter. Here we explore the use of several FIR filter based Hilbert transforms for calibration, explicitly considering the impact of filter choice on phase sensitivity and OCT image quality. Our results indicate that the complex FIR filter approach is the most robust and accurate among those considered. It provides similar image quality and slightly better phase sensitivity than the traditional FFT-IFFT based Hilbert transform while consuming fewer resources in an FPGA implementation. We also explored utilizing the Hilbert magnitude of the reference interferogram to calculate an ideal window function for spectral amplitude calibration. The ideal window function is designed to carefully control sidelobes on the axial point spread function. We found that after a simple chromatic correction, calculating the window function using the complex FIR filter and the reference interferometer gave similar results to window functions calculated using a mirror sample and the FFT-IFFT Hilbert transform. Hence, the complex FIR filter can enable accurate and high-speed calibration of the magnitude and phase of spectral interferograms. PMID:27446666

  16. High-speed spectral calibration by complex FIR filter in phase-sensitive optical coherence tomography

    PubMed Central

    Kim, Sangmin; Raphael, Patrick D.; Oghalai, John S.; Applegate, Brian E.

    2016-01-01

    Swept-laser sources offer a number of advantages for Phase-sensitive Optical Coherence Tomography (PhOCT). However, inter- and intra-sweep variability leads to calibration errors that adversely affect phase sensitivity. While there are several approaches to overcoming this problem, our preferred method is to simply calibrate every sweep of the laser. This approach offers high accuracy and phase stability at the expense of a substantial processing burden. In this approach, the Hilbert phase of the interferogram from a reference interferometer provides the instantaneous wavenumber of the laser, but is computationally expensive. Fortunately, the Hilbert transform may be approximated by a Finite Impulse-Response (FIR) filter. Here we explore the use of several FIR filter based Hilbert transforms for calibration, explicitly considering the impact of filter choice on phase sensitivity and OCT image quality. Our results indicate that the complex FIR filter approach is the most robust and accurate among those considered. It provides similar image quality and slightly better phase sensitivity than the traditional FFT-IFFT based Hilbert transform while consuming fewer resources in an FPGA implementation. We also explored utilizing the Hilbert magnitude of the reference interferogram to calculate an ideal window function for spectral amplitude calibration. The ideal window function is designed to carefully control sidelobes on the axial point spread function. We found that after a simple chromatic correction, calculating the window function using the complex FIR filter and the reference interferometer gave similar results to window functions calculated using a mirror sample and the FFT-IFFT Hilbert transform. Hence, the complex FIR filter can enable accurate and high-speed calibration of the magnitude and phase of spectral interferograms. PMID:27446666

  17. High-speed response to laser heating and cooling in thermo-magnetic writing on magneto-optical disk memory

    NASA Astrophysics Data System (ADS)

    Miyata, Kazutomo; Saito, Jun; Akasaka, Hideki

    1994-10-01

    In order to use Magneto-Optical (MO) media for multi media applications, it is necessary to achieve higher density, higher data transfer rate and lower cost technologies than current MO media. MO recording is thermo- magnetic recording. MO recordings makes use of temperature modulation caused by light intensity modulation from the laser diode for recording. So, it is important to realize high speed response to the light intensity modulation for high data transfer rate recording. The high speed response is also indispensable to make small magnetic domains. So, it is important for high density recording, too. We investigate the temperature response to the light intensity modulation on MO disk. consequently, we found that MO medium shows the high speed response when the laser spot scanning velocity is large.

  18. High-Speed Photography

    SciTech Connect

    Paisley, D.L.; Schelev, M.Y.

    1998-08-01

    The applications of high-speed photography to a diverse set of subjects including inertial confinement fusion, laser surgical procedures, communications, automotive airbags, lightning etc. are briefly discussed. (AIP) {copyright} {ital 1998 Society of Photo-Optical Instrumentation Engineers.}

  19. LGSD/NGSD: high speed optical CMOS imagers for E-ELT adaptive optics

    NASA Astrophysics Data System (ADS)

    Downing, Mark; Kolb, Johann; Balard, Philippe; Dierickx, Bart; Defernez, Arnaud; Feautrier, Philippe; Finger, Gert; Fryer, Martin; Gach, Jean-Luc; Guillaume, Christian; Hubin, Norbert; Jerram, Paul; Jorden, Paul; Meyer, Manfred; Payne, Andrew; Pike, Andrew; Reyes, Javier; Simpson, Robert; Stadler, Eric; Stent, Jeremy; Swift, Nick

    2014-07-01

    The success of the next generation of instruments for ELT class telescopes will depend upon improving the image quality by exploiting sophisticated Adaptive Optics (AO) systems. One of the critical components of the AO systems for the E-ELT has been identified as the optical Laser/Natural Guide Star WFS detector. The combination of large format, 1760×1680 pixels to finely sample the wavefront and the spot elongation of laser guide stars, fast frame rate of 700 frames per second (fps), low read noise (< 3e-), and high QE (> 90%) makes the development of this device extremely challenging. Design studies concluded that a highly integrated Backside Illuminated CMOS Imager built on High Resistivity silicon as the most likely technology to succeed. Two generations of the CMOS Imager are being developed: a) the already designed and manufactured NGSD (Natural Guide Star Detector), a quarter-sized pioneering device of 880×840 pixels capable of meeting first light needs of the E-ELT; b) the LGSD (Laser Guide Star Detector), the larger full size device. The detailed design is presented including the approach of using massive parallelism (70,400 ADCs) to achieve the low read noise at high pixel rates of ~3 Gpixel/s and the 88 channel LVDS 220Mbps serial interface to get the data off-chip. To enable read noise closer to the goal of 1e- to be achieved, a split wafer run has allowed the NGSD to be manufactured in the more speculative, but much lower read noise, Ultra Low Threshold Transistors in the unit cell. The NGSD has come out of production, it has been thinned to 12μm, backside processed and packaged in a custom 370pin Ceramic PGA (Pin Grid Array). First results of tests performed both at e2v and ESO are presented.

  20. A low power electro-optic polymer clad Mach-Zehnder modulator for high speed optical interconnects

    NASA Astrophysics Data System (ADS)

    Block, Bruce; Liff, Shawna; Kobrinsky, Mauro; Reshotko, Miriam; Tseng, Ricky; Ban, Ibrahim; Chang, Peter

    2013-02-01

    Electro-optic (EO) polymer cladding modulators are an option for low-power high-speed optical interconnects on a silicon platform. EO polymers have inherently high switching speeds and have shown 40 Gb/s operation in EO polymer clad ring resonator modulators (RRM). In EO polymer clad RRM, the modulator's area is small enough to be treated as a lumped capacitor; the capacitance is sufficiently low that the modulation speed is limited by the bandwidth of the resonator. A high Q resonator is needed for low voltage operation, but this can limit the speed and/or require precise control of the resonator's wavelength, necessitating power consuming heaters to maintain optimal performance over a large temperature range. Mach Zehnder modulators (MZM), on the other hand, are not as sensitive to temperature fluctuations, but typically are relatively long and must employ power consuming terminated travelling wave electrodes. In this paper, a novel MZM design is presented using an EO polymer clad device. In this device, the electrodes are broken into short parallel segments and the waveguide folds around them. The segments of the electrode length are designed to provide good signal integrity up to 20 GHz without termination. The electrodes are driven by a single drive voltage and provide push-pull modulation. Modulators were designed and fabricated using silicon nitride waveguides on bulk silicon wafers and were demonstrated at high speed (20 GHz). A VπL as low as 1.7 Vcm is measured on initial devices. An optimized device could provide 40 Gb/s performance at 1 V drive voltages, ~100 fF total device capacitance and less than 2 dB optical insertion loss.

  1. Novel monolithic integration scheme for high-speed electroabsorption modulators and semiconductor optical amplifiers using cascaded structure.

    PubMed

    Lin, Fang-Zheng; Wu, Tsu-Hsiu; Chiu, Yi-Jen

    2009-06-01

    A new monolithic integration scheme, namely cascaded-integration (CI), for improving high-speed optical modulation is proposed and demonstrated. High-speed electroabsorption modulators (EAMs) and semiconductor optical amplifiers (SOAs) are taken as the integrated elements of CI. This structure is based on an optical waveguide defined by cascading segmented EAMs with segmented SOAs, while high-impedance transmission lines (HITLs) are used for periodically interconnecting EAMs, forming a distributive optical re-amplification and re-modulation. Therefore, not only the optical modulation can be beneficial from SOA gain, but also high electrical reflection due to EAM low characteristic impedance can be greatly reduced. Two integration schemes, CI and conventional single-section (SS), with same total EAM- and SOA- lengths are fabricated and compared to examine the concept. Same modulation-depth against with EAM bias (up to 5V) as well as SOA injection current (up to 60mA) is found in both structures. In comparison with SS, a < 1dB extra optical-propagation loss in CI is measured due to multi-sections of electrical-isolation regions between EAMs and SOAs, suggesting no significant deterioration in CI on DC optical modulation efficiency. Lower than -12dB of electrical reflection from D.C. to 30GHz is observed in CI, better than -5dB reflection in SS for frequency of above 5GHz. Superior high-speed electrical properties in CI structure can thus lead to higher speed of electrical-to-optical (EO) response, where -3dB bandwidths are >30GHz and 13GHz for CI and SS respectively. Simulation results on electrical and EO response are quite consistent with measurement, confirming that CI can lower the driving power at high-speed regime, while the optical loss is still kept the same level. Taking such distributive advantage (CI) with optical gain, not only higher-speed modulation with high output optical power can be attained, but also the trade-off issue due to impedance mismatch

  2. High-speed semiconductor devices

    NASA Astrophysics Data System (ADS)

    Sze, S. M.

    An introduction to the physical principles and operational characteristics of high-speed semiconductor devices is presented. Consideration is given to materials and technologies for high-speed devices, device building blocks, the submicron MOSFET, homogeneous field-effect transistors, and heterostructure field-effect transistors. Also considered are quantum-effect devices, microwave diodes, and high-speed photonic devices.

  3. High-speed optical beam alignment based on a motion control technique for three-dimensional microelectromechanical systems optical switch modules

    NASA Astrophysics Data System (ADS)

    Mizukami, Masato; Yamaguchi, Joji; Nemoto, Naru

    2011-07-01

    For optical axis alignment when light deflection control of a MEMS mirror is done at high speed, we propose a method based on identifying the quadratic surface shape. The method uses information about the optical power monitored when the mirror is inclined to a small angle. It is shown that the search for maximum optical power is possible by using this method. We also designed a control system with a band-stop filter for resonance frequency to decrease residual vibration generated when the mirror is moved at high speed. We confirm that the searchable level of optical power can be improved.

  4. Dynamic high-speed spatial manipulation of cold atoms using acousto-optic and spatial light modulation.

    PubMed

    Fatemi, F K; Bashkansky, M; Dutton, Z

    2007-03-19

    We demonstrate an experimental technique for high-resolution, high-speed spatial manipulation of atom clouds. By combining holographically engineered laser beams from a spatial light modulator with off-axis shear mode acousto-optic deflectors, we manipulate 1 x 3 arrays of cold atoms with individual site addressability. Additionally, we demonstrate smooth 2-dimensional motion of atomic ensembles, and the ability to guide multiple atomic ensembles independently.

  5. High-speed impact test using an inertial mass and an optical interferometer.

    PubMed

    Jin, T; Watanabe, K; Prayogi, I A; Takita, A; Mitatha, S; Djamal, M; Jia, H Z; Hou, W M; Fujii, Y

    2013-07-01

    A high-speed impact testing method for evaluating mechanical properties of materials is proposed using an inertial mass and a dual beat-frequencies laser Doppler interferometer (DB-LDI). In this method, an inertial mass levitated using an aerostatic linear bearing is made to collide with the material being tested at a high initial velocity. During the collision, the velocity of the mass, which is even higher than the critical velocity (±0.56 m/s) defined by the frequency difference of the Zeeman laser, is accurately measured using the DB-LDI. The position, acceleration, and impact force of the mass are calculated from the measured velocity. Using the proposed method, the mechanical properties of a visco-elastic material under a high-speed impact loading condition can be accurately evaluated.

  6. SPLASSH: Open source software for camera-based high-speed, multispectral in-vivo optical image acquisition

    PubMed Central

    Sun, Ryan; Bouchard, Matthew B.; Hillman, Elizabeth M. C.

    2010-01-01

    Camera-based in-vivo optical imaging can provide detailed images of living tissue that reveal structure, function, and disease. High-speed, high resolution imaging can reveal dynamic events such as changes in blood flow and responses to stimulation. Despite these benefits, commercially available scientific cameras rarely include software that is suitable for in-vivo imaging applications, making this highly versatile form of optical imaging challenging and time-consuming to implement. To address this issue, we have developed a novel, open-source software package to control high-speed, multispectral optical imaging systems. The software integrates a number of modular functions through a custom graphical user interface (GUI) and provides extensive control over a wide range of inexpensive IEEE 1394 Firewire cameras. Multispectral illumination can be incorporated through the use of off-the-shelf light emitting diodes which the software synchronizes to image acquisition via a programmed microcontroller, allowing arbitrary high-speed illumination sequences. The complete software suite is available for free download. Here we describe the software’s framework and provide details to guide users with development of this and similar software. PMID:21258475

  7. Novel Architecture for High Speed and High Fidelity Readout of a Quantum Annealing Processor

    NASA Astrophysics Data System (ADS)

    Altomare, Fabio; Berkley, Andrew J.; Harris, Richard; Hoskinson, Emile M.; Johnson, Mark W.; Lanting, Trevor M.; Uchaikin, Sergey; Whittaker, Jed D.; Bunyk, Paul; Tolkacheva, Elena; Perminov, Ilya

    2014-03-01

    Hysteretic dc SQUIDs provide an easy method to read the state of hundreds of qubits[1]. However, this approach becomes impractical for circuits with an even larger number of qubits due to heating when dc SQUIDs switch, the relatively slow retrapping dynamics of high quality devices, and suboptimal scaling of the number of control lines with increasing numbers of qubits. The D-Wave Two processor uses an architecture that addresses all three of these issues. This new architecture makes use of Quantum Flux Parametron based shift registers that transfer the classical information produced as the output of the quantum annealing algorithm to a small number of fast non-dissipative and high fidelity microwave readout devices. We will provide an introduction to our implementation, and present data pertaining to readout performance from a 512-qubit quantum annealing processor.

  8. Initial evaluation of commercially available InGaAsP DFB laser diodes for use in high-speed digital fiber optic transceivers

    NASA Technical Reports Server (NTRS)

    Cook, Anthony L.; Hendricks, Herbert D.

    1990-01-01

    NASA has been pursuing the development of high-speed fiber-optic transceivers for use in a number of space data system applications. Current efforts are directed toward a high-performance all-integrated-circuit transceiver operating up to the 3-5 Gb/s range. Details of the evaluation and selection of candidate high-speed optical sources to be used in the space-qualified high-performance transceiver are presented. Data on the performance of commercially available DFB (distributed feedback) lasers are presented, and their performance relative to each other and to their structural design with regard to their use in high-performance fiber-optic transceivers is discussed. The DFB lasers were obtained from seven commercial manufacturers. The data taken on each laser included threshold current, differential quantum efficiency, CW side mode suppression radio, wavelength temperature coefficient, threshold temperature coefficient, natural linewidth, and far field pattern. It was found that laser diodes with buried heterostructures and first-order gratings had, in general, the best CW operating characteristics. The modulated characteristics of the DFB laser diodes are emphasized. Modulated linewidth, modulated side mode suppression ratio, and frequency response are discussed.

  9. Lamb wave-based damage detection of composite shells using high-speed fiber-optic sensing

    NASA Astrophysics Data System (ADS)

    Sotoudeh, Vahid; Black, Richard J.; Moslehi, Behzad; Qiao, Pizhong

    2014-04-01

    A Lamb wave-based damage identification method called damage imaging method for composite shells is presented. A damage index (DI) is generated from the delay matrix of the Lamb wave response signals, and it is used to indicate the location and approximate area of the damage. A piezoelectric actuator is employed to generate the Lamb waves that are subsequently captured by a fiber Bragg grating (FBG) sensor element array multiplexed in a single fiber connected to a high-speed fiber-optic sensor system. The high-speed sensing is enabled by an innovative parallel-architecture optical interrogation system. The viability of this method is demonstrated by analyzing the numerical and experimental Lamb wave response signals from laminated composite shells. The technique only requires the response signals from the plate after damage, and it is capable of performing near real-time damage identification. This study sheds some light on the application of a Lamb wave-based damage detection algorithm for curved plate/shell-type structures by using the relatively low frequency (around 100 kHz) Lamb wave response and the high-speed FBG sensor system.

  10. Application of ultra-high-speed optical observations and high-speed x-ray radiography measurements to the study of explosively driven copper tube expansion

    NASA Astrophysics Data System (ADS)

    Voltz, C.; Lagrange, J. M.; Besnard, G.; Etchessahar, B.

    2008-11-01

    The purpose of this experiment is to study the behavior of expanding copper cylinder under explosive loading. The apparatus is designed to submit the target to high strain, high stain rate in quasi-plane deformation constraints. Using high-speed cinematography we evaluate the expansion characteristics and observe plastic instability and striction phenomena. Stereoscopic observation is used to give us the possibility to reconstruct the 3D shape and to access to free moving and strain fields. In order to measure the residual thickness and characterize striction patterns, we employ a flash X-Ray imaging diagnostic. Experimental results are presented and compared with hydrocode calculations.

  11. High-speed tunable and fixed-wavelength VCSELs for short-reach optical links and interconnects

    NASA Astrophysics Data System (ADS)

    Larsson, A.; Gustavsson, J. S.; Haglund, Å.; Kögel, B.; Bengtsson, J.; Westbergh, P.; Haglund, E.; Baveja, P. P.

    2012-03-01

    This paper presents a review of recent work on high speed tunable and fixed wavelength vertical cavity surface emitting lasers (VCSELs) at Chalmers University of Technology. All VCSELs are GaAs-based, employ an oxide aperture for current and/or optical confinement, and emit around 850 nm. With proper active region and cavity designs, and techniques for reducing capacitance and thermal impedance, our fixed wavelength VCSELs have reached a modulation bandwidth of 23 GHz, which has enabled error-free 40 Gbps back-to-back transmission and 35 Gbps transmission over 100 m of multimode fiber. A MEMS-technology for wafer scale integration of tunable high speed VCSELs has also been developed. A tuning range of 24 nm and a modulation bandwidth of 6 GHz have been achieved, enabling error-free back-to-back transmission at 5 Gbps.

  12. Advanced organic dye for high-speed, high-density optical media

    NASA Astrophysics Data System (ADS)

    Kodaira, Takuo; Matsuda, Isao; Somei, Hidenori; Tsuzuki, Takeo; Yokoyama, Daizo; Endo, Akihisa; Takeguchi, Kazunobu; Kojo, Shinichi; Miyazawa, Fuyuki; Otsu, Takeshi; Murai, Wakaaki; Hattori, Masashi; Shimomai, Kenichi; Oshita, Junji; Asano, Sho; Shimizu, Atsuo; Fujii, Toru

    2015-09-01

    Advances in organic dye progress are indispensable for high-speed, high-density recording of recordable Blu-ray Disc™ (BD-R) low-to-high (LTH) discs without a low elastic modulus layer. The optimal physical properties of the organic dyes, i.e., a low decomposition calorific value, a low decomposition temperature, and a large n-value, were determined, and a dye with these properties was synthesized. A BD-R disc using the dye conformed to the BD-R LTH standard at 8× recording and ever higher speeds should be possible. Furthermore, the possibility of 33 GB/layer high-density recording was suggested.

  13. Overview and applications of Grating-Light-Valve-based optical write engines for high-speed digital imaging

    NASA Astrophysics Data System (ADS)

    Trisnadi, Jahja I.; Carlisle, Clinton B.; Monteverde, Robert

    2004-01-01

    The Grating Light Valve (GLV) is a diffractive MOEMS spatial light modulator capable of very high-speed modulation of light combined with fine gray-scale attenuation. GLV-based products are field-proven in a variety of applications. In this paper, we describe the GLV device, its structure, theory of operation, and optical performance. The versatility and speed of the GLV device are described. We explain how the GLV device is integrated into an optical write engine to create a complete digital imaging system. In addition to the MOEMS die and drive electronics, the light engine also comprises illumination optics, Fourier filter, and imaging optics. We present current applications of the GLV device for high-resolution displays, and computer-to-plate printing, as well as future plans for digital imaging applications opened up by the unique properties of this diffractive MOEMS technology.

  14. High speed and adaptable error correction for megabit/s rate quantum key distribution

    PubMed Central

    Dixon, A. R.; Sato, H.

    2014-01-01

    Quantum Key Distribution is moving from its theoretical foundation of unconditional security to rapidly approaching real world installations. A significant part of this move is the orders of magnitude increases in the rate at which secure key bits are distributed. However, these advances have mostly been confined to the physical hardware stage of QKD, with software post-processing often being unable to support the high raw bit rates. In a complete implementation this leads to a bottleneck limiting the final secure key rate of the system unnecessarily. Here we report details of equally high rate error correction which is further adaptable to maximise the secure key rate under a range of different operating conditions. The error correction is implemented both in CPU and GPU using a bi-directional LDPC approach and can provide 90–94% of the ideal secure key rate over all fibre distances from 0–80 km. PMID:25450416

  15. High speed prototype quantum key distribution system and long term field trial.

    PubMed

    Dixon, A R; Dynes, J F; Lucamarini, M; Fröhlich, B; Sharpe, A W; Plews, A; Tam, S; Yuan, Z L; Tanizawa, Y; Sato, H; Kawamura, S; Fujiwara, M; Sasaki, M; Shields, A J

    2015-03-23

    Securing information in communication networks is an important challenge in today's world. Quantum Key Distribution (QKD) can provide unique capabilities towards achieving this security, allowing intrusions to be detected and information leakage avoided. We report here a record high bit rate prototype QKD system providing a total of 878 Gbit of secure key data over a 34 day period corresponding to a sustained key rate of around 300 kbit/s. The system was deployed over a standard 45 km link of an installed metropolitan telecommunication fibre network in central Tokyo. The prototype QKD system is compact, robust and automatically stabilised, enabling key distribution during diverse weather conditions. The security analysis includes an efficient protocol, finite key size effects and decoy states, with a quantified key failure probability of ε = 10⁻¹⁰.

  16. QUANTUM OPTICS. Universal linear optics.

    PubMed

    Carolan, Jacques; Harrold, Christopher; Sparrow, Chris; Martín-López, Enrique; Russell, Nicholas J; Silverstone, Joshua W; Shadbolt, Peter J; Matsuda, Nobuyuki; Oguma, Manabu; Itoh, Mikitaka; Marshall, Graham D; Thompson, Mark G; Matthews, Jonathan C F; Hashimoto, Toshikazu; O'Brien, Jeremy L; Laing, Anthony

    2015-08-14

    Linear optics underpins fundamental tests of quantum mechanics and quantum technologies. We demonstrate a single reprogrammable optical circuit that is sufficient to implement all possible linear optical protocols up to the size of that circuit. Our six-mode universal system consists of a cascade of 15 Mach-Zehnder interferometers with 30 thermo-optic phase shifters integrated into a single photonic chip that is electrically and optically interfaced for arbitrary setting of all phase shifters, input of up to six photons, and their measurement with a 12-single-photon detector system. We programmed this system to implement heralded quantum logic and entangling gates, boson sampling with verification tests, and six-dimensional complex Hadamards. We implemented 100 Haar random unitaries with an average fidelity of 0.999 ± 0.001. Our system can be rapidly reprogrammed to implement these and any other linear optical protocol, pointing the way to applications across fundamental science and quantum technologies. PMID:26160375

  17. >400 kHz repetition rate wavelength-swept laser and application to high-speed optical frequency domain imaging.

    PubMed

    Oh, Wang-Yuhl; Vakoc, Benjamin J; Shishkov, Milen; Tearney, Guillermo J; Bouma, Brett E

    2010-09-01

    We demonstrate a high-speed wavelength-swept laser with a tuning range of 104 nm (1228-1332 nm) and a repetition rate of 403 kHz. The design of the laser utilizes a high-finesse polygon-based wavelength-scanning filter and a short-length unidirectional ring resonator. Optical frequency domain imaging of the human skin in vivo is presented using this laser, and the system shows sensitivity of higher than 98 dB with single-side ranging depth of 1.7 mm over 4 dB sensitivity roll-off.

  18. Study on the impact of PMD to high-speed optical fiber communication system with different modulation formats

    NASA Astrophysics Data System (ADS)

    Liu, Hongjie

    2004-05-01

    As data rate in optical fiber communication system increases to 40Gbit/s in single channel, the impact of polarization mode dispersion (PMD) on system performance becomes more important in high speed and long distance transmission system. This paper studies on the system penalties induced by PMD with different electrical bandwidths of receiver for four different modulation formats such as NRZ (not return to zero), RZ (return to zero), CSRZ (carrier suppressed return to zero) and duobinary. We find that the system penalties induced by PMD show a strong dependence on both the electrical bandwidth of the receiver and modulation format.

  19. Compressive sensing based high-speed time-stretch optical microscopy for two-dimensional image acquisition.

    PubMed

    Guo, Qiang; Chen, Hongwei; Weng, Zhiliang; Chen, Minghua; Yang, Sigang; Xie, Shizhong

    2015-11-16

    In this paper, compressive sensing based high-speed time-stretch optical microscopy for two-dimensional (2D) image acquisition is proposed and experimentally demonstrated for the first time. A section of dispersion compensating fiber (DCF) is used to perform wavelength-to-time conversion and then ultrafast spectral shaping of broadband optical pulses can be achieved via high-speed intensity modulation. A 2D spatial disperser comprising a pair of orthogonally oriented dispersers is employed to produce spatially structured illumination for 2D image acquisition and a section of single mode fiber (SMF) is utilized for pulse compression in the optical domain. In our scheme, a 1.2-GHz photodetector and a 50-MHz analog-to-digital converter (ADC) are used to acquire the energy of the compressed pulses. Image reconstructions are demonstrated at a frame rate of 500 kHz and a sixteen-fold image compression is achieved in our proof-of-concept demonstration.

  20. High speed data encryption and decryption using stimulated Brillouin scattering effect in optical fiber

    NASA Astrophysics Data System (ADS)

    Yi, Lilin; Zhang, Tao; Hu, Weisheng

    2011-11-01

    A novel all-optical encryption/decryption method based on stimulated Brillouin scattering (SBS) effect in optical fiber is proposed for the first time. The operation principle is explained in detail and the encryption and decryption performance is experimentally evaluated. The encryption keys could be the SBS gain amplitude, bandwidth, central wavelength and spectral shape, which are configurable and flexibly controlled by the users. We experimentally demonstrate the SBS encryption/decryption process of a 10.86-Gb/s non-return-to-zero (NRZ) data by using both phase-modulated and current-dithered Brillouin pumps for proof-of-concept. Unlike the traditional optical encryption methods of chaotic communications and optical code-division-multiplexing access (OCDMA), the SBS based encryption/decryption technique can directly upgrade the current optical communication system to a secure communication system without changing the terminal transceivers, which is completely compatible with the current optical communication systems.

  1. Optical Design of Plant Canopy Measurement System and Fabrication of Two-Dimensional High-Speed Metal-Semiconductor-Metal Photodetector Arrays

    NASA Technical Reports Server (NTRS)

    Sarto, Anthony; VanZeghbroeck, Bart; Vanderbilt, Vern C.

    1996-01-01

    Electrical and optical designs for the prototype plant canopy architecture measurement system, including specified component and parts lists, are presented. Six single Metal-Semiconductor-Metal (MSM) detectors are mounted in high-speed packages.

  2. Scalable optical quantum computer

    SciTech Connect

    Manykin, E A; Mel'nichenko, E V

    2014-12-31

    A way of designing a scalable optical quantum computer based on the photon echo effect is proposed. Individual rare earth ions Pr{sup 3+}, regularly located in the lattice of the orthosilicate (Y{sub 2}SiO{sub 5}) crystal, are suggested to be used as optical qubits. Operations with qubits are performed using coherent and incoherent laser pulses. The operation protocol includes both the method of measurement-based quantum computations and the technique of optical computations. Modern hybrid photon echo protocols, which provide a sufficient quantum efficiency when reading recorded states, are considered as most promising for quantum computations and communications. (quantum computer)

  3. DEVELOPMENT OF AN OPTICAL SYSTEM FOR HIGH-SPEED, SMALL-SCALE VELOCITY MEASUREMENTS

    SciTech Connect

    Davies, H. R.; Chapman, D. J.; Proud, W. G.; Vine, T. A.

    2009-12-28

    An optical system was developed to allow the accurate focussing and alignment of small samples for velocity analysis with streak photography Even at low magnifications, a narrow streak slit means that any vibration or instability in the system greatly reduces the accuracy of the velocity measurements achieved. The optical system was designed to reduce the effects of such vibration. A spatial mount and rotation stage were modified to allow three spatial axis and rotational freedom of a custom-made sample mount. Markers within the sample mount were used to achieve precise alignment of the sample with the optical axis of the streak camera.

  4. High-speed asynchronous optical sampling for high-sensitivity detection of coherent phonons

    NASA Astrophysics Data System (ADS)

    Dekorsy, T.; Taubert, R.; Hudert, F.; Schrenk, G.; Bartels, A.; Cerna, R.; Kotaidis, V.; Plech, A.; Köhler, K.; Schmitz, J.; Wagner, J.

    2007-12-01

    A new optical pump-probe technique is implemented for the investigation of coherent acoustic phonon dynamics in the GHz to THz frequency range which is based on two asynchronously linked femtosecond lasers. Asynchronous optical sampling (ASOPS) provides the performance of on all-optical oscilloscope and allows us to record optically induced lattice dynamics over nanosecond times with femtosecond resolution at scan rates of 10 kHz without any moving part in the set-up. Within 1 minute of data acquisition time signal-to-noise ratios better than 107 are achieved. We present examples of the high-sensitivity detection of coherent phonons in superlattices and of the coherent acoustic vibration of metallic nanoparticles.

  5. High-Speed Optical Wide-Area Data-Communication Network

    NASA Technical Reports Server (NTRS)

    Monacos, Steve P.

    1994-01-01

    Proposed fiber-optic wide-area network (WAN) for digital communication balances input and output flows of data with its internal capacity by routing traffic via dynamically interconnected routing planes. Data transmitted optically through network by wavelength-division multiplexing in synchronous or asynchronous packets. WAN implemented with currently available technology. Network is multiple-ring cyclic shuffle exchange network ensuring traffic reaches its destination with minimum number of hops.

  6. Designing coherent optical wireless systems for high speed indoor telecom applications

    NASA Astrophysics Data System (ADS)

    Kamalakis, Thomas; Kanakis, Panagiotis; Bogris, Adonis; Dalakas, Vasilis; Dede, Georgia

    2016-01-01

    This paper focuses on several design issues of coherent optical wireless systems as a means of providing high data rate optical links in indoor environments enabling the realization of ultra-broadband wireless local area networks. We show how the performance specifications can be translated into signal-to-noise ratio requirements inside the coverage area, taking into account the laser phase noise mitigation scheme. We then discuss the power budget details using Gaussian beam optics incorporating the transceiver positioning and the optical systems used at the transmitter and receiver side. We also treat the influence of ambient light noise. We show that coherent optical wireless systems are characterized by excellent signal-to-noise performance enabling networking at very high data rates. Our results indicate that 2 Gb/s and 10 Gb/s data rates can be easily sustained at 3 m distances over a circular coverage area of 1 m radius using Class-1 lasers for the transmitter and the local oscillator. We also discuss the power gain compared to intensity modulated/direct detection optical wireless and show that it can be as high as 20 dB, especially near the edge of the coverage area.

  7. Closed-loop motor control using high-speed fiber optics

    NASA Technical Reports Server (NTRS)

    Dawson, Reginald (Inventor); Rodriquiz, Dagobert (Inventor)

    1991-01-01

    A closed-loop control system for controlling the operation of one or more servo motors or other controllable devices is described. The system employs a fiber optics link immune to electromagnetic interference, for transmission of control signals from a controller or controllers at a remote station to the power electronics located in proximity to the motors or other devices at the local station. At the remote station the electrical control signals are time-multiplexed, converted to a formatted serial bit stream, and converted to light signals for transmission over a single fiber of the fiber optics link. At the local station, the received optical signals are reconstructed as electrical control signals for the controlled motors or other devices. At the local station, an encoder sensor linked to the driven device generates encoded feedback signals which provide information as to a condition of the controlled device. The encoded signals are placed in a formatted serial bit stream, multiplexed, and transmitted as optical signals over a second fiber of the fiber optic link which closes the control loop of the closed-loop motor controller. The encoded optical signals received at the remote station are demultiplexed, reconstructed and coupled to the controller(s) as electrical feedback signals.

  8. Sub-micron resolution high-speed spectral domain optical coherence tomography in quality inspection for printed electronics

    NASA Astrophysics Data System (ADS)

    Czajkowski, J.; Lauri, J.; Sliz, R.; Fält, P.; Fabritius, T.; Myllylä, R.; Cense, B.

    2012-04-01

    We present the use of sub-micron resolution optical coherence tomography (OCT) in quality inspection for printed electronics. The device used in the study is based on a supercontinuum light source, Michelson interferometer and high-speed spectrometer. The spectrometer in the presented spectral-domain optical coherence tomography setup (SD-OCT) is centered at 600 nm and covers a 400 nm wide spectral region ranging from 400 nm to 800 nm. Spectra were acquired at a continuous rate of 140,000 per second. The full width at half maximum of the point spread function obtained from a Parylene C sample was 0:98 m. In addition to Parylene C layers, the applicability of sub-micron SD-OCT in printed electronics was studied using PET and epoxy covered solar cell, a printed RFID antenna and a screen-printed battery electrode. A commercial SD-OCT system was used for reference measurements.

  9. Quantitative assessment of rat corneal thickness and morphology during stem cell therapy by high-speed optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Lal, Cerine; McGrath, James; Subhash, Hrebesh; Rani, Sweta; Ritter, Thomas; Leahy, Martin

    2016-03-01

    Optical Coherence Tomography (OCT) is a non-invasive 3 dimensional optical imaging modality that enables high resolution cross sectional imaging in biological tissues and materials. Its high axial and lateral resolution combined with high sensitivity, imaging depth and wide field of view makes it suitable for wide variety of high resolution medical imaging applications at clinically relevant speed. With the advent of swept source lasers, the imaging speed of OCT has increased considerably in recent years. OCT has been used in ophthalmology to study dynamic changes occurring in the cornea and iris, thereby providing physiological and pathological changes that occur within the anterior segment structures such as in glaucoma, during refractive surgery, lamellar keratoplasty and corneal diseases. In this study, we assess the changes in corneal thickness in the anterior segment of the eye during wound healing process in a rat corneal burn model following stem cell therapy using high speed swept source OCT.

  10. Monolithic InP strictly non-blocking 8×8 switch for high-speed WDM optical interconnection.

    PubMed

    Kwack, Myung-Joon; Tanemura, Takuo; Higo, Akio; Nakano, Yoshiaki

    2012-12-17

    A strictly non-blocking 8 × 8 switch for high-speed WDM optical interconnection is realized on InP by using the phased-array scheme for the first time. The matrix switch architecture consists of over 200 functional devices such as star couplers, phase-shifters and so on without any waveguide cross-section. We demonstrate ultra-broad optical bandwidth covering the entire C-band through several Input/Output ports combination with extinction ratio performance of more than 20dB. Also, nanoseconds reconfiguration time was successfully achieved by dynamic switching experiment. Error-free transmission was verified for 40-Gbps (10-Gbps × 4ch) WDM signal.

  11. Fiber-optic links based on silicon photonics for high-speed readout of trackers

    NASA Astrophysics Data System (ADS)

    Drake, G.; Garcia-Scivres, M.; Paramonov, A.; Stanek, R.; Underwood, D.

    2014-10-01

    We propose to use silicon photonics technology to build radiation-hard fiber-optic links for high-bandwidth readout of tracking detectors. The CMOS integrated silicon photonics was developed by Luxtera and commercialized by Molex. The commercial off-the-shelf (COTS) fiber-optic links feature moderate radiation tolerance insufficient for trackers. A transceiver contains four RX and four TX channels operating at 10 Gbps each. The next generation will likely operate at 25 Gbps per channel. The approach uses a standard CMOS process and single-mode fibers, providing low power consumption and good scalability and reliability.

  12. Time-Resolved Optical Measurements of Fuel-Air Mixedness in Windowless High Speed Research Combustors

    NASA Technical Reports Server (NTRS)

    Nguyen, Quang-Viet

    1998-01-01

    Fuel distribution measurements in gas turbine combustors are needed from both pollution and fuel-efficiency standpoints. In addition to providing valuable data for performance testing and engine development, measurements of fuel distributions uniquely complement predictive numerical simulations. Although equally important as spatial distribution, the temporal distribution of the fuel is an often overlooked aspect of combustor design and development. This is due partly to the difficulties in applying time-resolved diagnostic techniques to the high-pressure, high-temperature environments inside gas turbine engines. Time-resolved measurements of the fuel-to-air ratio (F/A) can give researchers critical insights into combustor dynamics and acoustics. Beginning in early 1998, a windowless technique that uses fiber-optic, line-of-sight, infrared laser light absorption to measure the time-resolved fluctuations of the F/A (refs. 1 and 2) will be used within the premixer section of a lean-premixed, prevaporized (LPP) combustor in NASA Lewis Research Center's CE-5 facility. The fiber-optic F/A sensor will permit optical access while eliminating the need for film-cooled windows, which perturb the flow. More importantly, the real-time data from the fiber-optic F/A sensor will provide unique information for the active feedback control of combustor dynamics. This will be a prototype for an airborne sensor control system.

  13. Studies of dynamic processes in biomedicine by high-speed spectral optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Wojtkowski, M.; Kowalczyk, A.

    2007-02-01

    This contribution demonstrates potential of Spectral Optical Coherence Tomography (SOCT) for studies of dynamic processes in biomedicine occurring at various time scales. Several examples from ophthalmology, optometry, surgery, neurology are given to illustrate the extension of SOCT beyond pure morphological investigations.

  14. A high speed, fibre optic, link for digital equipment corporation VAXES

    SciTech Connect

    McLaren, R.A.; Gallno, P.; Hollingworth, K. ); Almeida, T.; Astor, C.; Gomes, P. ); Castro, J.; Moreira, P. )

    1989-10-01

    This paper describes a fibre optic link that has been constructed which, used in conjunction with the CERN Host Interface family, connects high performance Digital Equipment Corporation (DEC) VAXes to VMEbus or FASTBUS over distances up to 1000 meters. The modular construction allows other permutations, including VAX/VAX, FASTBUS/FASTBUS, VMEbus/VMEbus, or FASTBUS/VMEbus connections, over similar distances.

  15. On numerical simulation of high-speed CCD/CMOS-based wavefront sensors in adaptive optics

    NASA Astrophysics Data System (ADS)

    Konnik, Mikhail V.; Welsh, James Stuart

    2011-10-01

    Wavefront sensors, which use solid-state CCD or CMOS photosensors, are sources of errors in adaptive optic systems. Inaccuracy in the detection of wavefront distortions introduces considerable errors into wavefront reconstruction and leads to overall performance degradation of the adaptive optics system. The accuracy of wavefront sensors is significantly affected by photosensor noise. Thus, it is crucial to formulate high-level photosensor models that enable adaptive optic engineers to simulate realistic effects of noise from wavefront sensors. However, the complexity of solid-state photosensors and multiple noise sources makes it difficult to formulate an adequate model of the photosensor. Moreover, the characterisation of the simulated sensor and comparison with real hardware is often incomplete due to lack of comprehensive standards and guidelines. Owe to these difficulties, engineers work with oversimplified models of the wavefront sensors and consequently have imprecise numerical simulation results. The paper presents an approach for the modelling of noise sources for CCD and CMOS sensors that are used for wavefront sensing in adaptive optics. Both dark and light noise such as fixed pattern noise, photon shot noise, and read noises, as well as, charge-to-voltage noises are described. Procedures for characterisation of both light and dark noises of the simulated photosensors are provided. Numerical simulation results of a photosensor for a high-frame rate Shack-Hartmann wavefront sensor are presented.

  16. A high-speed readout scheme for fast optical correlation-based pattern recognition

    NASA Astrophysics Data System (ADS)

    McDonald, Gregor J.; Lewis, Meirion F.; Wilson, Rebecca

    2004-12-01

    We describe recent developments to a novel form of hybrid electronic/photonic correlator, which exploits component innovations in both electronics and photonics to provide fast, compact and rugged target recognition, applicable to a wide range of security applications. The system benefits from a low power, low volume, optical processing core which has the potential to realise man portable pattern recognition for a wide range of security based imagery and target databases. In the seminal Vander Lugt correlator the input image is Fourier transformed optically and multiplied optically with the conjugate Fourier transform of a reference pattern; the required correlation function is completed by taking the inverse Fourier transform of the product optically. The correlator described here is similar in principle, but performs the initial Fourier transforms and multiplication electronically, with only the final most computationally demanding output Fourier transform being performed optically. In this scheme the Fourier transforms of both the input scene and reference pattern are reduced to a binary phase-only format, where the multiplication process simplifies to a simple Boolean logic XOR function. The output of this XOR gate is displayed on a state-of-the-art Fast Bit Plane Spatial Light Modulator (FBPSLM). A novel readout scheme has been developed which overcomes the previous system output bottleneck and for the first time allows correlation frame readout rates capable of matching the inherently fast nature of the SLM. Readout rates of up to ~1 MHz are now possible, exceeding current SLM capabilities and meeting potential medium term SLM developments promised by SLMs based on novel materials and architectures.

  17. Three-Dimensional Optical Reconstruction of Vocal Fold Kinematics Using High-Speed Video With a Laser Projection System.

    PubMed

    Luegmair, Georg; Mehta, Daryush D; Kobler, James B; Döllinger, Michael

    2015-12-01

    Vocal fold kinematics and its interaction with aerodynamic characteristics play a primary role in acoustic sound production of the human voice. Investigating the temporal details of these kinematics using high-speed videoendoscopic imaging techniques has proven challenging in part due to the limitations of quantifying complex vocal fold vibratory behavior using only two spatial dimensions. Thus, we propose an optical method of reconstructing the superior vocal fold surface in three spatial dimensions using a high-speed video camera and laser projection system. Using stereo-triangulation principles, we extend the camera-laser projector method and present an efficient image processing workflow to generate the three-dimensional vocal fold surfaces during phonation captured at 4000 frames per second. Initial results are provided for airflow-driven vibration of an ex vivo vocal fold model in which at least 75% of visible laser points contributed to the reconstructed surface. The method captures the vertical motion of the vocal folds at a high accuracy to allow for the computation of three-dimensional mucosal wave features such as vibratory amplitude, velocity, and asymmetry.

  18. Visualization of hair follicles using high-speed optical coherence tomography based on a Fourier domain mode locking laser

    NASA Astrophysics Data System (ADS)

    Tsai, M.-T.; Chang, F.-Y.

    2012-04-01

    In this study, a swept-source optical coherence tomography (SS-OCT) system with a Fourier domain mode locking (FDML) laser is proposed for a dermatology study. The homemade FDML laser is one kind of frequency-sweeping light source, which can provide output power of >20 mW and an output spectrum of 65 nm in bandwidth centered at 1300 nm, enabling imaging with an axial resolution of 12 μm in the OCT system. To eliminate the forward scans from the laser output and insert the delayed backward scans, a Mach-Zehnder configuration is implemented. Compared with conventional frequency-sweeping light sources, the FDML laser can achieve much higher scan rates, as high as ˜240 kHz, which can provide a three-dimensional imaging rate of 4 volumes/s. Furthermore, the proposed high-speed SS-OCT system can provide three-dimensional (3D) images with reduced motion artifacts. Finally, a high-speed SS-OCT system is used to visualize hair follicles, demonstrating the potential of this technology as a tool for noninvasive diagnosis of alopecia.

  19. Three-dimensional optical reconstruction of vocal fold kinematics using high-speed video with a laser projection system

    PubMed Central

    Luegmair, Georg; Mehta, Daryush D.; Kobler, James B.; Döllinger, Michael

    2015-01-01

    Vocal fold kinematics and its interaction with aerodynamic characteristics play a primary role in acoustic sound production of the human voice. Investigating the temporal details of these kinematics using high-speed videoendoscopic imaging techniques has proven challenging in part due to the limitations of quantifying complex vocal fold vibratory behavior using only two spatial dimensions. Thus, we propose an optical method of reconstructing the superior vocal fold surface in three spatial dimensions using a high-speed video camera and laser projection system. Using stereo-triangulation principles, we extend the camera-laser projector method and present an efficient image processing workflow to generate the three-dimensional vocal fold surfaces during phonation captured at 4000 frames per second. Initial results are provided for airflow-driven vibration of an ex vivo vocal fold model in which at least 75% of visible laser points contributed to the reconstructed surface. The method captures the vertical motion of the vocal folds at a high accuracy to allow for the computation of three-dimensional mucosal wave features such as vibratory amplitude, velocity, and asymmetry. PMID:26087485

  20. Electro-optic modulation for high-speed characterization of entangled photon pairs

    SciTech Connect

    Lukens, Joseph M.; Odele, Ogaga D.; Leaird, Daniel E.; Weiner, Andrew M.

    2015-11-10

    In this study, we demonstrate a new biphoton manipulation and characterization technique based on electro-optic intensity modulation and time shifting. By applying fast modulation signals with a sharply peaked cross-correlation to each photon from an entangled pair, it is possible to measure temporal correlations with significantly higher precision than that attainable using standard single-photon detection. Low-duty-cycle pulses and maximal-length sequences are considered as modulation functions, reducing the time spread in our correlation measurement by a factor of five compared to our detector jitter. With state-of-the-art electro-optic components, we expect the potential to surpass the speed of any single-photon detectors currently available.

  1. Electro-optic modulation for high-speed characterization of entangled photon pairs

    DOE PAGESBeta

    Lukens, Joseph M.; Odele, Ogaga D.; Leaird, Daniel E.; Weiner, Andrew M.

    2015-11-10

    In this study, we demonstrate a new biphoton manipulation and characterization technique based on electro-optic intensity modulation and time shifting. By applying fast modulation signals with a sharply peaked cross-correlation to each photon from an entangled pair, it is possible to measure temporal correlations with significantly higher precision than that attainable using standard single-photon detection. Low-duty-cycle pulses and maximal-length sequences are considered as modulation functions, reducing the time spread in our correlation measurement by a factor of five compared to our detector jitter. With state-of-the-art electro-optic components, we expect the potential to surpass the speed of any single-photon detectors currentlymore » available.« less

  2. High-speed imaging system based on spectral optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Chen, Xiaodong; Li, Wanhui; Wang, Yi; Yu, Daoyin

    2005-01-01

    Optical coherence tomography (OCT) is an emerging technology for producing high-resolution cross-sectional imaging based on the principles of low-coherence interferometry. Tissue structure can be imaged on the micron scale in real time. The principle of OCT is analogous to that of ultrasound imaging, except that it measures the intensity of reflected infrared (IR) light rather than sound waves. A new spectral OCT(SOCT) technique is introduced. SOCT and its application to measure depth resolved spectral absorption is described. The crucial parameters of this method like transversal, depth, and spectral resolution and their relations are discussed. In combination with SOCT technique and endoscopes, SOCT enables high-resolution imaging in lumens of, for example, the esophagus and stomach. SOCT can be used to perform 'optical biopsy', or to guide surgery, by providing images in situ and in real time.

  3. Optical interconnects for in-plane high-speed signal distribution at 10 Gb/s: Analysis and demonstration

    NASA Astrophysics Data System (ADS)

    Chang, Yin-Jung

    With decreasing transistor size, increasing chip speed, and larger numbers of processors in a system, the performance of a module/system is being limited by the off-chip and off-module bandwidth-distance products. Optical links have moved from fiber-based long distance communications to the cabinet level of 1m--100m, and recently to the backplane-level (10cm--1m). Board-level inter-chip parallel optical interconnects have been demonstrated recently by researchers from Intel, IBM, Fujitsu, NTT and a few research groups in universities. However, the board-level signal/clock distribution function using optical interconnects, the lightwave circuits, the system design, a practically convenient integration scheme committed to the implementation of a system prototype have not been explored or carefully investigated. In this dissertation, the development of a board-level 1 x 4 optical-to-electrical signal distribution at 10Gb/s is presented. In contrast to other prototypes demonstrating board-level parallel optical interconnects that have been drawing much attention for the past decade, the optical link design for the high-speed signal broadcasting is even more complicated and the pitch between receivers could be varying as opposed to fixed-pitch design that has been widely-used in the parallel optical interconnects. New challenges for the board-level high-speed signal broadcasting include, but are not limited to, a new optical link design, a lightwave circuit as a distribution network, and a novel integration scheme that can be a complete radical departure from the traditional assembly method. One of the key building blocks in the lightwave circuit is the distribution network in which a 1 x 4 multimode interference (MMI) splitter is employed. MMI devices operating at high data rates are important in board-level optical interconnects and need to be characterized in the application of board-level signal broadcasting. To determine the speed limitations of MMI devices, the

  4. Data Relay Board with Protocol for High-Speed, Free-Space Optical Communications

    NASA Technical Reports Server (NTRS)

    Wright, Malcolm; Clare, Loren; Gould, Gary; Pedyash, Maxim

    2004-01-01

    In a free-space optical communication system, the mitigation of transient outages through the incorporation of error-control methods is of particular concern, the outages being caused by scintillation fades and obscurants. The focus of this innovative technology is the development of a data relay system for a reliable high-data-rate free-spacebased optical-transport network. The data relay boards will establish the link, maintain synchronous connection, group the data into frames, and provide for automatic retransmission (ARQ) of lost or erred frames. A certain Quality of Service (QoS) can then be ensured, compatible with the required data rate. The protocol to be used by the data relay system is based on the draft CCSDS standard data-link protocol Proximity-1, selected by orbiters to multiple lander assets in the Mars network, for example. In addition to providing data-link protocol capabilities for the free-space optical link and buffering the data, the data relay system will interface directly with user applications over Gigabit Ethernet and/or with highspeed storage resources via Fibre Channel. The hardware implementation is built on a network-processor-based architecture. This technology combines the power of a hardware switch capable of data switching and packet routing at Gbps rates, with the flexibility of a software- driven processor that can host highly adaptive and reconfigurable protocols used, for example, in wireless local-area networks (LANs). The system will be implemented in a modular multi-board fashion. The main hardware elements of the data relay system are the new data relay board developed by Rockwell Scientific, a COTS Gigabit Ethernet board for user interface, and a COTS Fibre Channel board that connects to local storage. The boards reside in a cPCI back plane, and can be housed in a VME-type enclosure.

  5. High speed low power optical detection of sub-wavelength scatterer

    NASA Astrophysics Data System (ADS)

    Roy, S.; Bouwens, Maryse; Wei, Lei; Pereira, S. F.; Urbach, H. P.; van der Walle, P.

    2015-12-01

    Optical detection of scatterers on a flat substrate, generally done using dark field microscopy technique, is challenging since it requires high power illumination to obtain sufficient SNR (Signal to Noise Ratio) to be able to detect sub-wavelength particles. We developed a bright field technique, based on Fourier scatterometry, with special illumination and detection control to achieve this goal with a power level that can be sustained by most substrates including polymers. The performance of the system in a roll-to-roll line in production environment and strict throughput requirement is shown.

  6. High speed low power optical detection of sub-wavelength scatterer.

    PubMed

    Roy, S; Bouwens, Maryse; Wei, Lei; Pereira, S F; Urbach, H P; van der Walle, P

    2015-12-01

    Optical detection of scatterers on a flat substrate, generally done using dark field microscopy technique, is challenging since it requires high power illumination to obtain sufficient SNR (Signal to Noise Ratio) to be able to detect sub-wavelength particles. We developed a bright field technique, based on Fourier scatterometry, with special illumination and detection control to achieve this goal with a power level that can be sustained by most substrates including polymers. The performance of the system in a roll-to-roll line in production environment and strict throughput requirement is shown. PMID:26724010

  7. High-Speed, Real-Time Scope Based on Optical Fiber Delay Line Loop Technology

    SciTech Connect

    Yin Yan

    2004-11-10

    Real-time oscilloscopes that are currently available go up only to 8 GHz. For transient signal measurements above 8 GHz, streak cameras have to be used. An instrument, developed by YY Labs, provides a convenient, low-cost method for such measurements. YY Labs' Single-Shot Scope captures single-shot signals in one or two channels and then regenerates 1000 copies of the one- or two-channel analogue signals to form a pulse train, with the aid of an optic-fiber delay line loop. A sampling scope recovers the original signals from the pulse train.

  8. High-speed duplex optical wireless communication system for indoor personal area networks.

    PubMed

    Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios

    2010-11-22

    In this paper a new hybrid wireless access system incorporating high bandwidth line-of-sight free space optical wireless and radio frequency localization is proposed and demonstrated. This system is capable of supporting several gigabits/second up-stream and down-stream data transmission and ideally suited for high bandwidth indoor applications such as personal area networks. A radio frequency signal is used to achieve localization of subscribers, offering limited mobility to subscribers within a practical office scenario. Even with the modest transmitted power of 5 dBm, we demonstrate satisfactory performance of bit error rates better than 10(-9) over the entire room in the presence of strong background light. Using simulations, the effectiveness of the proposed system architecture is investigated and the key performance trade-offs identified. Proof-of-concept experiments have also been carried out to validate simulation model, and initial experimental results successfully demonstrate the feasibility of the system capable of supporting 2.5 Gbps over a 1-2 m optical wireless link (limited by the length of the sliding rail used in the experiment) with a 45 degrees diffused beam in an indoor environment for the first time.

  9. Energy efficient rateless codes for high speed data transfer over free space optical channels

    NASA Astrophysics Data System (ADS)

    Prakash, Geetha; Kulkarni, Muralidhar; Acharya, U. S.

    2015-03-01

    Terrestrial Free Space Optical (FSO) links transmit information by using the atmosphere (free space) as a medium. In this paper, we have investigated the use of Luby Transform (LT) codes as a means to mitigate the effects of data corruption induced by imperfect channel which usually takes the form of lost or corrupted packets. LT codes, which are a class of Fountain codes, can be used independent of the channel rate and as many code words as required can be generated to recover all the message bits irrespective of the channel performance. Achieving error free high data rates with limited energy resources is possible with FSO systems if error correction codes with minimal overheads on the power can be used. We also employ a combination of Binary Phase Shift Keying (BPSK) with provision for modification of threshold and optimized LT codes with belief propagation for decoding. These techniques provide additional protection even under strong turbulence regimes. Automatic Repeat Request (ARQ) is another method of improving link reliability. Performance of ARQ is limited by the number of retransmissions and the corresponding time delay. We prove through theoretical computations and simulations that LT codes consume less energy per bit. We validate the feasibility of using energy efficient LT codes over ARQ for FSO links to be used in optical wireless sensor networks within the eye safety limits.

  10. High-speed duplex optical wireless communication system for indoor personal area networks.

    PubMed

    Wang, Ke; Nirmalathas, Ampalavanapillai; Lim, Christina; Skafidas, Efstratios

    2010-11-22

    In this paper a new hybrid wireless access system incorporating high bandwidth line-of-sight free space optical wireless and radio frequency localization is proposed and demonstrated. This system is capable of supporting several gigabits/second up-stream and down-stream data transmission and ideally suited for high bandwidth indoor applications such as personal area networks. A radio frequency signal is used to achieve localization of subscribers, offering limited mobility to subscribers within a practical office scenario. Even with the modest transmitted power of 5 dBm, we demonstrate satisfactory performance of bit error rates better than 10(-9) over the entire room in the presence of strong background light. Using simulations, the effectiveness of the proposed system architecture is investigated and the key performance trade-offs identified. Proof-of-concept experiments have also been carried out to validate simulation model, and initial experimental results successfully demonstrate the feasibility of the system capable of supporting 2.5 Gbps over a 1-2 m optical wireless link (limited by the length of the sliding rail used in the experiment) with a 45 degrees diffused beam in an indoor environment for the first time. PMID:21164867

  11. Natural motion of the optic nerve head revealed by high speed phase-sensitive OCT

    NASA Astrophysics Data System (ADS)

    OHara, Keith; Schmoll, Tilman; Vass, Clemens; Leitgeb, Rainer A.

    2013-03-01

    We use phase-sensitive optical coherence tomography (OCT) to measure the deformation of the optic nerve head during the pulse cycle, motivated by the possibility that these deformations might be indicative of the progression of glaucoma. A spectral-domain OCT system acquired 100k A-scans per second, with measurements from a pulse-oximeter recorded simultaneously, correlating OCT data to the subject's pulse. Data acquisition lasted for 2 seconds, to cover at least two pulse cycles. A frame-rate of 200-400 B-scans per second results in a sufficient degree of correlated speckle between successive frames that the phase-differences between fames can be extracted. Bulk motion of the entire eye changes the phase by several full cycles between frames, but this does not severely hinder extracting the smaller phase-changes due to differential motion within a frame. The central cup moves about 5 μm/s relative to the retinal-pigment-epithelium edge, with tissue adjacent to blood vessels showing larger motion.

  12. Full-range imaging of eye accommodation by high-speed long-depth range optical frequency domain imaging

    PubMed Central

    Furukawa, Hiroyuki; Hiro-Oka, Hideaki; Satoh, Nobuyuki; Yoshimura, Reiko; Choi, Donghak; Nakanishi, Motoi; Igarashi, Akihito; Ishikawa, Hitoshi; Ohbayashi, Kohji; Shimizu, Kimiya

    2010-01-01

    We describe a high-speed long-depth range optical frequency domain imaging (OFDI) system employing a long-coherence length tunable source and demonstrate dynamic full-range imaging of the anterior segment of the eye including from the cornea surface to the posterior capsule of the crystalline lens with a depth range of 12 mm without removing complex conjugate image ambiguity. The tunable source spanned from 1260 to 1360 nm with an average output power of 15.8 mW. The fast A-scan rate of 20,000 per second provided dynamic OFDI and dependence of the whole anterior segment change on time following abrupt relaxation from the accommodated to the relaxed status, which was measured for a healthy eye and that with an intraocular lens. PMID:21258564

  13. High-speed electro-optic switch using buried electrode structure in polymer Mach-Zehnder waveguide

    NASA Astrophysics Data System (ADS)

    Sun, Jingwen; Sun, Jian; Yi, Yunji; Qv, Lucheng; Sun, Shiqi; Wang, Fei; Wang, Xibin; Zhang, Daming

    2016-02-01

    A low-cost and high-speed electro-optic (EO) switch using the guest-host EO material Disperse Red 1/Polymethyl Methacrylate (DR1/PMMA) was designed and fabricated. The DR1/PMMA material presented a low processing cost, an excellent photostability and a large EO coefficient of 13.1 pm/V. To improve the performance of the switch, the in-plane buried electrode structure was introduced in the polymer Mach-Zehnder waveguide to improve the poling and modulating efficiency. The characteristic parameters of the waveguide and the electrodes were carefully designed and the fabrication process was strictly controlled. Under 1550 nm, the insertion loss of the device was 12.7 dB. The measured switching rise time and fall time of the switch were 50.00 ns and 54.29 ns, respectively.

  14. Generation 3 programmable array microscope (PAM) for high speed large format optical sectioning in fluorescence

    NASA Astrophysics Data System (ADS)

    de Vries, Anthony H. B.; Cook, Nathan P.; Kramer, Stephan; Arndt-Jovin, Donna J.; Jovin, Thomas M.

    2015-03-01

    We report on the current version of the optical sectioning programmable array microscope (PAM) implemented with a single digital micro-mirror device (DMD) spatial light modulator utilized as a mask in both the fluorescence excitation and emission paths. The PAM incorporates structured illumination and structured detection operating in synchrony. A sequence of binary patterns of excitation light in high definition format (1920×1080 elements) is projected into the focal plane of the microscope at the 18 kHz binary frame rate of the Texas Instruments 1080p DMD. The resulting fluorescent emission is captured as two distinct signals: conjugate (c, ca. "on-focus") consisting of light impinging on and deviated from the "on" elements of the DMD, and the non-conjugate (nc, ca. "out-of-focus") light falling on and deviated from the "off" elements. The two distinct, deflected beams are optically filtered and detected either by two individual cameras or captured as adjacent images on a single camera after traversing an image combiner. The sectioned image is gained from a subtraction of the nc image from the c image, weighted in accordance with the pattern(s) used for illumination and detection and the relative exposure times of the cameras. The widefield image is given by the sum of the c and nc images. This procedure allows a high duty cycle (typically 25-50%) of on-elements in the excitation patterns and thus functions with low light intensities, preventing saturation and minimizing photobleaching of sensitive fluorophores. The corresponding acquisition speed is also very high, limited only by the bandwidth of the camera(s) (100 fps full frame with the sCMOS camera in current use) and the optical power of the light source (lasers, large area LEDs). In contrast to the static patterns typical of SIM systems, the programmable array allows optimization of the patterns (duty cycle, feature size and distribution), thus enabling a wide range of applications, ranging from patterned

  15. Multiscale quantum optical networks

    NASA Astrophysics Data System (ADS)

    Jaroszkiewicz, George

    2007-04-01

    Quantum experiments are described in terms of time-dependent networks of quantum bits, each qubit representing an elementary information gateway. The emphasis is on the signal properties of apparatus rather than on systems under observation (SUOs), with the quantum states of the theory (the labstates) representing the observer's information about the state of their apparatus, rather than of any SUO. The formalism gives an efficient quantum register description related to the formalism of quantum computation. Experiments conventionally described by the PVM and POVM formalisms are treated in identical terms, the formalism providing an efficient modular approach to quantum optics experiments of arbitrary complexity.

  16. A good performance watermarking LDPC code used in high-speed optical fiber communication system

    NASA Astrophysics Data System (ADS)

    Zhang, Wenbo; Li, Chao; Zhang, Xiaoguang; Xi, Lixia; Tang, Xianfeng; He, Wenxue

    2015-07-01

    A watermarking LDPC code, which is a strategy designed to improve the performance of the traditional LDPC code, was introduced. By inserting some pre-defined watermarking bits into original LDPC code, we can obtain a more correct estimation about the noise level in the fiber channel. Then we use them to modify the probability distribution function (PDF) used in the initial process of belief propagation (BP) decoding algorithm. This algorithm was tested in a 128 Gb/s PDM-DQPSK optical communication system and results showed that the watermarking LDPC code had a better tolerances to polarization mode dispersion (PMD) and nonlinearity than that of traditional LDPC code. Also, by losing about 2.4% of redundancy for watermarking bits, the decoding efficiency of the watermarking LDPC code is about twice of the traditional one.

  17. A fast IPv6 route lookup scheme for high-speed optical link

    NASA Astrophysics Data System (ADS)

    Yao, Xingmiao; Li, Lemin

    2004-05-01

    A fast IPv6 route lookup scheme implemented by hardware is proposed in this paper. It supports a fast IP address lookup and can insert and delete the prefixes effectively. A novel compressed multibit trie algorithm that decreases the memory space occupied and the average searching time is applied. The scheme proposed in this paper is superior to other IPV6 route lookup ones, for example, by using SRAM pipeline, a lookup speed of 125 x 106 per second can be realized to satisfy 40Gbps optical link rate with only 1.9Mbyte consumption of memory space. As there is no actual IPv6 route prefix, we generate various simulation databases in which prefix length distribution is different. Simulation results show that our scheme has reasonable lookup time, memory space for all the prefix length distribution.

  18. Automated optical inspection for high-speed electron in synchrotron accelerator

    NASA Astrophysics Data System (ADS)

    Guo, Congliang; Liu, Tonghui; Wang, Rongsheng

    1998-08-01

    Automated optical inspection for accelerated electron beam in synchrotron accelerator or storage electron beam in storage ring is important method of electron beam diagnostic.It is also the very convenient aided method for us to se the real beam size and structure. In this paper, we will discuss the physical characters of detector and cable in both of electromagnet wave and photon beam. Our main study is how to measure the signal finest and how to transfer signal data into computer on-line fast enough. The system signal is relative to transfer model and photon sensor, and it is so easy to find a good real time beam signal for us to see moveable electron beam image as best as the system does. We can analysis the beam character and its parameters in one smart system. At the end, we introduce some analysis result and new design ideas. it will have more potential prospects on industry application and other applications.

  19. High-speed FRET screening for optical proteomics in a microfluidic format

    NASA Astrophysics Data System (ADS)

    Visitkul, Viput; Matthews, Daniel R.; Weitsman, Gregory E.; Keppler, Melanie D.; Ameer-Beg, Simon M.

    2011-02-01

    Cancer studies require a thorough understanding of how human gene expressions and DNA modifications are translated at the proteome level. In order to unravel the large and complex interactions between proteins, we have developed a compact lifetime-based flow cytometer, utilising a commercial microfluidic chip, to screen large non-adherent cell populations. Fluorescent signals from cells are detected using time correlated single photon counting (TCSPC) in the burst integrated fluorescence lifetime (BIFL) mode and used to determine the lifetime of each cell. Initially, the system was tested using 10 μm highly fluorescent beads to determine optical throughput and detection efficiency. The system was validated with 293T monkey kidney adenocarcinoma cell line transiently transfected with a FRET standard, consisting of eGPF and mRFP1 fluorescent proteins linked by a19 amino-acid chain. Analysis software was developed to process detected signals in BIFL mode and chronologically save the transient burst data for each cell in a multi-dimensional image file.

  20. On the optimum signal constellation design for high-speed optical transport networks.

    PubMed

    Liu, Tao; Djordjevic, Ivan B

    2012-08-27

    In this paper, we first describe an optimum signal constellation design algorithm, which is optimum in MMSE-sense, called MMSE-OSCD, for channel capacity achieving source distribution. Secondly, we introduce a feedback channel capacity inspired optimum signal constellation design (FCC-OSCD) to further improve the performance of MMSE-OSCD, inspired by the fact that feedback channel capacity is higher than that of systems without feedback. The constellations obtained by FCC-OSCD are, however, OSNR dependent. The optimization is jointly performed together with regular quasi-cyclic low-density parity-check (LDPC) code design. Such obtained coded-modulation scheme, in combination with polarization-multiplexing, is suitable as both 400 Gb/s and multi-Tb/s optical transport enabling technology. Using large girth LDPC code, we demonstrate by Monte Carlo simulations that a 32-ary signal constellation, obtained by FCC-OSCD, outperforms previously proposed optimized 32-ary CIPQ signal constellation by 0.8 dB at BER of 10(-7). On the other hand, the LDPC-coded 16-ary FCC-OSCD outperforms 16-QAM by 1.15 dB at the same BER.

  1. Phase-transition thresholds and vaporization phenomena for ultrasound phase-change nanoemulsions assessed via high-speed optical microscopy.

    PubMed

    Sheeran, Paul S; Matsunaga, Terry O; Dayton, Paul A

    2013-07-01

    Ultrasonically activated phase-change contrast agents (PCCAs) based on perfluorocarbon droplets have been proposed for a variety of therapeutic and diagnostic clinical applications. When generated at the nanoscale, droplets may be small enough to exit the vascular space and then be induced to vaporize with high spatial and temporal specificity by externally-applied ultrasound. The use of acoustical techniques for optimizing ultrasound parameters for given applications can be a significant challenge for nanoscale PCCAs due to the contributions of larger outlier droplets. Similarly, optical techniques can be a challenge due to the sub-micron size of nanodroplet agents and resolution limits of optical microscopy. In this study, an optical method for determining activation thresholds of nanoscale emulsions based on the in vitro distribution of bubbles resulting from vaporization of PCCAs after single, short (<10 cycles) ultrasound pulses is evaluated. Through ultra-high-speed microscopy it is shown that the bubbles produced early in the pulse from vaporized droplets are strongly affected by subsequent cycles of the vaporization pulse, and these effects increase with pulse length. Results show that decafluorobutane nanoemulsions with peak diameters on the order of 200 nm can be optimally vaporized with short pulses using pressures amenable to clinical diagnostic ultrasound machines. PMID:23760161

  2. Ultra-high Speed Optical Imaging of Ultrasound-activated Microbubbles in Mesenteric Microvessels

    NASA Astrophysics Data System (ADS)

    Chen, Hong

    Ultrasound contrast agent microbubbles have gained widespread applications in diagnostic and therapeutic ultrasound. Animal studies of bioeffects induced by ultrasound-activated microbubbles have demonstrated that microbubbles can cause microvessel damage. Much scientific attention has been attracted to such microvascular bioeffects, not only because of the related safety concerns, but also because of the potential useful applications of microbubbles in the intravascular delivery of drugs and genetic materials into target tissues. A significant challenge in using microbubbles in medical ultrasound is the lack of knowledge about how the microbubbles behave in blood vessels when exposed to ultrasound and how their interactions with ultrasound cause vascular damage. Although extensive studies were performed in the past to study the dynamics of microbubbles, most of those studies were performed in vitro and did not directly address the clinical environment in which microbubbles are injected into blood vessels. In this thesis work, a synchronized optical-acoustic system was set up for ultrahigh speed imaging of insonated microbubbles in microvessels. The recorded images revealed the formation of microjets penetrating the microbubbles, as well as vessel distention (motion outward against the surrounding tissue) and vessel invagination (motion inward toward the lumen) caused by the expansion and collapse of the microbubbles, respectively. Contrary to current paradigms which propose that microbubbles damage vessels either by distending them or by forming liquid jets impinging on them, microbubbles translation and jetting were in the direction away from the nearest vessel wall; furthermore, invagination typically exceeded distention in arterioles and venules. Vessel invagination was found to be associated with vascular damage. These studies suggest that vessel invagination may be a newly discovered potential mechanism for vascular damage by ultrasound-activated microbubbles

  3. High Speed Optical Imaging Photon Counting Microchannel Plate Detectors for Astronomical and Space Sensing Applications

    NASA Astrophysics Data System (ADS)

    Siegmund, O.; Vallerga, J.; Welsh, B.; McPhate, J.; Rogers, D.

    In recent years we have implemented a variety of high-resolution, photon-counting MCP detectors in space instrumentation for satellite FUSE, GALEX, IMAGE, SOHO, SSULI, HST-COS, rocket, and shuttle payloads as well as sensors for ground based Astronomy, reconnaissance and biology. These detectors can meet many of the challenging imaging and timing demands of applications including astronomy of transient and time-variable sources, Earth atmospheric imaging and spectroscopy for real time space weather monitoring, biological single-molecule fluorescence lifetime microscopy, airborne and space situational awareness, and optical night-time/reconnaissance. Our recent work on high performance photon counting imaging readouts enables significant advancements over previous detector systems used for these applications. We have developed novel Cross-Strip and Cross-Delay-Line anode structures that can, in combination with small pore MCP's in sealed tube detectors, can achieve high spatial resolution (better than 10 um FWHM) with self triggered ~1 ns timing accuracy at up to 10 MHz event rates. Sealed tubes with formats, of 18mm, and 25mm with efficient S25 photocathodes have been built and are being used in several applications. The detectors and their properties will be discussed in this paper. Our installation and astronomical commissioning of one of these detectors at the South African Astronomical Observatory, South African Large Telescope (SALT) 10m telescope will be described. Our photometer is positioned in an auxiliary instrument port of the SALT. This is a stand-alone instrument that includes our detector system with two filter wheels (neutral density and U, B, V), an iris, and all the control modules necessary to operate the system. This instrument gives us access to the southern sky with significant sensitivity and unprecedented time resolution (microsec). High time resolution astronomy is still in its infancy, such that high cadence observations of the variable

  4. Innovations of wide-field optical-sectioning fluorescence microscopy: toward high-speed volumetric bio-imaging with simplicity

    NASA Astrophysics Data System (ADS)

    Yu, Jiun-Yann

    result in certain degrees of photo-damages because of the high focal intensity at the scanning point. In order to overcome such an issue, several wide-field optical-sectioning techniques have been proposed and demonstrated, although not without introducing new limitations and compromises such as low signal-to-background ratios and reduced axial resolutions. As a result, single-point-scanning optical-sectioning techniques remain the most widely used instrumentations for volumetric imaging of living biological systems to date. In order to develop wide-field optical-sectioning techniques that has equivalent optical performance as single-point-scanning ones, this thesis first introduces the mechanisms and limitations of existing wide-field optical-sectioning techniques, and then brings in our innovations that aim to overcome these limitations. We demonstrate, theoretically and experimentally, that our proposed wide-field optical-sectioning techniques can achieve diffraction-limited optical sectioning, low out-of-focus excitation and high-frame-rate imaging in living biological systems. In addition to such imaging capabilities, our proposed techniques can be instrumentally simple and economic, and are straightforward for implementation on conventional wide-field microscopes. These advantages together show the potential of our innovations to be widely used for high-speed, volumetric fluorescence imaging of living biological systems.

  5. Quantum teleportation of optical quantum gates.

    PubMed

    Bartlett, Stephen D; Munro, William J

    2003-03-21

    We show that a universal set of gates for quantum computation with optics can be quantum teleported through the use of EPR entangled states, homodyne detection, and linear optics and squeezing operations conditioned on measurement outcomes. This scheme may be used for fault-tolerant quantum computation in any optical scheme (qubit or continuous-variable). The teleportation of nondeterministic nonlinear gates employed in linear optics quantum computation is discussed.

  6. Dynamic Aberration Correction for Conformal Window of High-Speed Aircraft Using Optimized Model-Based Wavefront Sensorless Adaptive Optics.

    PubMed

    Dong, Bing; Li, Yan; Han, Xin-Li; Hu, Bin

    2016-09-02

    For high-speed aircraft, a conformal window is used to optimize the aerodynamic performance. However, the local shape of the conformal window leads to large amounts of dynamic aberrations varying with look angle. In this paper, deformable mirror (DM) and model-based wavefront sensorless adaptive optics (WSLAO) are used for dynamic aberration correction of an infrared remote sensor equipped with a conformal window and scanning mirror. In model-based WSLAO, aberration is captured using Lukosz mode, and we use the low spatial frequency content of the image spectral density as the metric function. Simulations show that aberrations induced by the conformal window are dominated by some low-order Lukosz modes. To optimize the dynamic correction, we can only correct dominant Lukosz modes and the image size can be minimized to reduce the time required to compute the metric function. In our experiment, a 37-channel DM is used to mimic the dynamic aberration of conformal window with scanning rate of 10 degrees per second. A 52-channel DM is used for correction. For a 128 × 128 image, the mean value of image sharpness during dynamic correction is 1.436 × 10(-5) in optimized correction and is 1.427 × 10(-5) in un-optimized correction. We also demonstrated that model-based WSLAO can achieve convergence two times faster than traditional stochastic parallel gradient descent (SPGD) method.

  7. Dynamic Aberration Correction for Conformal Window of High-Speed Aircraft Using Optimized Model-Based Wavefront Sensorless Adaptive Optics.

    PubMed

    Dong, Bing; Li, Yan; Han, Xin-Li; Hu, Bin

    2016-01-01

    For high-speed aircraft, a conformal window is used to optimize the aerodynamic performance. However, the local shape of the conformal window leads to large amounts of dynamic aberrations varying with look angle. In this paper, deformable mirror (DM) and model-based wavefront sensorless adaptive optics (WSLAO) are used for dynamic aberration correction of an infrared remote sensor equipped with a conformal window and scanning mirror. In model-based WSLAO, aberration is captured using Lukosz mode, and we use the low spatial frequency content of the image spectral density as the metric function. Simulations show that aberrations induced by the conformal window are dominated by some low-order Lukosz modes. To optimize the dynamic correction, we can only correct dominant Lukosz modes and the image size can be minimized to reduce the time required to compute the metric function. In our experiment, a 37-channel DM is used to mimic the dynamic aberration of conformal window with scanning rate of 10 degrees per second. A 52-channel DM is used for correction. For a 128 × 128 image, the mean value of image sharpness during dynamic correction is 1.436 × 10(-5) in optimized correction and is 1.427 × 10(-5) in un-optimized correction. We also demonstrated that model-based WSLAO can achieve convergence two times faster than traditional stochastic parallel gradient descent (SPGD) method. PMID:27598161

  8. Low power consumption high speed CMOS dual-modulus 15/16 prescaler for optical and wireless communications

    NASA Astrophysics Data System (ADS)

    Liu, Hui-Min; Zhang, Xiao-Xing; Dai, Yu-Jie; Lv, Ying-Jie

    2011-09-01

    Frequency synthesizer is an important part of optical and wireless communication system. Low power comsumption prescaler is one of the most critical unit of frequency synthesizer. For the frequency divider, it must be programmable for channel selection in multi-channel communication systems. A dual-modulus prescaler (DMP) is needed to provide variable division ratios. DMP is considered as a critical power dissipative block since it always operates at full speed. This paper introduces a high speed and low power complementary metal oxide semiconductor (CMOS) 15/16 DMP based on true single-phase-clock (TSPC) and transmission gates (TGs) cell. A conventional TSPC is optimized in terms of devices size, and it is resimulated. The TSPC is used in the synchronous and asynchronous counter. TGs are used in the control logic. The DMP circuit is implemented in 0.18 μm CMOS process. The simulation results are provided. The results show wide operating frequency range from 7.143 MHz to 4.76 GHz and it comsumes 3.625 mW under 1.8 V power supply voltage at 4.76 GHz.

  9. Parallelized multi-graphics processing unit framework for high-speed Gabor-domain optical coherence microscopy.

    PubMed

    Tankam, Patrice; Santhanam, Anand P; Lee, Kye-Sung; Won, Jungeun; Canavesi, Cristina; Rolland, Jannick P

    2014-07-01

    Gabor-domain optical coherence microscopy (GD-OCM) is a volumetric high-resolution technique capable of acquiring three-dimensional (3-D) skin images with histological resolution. Real-time image processing is needed to enable GD-OCM imaging in a clinical setting. We present a parallelized and scalable multi-graphics processing unit (GPU) computing framework for real-time GD-OCM image processing. A parallelized control mechanism was developed to individually assign computation tasks to each of the GPUs. For each GPU, the optimal number of amplitude-scans (A-scans) to be processed in parallel was selected to maximize GPU memory usage and core throughput. We investigated five computing architectures for computational speed-up in processing 1000×1000 A-scans. The proposed parallelized multi-GPU computing framework enables processing at a computational speed faster than the GD-OCM image acquisition, thereby facilitating high-speed GD-OCM imaging in a clinical setting. Using two parallelized GPUs, the image processing of a 1×1×0.6  mm3 skin sample was performed in about 13 s, and the performance was benchmarked at 6.5 s with four GPUs. This work thus demonstrates that 3-D GD-OCM data may be displayed in real-time to the examiner using parallelized GPU processing.

  10. Parallelized multi–graphics processing unit framework for high-speed Gabor-domain optical coherence microscopy

    PubMed Central

    Tankam, Patrice; Santhanam, Anand P.; Lee, Kye-Sung; Won, Jungeun; Canavesi, Cristina; Rolland, Jannick P.

    2014-01-01

    Abstract. Gabor-domain optical coherence microscopy (GD-OCM) is a volumetric high-resolution technique capable of acquiring three-dimensional (3-D) skin images with histological resolution. Real-time image processing is needed to enable GD-OCM imaging in a clinical setting. We present a parallelized and scalable multi-graphics processing unit (GPU) computing framework for real-time GD-OCM image processing. A parallelized control mechanism was developed to individually assign computation tasks to each of the GPUs. For each GPU, the optimal number of amplitude-scans (A-scans) to be processed in parallel was selected to maximize GPU memory usage and core throughput. We investigated five computing architectures for computational speed-up in processing 1000×1000 A-scans. The proposed parallelized multi-GPU computing framework enables processing at a computational speed faster than the GD-OCM image acquisition, thereby facilitating high-speed GD-OCM imaging in a clinical setting. Using two parallelized GPUs, the image processing of a 1×1×0.6  mm3 skin sample was performed in about 13 s, and the performance was benchmarked at 6.5 s with four GPUs. This work thus demonstrates that 3-D GD-OCM data may be displayed in real-time to the examiner using parallelized GPU processing. PMID:24695868

  11. Assessment of corneal dynamics with high-speed swept source Optical Coherence Tomography combined with an air puff system

    NASA Astrophysics Data System (ADS)

    Alonso-Caneiro, David; Karnowski, Karol; Kaluzny, Bartlomiej J.; Kowalczyk, Andrzej; Wojtkowski, Maciej

    2011-07-01

    We present a novel method and instrument for in vivo imaging and measurement of the human corneal dynamics during an air puff. The instrument is based on high-speed swept source optical coherence tomography (ssOCT) combined with a custom adapted air puff chamber from a non-contact tonometer, which uses an air stream to deform the cornea in a non-invasive manner. During the short period of time that the deformation takes place, the ssOCT acquires multiple A-scans in time (M-scan) at the center of the air puff, allowing observation of the dynamics of the anterior and posterior corneal surfaces as well as the anterior lens surface. The dynamics of the measurement are driven by the biomechanical properties of the human eye as well as its intraocular pressure. Thus, the analysis of the M-scan may provide useful information about the biomechanical behavior of the anterior segment during the applanation caused by the air puff. An initial set of controlled clinical experiments are shown to comprehend the performance of the instrument and its potential applicability to further understand the eye biomechanics and intraocular pressure measurements. Limitations and possibilities of the new apparatus are discussed.

  12. Assessment of corneal dynamics with high-speed swept source optical coherence tomography combined with an air puff system.

    PubMed

    Alonso-Caneiro, David; Karnowski, Karol; Kaluzny, Bartlomiej J; Kowalczyk, Andrzej; Wojtkowski, Maciej

    2011-07-18

    We present a novel method and instrument for in vivo imaging and measurement of the human corneal dynamics during an air puff. The instrument is based on high-speed swept source optical coherence tomography (ssOCT) combined with a custom adapted air puff chamber from a non-contact tonometer, which uses an air stream to deform the cornea in a non-invasive manner. During the short period of time that the deformation takes place, the ssOCT acquires multiple A-scans in time (M-scan) at the center of the air puff, allowing observation of the dynamics of the anterior and posterior corneal surfaces as well as the anterior lens surface. The dynamics of the measurement are driven by the biomechanical properties of the human eye as well as its intraocular pressure. Thus, the analysis of the M-scan may provide useful information about the biomechanical behavior of the anterior segment during the applanation caused by the air puff. An initial set of controlled clinical experiments are shown to comprehend the performance of the instrument and its potential applicability to further understand the eye biomechanics and intraocular pressure measurements. Limitations and possibilities of the new apparatus are discussed.

  13. Dynamic Aberration Correction for Conformal Window of High-Speed Aircraft Using Optimized Model-Based Wavefront Sensorless Adaptive Optics

    PubMed Central

    Dong, Bing; Li, Yan; Han, Xin-li; Hu, Bin

    2016-01-01

    For high-speed aircraft, a conformal window is used to optimize the aerodynamic performance. However, the local shape of the conformal window leads to large amounts of dynamic aberrations varying with look angle. In this paper, deformable mirror (DM) and model-based wavefront sensorless adaptive optics (WSLAO) are used for dynamic aberration correction of an infrared remote sensor equipped with a conformal window and scanning mirror. In model-based WSLAO, aberration is captured using Lukosz mode, and we use the low spatial frequency content of the image spectral density as the metric function. Simulations show that aberrations induced by the conformal window are dominated by some low-order Lukosz modes. To optimize the dynamic correction, we can only correct dominant Lukosz modes and the image size can be minimized to reduce the time required to compute the metric function. In our experiment, a 37-channel DM is used to mimic the dynamic aberration of conformal window with scanning rate of 10 degrees per second. A 52-channel DM is used for correction. For a 128 × 128 image, the mean value of image sharpness during dynamic correction is 1.436 × 10−5 in optimized correction and is 1.427 × 10−5 in un-optimized correction. We also demonstrated that model-based WSLAO can achieve convergence two times faster than traditional stochastic parallel gradient descent (SPGD) method. PMID:27598161

  14. Optical quantum computing.

    PubMed

    O'Brien, Jeremy L

    2007-12-01

    In 2001, all-optical quantum computing became feasible with the discovery that scalable quantum computing is possible using only single-photon sources, linear optical elements, and single-photon detectors. Although it was in principle scalable, the massive resource overhead made the scheme practically daunting. However, several simplifications were followed by proof-of-principle demonstrations, and recent approaches based on cluster states or error encoding have dramatically reduced this worrying resource overhead, making an all-optical architecture a serious contender for the ultimate goal of a large-scale quantum computer. Key challenges will be the realization of high-efficiency sources of indistinguishable single photons, low-loss, scalable optical circuits, high-efficiency single-photon detectors, and low-loss interfacing of these components.

  15. High speed handpieces.

    PubMed

    Bhandary, Nayan; Desai, Asavari; Shetty, Y Bharath

    2014-02-01

    High speed instruments are versatile instruments used by clinicians of all specialties of dentistry. It is important for clinicians to understand the types of high speed handpieces available and the mechanism of working. The centers for disease control and prevention have issued guidelines time and again for disinfection and sterilization of high speed handpieces. This article presents the recent developments in the design of the high speed handpieces. With a view to prevent hospital associated infections significant importance has been given to disinfection, sterilization & maintenance of high speed handpieces. How to cite the article: Bhandary N, Desai A, Shetty YB. High speed handpieces. J Int Oral Health 2014;6(1):130-2.

  16. Quantum optical arbitrary waveform manipulation and measurement in real time.

    PubMed

    Kowligy, Abijith S; Manurkar, Paritosh; Corzo, Neil V; Velev, Vesselin G; Silver, Michael; Scott, Ryan P; Yoo, S J B; Kumar, Prem; Kanter, Gregory S; Huang, Yu-Ping

    2014-11-17

    We describe a technique for dynamic quantum optical arbitrary-waveform generation and manipulation, which is capable of mode selectively operating on quantum signals without inducing significant loss or decoherence. It is built upon combining the developed tools of quantum frequency conversion and optical arbitrary waveform generation. Considering realistic parameters, we propose and analyze applications such as programmable reshaping of picosecond-scale temporal modes, selective frequency conversion of any one or superposition of those modes, and mode-resolved photon counting. We also report on experimental progress to distinguish two overlapping, orthogonal temporal modes, demonstrating over 8 dB extinction between picosecond-scale time-frequency modes, which agrees well with our theory. Our theoretical and experimental progress, as a whole, points to an enabling optical technique for various applications such as ultradense quantum coding, unity-efficiency cavity-atom quantum memories, and high-speed quantum computing. PMID:25402035

  17. Quantum optical arbitrary waveform manipulation and measurement in real time.

    PubMed

    Kowligy, Abijith S; Manurkar, Paritosh; Corzo, Neil V; Velev, Vesselin G; Silver, Michael; Scott, Ryan P; Yoo, S J B; Kumar, Prem; Kanter, Gregory S; Huang, Yu-Ping

    2014-11-17

    We describe a technique for dynamic quantum optical arbitrary-waveform generation and manipulation, which is capable of mode selectively operating on quantum signals without inducing significant loss or decoherence. It is built upon combining the developed tools of quantum frequency conversion and optical arbitrary waveform generation. Considering realistic parameters, we propose and analyze applications such as programmable reshaping of picosecond-scale temporal modes, selective frequency conversion of any one or superposition of those modes, and mode-resolved photon counting. We also report on experimental progress to distinguish two overlapping, orthogonal temporal modes, demonstrating over 8 dB extinction between picosecond-scale time-frequency modes, which agrees well with our theory. Our theoretical and experimental progress, as a whole, points to an enabling optical technique for various applications such as ultradense quantum coding, unity-efficiency cavity-atom quantum memories, and high-speed quantum computing.

  18. PREFACE: Quantum Optics III

    NASA Astrophysics Data System (ADS)

    Orszag, M.; Retamal, J. C.; Saavedra, C.; Wallentowitz, S.

    2007-06-01

    All the 50 years of conscious pondering did not bring me nearer to an answer to the question `what is light quanta?'. Nowadays, every rascal believes, he knows it, however, he is mistaken. (A Einstein, 1951 in a letter to M Besso) Quantum optics has played a key role in physics in the last several decades. On the other hand, in these early decades of the information age, the flow of information is becoming more and more central to our daily life. Thus, the related fields of quantum information theory as well as Bose-Einstein condensation have acquired tremendous importance in the last couple of decades. In Quantum Optics III, a fusion of these fields appears in a natural way. Quantum Optics III was held in Pucón, Chile, in 27-30 of November, 2006. This beautiful location in the south of Chile is near the lake Villarrica and below the snow covered volcano of the same name. This fantastic environment contributed to a relaxed atmosphere, suitable for informal discussion and for the students to have a chance to meet the key figures in the field. The previous Quantum Optics conferences took place in Santiago, Chile (Quantum Optics I, 2000) and Cozumel, Mexico (Quantum Optics II, 2004). About 115 participants from 19 countries attended and participated in the meeting to discuss a wide variety of topics such as quantum-information processing, experiments related to non-linear optics and squeezing, various aspects of entanglement including its sudden death, correlated twin-photon experiments, light storage, decoherence-free subspaces, Bose-Einstein condensation, discrete Wigner functions and many more. There was a strong Latin-American participation from Argentina, Brazil, Chile, Colombia, Peru, Uruguay, Venezuela and Mexico, as well as from Europe, USA, China, and Australia. New experimental and theoretical results were presented at the conference. In Latin-America a quiet revolution has taken place in the last twenty years. Several groups working in quantum optics and

  19. Moving of the High-Speed Plasma jet Through the Ionosphere of the Different Density: Optical and Radiation Effects

    NASA Astrophysics Data System (ADS)

    Zetzer, J. I.; Erlandson, R. E.; Gavrilov, B. G.; Kiselev, Y. N.; Lynch, K. A.; Meng, C. I.; Pfaff, R. F.; Poklad, Y. V.; Rybakov, V. A.; Stenbaek-Nielsen, H.

    2003-12-01

    The investigation of the high-speed plasma jet dynamics in the geomagnetic field has important implications to the basic magnetospheric and ionospheric physics and to the applied problems. The new results of the active geophysical rocket experiment (AGRE) "North Star" (1999) are represented. The high-speed plasma jet was injected on the altitudes 360 and 280 km perpendicular to the geomagnetic field. During first injection plasma jet was injected in the artificial air cloud with the density ~ 10-12 g/cm3, during second one - in the free space with the density ~ 10-15 g/cm3. The design and characteristics of the plasma jet generator, the radiation dynamics of the plasma cloud and dynamics of the charged particles takes place during of the process of the interaction of the plasma jet with environment are discussed.

  20. The NACA High-Speed Motion-Picture Camera Optical Compensation at 40,000 Photographs Per Second

    NASA Technical Reports Server (NTRS)

    Miller, Cearcy D

    1946-01-01

    The principle of operation of the NACA high-speed camera is completely explained. This camera, operating at the rate of 40,000 photographs per second, took the photographs presented in numerous NACA reports concerning combustion, preignition, and knock in the spark-ignition engine. Many design details are presented and discussed, details of an entirely conventional nature are omitted. The inherent aberrations of the camera are discussed and partly evaluated. The focal-plane-shutter effect of the camera is explained. Photographs of the camera are presented. Some high-speed motion pictures of familiar objects -- photoflash bulb, firecrackers, camera shutter -- are reproduced as an illustration of the quality of the photographs taken by the camera.

  1. High-speed all-optical pattern recognition of dispersive Fourier images through a photonic reservoir computing subsystem.

    PubMed

    Mesaritakis, Charis; Bogris, Adonis; Kapsalis, Alexandros; Syvridis, Dimitris

    2015-07-15

    In this Letter, we present and fully model a photonic scheme that allows the high-speed identification of images acquired through the dispersive Fourier technique. The proposed setup consists of a photonic reservoir-computing scheme that is based on the nonlinear response of randomly interconnected InGaAsP microring resonators. This approach allowed classification errors of 0.6%, whereas it alleviates the need for complex high-cost optoelectronic sampling and digital processing.

  2. Quantum optical rotatory dispersion

    PubMed Central

    Tischler, Nora; Krenn, Mario; Fickler, Robert; Vidal, Xavier; Zeilinger, Anton; Molina-Terriza, Gabriel

    2016-01-01

    The phenomenon of molecular optical activity manifests itself as the rotation of the plane of linear polarization when light passes through chiral media. Measurements of optical activity and its wavelength dependence, that is, optical rotatory dispersion, can reveal information about intricate properties of molecules, such as the three-dimensional arrangement of atoms comprising a molecule. Given a limited probe power, quantum metrology offers the possibility of outperforming classical measurements. This has particular appeal when samples may be damaged by high power, which is a potential concern for chiroptical studies. We present the first experiment in which multiwavelength polarization-entangled photon pairs are used to measure the optical activity and optical rotatory dispersion exhibited by a solution of chiral molecules. Our work paves the way for quantum-enhanced measurements of chirality, with potential applications in chemistry, biology, materials science, and the pharmaceutical industry. The scheme that we use for probing wavelength dependence not only allows one to surpass the information extracted per photon in a classical measurement but also can be used for more general differential measurements. PMID:27713928

  3. Introduction to optical quantum cryptography

    NASA Astrophysics Data System (ADS)

    Adamski, Tomasz

    2008-01-01

    In recent years very fast progress in the domain of Optical Quantum Cryptography is observed both in theoretical and practical aspects. The paper is a short tutorial review of basic concepts of Optical Quantum Cryptography (OQC) and Quantum Key Distribution (QKD).

  4. A high-speed multi-protocol quantum key distribution transmitter based on a dual-drive modulator.

    PubMed

    Korzh, Boris; Walenta, Nino; Houlmann, Raphael; Zbinden, Hugo

    2013-08-26

    We propose a novel source based on a dual-drive modulator that is adaptable and allows Alice to choose between various practical quantum key distribution (QKD) protocols depending on what receiver she is communicating with. Experimental results show that the proposed transmitter is suitable for implementation of the Bennett and Brassard 1984 (BB84), coherent one-way (COW) and differential phase shift (DPS) protocols with stable and low quantum bit error rate. This could become a useful component in network QKD, where multi-protocol capability is highly desirable. PMID:24105505

  5. Characterization and control of a multielement dual-frequency liquid-crystal device for high-speed adaptive optical wave-front correction.

    PubMed

    Dayton, D; Browne, S; Gonglewski, J; Restaino, S

    2001-05-20

    Multielement nematic liquid-crystal devices have been used by others and ourselves for closed-loop adaptive control of optical wave-front distortions. Until recently the phase retardance of available devices could be controlled rapidly in only one direction. The phase retardance of the dual-frequency device can be controlled rapidly in both directions. Understanding the dynamics of the phase retardance change is critical to the development of a high-speed control algorithm. We describe measurements and experiments leading to the closed-loop control of a multielement dual-frequency liquid-crystal adaptive optic.

  6. Characterization and Control of a Multielement Dual-Frequency Liquid-Crystal Device for High-Speed Adaptive Optical Wave-Front Correction

    NASA Astrophysics Data System (ADS)

    Dayton, David; Browne, Stephen; Gonglewski, John; Restaino, Sergio

    2001-05-01

    Multielement nematic liquid-crystal devices have been used by others and ourselves for closed-loop adaptive control of optical wave-front distortions. Until recently the phase retardance of available devices could be controlled rapidly in only one direction. The phase retardance of the dual-frequency device can be controlled rapidly in both directions. Understanding the dynamics of the phase retardance change is critical to the development of a high-speed control algorithm. We describe measurements and experiments leading to the closed-loop control of a multielement dual-frequency liquid-crystal adaptive optic.

  7. Characterization and control of a multielement dual-frequency liquid-crystal device for high-speed adaptive optical wave-front correction.

    PubMed

    Dayton, D; Browne, S; Gonglewski, J; Restaino, S

    2001-05-20

    Multielement nematic liquid-crystal devices have been used by others and ourselves for closed-loop adaptive control of optical wave-front distortions. Until recently the phase retardance of available devices could be controlled rapidly in only one direction. The phase retardance of the dual-frequency device can be controlled rapidly in both directions. Understanding the dynamics of the phase retardance change is critical to the development of a high-speed control algorithm. We describe measurements and experiments leading to the closed-loop control of a multielement dual-frequency liquid-crystal adaptive optic. PMID:18357243

  8. High speed handpieces

    PubMed Central

    Bhandary, Nayan; Desai, Asavari; Shetty, Y Bharath

    2014-01-01

    High speed instruments are versatile instruments used by clinicians of all specialties of dentistry. It is important for clinicians to understand the types of high speed handpieces available and the mechanism of working. The centers for disease control and prevention have issued guidelines time and again for disinfection and sterilization of high speed handpieces. This article presents the recent developments in the design of the high speed handpieces. With a view to prevent hospital associated infections significant importance has been given to disinfection, sterilization & maintenance of high speed handpieces. How to cite the article: Bhandary N, Desai A, Shetty YB. High speed handpieces. J Int Oral Health 2014;6(1):130-2. PMID:24653618

  9. Monolithically integrated quantum dot optical modulator with Semiconductor optical amplifier for short-range optical communications

    NASA Astrophysics Data System (ADS)

    Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Kawanishi, Tetsuya

    2015-04-01

    A monolithically integrated quantum dot (QD) optical gain modulator (OGM) with a QD semiconductor optical amplifier (SOA) was successfully developed. Broadband QD optical gain material was used to achieve Gbps-order high-speed optical data transmission, and an optical gain change as high as approximately 6-7 dB was obtained with a low OGM voltage of 2.0 V. Loss of optical power due to insertion of the device was also effectively compensated for by the SOA section. Furthermore, it was confirmed that the QD-OGM/SOA device helped achieve 6.0-Gbps error-free optical data transmission over a 2.0-km-long photonic crystal fiber. We also successfully demonstrated generation of Gbps-order, high-speed, and error-free optical signals in the >5.5-THz broadband optical frequency bandwidth larger than the C-band. These results suggest that the developed monolithically integrated QD-OGM/SOA device will be an advantageous and compact means of increasing the usable optical frequency channels for short-reach communications.

  10. Static gain saturation in quantum dot semiconductor optical amplifiers.

    PubMed

    Meuer, Christian; Kim, Jungho; Laemmlin, Matthias; Liebich, Sven; Capua, Amir; Eisenstein, Gadi; Kovsh, Alexey R; Mikhrin, Sergey S; Krestnikov, Igor L; Bimberg, Dieter

    2008-05-26

    Measurements of saturated amplified spontaneous emission-spectra of quantum dot semiconductor optical amplifiers demonstrate efficient replenishment of the quantum-dot ground state population from excited states. This saturation behavior is perfectly modeled by a rate equation model. We examined experimentally the dependence of saturation on the drive current and the saturating optical pump power as well as on the pump wavelength. A coherent noise spectral hole is observed with which we assess dynamical properties and propose optimization of the SOA operating parameters for high speed applications.

  11. Optically controlled waveplate at a telecom wavelength using a ladder transition in Rb atoms for all-optical switching and high speed Stokesmetric imaging.

    PubMed

    Krishnamurthy, Subramanian; Tu, Y; Wang, Y; Tseng, S; Shahriar, M S

    2014-11-17

    We demonstrate an optically controlled waveplate at ~1323 nm using the 5S(1/2)-5P(1/2)-6S(1/2) ladder transition in a Rb vapor cell. The lower leg of the transitions represents the control beam, while the upper leg represents the signal beam. We show that we can place the signal beam in any arbitrary polarization state with a suitable choice of polarization of the control beam. Specifically, we demonstrate a differential phase retardance of ~180 degrees between the two circularly polarized components of a linearly polarized signal beam. We also demonstrate that the system can act as a Quarter Wave plate. The optical activity responsible for the phase retardation process is explained in terms of selection rules involving the Zeeman sublevels. As such, the system can be used to realize a fast Stokesmetric imaging system with a speed of ~3 MHz. When implemented using a tapered nano fiber embedded in a vapor cell, this system can be used to realize an ultra-low power all-optical switch as well as a Quantum Zeno Effect based all-optical logic gate by combining it with an optically controlled polarizer, previously demonstrated by us. We present numerical simulations of the system using a comprehensive model which incorporates all the relevant Zeeman sub-levels in the system, using a novel algorithm recently developed by us for efficient computation of the evolution of an arbitrary large scale quantum system. PMID:25402129

  12. High-speed InGaAs thin film MSM photodetector characterization using a fiber-based electro-optic sampling system

    NASA Astrophysics Data System (ADS)

    Seo, Sang-Woo; Cho, Sang-Yeon; Huang, Sa; Brown, April; Jokerst, Nan M.

    2004-06-01

    As optoelectronic devices increase in speed, the measurement system used to characterize these devices must have sufficient bandwidth and minimum parasitic loading during test to accurately determine the intrinsic performance of the device under test. Conventional electrical measurement systems have an intrinsic bandwidth due to the available components for test and have parasitic loading due to direct electrical contact to the device under the test. Electro-optic sampling is an excellent measurement technique for characterizing ultra-fast devices because it has high bandwidth, is non-contact, is non-destructive, and relatively non-invasive. In this paper, an optical fiber-based electro-optic sampling system is designed and used for characterizing high speed InGaAs thin film MSM photodetectors. A fiber laser which is operating at 1556 nm wavelength was used for the sampling and excitation beam. Optical fibers were used to connect each component in the system for flexibility. InGaAs thin film MSM photodetectors were fabricated and characterized. InGaAs thin film MSM photodetectors were bonded onto a coplanar strip line deposited on a benzocyclobutene (BCB)-coated glass substrate for characterization. These thin film photodetectors show high speed operation combined with high responsivity and large detection area compared to P-I-N photodetectors operating at similar speeds

  13. High-speed and high-efficiency Si optical modulator with MOS junction, using solid-phase crystallization of polycrystalline silicon

    NASA Astrophysics Data System (ADS)

    Fujikata, Junichi; Takahashi, Masashi; Takahashi, Shigeki; Horikawa, Tsuyoshi; Nakamura, Takahiro

    2016-04-01

    We developed a high-speed and high-efficiency MOS-capacitor-type Si optical modulator (Si-MOD) by applying a low optical loss and a low resistivity of a polycrystalline silicon (poly-Si) gate with large grains. To achieve a low resistivity of a poly-Si film, a P-doped poly-Si film based on Si2H6 solid-phase crystallization (SPC) was developed, which showed a comparable resistivity to that of P-doped single-crystal Si. In addition, high-temperature annealing (HTA) after SPC was effective for realizing low optical loss. We designed the optimum Si-MOD structure and demonstrated a very high modulation efficiency of 0.3 V cm, which is very efficient among the Si-MODs developed thus far. High-speed (15 Gbps) operation was achieved with a small footprint of the 200-µm-long phase shifter and a low drive voltage of 1.5 Vpp at a low optical insertion loss of -2.2 dB and 1.55 µm wavelength.

  14. Fabrication and characteristics of high speed InGaAs/GaAs quantum-wells superluminescent diode emitting at 1053 nm

    NASA Astrophysics Data System (ADS)

    Duan, L. H.; Fang, L.; Zhang, J.; Zhou, Y.; Guo, H.; Luo, Q. C.; Zhang, S. F.

    2014-05-01

    A high speed 1053 nm superluminescent diode (SLD) with a ridge-waveguide structure has been fabricated for the first time to the best of our knowledge. InGaAs/GaAs quantum well epitaxial structure, the etched depth of the insulation channel and the area of p-side electrode were optimized to enhance the modulation bandwidth of the SLD. Bend-waveguide unpumped absorbing region structure and facet coating methods have been adopted to suppress the lasing oscillation. As a result, a -3 dB cutoff frequency of 1.7 GHz is obtained at a dc bias current of 100 mA and 25 °C heat-sink temperature, corresponding to 2.5 mW output power from single-mode fiber with spectral modulation of less than 0.15 dB and spectral width of 24 nm. The SLD module shows a good reliability.

  15. Roadmap on quantum optical systems

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

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

  16. High-speed organic photo-detectors fabricated by vacuum and solution processes and application for optical transmission

    NASA Astrophysics Data System (ADS)

    Ohmori, Yutaka; Hamasaki, Tatsunari; Morimune, Taichiro; Kajii, Hirotake

    2008-04-01

    Organic photo-detectors (OPDs) have been discussed as high-speed photo-detectors fabricated by vacuum and solution processes. By vacuum process, OPD was fabricated on an ITO-coated glass substrate by organic molecular beam deposition (OMBD). Copper phthalocyanine (CuPc) and N,N'-bis(2,5-di-tert-butylphenyl) 3,4,9,10-perylene dicarboximide (BPPC) were used as a p-type and an n-type material. The photo response of OPD was evaluated using a laser (λ=650 nm) and clear response signals at 100 MHz were observed. The imaging signals were successfully received using the OPDs. For solution processed OPDs, poly(9,9-dioctylfluorene) and a phosphorescent iridium derivative were used as a host and a dopant material, respectively. A pulsed signal of 100MHz and amore than 40 MHz were observed by the OPDs fabricated by the vacuum processed and the solution processed devices, respectively.

  17. Full-range imaging of the whole anterior segment of eye by high-speed optical frequency domain imaging using a reflective Fabry-Perot tunable laser

    NASA Astrophysics Data System (ADS)

    Furukawa, Hiroyuki; Hiro-Oka, Hideaki; Yoshimura, Reiko; Choi, Dong-Hak; Nakanishi, Motoi; Igarashi, Akihito; Ohbayashi, Kohji; Shimizu, Kimiya

    2011-03-01

    We describe a high-speed long-depth range optical frequency domain imaging (OFDI) system employing a long-coherence length tunable source and demonstrate dynamic full-range imaging of the anterior segment of the eye including from the cornea surface to the posterior capsule of the crystalline lens with a depth range of 12 mm without removing complex conjugate image ambiguity. The dependence of the whole anterior segment change on time following abrupt relaxation from the accommodated to the relaxed status was measured for a healthy eye and that with an intraocular lens.

  18. Quantum optics. Gravity meets quantum physics

    SciTech Connect

    Adams, Bernhard W.

    2015-02-27

    Albert Einstein’s general theory of relativity is a classical formulation but a quantum mechanical description of gravitational forces is needed, not only to investigate the coupling of classical and quantum systems but simply to give a more complete description of our physical surroundings. In this issue of Nature Photonics, Wen-Te Liao and Sven Ahrens reveal a link between quantum and gravitational physics. They propose that in the quantum-optical effect of superradiance, the world line of electromagnetic radiation is changed by the presence of a gravitational field.

  19. Rapid programmable/code-length-variable, time-domain bit-by-bit code shifting for high-speed secure optical communication.

    PubMed

    Gao, Zhensen; Dai, Bo; Wang, Xu; Kataoka, Nobuyuki; Wada, Naoya

    2011-05-01

    We propose and experimentally demonstrate a time-domain bit-by-bit code-shifting scheme that can rapidly program ultralong, code-length variable optical code by using only a dispersive element and a high-speed phase modulator for improving information security. The proposed scheme operates in the bit overlap regime and could eliminate the vulnerability of extracting the code by analyzing the fine structure of the time-domain spectral phase encoded signal. It is also intrinsically immune to eavesdropping via conventional power detection and differential-phase-shift-keying (DPSK) demodulation attacks. With this scheme, 10 Gbits/s of return-to-zero-DPSK data secured by bit-by-bit code shifting using up to 1024 chip optical code patterns have been transmitted over 49 km error free. The proposed scheme exhibits the potential for high-data-rate secure optical communication and to realize even one time pad.

  20. Linear optics and quantum maps

    SciTech Connect

    Aiello, A.; Puentes, G.; Woerdman, J. P.

    2007-09-15

    We present a theoretical analysis of the connection between classical polarization optics and quantum mechanics of two-level systems. First, we review the matrix formalism of classical polarization optics from a quantum information perspective. In this manner the passage from the Stokes-Jones-Mueller description of classical optical processes to the representation of one- and two-qubit quantum operations, becomes straightforward. Second, as a practical application of our classical-vs-quantum formalism, we show how two-qubit maximally entangled mixed states can be generated by using polarization and spatial modes of photons generated via spontaneous parametric down conversion.

  1. Quantum cryptography using optical fibers.

    PubMed

    Franson, J D; Lives, H

    1994-05-10

    Quantum cryptography permits the transmission of secret information whose security is guaranteed by the uncertainty principle. An experimental system for quantum crytography is implemented based on the linear polarization of single photons transmitted by an optical fiber. Polarization-preserving optical fiber and a feedback loop are employed to maintain the state of polarization. Error rates of less than 0.5% are obtained.

  2. Review of high speed communications photomultiplier detectors

    NASA Technical Reports Server (NTRS)

    Enck, R. S.; Abraham, W. G.

    1978-01-01

    Four types of newly developed high speed photomultipliers are discussed: all electrostatic; static crossed field; dynamic crossed field; and hybrid (EBS). Design, construction, and performance parameters of each class are presented along with limitations of each class of device and prognosis for its future in high speed light detection. The particular advantage of these devices lies in high speed applications using low photon flux, large cathode areas, and broadband optical detection.

  3. Two-tone intensity-modulated optical stimulus for self-referencing microwave characterization of high-speed photodetectors

    NASA Astrophysics Data System (ADS)

    Wang, Heng; Zhang, Shangjian; Zou, Xinhai; Zhang, Yali; Lu, Rongguo; Zhang, Zhiyao; Zhang, Xiaoxia; Liu, Yong

    2016-08-01

    The two-tone intensity modulated optical stimulus is proposed and demonstrated for measuring the high-frequency response of photodetectors. The method provides a narrow linewidth and wide bandwidth optical stimulus based on the two-tone modulation of a Mach-Zehnder electro-optical intensity modulator, and achieves the self-referenced measurement of photodetectors without the need for correcting the power variation of optical stimulus. Moreover, the two-tone intensity modulation method allows bias-independent measurement with doubled measuring frequency range. In the experiment, the consistency between our method and the conventional methods verifies the simple but accurate measurement.

  4. Analysis of the temporal flame kernel development in an optically accessible IC engine using high-speed OH-PLIF

    NASA Astrophysics Data System (ADS)

    Müller, S. H. R.; Böhm, B.; Gleißner, M.; Arndt, S.; Dreizler, A.

    2010-09-01

    The investigation of the combustion process of a direct injection spark-ignition internal combustion (IC) engine is crucial in modern engine development. The present study is aimed at inspecting the temporal development of the spark induced flame kernel within single combustion cycles using high-speed planar laser-induced fluorescence (PLIF). The analysis is based upon the excitation of OH radicals, which are an indicator of the transient flame front. To achieve an adequate temporal resolution of the early combustion phase, the image sampling rate was set to 6 kHz, recording one image per crank-angle (CA) degree at 1000 rpm. A further feature of the technique is a large field of view spanning ˜54×53 mm. The performance of the transient combustion process is characterized by temporally tracking subsequential engine cycles individually. Flame front dynamics with different dilution levels of the intake air, simulating exhaust gas recirculation (EGR) are investigated. Resolving flame front dynamics especially with varying EGR is an important step towards an improved understanding of cyclic variations and pollutant formation.

  5. High Speed Research Program

    NASA Technical Reports Server (NTRS)

    Anderson, Robert E.; Corsiglia, Victor R.; Schmitz, Frederic H. (Technical Monitor)

    1994-01-01

    An overview of the NASA High Speed Research Program will be presented from a NASA Headquarters perspective. The presentation will include the objectives of the program and an outline of major programmatic issues.

  6. Implementation of wavelength selector based on electro-optic effect in Mach-Zehnder interferometers for high speed communications

    NASA Astrophysics Data System (ADS)

    Kumar, Santosh; Bisht, Ashish; Singh, Gurdeep; Choudhary, Kuldeep; Sharma, Divya

    2015-09-01

    The design of 4×1 and 8×1 wavelength selectors have been presented with complete functionality and configuration, which can be used as DWDM components in optical networks. The proposed optical logic unit is based on electro-optic effect in Mach-Zehnder interferometer (MZI). The Mach-Zehnder interferometer (MZI) structures collectively show the powerful capability in switching an input optical signal to a desired output port from a collection of output ports. A strategy for optical wavelength switching has been shown by constructing a design of wavelength selector using MZIs. The paper constitutes the mathematical description of proposed device and thereafter the wavelength switching behavior is analyzed using beam propagation method (BPM). The results are also verified with the help of MATLAB simulations and truth table.

  7. Quantum optics, cavity QED, and quantum optomechanics

    NASA Astrophysics Data System (ADS)

    Meystre, Pierre

    2013-05-01

    Quantum optomechanics provides a universal tool to achieve the quantum control of mechanical motion. It does that in devices spanning a vast range of parameters, with mechanical frequencies from a few Hertz to GHz, and with masses from 10-20 g to several kilos. Its underlying ideas can be traced back to the study of gravitational wave antennas, quantum optics, cavity QED and laser cooling which, when combined with the recent availability of advanced micromechanical and nanomechanical devices, opens a path to the realization of macroscopic mechanical systems that operate deep in the quantum regime. At the fundamental level this development paves the way to experiments that will lead to a more profound understanding of quantum mechanics; and from the point of view of applications, quantum optomechanical techniques will provide motion and force sensing near the fundamental limit imposed by quantum mechanics (quantum metrology) and significantly expand the toolbox of quantum information science. After a brief summary of key historical developments, the talk will give a broad overview of the current state of the art of quantum optomechanics, and comment on future prospects both in applied and in fundamental science. Work supported by NSF, ARO and the DARPA QuASAR and ORCHID programs.

  8. Entire thickness profiles of the epithelium and contact lens in vivo imaged with high speed and high resolution optical coherence tomography

    PubMed Central

    Tao, Aizhu; Shao, Yilei; Jiang, Hong; Ye, Yufeng; Lu, Fan; Shen, Meixiao; Zhu, Dexi; Wang, Jianhua

    2013-01-01

    Purpose To test the feasibility of measuring the entire thickness profiles of the epithelium and contact lens in vivo, using high speed and high resolution spectral domain optical coherence tomography (SD-OCT). Methods A custom-built, long scan depth SD-OCT was developed based on a CMOS camera and the axial resolution was about 5.1 µm in tissue. Five eyes of 5 subjects were imaged twice across the horizontal meridian before and while wearing one contact lens (CL). Semi-automatic measurement was done to yield the entire thickness profiles of the epithelium, total cornea, and contact lens after correcting for optical distortion. Results The full width and depth of the epithelium, ocular surface and contact lens were clearly visualized. The epithelial thickness (ET) at the center was 51.9 ± 3.5 µm, it remained at this thickness across the central 7 mm diameter and then increased at both temporal and nasal peripheries. The contact lens profile showed the thinnest point at the center with thickness of 100.3 ± 4.9 µm. The thickness increased towards the mid-periphery and then decreased at the edge. Conclusions This pilot study demonstrated the feasibility of using high speed CMOS-based OCT to evaluate the entire thickness profiles of the epithelium and contact lens in vivo. Further development will be needed to extend the scanning from 2D to 3D with a robust automatic image processing ability. PMID:23982471

  9. High Capacity High Speed Optical Data Storage System Based on Diffraction-Free Nanobeam. Final Report, 09-02-98 to 03-17-99

    SciTech Connect

    Tin Aye

    1999-06-16

    Physical Optics Corporation (POC) investigated the development of an optical data storage system built around a current well-engineered high-speed optical disk system with an innovative diffraction-free micro-optical element to produce a beam {approximately}250 nm wide with {approximately}4-5 mm depth of focus, allowing the system to address data at {approximately}100 Mbits/second and to store it 100 to 1,000 times more densely ({approximately}10 Gbit/in.{sup 2}) than in present systems. In Phase 1 of this project POC completed a thorough feasibility study by system design and analysis, successfully demonstrated fabrication of the key components, and conducted a proof-of-principle experimental demonstration. Specifically, production of a subwavelength ({approximately}380 nm) large depth of focus ({approximately}4-5 mm) addressing beam was demonstrated by fabricating a special microdiffractive optical element and recording this beam on a standard optical recording disk coated with a photopolymer material.

  10. Optically deviated focusing method based high-speed SD-OCT for in vivo retinal clinical applications

    NASA Astrophysics Data System (ADS)

    Wijesinghe, Ruchire Eranga; Park, Kibeom; Kim, Pilun; Oh, Jaeryung; Kim, Seong-Woo; Kim, Kwangtae; Kim, Beop-Min; Jeon, Mansik; Kim, Jeehyun

    2016-04-01

    The aim of this study is to provide accurately focused, high-resolution in vivo human retinal depth images using an optically deviated focusing method with spectral-domain optical coherence tomography (SD-OCT) system. The proposed method was applied to increase the retinal diagnosing speed of patients with various values of retinal distances (i.e., the distance between the crystalline eye lens and the retina). The increased diagnosing speed was facilitated through an optical modification in the OCT sample arm configuration. Moreover, the optical path length matching process was compensated using the proposed optically deviated focusing method. The developed system was mounted on a bench-top cradle to overcome the motion artifacts. Further, we demonstrated the capability of the system by carrying out in vivo retinal imaging experiments. The clinical trials confirmed that the system was effective in diagnosing normal and abnormal retinal layers as several retinal abnormalities were identified using non-averaged single-shot OCT images, which demonstrate the feasibility of the method for clinical applications.

  11. Low-noise and high-speed photodetection system using optical feedback with a current amplification function.

    PubMed

    Akiba, M

    2015-09-01

    A photodetection system with an optical-feedback circuit accompanied by current amplification was fabricated to minimize the drawbacks associated with a transimpedance amplifier (TIA) with a very high resistance feedback resistor. Current amplification was implemented by extracting an output light from the same light source that emitted the feedback light. The current gain corresponds to the ratio of the photocurrent created by the output light to that created by the feedback light because the feedback current value is identical to the input photocurrent value generated by an input light to be measured. The current gain has no theoretical limit. The output light was detected by a photodiode with a TIA having a small feedback resistance. The expression for the input-referred noise current of the optical-feedback photodetection system was derived, and the trade-off between sensitivity and response, which is a characteristic of TIA, was found to considerably improve. An optical-feedback photodetection system with an InGaAs pin photodiode was fabricated. The measured noise equivalent power of the system was 1.7 fW/Hz(1/2) at 10 Hz and 1.3 μm, which is consistent with the derived expression. The time response of the system was found to deteriorate with decreasing photocurrent. The 50% rise time for a light pulse input increased from 3.1 μs at a photocurrent of 10 nA to 15 μs at photocurrents below 10 pA. The bandwidth of the input-referred noise current was 7 kHz, which is consistent with rise times below 10 pA. PMID:26429465

  12. FPGA implementation of concatenated non-binary QC-LDPC codes for high-speed optical transport.

    PubMed

    Zou, Ding; Djordjevic, Ivan B

    2015-06-01

    In this paper, we propose a soft-decision-based FEC scheme that is the concatenation of a non-binary LDPC code and hard-decision FEC code. The proposed NB-LDPC + RS with overhead of 27.06% provides a superior NCG of 11.9dB at a post-FEC BER of 10-15. As a result, the proposed NB-LDPC codes represent the strong FEC candidate of soft-decision FEC for beyond 100Gb/s optical transmission systems.

  13. High speed optical tomography system for quantitative measurement and visualization of dynamic features in a round jet

    NASA Astrophysics Data System (ADS)

    McMackin, L.; Hugo, R. J.; Bishop, K. P.; Chen, E. Y.; Pierson, R. E.; Truman, C. R.

    An optical tomography system that is capable of operating at frame rates of up to 5 kHz has been used to obtain spatially resolved cross-sectional temperature images of a heated round jet. These tomographic images show dynamic details in the evolving vortical flow structures found in the near field of the jet that are consistent with previous studies of low speed jet flow. Reconstructions produced by the system are quantitative temperature distributions of a planar cross section of the jet measuring temperature differences with a spatial resolution of 1.4 mm.

  14. High speed optical and X-ray methods for evaluating laser-generated shock-wave in materials

    SciTech Connect

    Paisley, D.; Swift, D.

    2000-11-01

    Optical diagnostic techniques including interferometry, electronic streak photography, and transient x-ray diffraction are used to study the dynamic material response to shock loading by direct laser irradiation and impact by laser-launched plates. The Los Alamos Trident laser is one of several lasers that have been used to generate shocks of 10 Kbar to several Mbar in single crystal and polycrystalline materials. Incorporating optical velocity interferometry (line-VISAR and point-VISAR) with transient x-ray diffraction can provide a complete understanding of the dynamic material response to shock compression and release. Laser-launched flyer plates provide an ideal method to generate one-dimensional shocks in materials. The quality of the one-dimensionality of the launch and acceleration of plates is evaluated by line-imaging VISA.R. The line-imaging VISAR images the fringes along a line across the diameter of the plate. Each fringe maxima and minima provide acceleration and velocity information at the specific point on the plate. By varying the fringe constant number of fringes and fringe spacing on the plate, detailed experimental data can be obtained. For our experiments, most plates are 3-mm diameter and accelerated to 0.2-->6 km/sec.

  15. Demonstration of 20Gb/s polarization-insensitive wavelength switching system for high-speed free-space optical network

    NASA Astrophysics Data System (ADS)

    Qian, Feng-chen; Ye, Ya-lin; Wen, Yu; Duan, Tao; Feng, Huan

    2015-10-01

    A 20Gb/s polarization-insensitive all-optical wavelength switching system for high-speed free-space optical communication (FSO) network is experimentally demonstrated All-optical wavelength conversion (AOWC) is implemented using four-wave mixing (FWM) by highly-nonlinear fiber (HNLF). In the experimental setup, a simple actively mode-locked fiber ring laser (AML-FRL) with repetition frequency from 1 to 15 GHz is used to generate eight 2.5Gb/s tributary signals, which are multiplexed into one 20Gb/s optical data stream. At the receiver, the 20 Gb/s OTDM data stream is demultiplexed down to 2.5 Gb/s via a polarization-insensitive FWM scheme. The whole space communication distance is over 10 meters in building hallway. The experimental results show that this system can stably run over 24 hours at 10-9 BER level, thus the proposed architecture can work at higher rate with wavelength-division multiplexing (WDM) and high order modulation schemes.

  16. High speed door assembly

    DOEpatents

    Shapiro, Carolyn

    1993-01-01

    A high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  17. High speed door assembly

    DOEpatents

    Shapiro, C.

    1993-04-27

    A high speed door assembly is described, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  18. High speed civil transport

    NASA Technical Reports Server (NTRS)

    Mcknight, R. L.

    1992-01-01

    The design requirements of the High Speed Civil Transport (HSCT) are discussed. The following design concerns are presented: (1) environmental impact (emissions and noise); (2) critical components (the high temperature combustor and the lightweight exhaust nozzle); and (3) advanced materials (high temperature ceramic matrix composites (CMC's)/intermetallic matrix composites (IMC's)/metal matrix composites (MMC's)).

  19. Visualization of explosion phenomena using a high-speed video camera with an uncoupled objective lens by fiber-optic

    NASA Astrophysics Data System (ADS)

    Tokuoka, Nobuyuki; Miyoshi, Hitoshi; Kusano, Hideaki; Hata, Hidehiro; Hiroe, Tetsuyuki; Fujiwara, Kazuhito; Yasushi, Kondo

    2008-11-01

    Visualization of explosion phenomena is very important and essential to evaluate the performance of explosive effects. The phenomena, however, generate blast waves and fragments from cases. We must protect our visualizing equipment from any form of impact. In the tests described here, the front lens was separated from the camera head by means of a fiber-optic cable in order to be able to use the camera, a Shimadzu Hypervision HPV-1, for tests in severe blast environment, including the filming of explosions. It was possible to obtain clear images of the explosion that were not inferior to the images taken by the camera with the lens directly coupled to the camera head. It could be confirmed that this system is very useful for the visualization of dangerous events, e.g., at an explosion site, and for visualizations at angles that would be unachievable under normal circumstances.

  20. Low-power, high-speed InGaAs/InP photoreceiver for highly-parallel optical data links

    SciTech Connect

    Lovejoy, M.L.; Patrizi, G.A.; Enquist, P.M.

    1995-09-01

    Low-power photoreceivers based on InGaAs/InP heterojunction bipolar transistors (HBTs) and p-i-n diodes for highly-parallel optical data links have been designed, fabricated and characterized. The receivers and designed to operate from 980 nm to over 1.3 {mu}m and interface directly with 3.3 V CMOS. SPICE was utilized to investigate circuit topographies that minimize power dissipation while maintaining large signal operation required to interface directly with CMOS. Low-power dissipation of {approximately}10 mW/channel has been achieved at bit rates up to 800 Mbits/sec. Performance characteristics of discrete HBTs and of low-power photoreceivers fabricated with p-i-n/HBT circuits are reported.

  1. Optimal signal constellation design for ultra-high-speed optical transport in the presence of nonlinear phase noise.

    PubMed

    Liu, Tao; Djordjevic, Ivan B

    2014-12-29

    In this paper, we first describe an optimal signal constellation design algorithm suitable for the coherent optical channels dominated by the linear phase noise. Then, we modify this algorithm to be suitable for the nonlinear phase noise dominated channels. In optimization procedure, the proposed algorithm uses the cumulative log-likelihood function instead of the Euclidian distance. Further, an LDPC coded modulation scheme is proposed to be used in combination with signal constellations obtained by proposed algorithm. Monte Carlo simulations indicate that the LDPC-coded modulation schemes employing the new constellation sets, obtained by our new signal constellation design algorithm, outperform corresponding QAM constellations significantly in terms of transmission distance and have better nonlinearity tolerance.

  2. Gain engineering for all-optical microwave and high speed pulse generation in mode-locked fiber lasers

    NASA Astrophysics Data System (ADS)

    Li, Fangxin; Helmy, Amr S.

    2014-03-01

    Pulsed sources based on approaches that employ only photonic components and no RF components will be discussed in this talk. Several technologies have been explored to generate actively mode-locked sources using electronically driven fiber ring cavities. However, for these sources the pulse repetition rate is usually limited by the bandwidth of the intracavity modulator. Filtering of highly-stable low repetition rate optical combs utilizing cavities such as Fabry-Perot etalons can be used to overcome this limitation. This scheme is not flexible as it requires highly precise control of ultrahigh finesse etalons which limits the repetition rate to the free spectral range of the filter. Pulsed sources based on semiconductor devices offer many advantages, including large gain bandwidth, rapid tunability, long-term stability. In this work we introduce a novel, simple method to generate optical clock with wavelength tunability using two continuous wave (CW) lasers. The lasers are injected into a conventional SOAs-based fiber ring laser. The beating signal generated by these two lasers causes the modulation of the SOA gain saturation inside the cavity. Thus, the SOA provides gain and functions as the modulator as well as the gain medium. When the lasing mode inside the cavity is amplified, it also results in gain-induced four wave mixing. The proposed technique is particularly versatile, overcoming the bandwidth limitation of other techniques, which require RF sources. Moreover, this technique provides the possibility for hybrid integration as it is comprised of semiconductor chips that can be heterogeneously integrated on a Si platform.

  3. Architectures and applications of high-speed vision

    NASA Astrophysics Data System (ADS)

    Watanabe, Yoshihiro; Oku, Hiromasa; Ishikawa, Masatoshi

    2014-11-01

    With the progress made in high-speed imaging technology, image processing systems that can process images at high frame rates, as well as their applications, are expected. In this article, we examine architectures for high-speed vision systems, and also dynamic image control, which can realize high-speed active optical systems. In addition, we also give an overview of some applications in which high-speed vision is used, including man-machine interfaces, image sensing, interactive displays, high-speed three-dimensional sensing, high-speed digital archiving, microvisual feedback, and high-speed intelligent robots.

  4. Volumetric in vivo imaging of intracochlear microstructures in mice by high-speed spectral domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Subhash, Hrebesh M.; Davila, Viviana; Sun, Hai; Nguyen-Huynh, Anh T.; Nuttall, Alfred L.; Wang, Ruikang K.

    2010-05-01

    There is considerable interest in developing new methods for in vivo imaging of the complex anatomy of the mammalian cochlea for clinical as well as fundamental studies. In this study, we explored, the feasibility of spectral domain optical coherence tomography (SD-OCT) for 3-D in vivo imaging of the cochlea in mice. The SD-OCT system employed in this study used a broadband light source centered at 1300 nm, and the imaging speed of the system was 47,000 A-scans per second using the InGaAs camera. The system was capable of providing fully processed, high-resolution B-scan images [512 (axial)×128 (lateral) pixels] at 280 frames per sec. The 3-D imaging acquisition time for a whole cochlea was ~0.45 sec. The traditional SD-OCT structural imaging algorithm was used to reconstruct 3-D cochlear morphology. We demonstrated that SD-OCT can be successfully used for in vivo imaging of important morphological features within the mouse cochlea, such as the otic capsule and structures within, including Reissner's membrane, the basilar membrane, tectorial membrane, organ of Corti, and modiolus of the apical and middle turns.

  5. Optical Hybrid Quantum Information Processing

    NASA Astrophysics Data System (ADS)

    Takeda, Shuntaro; Furusawa, Akira

    Historically, two complementary approaches to optical quantum information processing have been pursued: qubits and continuous-variables, each exploiting either particle or wave nature of light. However, both approaches have pros and cons. In recent years, there has been a significant progress in combining both approaches with a view to realizing hybrid protocols that overcome the current limitations. In this chapter, we first review the development of the two approaches with a special focus on quantum teleportation and its applications. We then introduce our recent research progress in realizing quantum teleportation by a hybrid scheme, and mention its future applications to universal and fault-tolerant quantum information processing.

  6. High-speed highly temperature stable 980 nm VCSELs operating at 25 Gb/s at up to 85 °C for short reach optical interconnects

    NASA Astrophysics Data System (ADS)

    Mutig, Alex; Lott, James A.; Blokhin, Sergey A.; Moser, Philip; Wolf, Philip; Hofmann, Werner; Nadtochiy, Alexey M.; Bimberg, Dieter

    2011-03-01

    The progressive penetration of optical communication links into traditional copper interconnect markets greatly expands the applications of vertical cavity surface emitting lasers (VCSELs) for the next-generation of board-to-board, moduleto- module, chip-to-chip, and on-chip optical interconnects. Stability of the VCSEL parameters at high temperatures is indispensable for such applications, since these lasers typically reside directly on or near integrated circuit chips. Here we present 980 nm oxide-confined VCSELs operating error-free at bit rates up to 25 Gbit/s at temperatures as high as 85 °C without adjustment of the drive current and peak-to-peak modulation voltage. The driver design is therefore simplified and the power consumption of the driver electronics is lowered, reducing the production and operational costs. Small and large signal modulation experiments at various temperatures from 20 up to 85 °C for lasers with different oxide aperture diameters are presented in order to analyze the physical processes controlling the performance of the VCSELs. Temperature insensitive maximum -3 dB bandwidths of around 13-15 GHz for VCSELs with aperture diameters of 10 μm and corresponding parasitic cut-off frequencies exceeding 22 GHz are observed. Presented results demonstrate the suitability of our VCSELs for practical high speed and high temperature stable short-reach optical links.

  7. Dispersion-optimized optical fiber for high-speed long-haul dense wavelength division multiplexing transmission

    NASA Astrophysics Data System (ADS)

    Wu, Jindong; Chen, Liuhua; Li, Qingguo; Wu, Wenwen; Sun, Keyuan; Wu, Xingkun

    2011-07-01

    Four non-zero-dispersion-shifted fibers with almost the same large effective area (Aeff) and optimized dispersion properties are realized by novel index profile designing and modified vapor axial deposition and modified chemical vapor deposition processes. An Aeff of greater than 71 μm2 is obtained for the designed fibers. Three of the developed fibers with positive dispersion are improved by reducing the 1550nm dispersion slope from 0.072ps/nm2/km to 0.063ps/nm2/km or 0.05ps/nm2/km, increasing the 1550nm dispersion from 4.972ps/nm/km to 5.679ps/nm/km or 7.776ps/nm/km, and shifting the zero-dispersion wavelength from 1500nm to 1450nm. One of these fibers is in good agreement with G655D and G.656 fibers simultaneously, and another one with G655E and G.656 fibers; both fibers are beneficial to high-bit long-haul dense wavelength division multiplexing systems over S-, C-, and L-bands. The fourth developed fiber with negative dispersion is also improved by reducing the 1550nm dispersion slope from 0.12ps/nm2/km to 0.085ps/nm2/km, increasing the 1550nm dispersion from -4ps/nm/km to -6.016ps/nm/km, providing facilities for a submarine transmission system. Experimental measurements indicate that the developed fibers all have excellent optical transmission and good macrobending and splice performances.

  8. All-optical reservoir computing system based on InGaAsP ring resonators for high-speed identification and optical routing in optical networks

    NASA Astrophysics Data System (ADS)

    Mesaritakis, Charis; Kapsalis, Alexandros; Syvridis, Dimitris

    2015-01-01

    In this paper an all-optical reservoir computing scheme is modeled, that paves an alternative route to photonic high bit rate header identification in optical networks and allow direct processing in the analog domain. The system consists of randomly interconnected InGaAsP micro-ring-resonators, whereas the computation efficiency of the scheme is based on the ultra-fast Kerr effect and two-photon absorption. Validation of the system's efficiency is confirmed through detailed numerical modeling and two application orientated benchmark tests that consists in the classification of 32bit digital headers, encoded an NRZ optical pulses, with a bitrate of 240Gbps,and the identification of pseudo-analog patters for real time sensing applications in the analog domain.

  9. Diamond Nanophotonics and Quantum Optics

    NASA Astrophysics Data System (ADS)

    Barclay, Paul

    2011-10-01

    The diamond nitrogen-vacancy (NV) center is an optically active impurity whose ``atom-like'' properties make it a promising solid state qubit, in which well-defined optical transitions are used to control the quantum state of single NV electron and nuclear spins. These properties have led to impressive demonstrations of quantum information storage in single NV nuclear spins, entanglement between NV electron spins and single photons, and implementations of high resolution optical magnetometers using single NVs. A missing ingredient for implementing quantum information processing architectures with NVs is creating scalable coherent coupling between them. Nanophotonic circuits, in which waveguides function as a ``quantum bus'' between NVs embedded in optical microcavities, offer a chip-based solution to this hurdle. In my talk I will review recent advances in realizing nanophotonic devices in diamond based materials. I will present results demonstrating Purcell enhanced coupling between optical nanocavities and NVs in single crystal diamond, and will discuss opportunities and challenges which lay ahead for diamond quantum optics.

  10. High speed door assembly

    SciTech Connect

    Shapiro, C.

    1991-12-31

    This invention is comprised of a high speed door assembly, comprising an actuator cylinder and piston rods, a pressure supply cylinder and fittings, an electrically detonated explosive bolt, a honeycomb structured door, a honeycomb structured decelerator, and a structural steel frame encasing the assembly to close over a 3 foot diameter opening within 50 milliseconds of actuation, to contain hazardous materials and vapors within a test fixture.

  11. Neutron Matter Wave Quantum Optics

    NASA Astrophysics Data System (ADS)

    Rauch, Helmut

    2012-06-01

    Neutron matter-wave optics provides the basis for new quantum experiments and a step towards applications of quantum phenomena. Most experiments have been performed with a perfect crystal neutron interferometer where widely separated coherent beams can be manipulated individually. Various geometric phases have been measured and their robustness against fluctuation effects has been proven, which may become a useful property for advanced quantum communication. Quantum contextuality for single particle systems shows that quantum correlations are to some extent more demanding than classical ones. In this case entanglement between external and internal degrees of freedom offers new insights into basic laws of quantum physics. Non-contextuality hidden variable theories can be rejected by arguments based on the Kochen-Specker theorem.

  12. Remote Transmission at High Speed

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Omni and NASA Test Operations at Stennis entered a Dual-Use Agreement to develop the FOTR-125, a 125 megabit-per-second fiber-optic transceiver that allows accurate digital recordings over a great distance. The transceiver s fiber-optic link can be as long as 25 kilometers. This makes it much longer than the standard coaxial link, which can be no longer than 50 meters.The FOTR-125 utilizes laser diode transmitter modules and integrated receivers for the optical interface. Two transmitters and two receivers are employed at each end of the link with automatic or manual switchover to maximize the reliability of the communications link. NASA uses the transceiver in Stennis High-Speed Data Acquisition System (HSDAS). The HSDAS consists of several identical systems installed on the Center s test stands to process all high-speed data related to its propulsion test programs. These transceivers allow the recorder and HSDAS controls to be located in the Test Control Center in a remote location while the digitizer is located on the test stand.

  13. High-speed, random-access fluorescence microscopy: I. High-resolution optical recording with voltage-sensitive dyes and ion indicators.

    PubMed Central

    Bullen, A; Patel, S S; Saggau, P

    1997-01-01

    The design and implementation of a high-speed, random-access, laser-scanning fluorescence microscope configured to record fast physiological signals from small neuronal structures with high spatiotemporal resolution is presented. The laser-scanning capability of this nonimaging microscope is provided by two orthogonal acousto-optic deflectors under computer control. Each scanning point can be randomly accessed and has a positioning time of 3-5 microseconds. Sampling time is also computer-controlled and can be varied to maximize the signal-to-noise ratio. Acquisition rates up to 200k samples/s at 16-bit digitizing resolution are possible. The spatial resolution of this instrument is determined by the minimal spot size at the level of the preparation (i.e., 2-7 microns). Scanning points are selected interactively from a reference image collected with differential interference contrast optics and a video camera. Frame rates up to 5 kHz are easily attainable. Intrinsic variations in laser light intensity and scanning spot brightness are overcome by an on-line signal-processing scheme. Representative records obtained with this instrument by using voltage-sensitive dyes and calcium indicators demonstrate the ability to make fast, high-fidelity measurements of membrane potential and intracellular calcium at high spatial resolution (2 microns) without any temporal averaging. Images FIGURE 6 PMID:9199810

  14. High-speed, random-access fluorescence microscopy: I. High-resolution optical recording with voltage-sensitive dyes and ion indicators.

    PubMed

    Bullen, A; Patel, S S; Saggau, P

    1997-07-01

    The design and implementation of a high-speed, random-access, laser-scanning fluorescence microscope configured to record fast physiological signals from small neuronal structures with high spatiotemporal resolution is presented. The laser-scanning capability of this nonimaging microscope is provided by two orthogonal acousto-optic deflectors under computer control. Each scanning point can be randomly accessed and has a positioning time of 3-5 microseconds. Sampling time is also computer-controlled and can be varied to maximize the signal-to-noise ratio. Acquisition rates up to 200k samples/s at 16-bit digitizing resolution are possible. The spatial resolution of this instrument is determined by the minimal spot size at the level of the preparation (i.e., 2-7 microns). Scanning points are selected interactively from a reference image collected with differential interference contrast optics and a video camera. Frame rates up to 5 kHz are easily attainable. Intrinsic variations in laser light intensity and scanning spot brightness are overcome by an on-line signal-processing scheme. Representative records obtained with this instrument by using voltage-sensitive dyes and calcium indicators demonstrate the ability to make fast, high-fidelity measurements of membrane potential and intracellular calcium at high spatial resolution (2 microns) without any temporal averaging. PMID:9199810

  15. High Speed Vortex Flows

    NASA Technical Reports Server (NTRS)

    Wood, Richard M.; Wilcox, Floyd J., Jr.; Bauer, Steven X. S.; Allen, Jerry M.

    2000-01-01

    A review of the research conducted at the National Aeronautics and Space Administration (NASA), Langley Research Center (LaRC) into high-speed vortex flows during the 1970s, 1980s, and 1990s is presented. The data reviewed is for flat plates, cavities, bodies, missiles, wings, and aircraft. These data are presented and discussed relative to the design of future vehicles. Also presented is a brief historical review of the extensive body of high-speed vortex flow research from the 1940s to the present in order to provide perspective of the NASA LaRC's high-speed research results. Data are presented which show the types of vortex structures which occur at supersonic speeds and the impact of these flow structures to vehicle performance and control is discussed. The data presented shows the presence of both small- and large scale vortex structures for a variety of vehicles, from missiles to transports. For cavities, the data show very complex multiple vortex structures exist at all combinations of cavity depth to length ratios and Mach number. The data for missiles show the existence of very strong interference effects between body and/or fin vortices and the downstream fins. It was shown that these vortex flow interference effects could be both positive and negative. Data are shown which highlights the effect that leading-edge sweep, leading-edge bluntness, wing thickness, location of maximum thickness, and camber has on the aerodynamics of and flow over delta wings. The observed flow fields for delta wings (i.e. separation bubble, classical vortex, vortex with shock, etc.) are discussed in the context of' aircraft design. And data have been shown that indicate that aerodynamic performance improvements are available by considering vortex flows as a primary design feature. Finally a discussing of a design approach for wings which utilize vortex flows for improved aerodynamic performance at supersonic speed is presented.

  16. High speed flywheel

    DOEpatents

    McGrath, Stephen V.

    1991-01-01

    A flywheel for operation at high speeds utilizes two or more ringlike coments arranged in a spaced concentric relationship for rotation about an axis and an expansion device interposed between the components for accommodating radial growth of the components resulting from flywheel operation. The expansion device engages both of the ringlike components, and the structure of the expansion device ensures that it maintains its engagement with the components. In addition to its expansion-accommodating capacity, the expansion device also maintains flywheel stiffness during flywheel operation.

  17. High speed transient sampler

    DOEpatents

    McEwan, T.E.

    1995-11-28

    A high speed sampler comprises a meandered sample transmission line for transmitting an input signal, a straight strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates along the transmission lines. The sampling gates comprise a four terminal diode bridge having a first strobe resistor connected from a first terminal of the bridge to the positive strobe line, a second strobe resistor coupled from the third terminal of the bridge to the negative strobe line, a tap connected to the second terminal of the bridge and to the sample transmission line, and a sample holding capacitor connected to the fourth terminal of the bridge. The resistance of the first and second strobe resistors is much higher than the signal transmission line impedance in the preferred system. This results in a sampling gate which applies a very small load on the sample transmission line and on the strobe generator. The sample holding capacitor is implemented using a smaller capacitor and a larger capacitor isolated from the smaller capacitor by resistance. The high speed sampler of the present invention is also characterized by other optimizations, including transmission line tap compensation, stepped impedance strobe line, a multi-layer physical layout, and unique strobe generator design. A plurality of banks of such samplers are controlled for concatenated or interleaved sample intervals to achieve long sample lengths or short sample spacing. 17 figs.

  18. High speed transient sampler

    DOEpatents

    McEwan, Thomas E.

    1995-01-01

    A high speed sampler comprises a meandered sample transmission line for transmitting an input signal, a straight strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates along the transmission lines. The sampling gates comprise a four terminal diode bridge having a first strobe resistor connected from a first terminal of the bridge to the positive strobe line, a second strobe resistor coupled from the third terminal of the bridge to the negative strobe line, a tap connected to the second terminal of the bridge and to the sample transmission line, and a sample holding capacitor connected to the fourth terminal of the bridge. The resistance of the first and second strobe resistors is much higher than the signal transmission line impedance in the preferred system. This results in a sampling gate which applies a very small load on the sample transmission line and on the strobe generator. The sample holding capacitor is implemented using a smaller capacitor and a larger capacitor isolated from the smaller capacitor by resistance. The high speed sampler of the present invention is also characterized by other optimizations, including transmission line tap compensation, stepped impedance strobe line, a multi-layer physical layout, and unique strobe generator design. A plurality of banks of such samplers are controlled for concatenated or interleaved sample intervals to achieve long sample lengths or short sample spacing.

  19. High speed bus technology development

    NASA Astrophysics Data System (ADS)

    Modrow, Marlan B.; Hatfield, Donald W.

    1989-09-01

    The development and demonstration of the High Speed Data Bus system, a 50 Million bits per second (Mbps) local data network intended for avionics applications in advanced military aircraft is described. The Advanced System Avionics (ASA)/PAVE PILLAR program provided the avionics architecture concept and basic requirements. Designs for wire and fiber optic media were produced and hardware demonstrations were performed. An efficient, robust token-passing protocol was developed and partially demonstrated. The requirements specifications, the trade-offs made, and the resulting designs for both a coaxial wire media system and a fiber optics design are examined. Also, the development of a message-oriented media access protocol is described, from requirements definition through analysis, simulation and experimentation. Finally, the testing and demonstrations conducted on the breadboard and brassboard hardware is presented.

  20. A novel optical apparatus for the study of rolling contact wear/fatigue based on a high-speed camera and multiple-source laser illumination.

    PubMed

    Bodini, I; Sansoni, G; Lancini, M; Pasinetti, S; Docchio, F

    2016-08-01

    Rolling contact wear/fatigue tests on wheel/rail specimens are important to produce wheels and rails of new materials for improved lifetime and performance, which are able to operate in harsh environments and at high rolling speeds. This paper presents a novel non-invasive, all-optical system, based on a high-speed video camera and multiple laser illumination sources, which is able to continuously monitor the dynamics of the specimens used to test wheel and rail materials, in a laboratory test bench. 3D macro-topography and angular position of the specimen are simultaneously performed, together with the acquisition of surface micro-topography, at speeds up to 500 rpm, making use of a fast camera and image processing algorithms. Synthetic indexes for surface micro-topography classification are defined, the 3D macro-topography is measured with a standard uncertainty down to 0.019 mm, and the angular position is measured on a purposely developed analog encoder with a standard uncertainty of 2.9°. The very small camera exposure time enables to obtain blur-free images with excellent definition. The system will be described with the aid of end-cycle specimens, as well as of in-test specimens. PMID:27587125

  1. The Repeatability Assessment of Three-Dimensional Capsule-Intraocular Lens Complex Measurements by Means of High-Speed Swept-Source Optical Coherence Tomography

    PubMed Central

    Chang, Pingjun; Li, Jin; Savini, Giacomo; Huang, Jinhai; Huang, Shenghai; Zhao, Yinying; Liao, Na; Lin, Lei; Yu, Xiaoyu; Zhao, Yun-e

    2015-01-01

    Purpose To rebuild the three-dimensional (3-D) model of the anterior segment by high-speed swept-source optical coherence tomography (SSOCT) and evaluate the repeatability of measurement for the parameters of capsule-intraocular lens (C-IOL) complex. Methods Twenty-two pseudophakic eyes from 22 patients were enrolled. Three continuous SSOCT measurements were performed in all eyes and the tomograms obtained were used for 3-D reconstruction. The output data were used to evaluate the measurement repeatability. The parameters included postoperative aqueous depth (PAD), the area and diameter of the anterior capsule opening (Area and D), IOL tilt (IOL-T), horizontal, vertical, and space decentration of the IOL, anterior capsule opening, and IOL-anterior capsule opening. Results PAD, IOL-T, Area, D, and all decentration measurements showed high repeatability. Repeated measure analysis showed there was no statistically significant difference among the three continuous measurements (all P > .05). Pearson correlation analysis showed high correlation between each pair of them (all r >0.90, P<0.001). ICCs were all more than 0.9 for all parameters. The 95% LoAs of all parameters were narrow for comparison of three measurements, which showed high repeatability for three measurements. Conclusion SSOCT is available to be a new method for the 3-D measurement of C-IOL complex after cataract surgery. This method presented high repeatability in measuring the parameters of the C-IOL complex. PMID:26600254

  2. A novel optical apparatus for the study of rolling contact wear/fatigue based on a high-speed camera and multiple-source laser illumination.

    PubMed

    Bodini, I; Sansoni, G; Lancini, M; Pasinetti, S; Docchio, F

    2016-08-01

    Rolling contact wear/fatigue tests on wheel/rail specimens are important to produce wheels and rails of new materials for improved lifetime and performance, which are able to operate in harsh environments and at high rolling speeds. This paper presents a novel non-invasive, all-optical system, based on a high-speed video camera and multiple laser illumination sources, which is able to continuously monitor the dynamics of the specimens used to test wheel and rail materials, in a laboratory test bench. 3D macro-topography and angular position of the specimen are simultaneously performed, together with the acquisition of surface micro-topography, at speeds up to 500 rpm, making use of a fast camera and image processing algorithms. Synthetic indexes for surface micro-topography classification are defined, the 3D macro-topography is measured with a standard uncertainty down to 0.019 mm, and the angular position is measured on a purposely developed analog encoder with a standard uncertainty of 2.9°. The very small camera exposure time enables to obtain blur-free images with excellent definition. The system will be described with the aid of end-cycle specimens, as well as of in-test specimens.

  3. Light weight, high-speed, and self-powered wireless fiber optic sensor (WiFOS) structural health monitor system for avionics and aerospace environments

    NASA Astrophysics Data System (ADS)

    Mendoza, Edgar A.; Kempen, Cornelia; Sun, Sunjian; Esterkin, Yan

    2014-09-01

    This paper describes recent progress towards the development of an innovative light weight, high-speed, and selfpowered wireless fiber optic sensor (WiFOS™) structural health monitor system suitable for the onboard and in-flight unattended detection, localization, and classification of load, fatigue, and structural damage in advanced composite materials commonly used in avionics and aerospace systems. The WiFOS™ system is based on ROI's advancements on monolithic photonic integrated circuit microchip technology, integrated with smart power management, on-board data processing, wireless data transmission optoelectronics, and self-power using energy harvesting tools such as solar, vibration, thermoelectric, and magneto-electric. The self-powered, wireless WiFOS™ system offers a versatile and powerful SHM tool to enhance the reliability and safety of avionics platforms, jet fighters, helicopters, commercial aircraft that use lightweight composite material structures, by providing comprehensive information about the structural integrity of the structure from a large number of locations. Immediate SHM applications are found in rotorcraft and aircraft, ships, submarines, and in next generation weapon systems, and in commercial oil and petrochemical, aerospace industries, civil structures, power utilities, portable medical devices, and biotechnology, homeland security and a wide spectrum of other applications.

  4. A novel optical apparatus for the study of rolling contact wear/fatigue based on a high-speed camera and multiple-source laser illumination

    NASA Astrophysics Data System (ADS)

    Bodini, I.; Sansoni, G.; Lancini, M.; Pasinetti, S.; Docchio, F.

    2016-08-01

    Rolling contact wear/fatigue tests on wheel/rail specimens are important to produce wheels and rails of new materials for improved lifetime and performance, which are able to operate in harsh environments and at high rolling speeds. This paper presents a novel non-invasive, all-optical system, based on a high-speed video camera and multiple laser illumination sources, which is able to continuously monitor the dynamics of the specimens used to test wheel and rail materials, in a laboratory test bench. 3D macro-topography and angular position of the specimen are simultaneously performed, together with the acquisition of surface micro-topography, at speeds up to 500 rpm, making use of a fast camera and image processing algorithms. Synthetic indexes for surface micro-topography classification are defined, the 3D macro-topography is measured with a standard uncertainty down to 0.019 mm, and the angular position is measured on a purposely developed analog encoder with a standard uncertainty of 2.9°. The very small camera exposure time enables to obtain blur-free images with excellent definition. The system will be described with the aid of end-cycle specimens, as well as of in-test specimens.

  5. A high-density EEG study of differences between three high speeds of simulated forward motion from optic flow in adult participants

    PubMed Central

    Vilhelmsen, Kenneth; van der Weel, F. R. (Ruud); van der Meer, Audrey L. H.

    2015-01-01

    A high-density EEG study was conducted to investigate evoked and oscillatory brain activity in response to high speeds of simulated forward motion. Participants were shown an optic flow pattern consisting of a virtual road with moving poles at either side of it, simulating structured forward motion at different driving speeds (25, 50, and 75 km/h) with a static control condition between each motion condition. Significant differences in N2 latencies and peak amplitudes between the three speeds of visual motion were found in parietal channels of interest P3 and P4. As motion speed increased, peak latency increased while peak amplitude decreased which might indicate that higher driving speeds are perceived as more demanding resulting in longer latencies, and as fewer neurons in the motion sensitive areas of the adult brain appear to be attuned to such high visual speeds this could explain the observed inverse relationship between speed and amplitude. In addition, significant differences between alpha de-synchronizations for forward motion and alpha synchronizations in the static condition were found in the parietal midline (PM) source. It was suggested that the alpha de-synchronizations reflect an activated state related to the visual processing of simulated forward motion, whereas the alpha synchronizations in response to the static condition reflect a deactivated resting period. PMID:26578903

  6. HIGH SPEED CAMERA

    DOEpatents

    Rogers, B.T. Jr.; Davis, W.C.

    1957-12-17

    This patent relates to high speed cameras having resolution times of less than one-tenth microseconds suitable for filming distinct sequences of a very fast event such as an explosion. This camera consists of a rotating mirror with reflecting surfaces on both sides, a narrow mirror acting as a slit in a focal plane shutter, various other mirror and lens systems as well as an innage recording surface. The combination of the rotating mirrors and the slit mirror causes discrete, narrow, separate pictures to fall upon the film plane, thereby forming a moving image increment of the photographed event. Placing a reflecting surface on each side of the rotating mirror cancels the image velocity that one side of the rotating mirror would impart, so as a camera having this short a resolution time is thereby possible.

  7. High speed civil transport

    NASA Technical Reports Server (NTRS)

    Bogardus, Scott; Loper, Brent; Nauman, Chris; Page, Jeff; Parris, Rusty; Steinbach, Greg

    1990-01-01

    The design process of the High Speed Civil Transport (HSCT) combines existing technology with the expectation of future technology to create a Mach 3.0 transport. The HSCT was designed to have a range in excess of 6000 nautical miles and carry up to 300 passengers. This range will allow the HSCT to service the economically expanding Pacific Basin region. Effort was made in the design to enable the aircraft to use conventional airports with standard 12,000 foot runways. With a takeoff thrust of 250,000 pounds, the four supersonic through-flow engines will accelerate the HSCT to a cruise speed of Mach 3.0. The 679,000 pound (at takeoff) HSCT is designed to cruise at an altitude of 70,000 feet, flying above most atmospheric disturbances.

  8. High-speed, bi-directional dual-core fiber transmission system for high-density, short-reach optical interconnects

    NASA Astrophysics Data System (ADS)

    Geng, Ying; Li, Shenping; Li, Ming-Jun; Sutton, Clifford G.; McCollum, Robert L.; McClure, Randy L.; Koklyushkin, Alexander V.; Matthews, Karen I.; Luther, James P.; Butler, Douglas L.

    2015-03-01

    A complete single mode dual-core fiber system for short-reach optical interconnects is fabricated and tested for high-speed data transmission. It includes dual-core fibers capable of bi-directional data transmission, dual-core simplex LC connectors, and fan-outs. The transmission system offers simplified bi-directional traffic engineering with integrated bidirectional transceivers and compact system design, utilizing simplex dual-core LC connectors that use half the space while increasing the bandwidth density by a factor of two. The fiber has two cores that are compatible with single mode fiber and conforms to the industry standard outer diameter of 125 μm. This reduces operational complexity by reducing the size and number of fibers, cables and connectors. Measured OTDR loss for both cores was 0.34 dB/km at 1310 nm and 0.19 dB/km at 1550 nm. Crosstalk for a piece of 5.8 km long dual-core fiber was measured to be below -75 dB at 1310 nm, and below -40 dB at 1550 nm. Both free-space optics fan-outs and tapered-fiber-coupler based MCF fan-outs were evaluated for the transmission system. Error-free and penalty-free 25 Gb/s bi-directional transmission performance was demonstrated for three different fiber lengths, 200 m, 2 km and 10 km, using the complete all-fiber-based system including connectors and fan-outs. This single mode, dual-core fiber transmission system adds complementary value to systems where additional increases in bandwidth density can come from wavelength division multiplexing and multiple bits per symbol.

  9. High-speed, efficient metal - semiconductor - metal photodetectors

    SciTech Connect

    Collin, St; Pardo, F; Bardou, N; Pelouard, J.-L.; Averin, S V

    2010-08-03

    Design principles and the fabrication technique of highly efficient, high-speed photodetectors based on MSM nanostructures are developed. To efficiently confine light in the region of the strong field as well as to decrease light losses due to reflection from the diode contacts, use is made of a nanoscale interdigital diffraction grating and a multilayer Bragg grating. Measurements of the reflection coefficients and the quantum efficiency for a multilayer structure are in good agreement with theoretical estimates. A record-high quantum efficiency (QE = 46 %) is obtained for high speed MSM photodetectors. The detector has a high spectral selectivity ({Delta}{lambda}{sub 1/2} = 17 nm) at a wavelength of 800 nm. Taking into account the diode capacitance and the drift time of photogenerated carriers, the performance of the detectors under study is {approx} 500 GHz. The low level of the dark current density in the structures under study (j={sup 1} pA {mu}m{sup -2}) makes it possible to realise on their basis highly sensitive, high-speed selective detectors of optical radiation.

  10. 25-Gbit/s burst-mode optical receiver using high-speed avalanche photodiode for 100-Gbit/s optical packet switching.

    PubMed

    Nada, Masahiro; Nakamura, Makoto; Matsuzaki, Hideaki

    2014-01-13

    25-Gbit/s error-free operation of an optical receiver is successfully demonstrated against burst-mode optical input signals without preambles. The receiver, with a high-sensitivity avalanche photodiode and burst-mode transimpedance amplifier, exhibits sufficient receiver sensitivity and an extremely quick response suitable for burst-mode operation in 100-Gbit/s optical packet switching.

  11. High-speed phosphor thermometry.

    PubMed

    Fuhrmann, N; Baum, E; Brübach, J; Dreizler, A

    2011-10-01

    Phosphor thermometry is a semi-invasive surface temperature measurement technique utilising the luminescence properties of doped ceramic materials. Typically, these phosphor materials are coated onto the object of interest and are excited by a short UV laser pulse. Up to now, primarily Q-switched laser systems with repetition rates of 10 Hz were employed for excitation. Accordingly, this diagnostic tool was not applicable to resolve correlated temperature transients at time scales shorter than 100 ms. This contribution reports on the first realisation of a high-speed phosphor thermometry system employing a highly repetitive laser in the kHz regime and a fast decaying phosphor. A suitable material was characterised regarding its temperature lifetime characteristic and its measurement precision. Additionally, the influence of laser power on the phosphor coating was investigated in terms of heating effects. A demonstration of this high-speed technique has been conducted inside the thermally highly transient system of an optically accessible internal combustion engine. Temperatures have been measured with a repetition rate of 6 kHz corresponding to one sample per crank angle degree at 1000 rpm. PMID:22047319

  12. High-speed phosphor thermometry

    NASA Astrophysics Data System (ADS)

    Fuhrmann, N.; Baum, E.; Brübach, J.; Dreizler, A.

    2011-10-01

    Phosphor thermometry is a semi-invasive surface temperature measurement technique utilising the luminescence properties of doped ceramic materials. Typically, these phosphor materials are coated onto the object of interest and are excited by a short UV laser pulse. Up to now, primarily Q-switched laser systems with repetition rates of 10 Hz were employed for excitation. Accordingly, this diagnostic tool was not applicable to resolve correlated temperature transients at time scales shorter than 100 ms. This contribution reports on the first realisation of a high-speed phosphor thermometry system employing a highly repetitive laser in the kHz regime and a fast decaying phosphor. A suitable material was characterised regarding its temperature lifetime characteristic and its measurement precision. Additionally, the influence of laser power on the phosphor coating was investigated in terms of heating effects. A demonstration of this high-speed technique has been conducted inside the thermally highly transient system of an optically accessible internal combustion engine. Temperatures have been measured with a repetition rate of 6 kHz corresponding to one sample per crank angle degree at 1000 rpm.

  13. High-speed phosphor thermometry.

    PubMed

    Fuhrmann, N; Baum, E; Brübach, J; Dreizler, A

    2011-10-01

    Phosphor thermometry is a semi-invasive surface temperature measurement technique utilising the luminescence properties of doped ceramic materials. Typically, these phosphor materials are coated onto the object of interest and are excited by a short UV laser pulse. Up to now, primarily Q-switched laser systems with repetition rates of 10 Hz were employed for excitation. Accordingly, this diagnostic tool was not applicable to resolve correlated temperature transients at time scales shorter than 100 ms. This contribution reports on the first realisation of a high-speed phosphor thermometry system employing a highly repetitive laser in the kHz regime and a fast decaying phosphor. A suitable material was characterised regarding its temperature lifetime characteristic and its measurement precision. Additionally, the influence of laser power on the phosphor coating was investigated in terms of heating effects. A demonstration of this high-speed technique has been conducted inside the thermally highly transient system of an optically accessible internal combustion engine. Temperatures have been measured with a repetition rate of 6 kHz corresponding to one sample per crank angle degree at 1000 rpm.

  14. III-V alloy heterostructure high speed avalanche photodiodes

    NASA Technical Reports Server (NTRS)

    Law, H. D.; Nakano, K.; Tomasetta, L. R.

    1979-01-01

    Heterostructure avalanche photodiodes have been successfully fabricated in several III-V alloy systems: GaAlAs/GaAs, GaAlSb/GaAlSb, and InGaAsP/InP. These diodes cover optical wavelengths from 0.4 to 1.8 micron. Early stages of development show very encouraging results. High speed response of less than 35 ps and high quantum efficiency more than 95 percent have been obtained. The dark currents and the excess avalanche noise are also dicussed. A direct comparison of GaAlSb, GaAlAsSb, and In GaAsP avalanche photodiodes is given.

  15. Optical realization of the dissipative quantum oscillator.

    PubMed

    Longhi, Stefano; Eaton, Shane M

    2016-04-15

    An optical realization of the damped quantum oscillator, based on transverse light dynamics in an optical resonator with slowly-moving mirrors, is theoretically suggested. The optical resonator setting provides a simple implementation of the time-dependent Caldirola-Kanai Hamiltonian of the dissipative quantum oscillator and enables the visualization of the effects of damped oscillations in the classical (ray optics) limit and wave packet collapse in the quantum (wave optics) regime.

  16. High speed packet switching

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This document constitutes the final report prepared by Proteon, Inc. of Westborough, Massachusetts under contract NAS 5-30629 entitled High-Speed Packet Switching (SBIR 87-1, Phase 2) prepared for NASA-Greenbelt, Maryland. The primary goal of this research project is to use the results of the SBIR Phase 1 effort to develop a sound, expandable hardware and software router architecture capable of forwarding 25,000 packets per second through the router and passing 300 megabits per second on the router's internal busses. The work being delivered under this contract received its funding from three different sources: the SNIPE/RIG contract (Contract Number F30602-89-C-0014, CDRL Sequence Number A002), the SBIR contract, and Proteon. The SNIPE/RIG and SBIR contracts had many overlapping requirements, which allowed the research done under SNIPE/RIG to be applied to SBIR. Proteon funded all of the work to develop new router interfaces other than FDDI, in addition to funding the productization of the router itself. The router being delivered under SBIR will be a fully product-quality machine. The work done during this contract produced many significant findings and results, summarized here and explained in detail in later sections of this report. The SNIPE/RIG contract was completed. That contract had many overlapping requirements with the SBIR contract, and resulted in the successful demonstration and delivery of a high speed router. The development that took place during the SNIPE/RIG contract produced findings that included the choice of processor and an understanding of the issues surrounding inter processor communications in a multiprocessor environment. Many significant speed enhancements to the router software were made during that time. Under the SBIR contract (and with help from Proteon-funded work), it was found that a single processor router achieved a throughput significantly higher than originally anticipated. For this reason, a single processor router was

  17. High speed laser tomography system.

    PubMed

    Samsonov, D; Elsaesser, A; Edwards, A; Thomas, H M; Morfill, G E

    2008-03-01

    A high speed laser tomography system was developed capable of acquiring three-dimensional (3D) images of optically thin clouds of moving micron-sized particles. It operates by parallel-shifting an illuminating laser sheet with a pair of galvanometer-driven mirrors and synchronously recording two-dimensional (2D) images of thin slices of the imaged volume. The maximum scanning speed achieved was 120,000 slices/s, sequences of 24 volume scans (up to 256 slices each) have been obtained. The 2D slices were stacked to form 3D images of the volume, then the positions of the particles were identified and followed in the consecutive scans. The system was used to image a complex plasma with particles moving at speeds up to cm/s.

  18. High speed laser tomography system.

    PubMed

    Samsonov, D; Elsaesser, A; Edwards, A; Thomas, H M; Morfill, G E

    2008-03-01

    A high speed laser tomography system was developed capable of acquiring three-dimensional (3D) images of optically thin clouds of moving micron-sized particles. It operates by parallel-shifting an illuminating laser sheet with a pair of galvanometer-driven mirrors and synchronously recording two-dimensional (2D) images of thin slices of the imaged volume. The maximum scanning speed achieved was 120,000 slices/s, sequences of 24 volume scans (up to 256 slices each) have been obtained. The 2D slices were stacked to form 3D images of the volume, then the positions of the particles were identified and followed in the consecutive scans. The system was used to image a complex plasma with particles moving at speeds up to cm/s. PMID:18377040

  19. High speed civil transport

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This report discusses the design and marketability of a next generation supersonic transport. Apogee Aeronautics Corporation has designated its High Speed Civil Transport (HSCT): Supercruiser HS-8. Since the beginning of the Concorde era, the general consensus has been that the proper time for the introduction of a next generation Supersonic Transport (SST) would depend upon the technical advances made in the areas of propulsion (reduction in emissions) and material composites (stronger, lighter materials). It is believed by many in the aerospace industry that these beforementioned technical advances lie on the horizon. With this being the case, this is the proper time to begin the design phase for the next generation HSCT. The design objective for a HSCT was to develop an aircraft that would be capable of transporting at least 250 passengers with baggage at a distance of 5500 nmi. The supersonic Mach number is currently unspecified. In addition, the design had to be marketable, cost effective, and certifiable. To achieve this goal, technical advances in the current SST's must be made, especially in the areas of aerodynamics and propulsion. As a result of these required aerodynamic advances, several different supersonic design concepts were reviewed.

  20. High Speed Ice Friction

    NASA Astrophysics Data System (ADS)

    Seymour-Pierce, Alexandra; Sammonds, Peter; Lishman, Ben

    2014-05-01

    Many different tribological experiments have been run to determine the frictional behaviour of ice at high speeds, ostensibly with the intention of applying results to everyday fields such as winter tyres and sports. However, experiments have only been conducted up to linear speeds of several metres a second, with few additional subject specific studies reaching speeds comparable to these applications. Experiments were conducted in the cold rooms of the Rock and Ice Physics Laboratory, UCL, on a custom built rotational tribometer based on previous literature designs. Preliminary results from experiments run at 2m/s for ice temperatures of 271 and 263K indicate that colder ice has a higher coefficient of friction, in accordance with the literature. These results will be presented, along with data from further experiments conducted at temperatures between 259-273K (in order to cover a wide range of the temperature dependent behaviour of ice) and speeds of 2-15m/s to produce a temperature-velocity-friction map for ice. The effect of temperature, speed and slider geometry on the deformation of ice will also be investigated. These speeds are approaching those exhibited by sports such as the luge (where athletes slide downhill on an icy track), placing the tribological work in context.

  1. High speed transition prediction

    NASA Technical Reports Server (NTRS)

    Gasperas, Gediminis

    1992-01-01

    The main objective of this work period was to develop, acquire and apply state-of-the-art tools for the prediction of transition at high speeds at NASA Ames. Although various stability codes as well as basic state codes were acquired, the development of a new Parabolized Stability Equation (PSE) code was minimal. The time that was initially allocated for development was used on other tasks, in particular for the Leading Edge Suction problem, in acquiring proficiency in various graphics tools, and in applying these tools to evaluate various Navier-Stokes and Euler solutions. The second objective of this work period was to attend the Transition and Turbulence Workshop at NASA Langley in July and August, 1991. A report on the Workshop follows. From July 8, 1991 to August 2, 1991, the author participated in the Transition and Turbulence Workshop at NASA Langley. For purposes of interest here, analysis can be said to consist of solving simplified governing equations by various analytical methods, such as asymptotic methods, or by use of very meager computer resources. From the composition of the various groups at the Workshop, it can be seen that analytical methods are generally more popular in Great Britain than they are in the U.S., possibly due to historical factors and the lack of computer resources. Experimenters at the Workshop were mostly concerned with subsonic flows, and a number of demonstrations were provided, among which were a hot-wire experiment to probe the boundary layer on a rotating disc, a hot-wire rake to map a free shear layer behind a cylinder, and the use of heating strips on a flat plate to control instability waves and consequent transition. A highpoint of the demonstrations was the opportunity to observe the rather noisy 'quiet' supersonic pilot tunnel in operation.

  2. Fabrication and integration of micro/nano-scale optical wire circuit arrays and devices for high-speed and compact optical printed circuit board (O-PCB) and VLSI photonic applications

    NASA Astrophysics Data System (ADS)

    Lee, El-Hang; Lee, S. G.; O, B. H.; Park, S. G.; Kim, K. H.; Kang, J. K.; Choi, Y. W.; Song, S. H.

    2005-09-01

    We report on the design, fabrication and integration of micro/nano-scale optical wire circuit arrays and devices for high-speed, compact, light-weight, low power optical printed circuit boards (O-PCBs) and VLSI photonic applications. The optical wires are formed in the form of waveguides by thermal embossing and ultraviolet (UV) radiated embossing of polymer materials. The photonic devices include vertically coupled surface emitting laser (VCSEL) microlasers, microlenses, 45-degree reflection couplers, directional couplers, arrayed waveguide grating structures, multimode interference (MMI) devices and photodetectors. These devices are optically interconnected and integrated for O-PCB assembly and VLSI micro/nano-photonics. The O-PCBs are to perform the functions of transporting, switching, routing and distributing optical signals on flat modular boards or substrates. We report on the result of the optical transmission performances of these assembled O-PCBs. For the design, fabrication, and VLSI integration of nano-scale photonic devices, we used photonic crystal structures and plasmonic metallic waveguide structures. We examined the bandwidth, power dissipation, thermal stability, weight, and the miniaturization and density of optical wires and the O-PCB module. Characteristics of these devices are also described.

  3. High-speed laser photography

    NASA Astrophysics Data System (ADS)

    Becker, Roger J.

    1988-08-01

    High-speed movies of solid propellant deflagration have long provided useful qualitative information on propellant behavior. Consequently, an extension of performance to include quantitative behavior of the surface, particularly the spatial relationship of particles across the surface, the temporal behavior of particles through extended periods of time, and accurate measurements of particle sizes, is highly desirable. Such measurements require the ability to take detailed movies across an extensive surface through the propellant flame for longer periods than the residence time of a given particle. The modulation transfer function (MTF) of the camera optics and film will greatly affect performance. The MTF of the optics can be improved by a factor of two or more at practical spatial frequencies by the use of monochromatic light, such as the reflected light from a laser. The use of an intense, short-pulsed laser has the additional advantage of suppressing flame brightness and motion blur. High resolution at unity magnification is achieved by the use of 2 mJ of illumination energy per pulse in conjunction with a fine-grain film. The surfaces of the wide-distribution propellants were found to be molten.

  4. Nonlinear optics quantum computing with circuit QED.

    PubMed

    Adhikari, Prabin; Hafezi, Mohammad; Taylor, J M

    2013-02-01

    One approach to quantum information processing is to use photons as quantum bits and rely on linear optical elements for most operations. However, some optical nonlinearity is necessary to enable universal quantum computing. Here, we suggest a circuit-QED approach to nonlinear optics quantum computing in the microwave regime, including a deterministic two-photon phase gate. Our specific example uses a hybrid quantum system comprising a LC resonator coupled to a superconducting flux qubit to implement a nonlinear coupling. Compared to the self-Kerr nonlinearity, we find that our approach has improved tolerance to noise in the qubit while maintaining fast operation.

  5. 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.

  6. High Speed Digital Camera Technology Review

    NASA Technical Reports Server (NTRS)

    Clements, Sandra D.

    2009-01-01

    A High Speed Digital Camera Technology Review (HSD Review) is being conducted to evaluate the state-of-the-shelf in this rapidly progressing industry. Five HSD cameras supplied by four camera manufacturers participated in a Field Test during the Space Shuttle Discovery STS-128 launch. Each camera was also subjected to Bench Tests in the ASRC Imaging Development Laboratory. Evaluation of the data from the Field and Bench Tests is underway. Representatives from the imaging communities at NASA / KSC and the Optical Systems Group are participating as reviewers. A High Speed Digital Video Camera Draft Specification was updated to address Shuttle engineering imagery requirements based on findings from this HSD Review. This draft specification will serve as the template for a High Speed Digital Video Camera Specification to be developed for the wider OSG imaging community under OSG Task OS-33.

  7. Quantum reading of unitary optical devices

    SciTech Connect

    Dall'Arno, Michele; Bisio, Alessandro; D'Ariano, Giacomo Mauro

    2014-12-04

    We address the problem of quantum reading of optical memories, namely the retrieving of classical information stored in the optical properties of a media with minimum energy. We present optimal strategies for ambiguous and unambiguous quantum reading of unitary optical memories, namely when one's task is to minimize the probability of errors in the retrieved information and when perfect retrieving of information is achieved probabilistically, respectively. A comparison of the optimal strategy with coherent probes and homodyne detection shows that the former saves orders of magnitude of energy when achieving the same performances. Experimental proposals for quantum reading which are feasible with present quantum optical technology are reported.

  8. High-speed pressure clamp.

    PubMed

    Besch, Stephen R; Suchyna, Thomas; Sachs, Frederick

    2002-10-01

    We built a high-speed, pneumatic pressure clamp to stimulate patch-clamped membranes mechanically. The key control element is a newly designed differential valve that uses a single, nickel-plated piezoelectric bending element to control both pressure and vacuum. To minimize response time, the valve body was designed with minimum dead volume. The result is improved response time and stability with a threefold decrease in actuation latency. Tight valve clearances minimize the steady-state air flow, permitting us to use small resonant-piston pumps to supply pressure and vacuum. To protect the valve from water contamination in the event of a broken pipette, an optical sensor detects water entering the valve and increases pressure rapidly to clear the system. The open-loop time constant for pressure is 2.5 ms for a 100-mmHg step, and the closed-loop settling time is 500-600 micros. Valve actuation latency is 120 micros. The system performance is illustrated for mechanically induced changes in patch capacitance.

  9. The Holy Grail of quantum optical communication

    SciTech Connect

    García-Patrón, Raúl; Navarrete-Benlloch, Carlos; Lloyd, Seth; Shapiro, Jeffrey H.; Cerf, Nicolas J.

    2014-12-04

    Optical parametric amplifiers together with phase-shifters and beamsplitters have certainly been the most studied objects in the field of quantum optics. Despite such an intensive study, optical parametric amplifiers still keep secrets from us. We will show how they hold the answer to one of the oldest problems in quantum communication theory, namely the calculation of the optimal communication rate of optical channels.

  10. High-Speed Operation of Interband Cascade Lasers

    NASA Technical Reports Server (NTRS)

    Soibel, Alexander; Hill, Cory J.; Keo, Sam A.; Wright, Malcom W.; Farr, William H.; Yang, Rui Q.; Liu, H. C.

    2010-01-01

    Optical sources operating in the atmospheric window of 3-5 microns are of particular interest for the development of free-space optical communication link. It is more advantageous to operate the free-space optical communication link in 3-5-microns atmospheric transmission window than at the telecom wavelength of 1.5 m due to lower optical scattering, scintillation, and background radiation. However, the realization of optical communications at the longer wavelength has encountered significant difficulties due to lack of adequate optical sources and detectors operating in the desirable wavelength regions. Interband Cascade (IC) lasers are novel semiconductor lasers that have a great potential for the realization of high-power, room-temperature optical sources in the 3-5-microns wavelength region, yet no experimental work, until this one, was done on high-speed direct modulation of IC lasers. Here, highspeed interband cascade laser, operating at wavelength 3.0 m, has been developed and the first direct measurement of the laser modulation bandwidth has been performed using a unique, highspeed quantum well infrared photodetector (QWIP). The developed laser has modulation bandwidth exceeding 3 GHz. This constitutes a significant increase of the IC laser modulation bandwidth over currently existing devices. This result has demonstrated suitability of IC lasers as a mid-IR light source for multi-GHz free-space optical communications links

  11. High-Speed Photography 101

    NASA Astrophysics Data System (ADS)

    Davidhazy, Andrew

    1997-05-01

    This paper describes the contents of a unique introductory, applications oriented, high speed photography course offered to Imaging and Photographic Technology majors at the Rochester Institute of Technology. The course covers the theory and practice of photographic systems designed to permit analysis of events of very short duration. Included are operational characteristics of intermittent and rotating prism cameras, rotating mirror and drum cameras, synchronization systems and timing controls and high speed flash and stroboscopic systems, and high speed video recording. Students gain basic experience not only in the use of fundamental equipment but also in proper planning, set-up and introductory data reduction techniques through a series of practical experiments.

  12. Overcoming quantum noise in optical fibers

    SciTech Connect

    Wu Lianao; Lidar, Daniel A.

    2004-12-01

    Noise in optical telecommunication fibers is an important limitation on optical quantum data transmission. Unfortunately, the classically successful amplifiers cannot be used in quantum communication because of the no-cloning theorem. We propose a simple method to reduce quantum noise: the insertion of phase shifters and/or beam splitters at regular distance intervals into a fiber. We analyze in detail the case of qubits encoded into polarization states of low-intensity light, which is of central importance to various quantum information tasks, such as quantum cryptography and communication. We discuss the experimental feasibility of our scheme and propose a simple experiment to test our method.

  13. Optical Fiber Sensing Using Quantum Dots

    PubMed Central

    Jorge, Pedro; Martins, Manuel António; Trindade, Tito; Santos, José Luís; Farahi, Faramarz

    2007-01-01

    Recent advances in the application of semiconductor nanocrystals, or quantum dots, as biochemical sensors are reviewed. Quantum dots have unique optical properties that make them promising alternatives to traditional dyes in many luminescence based bioanalytical techniques. An overview of the more relevant progresses in the application of quantum dots as biochemical probes is addressed. Special focus will be given to configurations where the sensing dots are incorporated in solid membranes and immobilized in optical fibers or planar waveguide platforms.

  14. Quantum correlations among optical and vibrational quanta

    NASA Astrophysics Data System (ADS)

    Carlig, Sergiu; Macovei, Mihai A.

    2014-05-01

    We investigate the feasibility of correlating an optical cavity field and a vibrational phonon mode. A laser pumped quantum dot fixed on a nanomechanical resonator beam interacts as a whole with the optical resonator mode. When the quantum dot variables are faster than the optical and phonon ones, we obtain a final master equation describing the involved modes only. Increasing the temperature, which directly affects the vibrational degrees of freedom, one can as well influence the cavity photon intensity, i.e., the optical and phonon modes are correlated. Furthermore, the corresponding Cauchy-Schwarz inequality is violated demonstrating the quantum nature of those correlations.

  15. A quantum optical firewall based on simple quantum devices

    NASA Astrophysics Data System (ADS)

    Amellal, H.; Meslouhi, A.; Hassouni, Y.; El Baz, M.

    2015-07-01

    In order to enhance the transmission security in quantum communications via coherent states, we propose a quantum optical firewall device to protect a quantum cryptosystem against eavesdropping through optical attack strategies. Similar to the classical model of the firewall, the proposed device gives legitimate users the possibility of filtering, controlling (input/output states) and making a decision (access or deny) concerning the traveling states. To prove the security and efficiency of the suggested optical firewall, we analyze its performances against the family of intercept and resend attacks, especially against one of the most prominent attack schemes known as "Faked State Attack."

  16. Functional quantum computing: An optical approach

    NASA Astrophysics Data System (ADS)

    Rambo, Timothy M.; Altepeter, Joseph B.; Kumar, Prem; D'Ariano, G. Mauro

    2016-05-01

    Recent theoretical investigations treat quantum computations as functions, quantum processes which operate on other quantum processes, rather than circuits. Much attention has been given to the N -switch function which takes N black-box quantum operators as input, coherently permutes their ordering, and applies the result to a target quantum state. This is something which cannot be equivalently done using a quantum circuit. Here, we propose an all-optical system design which implements coherent operator permutation for an arbitrary number of input operators.

  17. HIGH SPEED KERR CELL FRAMING CAMERA

    DOEpatents

    Goss, W.C.; Gilley, L.F.

    1964-01-01

    The present invention relates to a high speed camera utilizing a Kerr cell shutter and a novel optical delay system having no moving parts. The camera can selectively photograph at least 6 frames within 9 x 10/sup -8/ seconds during any such time interval of an occurring event. The invention utilizes particularly an optical system which views and transmits 6 images of an event to a multi-channeled optical delay relay system. The delay relay system has optical paths of successively increased length in whole multiples of the first channel optical path length, into which optical paths the 6 images are transmitted. The successively delayed images are accepted from the exit of the delay relay system by an optical image focusing means, which in turn directs the images into a Kerr cell shutter disposed to intercept the image paths. A camera is disposed to simultaneously view and record the 6 images during a single exposure of the Kerr cell shutter. (AEC)

  18. Monolithically integrated quantum dot optical modulator with semiconductor optical amplifier for thousand and original band optical communication

    NASA Astrophysics Data System (ADS)

    Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Matsumoto, Atsushi; Kawanishi, Tetsuya

    2016-04-01

    A monolithically integrated quantum dot (QD) optical gain modulator (OGM) with a QD semiconductor optical amplifier (SOA) was successfully developed with T-band (1.0 µm waveband) and O-band (1.3 µm waveband) QD optical gain materials for Gbps-order, high-speed optical data generation. The insertion loss due to coupling between the device and the optical fiber was effectively compensated for by the SOA section. It was also confirmed that the monolithic QD-OGM/SOA device enabled >4.8 Gbps optical data generation with a clear eye opening in the T-band. Furthermore, we successfully demonstrated error-free 4.8 Gbps optical data transmissions in each of the six wavelength channels over a 10-km-long photonic crystal fiber using the monolithic QD-OGM/SOA device in multiple O-band wavelength channels, which were generated by the single QD gain chip. These results suggest that the monolithic QD-OGM/SOA device will be advantageous in ultra-broadband optical frequency systems that utilize the T+O-band for short- and medium-range optical communications.

  19. Strongly correlated quantum walks in optical lattices

    NASA Astrophysics Data System (ADS)

    Preiss, Philipp M.; Ma, Ruichao; Tai, M. Eric; Lukin, Alexander; Rispoli, Matthew; Zupancic, Philip; Lahini, Yoav; Islam, Rajibul; Greiner, Markus

    2015-03-01

    Full control over the dynamics of interacting, indistinguishable quantum particles is an important prerequisite for the experimental study of strongly correlated quantum matter and the implementation of high-fidelity quantum information processing. We demonstrate such control over the quantum walk—the quantum mechanical analog of the classical random walk—in the regime where dynamics are dominated by interparticle interactions. Using interacting bosonic atoms in an optical lattice, we directly observed fundamental effects such as the emergence of correlations in two-particle quantum walks, as well as strongly correlated Bloch oscillations in tilted optical lattices. Our approach can be scaled to larger systems, greatly extending the class of problems accessible via quantum walks.

  20. Optical technologies for quantum information science

    NASA Astrophysics Data System (ADS)

    Kwiat, Paul G.; Altepeter, Joseph; Barreiro, Julio; Branning, David A.; Jeffrey, Evan R.; Peters, Nicholas; VanDevender, Aaron P.

    2004-02-01

    A number of optical technologies remain to be developed and optimized for various applications in quantum information processing, especially quantum communication. We will give an overview of our approach to some of these, including periodic heralded single-photon sources based on spontaneous parametric down-conversion, ultrabright sources of tunable entangled photons, near unit efficiency single- and multi-photon detectors based on an atomic vapor interaction, quantum state transducers based on high efficiency frequency up-conversion, and low-loss optical quantum memories.

  1. Practical Quantum Communication and Cryptography for WDM Optical Networks

    NASA Astrophysics Data System (ADS)

    Kumar, Prem

    2004-11-01

    Keeping in mind the ubiquitous standard optical fiber for long-distance transmission and the widespread availability of efficient active and passive fiber devices, we have been developing telecom-band resources for practical quantum communication and cryptography in wave-division-multiplexed (WDM) optical networks. In this talk I present our recent results on two fronts: i) telecom-band in-fiber entanglement generation, storage, and long-distance distribution and ii) quantum-noise protected high-speed data encryption through an optically-amplified WDM line. Along the first front, with our in-fiber entanglement source all four Bell states can be readily produced and we have demonstrated violation of Bell's inequalities by up to 10 standard deviations of measurement uncertainty. With such a source we have demonstrated storage of entanglement for up to 1/8 of a millisecond. Furthermore, when each photon of the entangled pair is propagated in separate 25km-long standard fibers, high visibility quantum interference is still observed, demonstrating that this system is capable of long-distance (> 50 km) entanglement distribution. Along the second front, we have implemented a new quantum cryptographic scheme, based on Yuen's KCQ protocol, in which the inherent quantum noise of coherent states of light is used to perform the cryptographic service of data encryption. In this scheme a legitimate receiver, with use of a short, shared, secret-key, executes a simple binary decision rule on every transmitted bit. An eavesdropper, on the other hand, who does not possess the secret-key, is subjected to an irreducible quantum uncertainty in each measurement, even with the use of ideal detectors. We have implemented this scheme to demonstrate quantum-noise-protected data encryption at 650 Mbps through a 200 km, in-line amplified, WDM line. The line simultaneously carried two 10 Gbps standard data channels, 100 GHz on either side of the encrypted channel, which shows that this scheme

  2. High-Speed Electrochemical Imaging.

    PubMed

    Momotenko, Dmitry; Byers, Joshua C; McKelvey, Kim; Kang, Minkyung; Unwin, Patrick R

    2015-09-22

    The design, development, and application of high-speed scanning electrochemical probe microscopy is reported. The approach allows the acquisition of a series of high-resolution images (typically 1000 pixels μm(-2)) at rates approaching 4 seconds per frame, while collecting up to 8000 image pixels per second, about 1000 times faster than typical imaging speeds used up to now. The focus is on scanning electrochemical cell microscopy (SECCM), but the principles and practicalities are applicable to many electrochemical imaging methods. The versatility of the high-speed scan concept is demonstrated at a variety of substrates, including imaging the electroactivity of a patterned self-assembled monolayer on gold, visualization of chemical reactions occurring at single wall carbon nanotubes, and probing nanoscale electrocatalysts for water splitting. These studies provide movies of spatial variations of electrochemical fluxes as a function of potential and a platform for the further development of high speed scanning with other electrochemical imaging techniques.

  3. SEAL FOR HIGH SPEED CENTRIFUGE

    DOEpatents

    Skarstrom, C.W.

    1957-12-17

    A seal is described for a high speed centrifuge wherein the centrifugal force of rotation acts on the gasket to form a tight seal. The cylindrical rotating bowl of the centrifuge contains a closure member resting on a shoulder in the bowl wall having a lower surface containing bands of gasket material, parallel and adjacent to the cylinder wall. As the centrifuge speed increases, centrifugal force acts on the bands of gasket material forcing them in to a sealing contact against the cylinder wall. This arrangememt forms a simple and effective seal for high speed centrifuges, replacing more costly methods such as welding a closure in place.

  4. Quantum cryptography over underground optical fibers

    SciTech Connect

    Hughes, R.J.; Luther, G.G.; Morgan, G.L.; Peterson, C.G.; Simmons, C.

    1996-05-01

    Quantum cryptography is an emerging technology in which two parties may simultaneously generated shared, secret cryptographic key material using the transmission of quantum states of light whose security is based on the inviolability of the laws of quantum mechanics. An adversary can neither successfully tap the key transmissions, nor evade detection, owing to Heisenberg`s uncertainty principle. In this paper the authors describe the theory of quantum cryptography, and the most recent results from their experimental system with which they are generating key material over 14-km of underground optical fiber. These results show that optical-fiber based quantum cryptography could allow secure, real-time key generation over ``open`` multi-km node-to-node optical fiber communications links between secure ``islands.``

  5. Ultrafast free electron quantum optics

    NASA Astrophysics Data System (ADS)

    Becker, Maria Gabriel

    Free electron quantum optics is an emerging sub-field of physics that uses laser light, often in combination with nano-structures, to manipulate electrons in free space. Integration of femtosecond lasers into this technology is facilitating the move of free electron quantum optics into the ultrafast regime. A vision for this technology is ultrahigh temporal resolution in free electron time-of-flight experiments. Such a system would make fundamental physics studies involving small forces accessible that are not feasible with current technology. Realization of this vision will require an ultrafast source and an ultrafast detection scheme. Tungsten nano-tip sources capable of generating sub-100 fs electron pulses are already in use in our lab. Elsewhere, this type of source has been reported to emit on a sub-cycle timescale. Following up on a proposed scheme for observing sub-cycle emission, a two-color interferometer has been built and pump-probe electron emission measurements have been performed. Other efforts to develop ultrafast sources have involved implementing additional control parameters. GaAs has been investigated as a possible ultrafast source of spin-polarized electrons, and tungsten nano-tips have been modified with an ion beam to create a double tip source. Spin control and transverse separation control are expected to make studies of Pauli degeneracy pressure possible. The temporal resolution of current electronic particle detectors is ~1 ns. Schemes involving the interaction of laser pulses with nanostructures could improve this resolution by several orders of magnitude. As a first step towards a femtosecond electron switch, the temporal resolution of a nano-fabricated plasmonic antenna has been measured in a femtosecond pump-probe experiment. The possibility of an ultrafast diffraction switch has also been analyzed for nonrelativistic and relativistic electrons. In an application of a free electron time-of-flight system, the prediction of

  6. Quantum ratchets for quantum communication with optical superlattices

    SciTech Connect

    Romero-Isart, Oriol; Garcia-Ripoll, Juan Jose

    2007-11-15

    We propose to use a quantum ratchet to transport quantum information in a chain of atoms trapped in an optical superlattice. The quantum ratchet is created by a continuous modulation of the optical superlattice which is periodic in time and in space. Though there is zero average force acting on the atoms, we show that indeed the ratchet effect permits atoms on even and odd sites to move along opposite directions. By loading the optical lattice with two-level bosonic atoms, this scheme permits us to perfectly transport a qubit or entangled state imprinted in one or more atoms to any desired position in the lattice. From the quantum computation point of view, the transport is achieved by a smooth concatenation of perfect swap gates. We analyze setups with noninteracting and interacting particles and in the latter case we use the tools of optimal control to design optimal modulations. We also discuss the feasibility of this method in current experiments.

  7. The High Speed Photometer for the Space Telescope

    NASA Technical Reports Server (NTRS)

    Bless, R. C.

    1982-01-01

    An overview of the high speed photometer (HSP), its optics and detectors, its electronics, its mechanical structure, and some observational considerations are presented. The capabilities and limitations of the HSP are outlined.

  8. High speed multiwire photon camera

    NASA Technical Reports Server (NTRS)

    Lacy, Jeffrey L. (Inventor)

    1989-01-01

    An improved multiwire proportional counter camera having particular utility in the field of clinical nuclear medicine imaging. The detector utilizes direct coupled, low impedance, high speed delay lines, the segments of which are capacitor-inductor networks. A pile-up rejection test is provided to reject confused events otherwise caused by multiple ionization events occurring during the readout window.

  9. High speed multiwire photon camera

    NASA Technical Reports Server (NTRS)

    Lacy, Jeffrey L. (Inventor)

    1991-01-01

    An improved multiwire proportional counter camera having particular utility in the field of clinical nuclear medicine imaging. The detector utilizes direct coupled, low impedance, high speed delay lines, the segments of which are capacitor-inductor networks. A pile-up rejection test is provided to reject confused events otherwise caused by multiple ionization events occuring during the readout window.

  10. High-speed pulse camera

    NASA Technical Reports Server (NTRS)

    Lawson, J. R.

    1968-01-01

    Miniaturized, 16 mm high speed pulse camera takes spectral photometric photographs upon instantaneous command. The design includes a low-friction, low-inertia film transport, a very thin beryllium shutter driven by a low-inertia stepper motor for minimum actuation time after a pulse command, and a binary encoder.

  11. Disturbance, the uncertainty principle and quantum optics

    NASA Technical Reports Server (NTRS)

    Martens, Hans; Demuynck, Willem M.

    1993-01-01

    It is shown how a disturbance-type uncertainty principle can be derived from an uncertainty principle for joint measurements. To achieve this, we first clarify the meaning of 'inaccuracy' and 'disturbance' in quantum mechanical measurements. The case of photon number and phase is treated as an example, and it is applied to a quantum non-demolition measurement using the optical Kerr effect.

  12. A self-assembled microbonded germanium/silicon heterojunction photodiode for 25 Gb/s high-speed optical interconnects

    PubMed Central

    Tseng, Chih-Kuo; Chen, Wei-Ting; Chen, Ku-Hung; Liu, Han-Din; Kang, Yimin; Na, Neil; Lee, Ming-Chang M.

    2013-01-01

    A novel technique using surface tension to locally bond germanium (Ge) on silicon (Si) is presented for fabricating high performance Ge/Si photodiodes. Surface tension is a cohesive force among liquid molecules that tends to bring contiguous objects in contact to maintain a minimum surface energy. We take advantage of this phenomenon to fabricate a heterojunction optoelectronic device where the lattice constants of joined semiconductors are different. A high-speed Ge/Si heterojunction waveguide photodiode is presented by microbonding a beam-shaped Ge, first grown by rapid-melt-growth (RMG) method, on top of a Si waveguide via surface tension. Excellent device performances such as an operating bandwidth of 17 GHz and a responsivity of 0.66 and 0.70 A/W at the reverse bias of −4 and −6 V, respectively, are demonstrated. This technique can be simply implemented via modern complementary metal-oxide-semiconductor (CMOS) fabrication technologies for integrating Ge on Si devices. PMID:24232956

  13. High speed data transmission at the Superconducting Super Collider

    SciTech Connect

    Leskovar, B.

    1990-04-01

    High speed data transmission using fiber optics in the data acquisition system of the Superconducting Super Collider has been investigated. Emphasis is placed on the high speed data transmission system overview, the local data network and on subassemblies, such as optical transmitters and receivers. Also, the performance of candidate subassemblies having a low power dissipation for the data acquisition system is discussed. 14 refs., 5 figs.

  14. Quantum and classical optics-emerging links

    NASA Astrophysics Data System (ADS)

    Eberly, J. H.; Qian, Xiao-Feng; Qasimi, Asma Al; Ali, Hazrat; Alonso, M. A.; Gutiérrez-Cuevas, R.; Little, Bethany J.; Howell, John C.; Malhotra, Tanya; Vamivakas, A. N.

    2016-06-01

    Quantum optics and classical optics are linked in ways that are becoming apparent as a result of numerous recent detailed examinations of the relationships that elementary notions of optics have with each other. These elementary notions include interference, polarization, coherence, complementarity and entanglement. All of them are present in both quantum and classical optics. They have historic origins, and at least partly for this reason not all of them have quantitative definitions that are universally accepted. This makes further investigation into their engagement in optics very desirable. We pay particular attention to effects that arise from the mere co-existence of separately identifiable and readily available vector spaces. Exploitation of these vector-space relationships are shown to have unfamiliar theoretical implications and new options for observation. It is our goal to bring emerging quantum-classical links into wider view and to indicate directions in which forthcoming and future work will promote discussion and lead to unified understanding.

  15. Quantum secured gigabit optical access networks

    NASA Astrophysics Data System (ADS)

    Fröhlich, Bernd; Dynes, James F.; Lucamarini, Marco; Sharpe, Andrew W.; Tam, Simon W.-B.; Yuan, Zhiliang; Shields, Andrew J.

    2015-12-01

    Optical access networks connect multiple endpoints to a common network node via shared fibre infrastructure. They will play a vital role to scale up the number of users in quantum key distribution (QKD) networks. However, the presence of power splitters in the commonly used passive network architecture makes successful transmission of weak quantum signals challenging. This is especially true if QKD and data signals are multiplexed in the passive network. The splitter introduces an imbalance between quantum signal and Raman noise, which can prevent the recovery of the quantum signal completely. Here we introduce a method to overcome this limitation and demonstrate coexistence of multi-user QKD and full power data traffic from a gigabit passive optical network (GPON) for the first time. The dual feeder implementation is compatible with standard GPON architectures and can support up to 128 users, highlighting that quantum protected GPON networks could be commonplace in the future.

  16. Quantum secured gigabit optical access networks

    PubMed Central

    Fröhlich, Bernd; Dynes, James F.; Lucamarini, Marco; Sharpe, Andrew W.; Tam, Simon W.-B.; Yuan, Zhiliang; Shields, Andrew J.

    2015-01-01

    Optical access networks connect multiple endpoints to a common network node via shared fibre infrastructure. They will play a vital role to scale up the number of users in quantum key distribution (QKD) networks. However, the presence of power splitters in the commonly used passive network architecture makes successful transmission of weak quantum signals challenging. This is especially true if QKD and data signals are multiplexed in the passive network. The splitter introduces an imbalance between quantum signal and Raman noise, which can prevent the recovery of the quantum signal completely. Here we introduce a method to overcome this limitation and demonstrate coexistence of multi-user QKD and full power data traffic from a gigabit passive optical network (GPON) for the first time. The dual feeder implementation is compatible with standard GPON architectures and can support up to 128 users, highlighting that quantum protected GPON networks could be commonplace in the future. PMID:26656307

  17. High sensitivity optically pumped quantum magnetometer.

    PubMed

    Tiporlini, Valentina; Alameh, Kamal

    2013-01-01

    Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz(½) over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz(½) in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz. PMID:23766716

  18. High Sensitivity Optically Pumped Quantum Magnetometer

    PubMed Central

    Tiporlini, Valentina; Alameh, Kamal

    2013-01-01

    Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz1/2 over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz1/2 in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz. PMID:23766716

  19. High sensitivity optically pumped quantum magnetometer.

    PubMed

    Tiporlini, Valentina; Alameh, Kamal

    2013-01-01

    Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz(½) over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz(½) in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz.

  20. High Speed Photometry for BUSCA

    NASA Astrophysics Data System (ADS)

    Cordes, O.; Reif, K.

    The camera BUSCA (Bonn University Simultaneous CAmera) is a standard instrument at the 2.2m telescope at Calar Alto Observatory (Spain) since 2001. At the moment some modifications of BUSCA are planned and partially realised. One major goal is the replacement of the old thick CCDs in the blue, yellow-green, and near-infrared channels. The newer CCDs have better cosmetics and performance in sensitivity. The other goal is to replace the old "Heidelberg"-style controller with a newly designed controller with the main focus on high-speed readout and on an advanced windowing mechanism. We present a theoretical analysis of the new controller design and its advantage in high speed photometry of rapidly pulsating stars. As an example PG1605+072 was chosen which was observed with BUSCA before in 2001 and 2002.

  1. Reversible optical-to-microwave quantum interface.

    PubMed

    Barzanjeh, Sh; Abdi, M; Milburn, G J; Tombesi, P; Vitali, D

    2012-09-28

    We describe a reversible quantum interface between an optical and a microwave field using a hybrid device based on their common interaction with a micromechanical resonator in a superconducting circuit. We show that, by employing state-of-the-art optoelectromechanical devices, one can realize an effective source of (bright) two-mode squeezing with an optical idler (signal) and a microwave signal, which can be used for high-fidelity transfer of quantum states between optical and microwave fields by means of continuous variable teleportation. PMID:23030075

  2. Implementation of a High-Speed FPGA and DSP Based FFT Processor for Improving Strain Demodulation Performance in a Fiber-Optic-Based Sensing System

    NASA Technical Reports Server (NTRS)

    Farley, Douglas L.

    2005-01-01

    NASA's Aviation Safety and Security Program is pursuing research in on-board Structural Health Management (SHM) technologies for purposes of reducing or eliminating aircraft accidents due to system and component failures. Under this program, NASA Langley Research Center (LaRC) is developing a strain-based structural health-monitoring concept that incorporates a fiber optic-based measuring system for acquiring strain values. This fiber optic-based measuring system provides for the distribution of thousands of strain sensors embedded in a network of fiber optic cables. The resolution of strain value at each discrete sensor point requires a computationally demanding data reduction software process that, when hosted on a conventional processor, is not suitable for near real-time measurement. This report describes the development and integration of an alternative computing environment using dedicated computing hardware for performing the data reduction. Performance comparison between the existing and the hardware-based system is presented.

  3. Narrow linewidth comb realized with a mode-locked fiber laser using an intra-cavity waveguide electro-optic modulator for high-speed control.

    PubMed

    Iwakuni, Kana; Inaba, Hajime; Nakajima, Yoshiaki; Kobayashi, Takumi; Hosaka, Kazumoto; Onae, Atsushi; Hong, Feng-Lei

    2012-06-18

    We have developed an optical frequency comb using a mode-locked fiber ring laser with an intra-cavity waveguide electro-optic modulator controlling the optical length in the laser cavity. The mode-locking is achieved with a simple ring configuration and a nonlinear polarization rotation mechanism. The beat note between the laser and a reference laser and the carrier envelope offset frequency of the comb were simultaneously phase locked with servo bandwidths of 1.3 MHz and 900 kHz, respectively. We observed an out-of-loop beat between two identical combs, and obtained a coherent δ-function peak with a signal to noise ratio of 70 dB/Hz.

  4. Cavity Quantum Electrodynamics: A Universal Quantum Optics Toolbox

    NASA Astrophysics Data System (ADS)

    Rempe, Gerhard

    2016-05-01

    Electromagnetic resonators provide unparalleled capabilities in controlling the interaction between light and matter. The recently developed techniques for trapping and cooling atoms between closely spaced mirrors now open up new experimental avenues for genuine quantum-mechanical experiments. Particularly exciting possibilities concern long-distance quantum networking and scalable quantum computation. Recent achievements like the nondestructive detection of an optical photon, the realization of a quantum gate between a single atom and a single photon, and the heralded and efficient conversion of a flying qubit into a stationary qubit are past highlights. The longstanding dream of a quantum gate between individually addressable photonic qubits might become reality in the future. The talk will summarize recent experiments and give an outlook onto future directions.

  5. High-speed multispectral confocal imaging

    NASA Astrophysics Data System (ADS)

    Carver, Gary E.; Locknar, Sarah A.; Morrison, William A.; Farkas, Daniel L.

    2013-02-01

    A new approach for generating high-speed multispectral images has been developed. The central concept is that spectra can be acquired for each pixel in a confocal spatial scan by using a fast spectrometer based on optical fiber delay lines. This concept merges fast spectroscopy with standard spatial scanning to create datacubes in real time. The spectrometer is based on a serial array of reflecting spectral elements, delay lines between these elements, and a single element detector. The spatial, spectral, and temporal resolution of the instrument is described, and illustrated by multispectral images of laser-induced autofluorescence in biological tissues.

  6. High-speed multispectral confocal biomedical imaging

    PubMed Central

    Carver, Gary E.; Locknar, Sarah A.; Morrison, William A.; Krishnan Ramanujan, V.; Farkas, Daniel L.

    2014-01-01

    Abstract. A new approach for generating high-speed multispectral confocal images has been developed. The central concept is that spectra can be acquired for each pixel in a confocal spatial scan by using a fast spectrometer based on optical fiber delay lines. This approach merges fast spectroscopy with standard spatial scanning to create datacubes in real time. The spectrometer is based on a serial array of reflecting spectral elements, delay lines between these elements, and a single element detector. The spatial, spectral, and temporal resolution of the instrument is described and illustrated by multispectral images of laser-induced autofluorescence in biological tissues. PMID:24658777

  7. High-Speed Ring Bus

    NASA Technical Reports Server (NTRS)

    Wysocky, Terry; Kopf, Edward, Jr.; Katanyoutananti, Sunant; Steiner, Carl; Balian, Harry

    2010-01-01

    The high-speed ring bus at the Jet Propulsion Laboratory (JPL) allows for future growth trends in spacecraft seen with future scientific missions. This innovation constitutes an enhancement of the 1393 bus as documented in the Institute of Electrical and Electronics Engineers (IEEE) 1393-1999 standard for a spaceborne fiber-optic data bus. It allows for high-bandwidth and time synchronization of all nodes on the ring. The JPL ring bus allows for interconnection of active units with autonomous operation and increased fault handling at high bandwidths. It minimizes the flight software interface with an intelligent physical layer design that has few states to manage as well as simplified testability. The design will soon be documented in the AS-1393 standard (Serial Hi-Rel Ring Network for Aerospace Applications). The framework is designed for "Class A" spacecraft operation and provides redundant data paths. It is based on "fault containment regions" and "redundant functional regions (RFR)" and has a method for allocating cables that completely supports the redundancy in spacecraft design, allowing for a complete RFR to fail. This design reduces the mass of the bus by incorporating both the Control Unit and the Data Unit in the same hardware. The standard uses ATM (asynchronous transfer mode) packets, standardized by ITU-T, ANSI, ETSI, and the ATM Forum. The IEEE-1393 standard uses the UNI form of the packet and provides no protection for the data portion of the cell. The JPL design adds optional formatting to this data portion. This design extends fault protection beyond that of the interconnect. This includes adding protection to the data portion that is contained within the Bus Interface Units (BIUs) and by adding to the signal interface between the Data Host and the JPL 1393 Ring Bus. Data transfer on the ring bus does not involve a master or initiator. Following bus protocol, any BIU may transmit data on the ring whenever it has data received from its host. There

  8. Quantum Computation Using Optically Coupled Quantum Dot Arrays

    NASA Technical Reports Server (NTRS)

    Pradhan, Prabhakar; Anantram, M. P.; Wang, K. L.; Roychowhury, V. P.; Saini, Subhash (Technical Monitor)

    1998-01-01

    A solid state model for quantum computation has potential advantages in terms of the ease of fabrication, characterization, and integration. The fundamental requirements for a quantum computer involve the realization of basic processing units (qubits), and a scheme for controlled switching and coupling among the qubits, which enables one to perform controlled operations on qubits. We propose a model for quantum computation based on optically coupled quantum dot arrays, which is computationally similar to the atomic model proposed by Cirac and Zoller. In this model, individual qubits are comprised of two coupled quantum dots, and an array of these basic units is placed in an optical cavity. Switching among the states of the individual units is done by controlled laser pulses via near field interaction using the NSOM technology. Controlled rotations involving two or more qubits are performed via common cavity mode photon. We have calculated critical times, including the spontaneous emission and switching times, and show that they are comparable to the best times projected for other proposed models of quantum computation. We have also shown the feasibility of accessing individual quantum dots using the NSOM technology by calculating the photon density at the tip, and estimating the power necessary to perform the basic controlled operations. We are currently in the process of estimating the decoherence times for this system; however, we have formulated initial arguments which seem to indicate that the decoherence times will be comparable, if not longer, than many other proposed models.

  9. High-Speed Tracking Method Using Zero Phase Error Tracking-Feed-Forward (ZPET-FF) Control for High-Data-Transfer-Rate Optical Disk Drives

    NASA Astrophysics Data System (ADS)

    Koide, Daiichi; Yanagisawa, Hitoshi; Tokumaru, Haruki; Nakamura, Shoichi; Ohishi, Kiyoshi; Inomata, Koichi; Miyazaki, Toshimasa

    2004-07-01

    We describe the effectiveness of feed-forward control using the zero phase error tracking method (ZPET-FF control) of the tracking servo for high-data-transfer-rate optical disk drives, as we are developing an optical disk system to replace the conventional professional videotape recorder for recording high-definition television signals for news gathering or producing broadcast contents. The optical disk system requires a high-data-transfer-rate of more than 200 Mbps and large recording capacity. Therefore, fast and precise track-following control is indispensable. Here, we compare the characteristics of ZPET-FF control with those of conventional feedback control or repetitive control. Experimental results show that ZPET-FF control is more precise than feedback control, and the residual tracking error level is achieved with a tolerance of 10 nm at a linear velocity of 26 m/s in the experimental setup using a blue-violet laser optical head and high-density media. The feasibility of achieving precise ZPET-FF control at 15000 rpm is also presented.

  10. A compact and high-speed plasmonic slot waveguide coupled with photonic waveguide based 2x2 electro-optic switch

    NASA Astrophysics Data System (ADS)

    Arya, Aditya; Manivasakan, R.

    2016-02-01

    We report an electro-optic switch at 1.55 μm wavelength based on Mach-Zehnder Interferometer (MZI) in which, the MZI arms and the input-output 3-dB couplers are designed using plasmonic and photonic waveguides re- spectively. More than 90% photons are successfully converted into surface plasmons through tapering the both photonic as well as plasmonic waveguide. The plasmonic and photonic mode profiles, interaction between plas- monic and RF fields, confinement of plasmonic field in plasmonic waveguide, and trade-off between loss and confinement are thoroughly examined before the combined optical and electrical simulation of the switch. The switching voltage is less than 6 Volts, the MZI arm length is only 15 μm, the crosstalk is less than -35 dB, and the maximum switching speed is 11.55 ps. The footprint of the switch is only 290x50 μm2.

  11. Mathematical simulation of an experimental prototype of a high-speed nonreturn-to-zero differential phase-shift-keying fibre-optic communication system

    SciTech Connect

    Redyuk, A A; Shtyrina, Ol'ga V; Nanii, Oleg E; Kapin, Yu A; Sachalin, E A; Titov, E B; Treshchikov, V N; Yaryshkin, A A; Fedoruk, Mikhail P

    2011-10-31

    The influence of chromatic dispersion, optical power, and nonlinear distortions in a fibre-optic communication system on the quality of data transmission based on nonreturn-to-zero differential phase-shift keying at a rate of 40 Gbit s{sup -1} in one spectral channel have been numerically simulated and experimental studied. The results of direct numerical calculations and estimates based on the quality factor (Q factor) are in qualitative agreement with the experimental data. It is found experimentally that the dependence of the error rate on the accumulated dispersion has a plateau in the range from -50 to 50 ps nm{sup -1}; a similar dependence is obtained in the numerical calculation based on the Q factor. The optimal calculated value of the power launched into each of 10 sections of a line with a total length of 1000 km is 2 - 4 dBm; it corresponds to the experimental value of 3 dBm.

  12. High-speed wavelength-swept lasers

    NASA Astrophysics Data System (ADS)

    Hsu, Kevin

    2006-05-01

    High-speed wavelength-swept lasers capable of providing wide frequency chirp and flexible temporal waveforms could enable numerous advanced functionalities for defense and security applications. Powered by high spectral intensity at rapid sweep rates across a wide wavelength range in each of the 1060nm, 1300nm, and 1550nm spectral windows, these swept-laser systems have demonstrated real-time monitoring and superior signal-to-noise ratio measurements in optical frequency domain imaging, fiber-optic sensor arrays, and near-IR spectroscopy. These same capabilities show promising potentials in laser radar and remote sensing applications. The core of the high-speed swept laser incorporates a semiconductor gain module and a high-performance fiber Fabry- Perot tunable filter (FFP-TF) to provide rapid wavelength scanning operations. This unique design embodies the collective advantages of the semiconductor amplifier's broad gain-bandwidth with direct modulation capability, and the FFP-TF's wide tuning ranges (>200nm), high finesse (1000 to 10,000), low-loss (<3dB), and fast scan rates reaching 20KHz. As a result, the laser can sweep beyond 100nm in 25μsec, output a scanning peak power near mW level, and exhibit excellent peak signal-to-spontaneous-emission ratio >80dB in static mode. When configured as a seed laser followed by post amplification, the swept spectrum and power can be optimized for Doppler ranging and remote sensing applications. Furthermore, when combined with a dispersive element, the wavelength sweep can be converted into high-speed and wide-angle spatial scanning without moving parts.

  13. Quantum optical properties in plasmonic systems

    SciTech Connect

    Ooi, C. H. Raymond

    2015-04-24

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

  14. Quantum Zeno effect in optical fibers

    NASA Astrophysics Data System (ADS)

    Yamane, K.; Ito, M.; Kitano, M.

    2001-06-01

    The quantum Zeno effect is a paradoxical phenomenon where the inhibition of transition or the guidance of system is realized with no losses in spite of the use of dissipative processes. It is universal and not limited to quantum systems. In this paper as a classical example we report the quantum Zeno effect in optical fibers. The fibers are spliced with transverse offset at fiber joints, and incident light transmits in the series of fibers. There are two kinds of light propagation modes in optical fibers - wave and ray modes. We find that the quantum Zeno effect appears only in the former mode and light is guided without power losses in the limit of the number of fiber joints N→∞ despite of the discontinuity at joints.

  15. Optically Loaded Semiconductor Quantum Memory Register

    NASA Astrophysics Data System (ADS)

    Kim, Danny; Kiselev, Andrey A.; Ross, Richard S.; Rakher, Matthew T.; Jones, Cody; Ladd, Thaddeus D.

    2016-02-01

    We propose and analyze an optically loaded quantum memory that exploits capacitive coupling between self-assembled quantum-dot molecules and electrically gated quantum-dot molecules. The self-assembled dots are used for spin-photon entanglement, which is transferred to the gated dots for long-term storage or processing via a teleportation process heralded by single-photon detection. We illustrate a device architecture enabling this interaction and outline both its operation and fabrication. We provide self-consistent Poisson-Schrödinger simulations to establish the design viability, to refine the design, and to estimate the physical coupling parameters and their sensitivities to dot placement. The device we propose generates heralded copies of an entangled state between a photonic qubit and a solid-state qubit with a rapid reset time upon failure. The resulting fast rate of entanglement generation is of high utility for heralded quantum networking scenarios involving lossy optical channels.

  16. Superplane! High Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The High Speed Civil Transport (HSCT). This light-hearted promotional piece explains what the HSCT 'Superplane' is and what advantages it will have over current aircraft. As envisioned, the HSCT is a next-generation supersonic (faster than the speed of sound) passenger jet that would fly 300 passengers at more than 1,500 miles per hour -- more than twice the speed of sound. It will cross the Pacific or Atlantic in less than half the time of modern subsonic jets, and at a ticket price less than 20 percent above comparable, slower flights

  17. High-Speed TCP Testing

    NASA Technical Reports Server (NTRS)

    Brooks, David E.; Gassman, Holly; Beering, Dave R.; Welch, Arun; Hoder, Douglas J.; Ivancic, William D.

    1999-01-01

    Transmission Control Protocol (TCP) is the underlying protocol used within the Internet for reliable information transfer. As such, there is great interest to have all implementations of TCP efficiently interoperate. This is particularly important for links exhibiting long bandwidth-delay products. The tools exist to perform TCP analysis at low rates and low delays. However, for extremely high-rate and lone-delay links such as 622 Mbps over geosynchronous satellites, new tools and testing techniques are required. This paper describes the tools and techniques used to analyze and debug various TCP implementations over high-speed, long-delay links.

  18. High speed quantitative digital microscopy

    NASA Technical Reports Server (NTRS)

    Castleman, K. R.; Price, K. H.; Eskenazi, R.; Ovadya, M. M.; Navon, M. A.

    1984-01-01

    Modern digital image processing hardware makes possible quantitative analysis of microscope images at high speed. This paper describes an application to automatic screening for cervical cancer. The system uses twelve MC6809 microprocessors arranged in a pipeline multiprocessor configuration. Each processor executes one part of the algorithm on each cell image as it passes through the pipeline. Each processor communicates with its upstream and downstream neighbors via shared two-port memory. Thus no time is devoted to input-output operations as such. This configuration is expected to be at least ten times faster than previous systems.

  19. Quantum metrology. Optically measuring force near the standard quantum limit.

    PubMed

    Schreppler, Sydney; Spethmann, Nicolas; Brahms, Nathan; Botter, Thierry; Barrios, Maryrose; Stamper-Kurn, Dan M

    2014-06-27

    The Heisenberg uncertainty principle sets a lower bound on the noise in a force measurement based on continuously detecting a mechanical oscillator's position. This bound, the standard quantum limit, can be reached when the oscillator subjected to the force is unperturbed by its environment and when measurement imprecision from photon shot noise is balanced against disturbance from measurement back-action. We applied an external force to the center-of-mass motion of an ultracold atom cloud in a high-finesse optical cavity and measured the resulting motion optically. When the driving force is resonant with the cloud's oscillation frequency, we achieve a sensitivity that is a factor of 4 above the standard quantum limit and consistent with theoretical predictions given the atoms' residual thermal disturbance and the photodetection quantum efficiency.

  20. Experimental quantum private queries with linear optics

    SciTech Connect

    De Martini, Francesco; Giovannetti, Vittorio; Lloyd, Seth; Maccone, Lorenzo; Nagali, Eleonora; Sansoni, Linda; Sciarrino, Fabio

    2009-07-15

    The quantum private query is a quantum cryptographic protocol to recover information from a database, preserving both user and data privacy: the user can test whether someone has retained information on which query was asked and the database provider can test the amount of information released. Here we discuss a variant of the quantum private query algorithm that admits a simple linear optical implementation: it employs the photon's momentum (or time slot) as address qubits and its polarization as bus qubit. A proof-of-principle experimental realization is implemented.

  1. Quantum optics of lossy asymmetric beam splitters

    NASA Astrophysics Data System (ADS)

    Uppu, Ravitej; Wolterink, Tom A. W.; Tentrup, Tristan B. H.; Pinkse, Pepijn W. H.

    2016-07-01

    We theoretically investigate quantum interference of two single photons at a lossy asymmetric beam splitter, the most general passive 2$\\times$2 optical circuit. The losses in the circuit result in a non-unitary scattering matrix with a non-trivial set of constraints on the elements of the scattering matrix. Our analysis using the noise operator formalism shows that the loss allows tunability of quantum interference to an extent not possible with a lossless beam splitter. Our theoretical studies support the experimental demonstrations of programmable quantum interference in highly multimodal systems such as opaque scattering media and multimode fibers.

  2. Quantum optics of lossy asymmetric beam splitters.

    PubMed

    Uppu, Ravitej; Wolterink, Tom A W; Tentrup, Tristan B H; Pinkse, Pepijn W H

    2016-07-25

    We theoretically investigate quantum interference of two single photons at a lossy asymmetric beam splitter, the most general passive 2×2 optical circuit. The losses in the circuit result in a non-unitary scattering matrix with a non-trivial set of constraints on the elements of the scattering matrix. Our analysis using the noise operator formalism shows that the loss allows tunability of quantum interference to an extent not possible with a lossless beam splitter. Our theoretical studies support the experimental demonstrations of programmable quantum interference in highly multimodal systems such as opaque scattering media and multimode fibers.

  3. Quantum state sharing using linear optical elements

    NASA Astrophysics Data System (ADS)

    Xia, Yan; Song, Jie; Song, He-Shan

    2008-10-01

    Motivated by protocols [G. Gordon, G. Rigolin, Phys. Rev. A 73 (2006) 062316] and [N.B. An, G. Mahler, Phys. Lett. A 365 (2007) 70], we propose a linear optical protocol for quantum state sharing of polarization entangled state in terms optical elements. Our protocol can realize a near-complete quantum state sharing of polarization entangled state with arbitrary coefficients, and it is possible to achieve unity fidelity transfer of the state if the parties collaborate. This protocol can also be generalized to the multi-party system.

  4. Sequential quantum teleportation of optical coherent states

    SciTech Connect

    Yonezawa, Hidehiro; Furusawa, Akira; Loock, Peter van

    2007-09-15

    We demonstrate a sequence of two quantum teleportations of optical coherent states, combining two high-fidelity teleporters for continuous variables. In our experiment, the individual teleportation fidelities are evaluated as F{sub 1}=0.70{+-}0.02 and F{sub 2}=0.75{+-}0.02, while the fidelity between the input and the sequentially teleported states is determined as F{sup (2)}=0.57{+-}0.02. This still exceeds the optimal fidelity of one half for classical teleportation of arbitrary coherent states and almost attains the value of the first (unsequential) quantum teleportation experiment with optical coherent states.

  5. Quantum Private Comparison Protocol with Linear Optics

    NASA Astrophysics Data System (ADS)

    Luo, Qing-bin; Yang, Guo-wu; She, Kun; Li, Xiaoyu

    2016-09-01

    In this paper, we propose an innovative quantum private comparison(QPC) protocol based on partial Bell-state measurement from the view of linear optics, which enabling two parties to compare the equality of their private information with the help of a semi-honest third party. Partial Bell-state measurement has been realized by using only linear optical elements in experimental measurement-device-independent quantum key distribution(MDI-QKD) schemes, which makes us believe that our protocol can be realized in the near future. The security analysis shows that the participants will not leak their private information.

  6. Quantum nonlinear optics: nonlinear optics meets the quantum world (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Boyd, Robert W.

    2016-02-01

    This presentation first reviews the historical development of the field of nonlinear optics, starting from its inception in 1961. It then reviews some of its more recent developments, including especially how nonlinear optics has become a crucial tool for the developing field of quantum technologies. Fundamental quantum processes enabled by nonlinear optics, such as the creation of squeezed and entangled light states, are reviewed. We then illustrate these concepts by means of specific applications, such as the development of secure communication systems based on the quantum states of light.

  7. Quantum Limits of Space-to-Ground Optical Communications

    NASA Technical Reports Server (NTRS)

    Hemmati, H.; Dolinar, S.

    2012-01-01

    Quantum limiting factors contributed by the transmitter, the optical channel, and the receiver of a space-to-ground optical communications link are described. Approaches to move toward the ultimate quantum limit are discussed.

  8. Tamper-indicating quantum optical seals

    SciTech Connect

    Humble, Travis S; Williams, Brian P

    2015-01-01

    Confidence in the means for identifying when tampering occurs is critical for containment and surveillance technologies. Fiber-optic seals have proven especially useful for actively surveying large areas or inventories due to the extended transmission range and flexible layout of fiber. However, it is reasonable to suspect that an intruder could tamper with a fiber-optic sensor by accurately replicating the light transmitted through the fiber. In this contribution, we demonstrate a novel approach to using fiber-optic seals for safeguarding large-scale inventories with increased confidence in the state of the seal. Our approach is based on the use of quantum mechanical phenomena to offer unprecedented surety in the authentication of the seal state. In particular, we show how quantum entangled photons can be used to monitor the integrity of a fiber-optic cable - the entangled photons serve as active sensing elements whose non-local correlations indicate normal seal operation. Moreover, we prove using the quantum no-cloning theorem that attacks against the quantum seal necessarily disturb its state and that these disturbances are immediately detected. Our quantum approach to seal authentication is based on physical principles alone and does not require the use of secret or proprietary information to ensure proper operation. We demonstrate an implementation of the quantum seal using a pair of entangled photons and we summarize our experimental results including the probability of detecting intrusions and the overall stability of the system design. We conclude by discussing the use of both free-space and fiber-based quantum seals for surveying large areas and inventories.

  9. Nonlinear quantum optics mediated by Rydberg interactions

    NASA Astrophysics Data System (ADS)

    Firstenberg, O.; Adams, C. S.; Hofferberth, S.

    2016-08-01

    By mapping the strong interaction between Rydberg excitations in ultra-cold atomic ensembles onto single photons via electromagnetically induced transparency, it is now possible to realize a medium which exhibits a strong optical nonlinearity at the level of individual photons. We review the theoretical concepts and the experimental state-of-the-art of this exciting new field, and discuss first applications in the field of all-optical quantum information processing.

  10. High speed photography and photonics applications: An underutilized technology

    SciTech Connect

    Paisley, D.L.

    1996-10-01

    Snapshot: Paisley describes the development of high-speed photography including the role of streak cameras, fiber optics, and lasers. Progress in this field has created a powerful tool for viewing such ultrafast processes as hypersonic events and ballistics. {copyright} {ital 1996 Optical Society of America.} [1047-6938-96-10-9939-04

  11. Small Scale High Speed Turbomachinery

    NASA Technical Reports Server (NTRS)

    London, Adam P. (Inventor); Droppers, Lloyd J. (Inventor); Lehman, Matthew K. (Inventor); Mehra, Amitav (Inventor)

    2015-01-01

    A small scale, high speed turbomachine is described, as well as a process for manufacturing the turbomachine. The turbomachine is manufactured by diffusion bonding stacked sheets of metal foil, each of which has been pre-formed to correspond to a cross section of the turbomachine structure. The turbomachines include rotating elements as well as static structures. Using this process, turbomachines may be manufactured with rotating elements that have outer diameters of less than four inches in size, and/or blading heights of less than 0.1 inches. The rotating elements of the turbomachines are capable of rotating at speeds in excess of 150 feet per second. In addition, cooling features may be added internally to blading to facilitate cooling in high temperature operations.

  12. High-speed data search

    NASA Technical Reports Server (NTRS)

    Driscoll, James N.

    1994-01-01

    The high-speed data search system developed for KSC incorporates existing and emerging information retrieval technology to help a user intelligently and rapidly locate information found in large textual databases. This technology includes: natural language input; statistical ranking of retrieved information; an artificial intelligence concept called semantics, where 'surface level' knowledge found in text is used to improve the ranking of retrieved information; and relevance feedback, where user judgements about viewed information are used to automatically modify the search for further information. Semantics and relevance feedback are features of the system which are not available commercially. The system further demonstrates focus on paragraphs of information to decide relevance; and it can be used (without modification) to intelligently search all kinds of document collections, such as collections of legal documents medical documents, news stories, patents, and so forth. The purpose of this paper is to demonstrate the usefulness of statistical ranking, our semantic improvement, and relevance feedback.

  13. Experiments on high speed ejectors

    NASA Technical Reports Server (NTRS)

    Wu, J. J.

    1986-01-01

    Experimental studies were conducted to investigate the flow and the performance of thrust augmenting ejectors for flight Mach numbers in the range of 0.5 to 0.8, primary air stagnation pressures up to 107 psig (738 kPa), and primary air stagnation temperatures up to 1250 F (677 C). The experiment verified the existence of the second solution ejector flow, where the flow after complete mixing is supersonic. Thrust augmentation in excess of 1.2 was demonstrated for both hot and cold primary jets. The experimental ejector performed better than the corresponding theoretical optimal first solution ejector, where the mixed flow is subsonic. Further studies are required to realize the full potential of the second solution ejector. The research program was started by the Flight Dynamics Research Corporation (FDRC) to investigate the characteristic of a high speed ejector which augments thrust of a jet at high flight speeds.

  14. High speed sampler and demultiplexer

    DOEpatents

    McEwan, T.E.

    1995-12-26

    A high speed sampling demultiplexer based on a plurality of sampler banks, each bank comprising a sample transmission line for transmitting an input signal, a strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates at respective positions along the sample transmission line for sampling the input signal in response to the strobe signal. Strobe control circuitry is coupled to the plurality of banks, and supplies a sequence of bank strobe signals to the strobe transmission lines in each of the plurality of banks, and includes circuits for controlling the timing of the bank strobe signals among the banks of samplers. Input circuitry is included for supplying the input signal to be sampled to the plurality of sample transmission lines in the respective banks. The strobe control circuitry can repetitively strobe the plurality of banks of samplers such that the banks of samplers are cycled to create a long sample length. Second tier demultiplexing circuitry is coupled to each of the samplers in the plurality of banks. The second tier demultiplexing circuitry senses the sample taken by the corresponding sampler each time the bank in which the sampler is found is strobed. A plurality of such samples can be stored by the second tier demultiplexing circuitry for later processing. Repetitive sampling with the high speed transient sampler induces an effect known as ``strobe kickout``. The sample transmission lines include structures which reduce strobe kickout to acceptable levels, generally 60 dB below the signal, by absorbing the kickout pulses before the next sampling repetition. 16 figs.

  15. High speed sampler and demultiplexer

    DOEpatents

    McEwan, Thomas E.

    1995-01-01

    A high speed sampling demultiplexer based on a plurality of sampler banks, each bank comprising a sample transmission line for transmitting an input signal, a strobe transmission line for transmitting a strobe signal, and a plurality of sampling gates at respective positions along the sample transmission line for sampling the input signal in response to the strobe signal. Strobe control circuitry is coupled to the plurality of banks, and supplies a sequence of bank strobe signals to the strobe transmission lines in each of the plurality of banks, and includes circuits for controlling the timing of the bank strobe signals among the banks of samplers. Input circuitry is included for supplying the input signal to be sampled to the plurality of sample transmission lines in the respective banks. The strobe control circuitry can repetitively strobe the plurality of banks of samplers such that the banks of samplers are cycled to create a long sample length. Second tier demultiplexing circuitry is coupled to each of the samplers in the plurality of banks. The second tier demultiplexing circuitry senses the sample taken by the corresponding sampler each time the bank in which the sampler is found is strobed. A plurality of such samples can be stored by the second tier demultiplexing circuitry for later processing. Repetitive sampling with the high speed transient sampler induces an effect known as "strobe kickout". The sample transmission lines include structures which reduce strobe kickout to acceptable levels, generally 60 dB below the signal, by absorbing the kickout pulses before the next sampling repetition.

  16. Topics in linear optical quantum computation

    NASA Astrophysics Data System (ADS)

    Glancy, Scott Charles

    This thesis covers several topics in optical quantum computation. A quantum computer is a computational device which is able to manipulate information by performing unitary operations on some physical system whose state can be described as a vector (or mixture of vectors) in a Hilbert space. The basic unit of information, called the qubit, is considered to be a system with two orthogonal states, which are assigned logical values of 0 and 1. Photons make excellent candidates to serve as qubits. They have little interactions with the environment. Many operations can be performed using very simple linear optical devices such as beam splitters and phase shifters. Photons can easily be processed through circuit-like networks. Operations can be performed in very short times. Photons are ideally suited for the long-distance communication of quantum information. The great difficulty in constructing an optical quantum computer is that photons naturally interact weakly with one another. This thesis first gives a brief review of two early approaches to optical quantum computation. It will describe how any discrete unitary operation can be performed using a single photon and a network of beam splitters, and how the Kerr effect can be used to construct a two photon logic gate. Second, this work provides a thorough introduction to the linear optical quantum computer developed by Knill, Laflamme, and Milburn. It then presents this author's results on the reliability of this scheme when implemented using imperfect photon detectors. This author finds that quantum computers of this sort cannot be built using current technology. Third, this dissertation describes a method for constructing a linear optical quantum computer using nearly orthogonal coherent states of light as the qubits. It shows how a universal set of logic operations can be performed, including calculations of the fidelity with which these operations may be accomplished. It discusses methods for reducing and

  17. Quantum optical implementation of Grover's algorithm

    PubMed Central

    Scully, Marlan O.; Zubairy, M. S.

    2001-01-01

    We present a scheme for a quantum optical implementation of Grover's algorithm based on resonant atomic interactions with classical fields and dispersive couplings with quantized cavity fields. The proposed scheme depends on preparation of entangled states and is within current state-of-the-art technology. PMID:11504938

  18. Excess optical quantum noise in atomic sensors

    NASA Astrophysics Data System (ADS)

    Novikova, Irina; Mikhailov, Eugeniy; Xiao, Yanhong

    2015-05-01

    Enhanced nonlinear optical response of a coherent atomic medium is the basis for many atomic sensors, and their performance is ultimately limited by the quantum fluctuations of the optical read-out. Here we demonstrate that off-resonant interactions can significantly modify the quantum noise of the optical field, even when their effect on the mean signal is negligible. We illustrate this concept by using an atomic magnetometer based on the nonlinear Faraday effect: the rotation of the light polarization is mainly determined by the resonant light-induced spin alignment, which alone does not change the photon statistics of the optical probe. Yet, we found that the minimum noise of output polarization rotation measurements is above the expected shot noise limit. This excess quantum noise is due to off-resonant coupling and grows with atomic density. We also show that the detection scheme can be modified to reduce the measured quantum noise (even below the shot-noise limit) but only at the expense of the reduced rotational sensitivity. These results show the existence of previously unnoticed factors in fundamental limitations in atomic magnetometry and could have impacts in many other atom-light based precision measurements. We acknowledge the support from AFOSR (grant FA9550-13-1-0098), NSF (grant PHY-1308281), NBRPC(973 Program Grant 2012CB921604 and 2011CB921604), and NNSFC (Grants No. 11322436).

  19. Violation of Bell's inequalities in quantum optics

    NASA Technical Reports Server (NTRS)

    Reid, M. D.; Walls, D. F.

    1984-01-01

    An optical field produced by intracavity four-wave mixing is shown to exhibit the following nonclassical features: photon antibunching, squeezing, and violation of Cauchy-Schwarz and Bell's inequalities. These intrinsic quantum mechanical effects are shown to be associated with the nonexistence of a positive normalizable Glauber-Sudarshan P function.

  20. Saturating optical resonances in quantum dots

    NASA Astrophysics Data System (ADS)

    Nair, Selvakumar V.; Rustagi, K. C.

    Optical bistability in quantum dots, recently proposed by Chemla and Miller, is studied in a two-resonance model. We show that for such classical electromagnetic resonances the applicability of a two-resonance model is far more restrictive than for those in atoms.

  1. Materials, structures, and devices for high-speed electronics

    NASA Astrophysics Data System (ADS)

    Woollam, John A.; Snyder, Paul G.

    1992-12-01

    Advances in materials, devices, and instrumentation made under this grant began with ex-situ null ellipsometric measurements of simple dielectric films on bulk substrates. Today highly automated and rapid spectroscopic ellipsometers are used for ex-situ characterization of very complex multilayer epitaxial structures. Even more impressive is the in-situ capability, not only for characterization but also for the actual control of the growth and etching of epitaxial layers. Spectroscopic ellipsometry has expanded from the research lab to become an integral part of the production of materials and structures for state of the art high speed devices. Along the way, it has contributed much to our understanding of the growth characteristics and material properties. The following areas of research are summarized: Si3N4 on GaAs, null ellipsometry; diamondlike carbon films; variable angle spectroscopic ellipsometry (VASE) development; GaAs-AlGaAs heterostructures; Ta-Cu diffusion barrier films on GaAs; GaAs-AlGaAs superlattices and multiple quantum wells; superconductivity; in situ elevated temperature measurements of III-V's; optical constants of thermodynamically stable InGaAs; doping dependence of optical constants of GaAs; in situ ellipsometric studies of III-V epitaxial growth; photothermal spectroscopy; microellipsometry; and Si passivation and Si/SiGe strained-layer superlattices.

  2. Materials, structures, and devices for high-speed electronics

    NASA Technical Reports Server (NTRS)

    Woollam, John A.; Snyder, Paul G.

    1992-01-01

    Advances in materials, devices, and instrumentation made under this grant began with ex-situ null ellipsometric measurements of simple dielectric films on bulk substrates. Today highly automated and rapid spectroscopic ellipsometers are used for ex-situ characterization of very complex multilayer epitaxial structures. Even more impressive is the in-situ capability, not only for characterization but also for the actual control of the growth and etching of epitaxial layers. Spectroscopic ellipsometry has expanded from the research lab to become an integral part of the production of materials and structures for state of the art high speed devices. Along the way, it has contributed much to our understanding of the growth characteristics and material properties. The following areas of research are summarized: Si3N4 on GaAs, null ellipsometry; diamondlike carbon films; variable angle spectroscopic ellipsometry (VASE) development; GaAs-AlGaAs heterostructures; Ta-Cu diffusion barrier films on GaAs; GaAs-AlGaAs superlattices and multiple quantum wells; superconductivity; in situ elevated temperature measurements of III-V's; optical constants of thermodynamically stable InGaAs; doping dependence of optical constants of GaAs; in situ ellipsometric studies of III-V epitaxial growth; photothermal spectroscopy; microellipsometry; and Si passivation and Si/SiGe strained-layer superlattices.

  3. Sub-Poissonian processes in quantum optics

    NASA Astrophysics Data System (ADS)

    Davidovich, Luiz

    1996-01-01

    The author reviews methods for generating sub-Poissonian light and related concepts. This light has energy fluctuations reduced below the level which corresponds to a classical Poissonian process (shot-noise level). After an introduction to the concept of nonclassical light, an overview is given of the main methods of quantum-noise reduction. Sub-Poissonian processes are exemplified in different areas of optics, ranging from single-atom resonance fluorescence to nonlinear optics, laser physics, and cavity quantum electrodynamics. Emphasis is placed on the conceptual foundations, and on developments in laser theory that lead to the possibility, already demonstrated experimentally, of linewidth narrowing and sub-Poissonian light generation in lasers and masers. The sources of quantum noise in these devices are analyzed, and four noise-suppression methods are discussed in detail: regularization of the pumping, suppression of spontaneous-emission noise, nonadiabatic evolution of the atomic variables, and twin-beam generation.

  4. On the nonlocal predictions of quantum optics

    NASA Technical Reports Server (NTRS)

    Marshall, Trevor W.; Santos, Emilio; Vidiella-Barranco, Antonio

    1994-01-01

    We give a definition of locality in quantum optics based upon Bell's work, and show that locality has been violated in no experiment performed up to now. We argue that the interpretation of the Wigner function as a probability density gives a very attractive local realistic picture of quantum optics provided that this function is nonnegative. We conjecture that this is the case for all states which can be realized in the laboratory. In particular, we believe that the usual representation of 'single photon states' by a Fock state of the Hilbert space is not correct and that a more physical, although less simple mathematically, representation involves density matrices. We study in some detail the experiment showing anticorrelation after a beam splitter and prove that it naturally involves a positive Wigner function. Our (quantum) predictions for this experiment disagree with the ones reported in the literature.

  5. Faster Is Better: High-Speed Modems.

    ERIC Educational Resources Information Center

    Roth, Cliff

    1995-01-01

    Discusses using high-speed modems to access the Internet. Examines internal and external modems, data speeds, compression and error reduction, faxing and voice capabilities, and software features. Considers ISDN (Integrated Services Digital Network) as the future replacement of high-speed modems. Sidebars present high-speed modem product…

  6. High-speed silicon modulator based on cascaded microring resonators.

    PubMed

    Hu, Yingtao; Xiao, Xi; Xu, Hao; Li, Xianyao; Xiong, Kang; Li, Zhiyong; Chu, Tao; Yu, Yude; Yu, Jinzhong

    2012-07-01

    A high-speed silicon modulator based on cascaded double microring resonators is demonstrated in this paper. The proposed modulator experimentally achieved 40 Gbit/s modulation with an extinction ratio of 3.9 dB. Enhancement of the modulator achieves with an ultra-high optical bandwidth of 0.41 nm, corresponding to 51 GHz, was accomplished by using cascaded double ring structure. The described modulator can provides an ultra-high-speed optical modulation with a further improvement in electrical bandwidth of the device. PMID:22772204

  7. The high speed bus technology development program

    NASA Astrophysics Data System (ADS)

    Ludvigson, M. T.; Modrow, M. B.; Goldman, P. C.

    The current development status of a high-speed data bus to link MIL-STD-1750A computers in avionics applications is reviewed and illustrated with diagrams and photographs. The bus requirements include data rate 50 Mb/s, a linear token-passing scheme permitting both electronic and fiber-optic implementation, up to 64-terminal capacity, maximum terminal separation 300 ft, latency control via token-rotation-timer priority, self-test and bus-loop test capability, and automatic clock synchronization. The design concept and performance of a breadboard wire bus tested in July 1986 are discussed in detail, with particular attention to the redundancy manager, the output controller, the input controller, the ringmaster topology manager, and typical initial-placement problems.

  8. Photovoltaic driven multiple quantum well optical modulator

    NASA Technical Reports Server (NTRS)

    Maserjian, Joseph (Inventor)

    1990-01-01

    Multiple quantum well (MQW) structures (12) are utilized to provide real-time, reliable, high-performance, optically-addressed spatial-light modulators (SLM) (10). The optically-addressed SLM comprises a vertical stack of quantum well layers (12a) within the penetration depth of an optical write signal 18, a plurality of space charge barriers (12b) having predetermined tunneling times by control of doping and thickness. The material comprising the quantum well layers has a lower bandgap than that of the space charge barrier layers. The write signal modulates a read signal (20). The modulation sensitivity of the device is high and no external voltage source is required. In a preferred embodiment, the SLM having interleaved doped semiconductor layers for driving the MQW photovoltaically is characterized by the use of a shift analogous to the Moss-Burnstein shift caused by the filling of two-dimensional states in the multiple quantum wells, thus allowing high modulation sensitivity in very narrow wells. Arrays (30) may be formed with a plurality of the modulators.

  9. High speed imager test station

    DOEpatents

    Yates, George J.; Albright, Kevin L.; Turko, Bojan T.

    1995-01-01

    A test station enables the performance of a solid state imager (herein called a focal plane array or FPA) to be determined at high image frame rates. A programmable waveform generator is adapted to generate clock pulses at determinable rates for clock light-induced charges from a FPA. The FPA is mounted on an imager header board for placing the imager in operable proximity to level shifters for receiving the clock pulses and outputting pulses effective to clock charge from the pixels forming the FPA. Each of the clock level shifters is driven by leading and trailing edge portions of the clock pulses to reduce power dissipation in the FPA. Analog circuits receive output charge pulses clocked from the FPA pixels. The analog circuits condition the charge pulses to cancel noise in the pulses and to determine and hold a peak value of the charge for digitizing. A high speed digitizer receives the peak signal value and outputs a digital representation of each one of the charge pulses. A video system then displays an image associated with the digital representation of the output charge pulses clocked from the FPA. In one embodiment, the FPA image is formatted to a standard video format for display on conventional video equipment.

  10. High speed imager test station

    DOEpatents

    Yates, G.J.; Albright, K.L.; Turko, B.T.

    1995-11-14

    A test station enables the performance of a solid state imager (herein called a focal plane array or FPA) to be determined at high image frame rates. A programmable waveform generator is adapted to generate clock pulses at determinable rates for clock light-induced charges from a FPA. The FPA is mounted on an imager header board for placing the imager in operable proximity to level shifters for receiving the clock pulses and outputting pulses effective to clock charge from the pixels forming the FPA. Each of the clock level shifters is driven by leading and trailing edge portions of the clock pulses to reduce power dissipation in the FPA. Analog circuits receive output charge pulses clocked from the FPA pixels. The analog circuits condition the charge pulses to cancel noise in the pulses and to determine and hold a peak value of the charge for digitizing. A high speed digitizer receives the peak signal value and outputs a digital representation of each one of the charge pulses. A video system then displays an image associated with the digital representation of the output charge pulses clocked from the FPA. In one embodiment, the FPA image is formatted to a standard video format for display on conventional video equipment. 12 figs.

  11. ADVANCED HIGH SPEED PROGRAMMABLE PREFORMING

    SciTech Connect

    Norris Jr, Robert E; Lomax, Ronny D; Xiong, Fue; Dahl, Jeffrey S; Blanchard, Patrick J

    2010-01-01

    Polymer-matrix composites offer greater stiffness and strength per unit weight than conventional materials resulting in new opportunities for lightweighting of automotive and heavy vehicles. Other benefits include design flexibility, less corrosion susceptibility, and the ability to tailor properties to specific load requirements. However, widespread implementation of structural composites requires lower-cost manufacturing processes than those that are currently available. Advanced, directed-fiber preforming processes have demonstrated exceptional value for rapid preforming of large, glass-reinforced, automotive composite structures. This is due to process flexibility and inherently low material scrap rate. Hence directed fiber performing processes offer a low cost manufacturing methodology for producing preforms for a variety of structural automotive components. This paper describes work conducted at the Oak Ridge National Laboratory (ORNL), focused on the development and demonstration of a high speed chopper gun to enhance throughput capabilities. ORNL and the Automotive Composites Consortium (ACC) revised the design of a standard chopper gun to expand the operational envelope, enabling delivery of up to 20kg/min. A prototype unit was fabricated and used to demonstrate continuous chopping of multiple roving at high output over extended periods. In addition fiber handling system modifications were completed to sustain the high output the modified chopper affords. These hardware upgrades are documented along with results of process characterization and capabilities assessment.

  12. Quiet High-Speed Fan

    NASA Technical Reports Server (NTRS)

    Lieber, Lysbeth; Repp, Russ; Weir, Donald S.

    1996-01-01

    A calibration of the acoustic and aerodynamic prediction methods was performed and a baseline fan definition was established and evaluated to support the quiet high speed fan program. A computational fluid dynamic analysis of the NASA QF-12 Fan rotor, using the DAWES flow simulation program was performed to demonstrate and verify the causes of the relatively poor aerodynamic performance observed during the fan test. In addition, the rotor flowfield characteristics were qualitatively compared to the acoustic measurements to identify the key acoustic characteristics of the flow. The V072 turbofan source noise prediction code was used to generate noise predictions for the TFE731-60 fan at three operating conditions and compared to experimental data. V072 results were also used in the Acoustic Radiation Code to generate far field noise for the TFE731-60 nacelle at three speed points for the blade passage tone. A full 3-D viscous flow simulation of the current production TFE731-60 fan rotor was performed with the DAWES flow analysis program. The DAWES analysis was used to estimate the onset of multiple pure tone noise, based on predictions of inlet shock position as a function of the rotor tip speed. Finally, the TFE731-60 fan rotor wake structure predicted by the DAWES program was used to define a redesigned stator with the leading edge configured to minimize the acoustic effects of rotor wake / stator interaction, without appreciably degrading performance.

  13. High-Speed Digital Interferometry

    NASA Technical Reports Server (NTRS)

    De Vine, Glenn; Shaddock, Daniel A.; Ware, Brent; Spero, Robert E.; Wuchenich, Danielle M.; Klipstein, William M.; McKenzie, Kirk

    2012-01-01

    Digitally enhanced heterodyne interferometry (DI) is a laser metrology technique employing pseudo-random noise (PRN) codes phase-modulated onto an optical carrier. Combined with heterodyne interferometry, the PRN code is used to select individual signals, returning the inherent interferometric sensitivity determined by the optical wavelength. The signal isolation arises from the autocorrelation properties of the PRN code, enabling both rejection of spurious signals (e.g., from scattered light) and multiplexing capability using a single metrology system. The minimum separation of optical components is determined by the wavelength of the PRN code.

  14. OPTICS. Quantum spin Hall effect of light.

    PubMed

    Bliokh, Konstantin Y; Smirnova, Daria; Nori, Franco

    2015-06-26

    Maxwell's equations, formulated 150 years ago, ultimately describe properties of light, from classical electromagnetism to quantum and relativistic aspects. The latter ones result in remarkable geometric and topological phenomena related to the spin-1 massless nature of photons. By analyzing fundamental spin properties of Maxwell waves, we show that free-space light exhibits an intrinsic quantum spin Hall effect—surface modes with strong spin-momentum locking. These modes are evanescent waves that form, for example, surface plasmon-polaritons at vacuum-metal interfaces. Our findings illuminate the unusual transverse spin in evanescent waves and explain recent experiments that have demonstrated the transverse spin-direction locking in the excitation of surface optical modes. This deepens our understanding of Maxwell's theory, reveals analogies with topological insulators for electrons, and offers applications for robust spin-directional optical interfaces. PMID:26113717

  15. OPTICS. Quantum spin Hall effect of light.

    PubMed

    Bliokh, Konstantin Y; Smirnova, Daria; Nori, Franco

    2015-06-26

    Maxwell's equations, formulated 150 years ago, ultimately describe properties of light, from classical electromagnetism to quantum and relativistic aspects. The latter ones result in remarkable geometric and topological phenomena related to the spin-1 massless nature of photons. By analyzing fundamental spin properties of Maxwell waves, we show that free-space light exhibits an intrinsic quantum spin Hall effect—surface modes with strong spin-momentum locking. These modes are evanescent waves that form, for example, surface plasmon-polaritons at vacuum-metal interfaces. Our findings illuminate the unusual transverse spin in evanescent waves and explain recent experiments that have demonstrated the transverse spin-direction locking in the excitation of surface optical modes. This deepens our understanding of Maxwell's theory, reveals analogies with topological insulators for electrons, and offers applications for robust spin-directional optical interfaces.

  16. Quantum memory in an optical lattice

    SciTech Connect

    Nunn, J.; Michelberger, P.; Reim, K. F.; Lee, K. C.; Langford, N. K.; Walmsley, I. A.; Dorner, U.; Jaksch, D.

    2010-08-15

    Arrays of atoms trapped in optical lattices are appealing as storage media for photons, since motional dephasing of the atoms is eliminated. The regular lattice is also associated with band structure in the dispersion experienced by incident photons. Here we study the influence of this band structure on the efficiency of quantum memories based on electromagnetically induced transparency (EIT) and on Raman absorption. We observe a number of interesting effects, such as both reduced and superluminal group velocities, enhanced atom-photon coupling, and anomalous transmission. These effects are ultimately deleterious to the memory efficiency, but they are easily avoided by tuning the optical fields away from the band edges.

  17. Quantum amplification and quantum optical tapping with squeezed states and correlated quantum states

    NASA Technical Reports Server (NTRS)

    Ou, Z. Y.; Pereira, S. F.; Kimble, H. J.

    1994-01-01

    Quantum fluctuations in a nondegenerate optical parametric amplifier (NOPA) are investigated experimentally with a squeezed state coupled into the internal idler mode of the NOPA. Reductions of the inherent quantum noise of the amplifier are observed with a minimum noise level 0.7 dB below the usual noise level of the amplifier with its idler mode in a vacuum state. With two correlated quantum fields as the amplifier's inputs and proper adjustment of the gain of the amplifier, it is shown that the amplifier's intrinsic quantum noise can be completely suppressed so that noise-free amplification is achieved. It is also shown that the NOPA, when coupled to either a squeezed state or a nonclassically correlated state, can realize quantum tapping of optical information.

  18. High-speed pulse-shape generator, pulse multiplexer

    DOEpatents

    Burkhart, Scott C.

    2002-01-01

    The invention combines arbitrary amplitude high-speed pulses for precision pulse shaping for the National Ignition Facility (NIF). The circuitry combines arbitrary height pulses which are generated by replicating scaled versions of a trigger pulse and summing them delayed in time on a pulse line. The combined electrical pulses are connected to an electro-optic modulator which modulates a laser beam. The circuit can also be adapted to combine multiple channels of high speed data into a single train of electrical pulses which generates the optical pulses for very high speed optical communication. The invention has application in laser pulse shaping for inertial confinement fusion, in optical data links for computers, telecommunications, and in laser pulse shaping for atomic excitation studies. The invention can be used to effect at least a 10.times. increase in all fiber communication lines. It allows a greatly increased data transfer rate between high-performance computers. The invention is inexpensive enough to bring high-speed video and data services to homes through a super modem.

  19. 850-nm Zn-diffusion vertical-cavity surface-emitting lasers with with oxide-relief structure for high-speed and energy-efficient optical interconnects from very-short to medium (2km) reaches

    NASA Astrophysics Data System (ADS)

    Shi, Jin-Wei; Wei, Chia-Chien; Chen, Jason (Jyehong); Yang, Ying-Jay

    2015-03-01

    High-speed and "green" ~850 nm vertical-cavity surface-emitting lasers (VCSELs) have lately attracted lots of attention due to their suitability for applications in optical interconnects (OIs). To further enhance the speed and its maximum allowable linking distance of VCSELs are two major trends to meet the requirement of OI in next generation data centers. Recently, by use of the advanced 850 nm VCSEL technique, data rate as high as 64 Gbit/sec over 57m and 20 Gbit/sec over 2km MMF transmission have been demonstrated, respectively. Here, we will review our recent work about 850 nm Zn-diffusion VCSELs with oxide-relief apertures to further enhance the above-mentioned performances. By using Zn-diffusion, we can not only reduce the device resistance but also manipulate the number of optical modes to benefit transmission. Combing such device, which has excellent single-mode (SMSR >30 dB) and high-power (~7mW) performance, with advanced modulation format (OFDM), record-high bit-rate-distance-product through MMF (2.3 km×28 Gbit/sec) has been demonstrated. Furthermore, by selective etching away the oxide aperture inside Zn-diffusion VCSEL, significant enhancement of device speed, D-factor, and reliability can be observed. With such unique VCSEL structure, >40 Gbit/sec energy-efficient transmission over 100m MMF under extremely low-driving current density (<10kA/cm2) has been successfully demonstrated.

  20. The Future Of High Speed Photography

    NASA Astrophysics Data System (ADS)

    Courtney-Pratt, J. S.

    1987-09-01

    The variety, range and precision of methods available for photographic recording of fast phenomena have been increasing steadily. The capabilities of the techniques are considered, classifying the methods by the kind of record obtained. descriptions of experimental techniques and apparatus, and illustrations, are given in earlier articles: "A Review of the Methods of High-Speed Photography," Reports on Progress in Physics in 1957; "Advances in High-Speed Photography 1957-1972," Proceedings of the Tenth International Congress on High-Speed Photography and also JSMPTE 82, pp. 167-175 (1973); "Advances in High-Speed Photograph, updated to 1983 in the Proceedings of SPIE Volume 427.

  1. Hubble Space Telescope, High Speed Photometer

    NASA Technical Reports Server (NTRS)

    1981-01-01

    This drawing illustrates the Hubble Space Telescope's (HST's) High Speed Photometer (HSP). The HSP measures the intensity of starlight (brightness), which will help determine astronomical distances. Its principal use will be to measure extremely-rapid variations or pulses in light from celestial objects, such as pulsating stars. The HSP produces brightness readings. Light passes into one of four special signal-multiplying tubes that record the data. The HSP can measure energy fluctuations from objects that pulsate as rapidly as once every 10 microseconds. From HSP data, astronomers expect to learn much about such mysterious objects as pulsars, black holes, and quasars. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors.

  2. High-Speed Fiber Switches

    NASA Astrophysics Data System (ADS)

    Margulis, Walter; Tarasenko, Oleksandr; Yu, Zhangwei; Fonjallaz, Pierre-Yves; Knape, Harald

    2008-10-01

    All-fiber optical switches based on fiber with electrodes exhibit transition times <10 ns. The devices are monolithic and robust, they are simple and could potentially be manufactured at low cost. The insertion loss is extremely low and the devices are compatible with single mode fiber technology. Two types of switches are discussed, one based on polarization rotation, the other one relying on the wavelength shift of a fiber Bragg grating (FBG).

  3. Investigation of fullerenes for high speed low latency, photonic switching

    SciTech Connect

    Lee, H. W. H; Shelton, R.N.

    1997-02-13

    The components in high-speed, all-optical photonic systems must satisfy two essential requirements: (1) high switching speeds in the range of Tbit/s, and (2) low latency, where the latency is the amount of time that the optical signal remains in the device. An important problem precluding the practical implementation of high-speed, all- optical switching is the lack of a material with appropriate nonlinear optical properties needed to effect the switching. Numerous material systems have been studied in the past, but none have met all the necessary requirements. Development of such a material and its incorporation into photonic devices would advance the field tremendously. This Lab-wide LDRD project resolved this critical problem.

  4. One-way quantum computing in the optical frequency comb.

    PubMed

    Menicucci, Nicolas C; Flammia, Steven T; Pfister, Olivier

    2008-09-26

    One-way quantum computing allows any quantum algorithm to be implemented easily using just measurements. The difficult part is creating the universal resource, a cluster state, on which the measurements are made. We propose a scalable method that uses a single, multimode optical parametric oscillator (OPO). The method is very efficient and generates a continuous-variable cluster state, universal for quantum computation, with quantum information encoded in the quadratures of the optical frequency comb of the OPO.

  5. Progress and issues for high-speed vertical cavity surface emitting lasers

    NASA Astrophysics Data System (ADS)

    Lear, Kevin L.; Al-Omari, Ahmad N.

    2007-02-01

    Extrinsic electrical, thermal, and optical issues rather than intrinsic factors currently constrain the maximum bandwidth of directly modulated vertical cavity surface emitting lasers (VCSELs). Intrinsic limits based on resonance frequency, damping, and K-factor analysis are summarized. Previous reports are used to compare parasitic circuit values and electrical 3dB bandwidths and thermal resistances. A correlation between multimode operation and junction heating with bandwidth saturation is presented. The extrinsic factors motivate modified bottom-emitting structures with no electrical pads, small mesas, copper plated heatsinks, and uniform current injection. Selected results on high speed quantum well and quantum dot VCSELs at 850 nm, 980 nm, and 1070 nm are reviewed including small-signal 3dB frequencies up to 21.5 GHz and bit rates up to 30 Gb/s.

  6. The WS2 quantum dot: preparation, characterization and its optical limiting effect in polymethylmethacrylate.

    PubMed

    Long, Hui; Tao, Lili; Chiu, Chun Pang; Tang, Chun Yin; Fung, Kin Hung; Chai, Yang; Tsang, Yuen Hong

    2016-10-14

    Due to the matching surface energy, WS2 quantum dots (QDs) can be obtained through direct liquid exfoliation in N-methyl-2-pyrrolidone rather than an ethanol and water mixture. Ultra-small WS2 QDs with a diameter of 2.4 nm are fabricated by an ultrasound method followed by high speed centrifugation up to 10 000 rpm. An excellent nonlinear optical (NLO) property of the WS2 QD/ polymethylmethacrylate (PMMA) composite for the nanosecond pulsed laser at both 532 and 1064 nm has been measured. Results illustrate the lower onset thresholds (F ON ), lower optical limiting thresholds (F OL ), and higher two-photon absorption coefficient (β) with respect to a higher concentration of embedded WS2 QDs into the PMMA solid state matrix for both 532 and 1064 nm.

  7. The WS2 quantum dot: preparation, characterization and its optical limiting effect in polymethylmethacrylate

    NASA Astrophysics Data System (ADS)

    Long, Hui; Tao, Lili; Chiu, Chun Pang; Tang, Chun Yin; Fung, Kin Hung; Chai, Yang; Tsang, Yuen Hong

    2016-10-01

    Due to the matching surface energy, WS2 quantum dots (QDs) can be obtained through direct liquid exfoliation in N-methyl-2-pyrrolidone rather than an ethanol and water mixture. Ultra-small WS2 QDs with a diameter of 2.4 nm are fabricated by an ultrasound method followed by high speed centrifugation up to 10 000 rpm. An excellent nonlinear optical (NLO) property of the WS2 QD/ polymethylmethacrylate (PMMA) composite for the nanosecond pulsed laser at both 532 and 1064 nm has been measured. Results illustrate the lower onset thresholds (F ON ), lower optical limiting thresholds (F OL ), and higher two-photon absorption coefficient (β) with respect to a higher concentration of embedded WS2 QDs into the PMMA solid state matrix for both 532 and 1064 nm.

  8. The WS2 quantum dot: preparation, characterization and its optical limiting effect in polymethylmethacrylate.

    PubMed

    Long, Hui; Tao, Lili; Chiu, Chun Pang; Tang, Chun Yin; Fung, Kin Hung; Chai, Yang; Tsang, Yuen Hong

    2016-10-14

    Due to the matching surface energy, WS2 quantum dots (QDs) can be obtained through direct liquid exfoliation in N-methyl-2-pyrrolidone rather than an ethanol and water mixture. Ultra-small WS2 QDs with a diameter of 2.4 nm are fabricated by an ultrasound method followed by high speed centrifugation up to 10 000 rpm. An excellent nonlinear optical (NLO) property of the WS2 QD/ polymethylmethacrylate (PMMA) composite for the nanosecond pulsed laser at both 532 and 1064 nm has been measured. Results illustrate the lower onset thresholds (F ON ), lower optical limiting thresholds (F OL ), and higher two-photon absorption coefficient (β) with respect to a higher concentration of embedded WS2 QDs into the PMMA solid state matrix for both 532 and 1064 nm. PMID:27607761

  9. High Speed Video for Airborne Instrumentation Application

    NASA Technical Reports Server (NTRS)

    Tseng, Ting; Reaves, Matthew; Mauldin, Kendall

    2006-01-01

    A flight-worthy high speed color video system has been developed. Extensive system development and ground and environmental. testing hes yielded a flight qualified High Speed Video System (HSVS), This HSVS was initially used on the F-15B #836 for the Lifting Insulating Foam Trajectory (LIFT) project.

  10. High-Speed Photography with Computer Control.

    ERIC Educational Resources Information Center

    Winters, Loren M.

    1991-01-01

    Describes the use of a microcomputer as an intervalometer for the control and timing of several flash units to photograph high-speed events. Applies this technology to study the oscillations of a stretched rubber band, the deceleration of high-speed projectiles in water, the splashes of milk drops, and the bursts of popcorn kernels. (MDH)

  11. Reducing Heating In High-Speed Cinematography

    NASA Technical Reports Server (NTRS)

    Slater, Howard A.

    1989-01-01

    Infrared-absorbing and infrared-reflecting glass filters simple and effective means for reducing rise in temperature during high-speed motion-picture photography. "Hot-mirror" and "cold-mirror" configurations, employed in projection of images, helps prevent excessive heating of scenes by powerful lamps used in high-speed photography.

  12. Tamper-indicating Quantum Optical Sensing

    NASA Astrophysics Data System (ADS)

    Humble, Travis; Earl, Duncan; Grice, Warren

    2011-05-01

    Monitoring systems based on fiber-optic seals actively monitor inventories of closed containers for tampering. However, the physics underlying these tamper-indicating optical systems make them susceptible to deception. The basis for this deception lies in the description of the electromagnetic field transmitted through the fiber. Within classical physics, knowledge of the light source, e.g., carrier frequency and pseudo-random modulation, can be used by an intruder to replicate the transmission. Once a replicated field is injected into the fiber, the downstream detector cannot discriminate it from the original transmission. Motivated by this context, we demonstrate a quantum optical, tamper-indicating device inherently immune to replication. We use time-bin entanglement (TBE) distributed through a pair of fibers, where each fiber couples to a Mach-Zehnder interferometer (MZI) detector. We monitor coincident detection as a function of the combined MZI phase φ =φ1 +φ2 to statistically quantify entanglement in terms of TBE visibility. The presence or absence of the expected interference consequently serves as a test for tampering, and we quantity the probability of detection and false alarm using this statistic. We anticipate this form of quantum-based sensing to support future intrusion detection technologies.

  13. Giant electro-optic effect in Ge/SiGe coupled quantum wells

    PubMed Central

    Frigerio, Jacopo; Vakarin, Vladyslav; Chaisakul, Papichaya; Ferretto, Marcello; Chrastina, Daniel; Le Roux, Xavier; Vivien, Laurent; Isella, Giovanni; Marris-Morini, Delphine

    2015-01-01

    Silicon-based photonics is now considered as the photonic platform for the next generation of on-chip communications. However, the development of compact and low power consumption optical modulators is still challenging. Here we report a giant electro-optic effect in Ge/SiGe coupled quantum wells. This promising effect is based on an anomalous quantum-confined Stark effect due to the separate confinement of electrons and holes in the Ge/SiGe coupled quantum wells. This phenomenon can be exploited to strongly enhance optical modulator performance with respect to the standard approaches developed so far in silicon photonics. We have measured a refractive index variation up to 2.3 × 10−3 under a bias voltage of 1.5 V, with an associated modulation efficiency VπLπ of 0.046 V cm. This demonstration paves the way for the development of efficient and high-speed phase modulators based on the Ge/SiGe material system. PMID:26477947

  14. Fibonacci optical lattices for tunable quantum quasicrystals

    NASA Astrophysics Data System (ADS)

    Singh, K.; Saha, K.; Parameswaran, S. A.; Weld, D. M.

    2015-12-01

    We describe a quasiperiodic optical lattice, created by a physical realization of the abstract cut-and-project construction underlying all quasicrystals. The resulting potential is a generalization of the Fibonacci tiling. Calculation of the energies and wave functions of ultracold atoms loaded into such a lattice demonstrate a multifractal energy spectrum, a singular continuous momentum-space structure, and the existence of controllable edge states. These results open the door to cold atom quantum simulation experiments in tunable or dynamic quasicrystalline potentials, including topological pumping of edge states and phasonic spectroscopy.

  15. High-Speed RaPToRS

    NASA Astrophysics Data System (ADS)

    Henchen, Robert; Esham, Benjamin; Becker, William; Pogozelski, Edward; Padalino, Stephen; Sangster, Thomas; Glebov, Vladimir

    2008-11-01

    The High-Speed Rapid Pneumatic Transport of Radioactive Samples (HS-RaPToRS) system, designed to quickly and safely move radioactive materials, was assembled and tested at the Mercury facility of the Naval Research Laboratory (NRL) in Washington D.C. A sample, which is placed inside a four-inch-diameter carrier, is activated before being transported through a PVC tube via airflow. The carrier travels from the reaction chamber to the end station where it pneumatically brakes prior to the gate. A magnetic latch releases the gate when the carrier arrives and comes to rest. The airflow, optical carrier-monitoring devices, and end gate are controlled manually or automatically with LabView software. The installation and testing of the RaPToRS system at NRL was successfully completed with transport times of less than 3 seconds. The speed of the carrier averaged 16 m/s. Prospective facilities for similar systems include the Laboratory for Laser Energetics and the National Ignition Facility.

  16. Sensor study for high speed autonomous operations

    NASA Astrophysics Data System (ADS)

    Schneider, Anne; La Celle, Zachary; Lacaze, Alberto; Murphy, Karl; Del Giorno, Mark; Close, Ryan

    2015-06-01

    As robotic ground systems advance in capabilities and begin to fulfill new roles in both civilian and military life, the limitation of slow operational speed has become a hindrance to the wide-spread adoption of these systems. For example, military convoys are reluctant to employ autonomous vehicles when these systems slow their movement from 60 miles per hour down to 40. However, these autonomous systems must operate at these lower speeds due to the limitations of the sensors they employ. Robotic Research, with its extensive experience in ground autonomy and associated problems therein, in conjunction with CERDEC/Night Vision and Electronic Sensors Directorate (NVESD), has performed a study to specify system and detection requirements; determined how current autonomy sensors perform in various scenarios; and analyzed how sensors should be employed to increase operational speeds of ground vehicles. The sensors evaluated in this study include the state of the art in LADAR/LIDAR, Radar, Electro-Optical, and Infrared sensors, and have been analyzed at high speeds to study their effectiveness in detecting and accounting for obstacles and other perception challenges. By creating a common set of testing benchmarks, and by testing in a wide range of real-world conditions, Robotic Research has evaluated where sensors can be successfully employed today; where sensors fall short; and which technologies should be examined and developed further. This study is the first step to achieve the overarching goal of doubling ground vehicle speeds on any given terrain.

  17. An elementary quantum network of single atoms in optical cavities.

    PubMed

    Ritter, Stephan; Nölleke, Christian; Hahn, Carolin; Reiserer, Andreas; Neuzner, Andreas; Uphoff, Manuel; Mücke, Martin; Figueroa, Eden; Bochmann, Joerg; Rempe, Gerhard

    2012-04-11

    Quantum networks are distributed quantum many-body systems with tailored topology and controlled information exchange. They are the backbone of distributed quantum computing architectures and quantum communication. Here we present a prototype of such a quantum network based on single atoms embedded in optical cavities. We show that atom-cavity systems form universal nodes capable of sending, receiving, storing and releasing photonic quantum information. Quantum connectivity between nodes is achieved in the conceptually most fundamental way-by the coherent exchange of a single photon. We demonstrate the faithful transfer of an atomic quantum state and the creation of entanglement between two identical nodes in separate laboratories. The non-local state that is created is manipulated by local quantum bit (qubit) rotation. This efficient cavity-based approach to quantum networking is particularly promising because it offers a clear perspective for scalability, thus paving the way towards large-scale quantum networks and their applications.

  18. Monolithically integrated quantum dot optical gain modulator with semiconductor optical amplifier for 10-Gb/s photonic transmission

    NASA Astrophysics Data System (ADS)

    Yamamoto, Naokatsu; Akahane, Kouichi; Umezawa, Toshimasa; Kawanishi, Tetsuya

    2015-03-01

    Short-range interconnection and/or data center networks require high capacity and a large number of channels in order to support numerous connections. Solutions employed to meet these requirements involve the use of alternative wavebands to increase the usable optical frequency range. We recently proposed the use of the T- and O-bands (Thousand band: 1000-1260 nm, Original band: 1260-1360 nm) as alternative wavebands because large optical frequency resources (>60 THz) can be easily employed. In addition, a simple and compact Gb/s-order high-speed optical modulator is a critical photonic device for short-range communications. Therefore, to develop an optical modulator that acts as a highfunctional photonic device, we focused on the use of self-assembled quantum dots (QDs) as a three-dimensional (3D) confined structure because QD structures are highly suitable for realizing broadband optical gain media in the T+O bands. In this study, we use the high-quality broadband QD optical gain to develop a monolithically integrated QD optical gain modulator (QD-OGM) device that has a semiconductor optical amplifier (QD-SOA) for Gb/s-order highspeed optical data generation in the 1.3-μm waveband. The insertion loss of the device can be compensated through the SOA, and we obtained an optical gain change of up to ~7 dB in the OGM section. Further, we successfully demonstrate a 10-Gb/s clear eye opening using the QD-OGM/SOA device with a clock-data recovery sequence at the receiver end. These results suggest that the monolithic QD-EOM/SOA is suitable for increasing the number of wavelength channels for smart short-range communications.

  19. Ultracold lanthanides: from optical clock to a quantum simulator

    NASA Astrophysics Data System (ADS)

    Vishnyakova, G. A.; Golovizin, A. A.; Kalganova, E. S.; Sorokin, V. N.; Sukachev, D. D.; Tregubov, D. O.; Khabarova, K. Yu; Kolachevsky, N. N.

    2016-02-01

    We review the current research on precision spectroscopy and quantum optics applications of laser-cooled lanthanides. We discuss the specific electronic structure of hollow atoms, which determine prospects for application in optical frequency standards and in quantum simulators based on spin interactions in optical lattices. Using the example of the thulium atom, we describe the specifics of laser cooling, optical lattice trapping techniques, and clock transition spectroscopy using spectrally narrow lasers.

  20. Heterostructures as a quantum optical klistron

    SciTech Connect

    Malov, Yu.A.

    1995-12-31

    THE beam of {open_quotes}hot{close_quotes} ballistic electrons which were first obtained experimentally in (1) is considered when passing through the heterostructures consisting of two potential barriers in barriers in the presence of FEL tuning in infra-red region. In the presence of the first barrier the electron beam in the FEL electromagnetic field can either absorb or emit the field quanta. The initial electron beam may split into states n=1 (absorption of one quantum), n=0 (the beam energy unchanged), and n=-1 (emission of one quantum). The interference of the states with n=0, n=1 and n=0, n=1 results in the initiation of two traveling modulation waves at electromagnetic frequency w. Beats between these waves in the region of the of their overlapping lead to a periodic dependence of the modulation from w. It has been found that the spontaneous coherent radiation (SCR) intensity oscillates with the period depending on FEL frequency w. It is possible to increase or to decrease the spectral intensity of SCR varying w. The suggested idea of modulation on the first barrier of heterostructures and the radiation of modulated electron beam on the second barrier is a scheme of an quantum optical klistron in infra-red region.

  1. Nonadiabatic quantum chaos in atom optics

    NASA Astrophysics Data System (ADS)

    Prants, S. V.

    2012-07-01

    Coherent dynamics of atomic matter waves in a standing-wave laser field is studied. In the dressed-state picture, wave packets of ballistic two-level atoms propagate simultaneously in two optical potentials. The probability to make a transition from one potential to another one is maximal when centroids of wave packets cross the field nodes and is given by a simple formula with the single exponent, the Landau-Zener parameter κ. If κ ≫ 1, the motion is essentially adiabatic. If κ ≪ 1, it is (almost) resonant and periodic. If κ ≃ 1, atom makes nonadiabatic transitions with a splitting of its wave packet at each node and strong complexification of the wave function as compared to the two other cases. This effect is referred as nonadiabatic quantum chaos. Proliferation of wave packets at κ ≃ 1 is shown to be connected closely with chaotic center-of-mass motion in the semiclassical theory of point-like atoms with positive values of the maximal Lyapunov exponent. The quantum-classical correspondence established is justified by the fact that the Landau-Zener parameter κ specifies the regime of the semiclassical dynamical chaos in the map simulating chaotic center-of-mass motion. Manifestations of nonadiabatic quantum chaos are found in the behavior of the momentum and position probabilities.

  2. Optical nuclear spin polarization in quantum dots

    NASA Astrophysics Data System (ADS)

    Li, Ai-Xian; Duan, Su-Qing; Zhang, Wei

    2016-10-01

    Hyperfine interaction between electron spin and randomly oriented nuclear spins is a key issue of electron coherence for quantum information/computation. We propose an efficient way to establish high polarization of nuclear spins and reduce the intrinsic nuclear spin fluctuations. Here, we polarize the nuclear spins in semiconductor quantum dot (QD) by the coherent population trapping (CPT) and the electric dipole spin resonance (EDSR) induced by optical fields and ac electric fields. By tuning the optical fields, we can obtain a powerful cooling background based on CPT for nuclear spin polarization. The EDSR can enhance the spin flip-flop rate which may increase the cooling efficiency. With the help of CPT and EDSR, an enhancement of 1300 times of the electron coherence time can be obtained after a 10-ns preparation time. Project partially supported by the National Natural Science Foundations of China (Grant Nos. 11374039 and 11174042) and the National Basic Research Program of China (Grant Nos. 2011CB922204 and 2013CB632805).

  3. Multilayered model in optics and quantum mechanics

    NASA Astrophysics Data System (ADS)

    Kovalev, M. D.

    2009-08-01

    Three types of dispersion equations are analyzed that describe the eigenvalues of the effective refractive index of a multilayer plane optical waveguide and the energy eigenvalues of a quantum particle placed in a piecewise constant potential field. The first equation (D1) is derived by setting to zero the determinant of the system of linear equations produced by matching the solutions in the layers. The second equation (D2) is obtained using the well-known method of characteristic matrices. The third equation has been obtained in the general case by the author and is known as a multilayer equation. Simple relations between the three equations are established. It is shown that the set of roots of D2 exactly coincides with the set of eigenvalues of the multilayer problem, while the roots of D1 and the multilayer equation contain those equal to the refractive index in the optical case (or to the potential in the quantum case) in internal layers of the system, which may be superfluous. Examples are presented.

  4. Arbitrary unitary transformations on optical states using a quantum memory

    SciTech Connect

    Campbell, Geoff T.; Pinel, Olivier; Hosseini, Mahdi; Buchler, Ben C.; Lam, Ping Koy

    2014-12-04

    We show that optical memories arranged along an optical path can perform arbitrary unitary transformations on frequency domain optical states. The protocol offers favourable scaling and can be used with any quantum memory that uses an off-resonant Raman transition to reversibly transfer optical information to an atomic spin coherence.

  5. PREFACE: International Conference on Quantum Optics and Quantum Information (icQoQi) 2013

    NASA Astrophysics Data System (ADS)

    2014-11-01

    Quantum Information can be understood as being naturally derived from a new understanding of information theory when quantum systems become information carriers and quantum effects become non negligible. Experiments and the realization of various interesting phenomena in quantum information within the established field of quantum optics have been reported, which has provided a very convenient framework for the former. Together, quantum optics and quantum information are among the most exciting areas of interdisciplinary research in modern day science which cover a broad spectrum of topics, from the foundations of quantum mechanics and quantum information science to the introduction of new types of quantum technologies and metrology. The International Conference on Quantum Optics and Quantum Information (icQoQi) 2013 was organized by the Faculty of Science, International Islamic University Malaysia with the objective of bringing together leading academic scientists, researchers and scholars in the domain of interest from around the world to share their experiences and research results about all aspects of quantum optics and quantum information. While the event was organized on a somewhat modest scale, it was in fact a rather fruitful meeting for established researchers and students as well, especially for the local scene where the field is relatively new. We would therefore, like to thank the organizing committee, our advisors and all parties for having made this event successful and last but not least would extend our sincerest gratitude to IOP for publishing these selected papers from icQoQi2013 in Journal of Physics: Conference Series.

  6. Quantum confinement in metal nanofilms: Optical spectra

    NASA Astrophysics Data System (ADS)

    Khmelinskii, Igor; Makarov, Vladimir I.

    2016-05-01

    We report optical absorption and photoluminescence spectra of Au, Fe, Co and Ni polycrystalline nanofilms in the UV-vis-NIR range, featuring discrete bands resulting from transverse quantum confinement. The film thickness ranged from 1.1 to 15.6 nm, depending on the material. The films were deposited on fused silica substrates by sputtering/thermo-evaporation, with Fe, Co and Ni protected by a SiO2 film deposited on top. The results are interpreted within the particle-in-a-box model, with the box width equal to the mass thickness of the nanofilm. The transverse-quantized energy levels and transition energies scale as the inverse square of the film thickness. The calculated values of the effective electron mass are 0.93 (Au), 0.027 (Fe), 0.21 (Co) and 0.16 (Ni), in units of mo - the mass of the free electron, being independent on the film thickness. The uncertainties in the effective mass values are ca. 2.5%, determined by the film thickness calibration. The second calculated model parameter, the quantum number n of the HOMO, was thickness-independent in Au (5.00) and Fe (6.00), and increased with the film thickness in Co (from 7 to 9) and Ni (from 7 to 11). The transitions observed in the absorbance all start at the level n and correspond to Δn=+1, +2, +3, etc. The photoluminescence bands exhibit large Stokes shifts, shifting to higher energies with the increased excitation energy. The photoluminescence quantum yields grow linearly with the excitation energy, showing evidence of multiple exciton generation. A prototype Fe-SnO2 nanofilm photovoltaic cell demonstrated at least 90% quantum yield of photoelectrons at 77 K.

  7. Laryngeal High-Speed Videoendoscopy: Rationale and Recommendation for Accurate and Consistent Terminology

    PubMed Central

    Deliyski, Dimitar D.; Hillman, Robert E.

    2015-01-01

    Purpose The authors discuss the rationale behind the term laryngeal high-speed videoendoscopy to describe the application of high-speed endoscopic imaging techniques to the visualization of vocal fold vibration. Method Commentary on the advantages of using accurate and consistent terminology in the field of voice research is provided. Specific justification is described for each component of the term high-speed videoendoscopy, which is compared and contrasted with alternative terminologies in the literature. Results In addition to the ubiquitous high-speed descriptor, the term endoscopy is necessary to specify the appropriate imaging technology and distinguish among modalities such as ultrasound, magnetic resonance imaging, and nonendoscopic optical imaging. Furthermore, the term video critically indicates the electronic recording of a sequence of optical still images representing scenes in motion, in contrast to strobed images using high-speed photography and non-optical high-speed magnetic resonance imaging. High-speed videoendoscopy thus concisely describes the technology and can be appended by the desired anatomical nomenclature such as laryngeal. Conclusions Laryngeal high-speed videoendoscopy strikes a balance between conciseness and specificity when referring to the typical high-speed imaging method performed on human participants. Guidance for the creation of future terminology provides clarity and context for current and future experiments and the dissemination of results among researchers. PMID:26375398

  8. Ultra-high speed communications based on solitons in fibers

    NASA Astrophysics Data System (ADS)

    Hasegawa, Akira

    2000-10-01

    The citation of the Maxwell prize reads: ``For innovative discoveries and seminal contributions to the theories of nonlinear drift wave turbulence, Alfvén wave propagation in laboratory and space plasmas, and optical solitons and their application to high speed communication". The prize is given to three somewhat unrelated contributions made during the course of my career as a plasma physicist. Traditionally an award talk summarizes works related to the citation. However, because of the diversified contents of the citations, I prepared my talk with the focus only on the last topic because some of the audience may be of more expertise on the other subjects. I apologize for the fact that the talk may be worth only one third of the prize. Multi-Terabits’s, ultra-high speed optical transmissions over several thousand kilometers on fibers are becoming reality and are expected to serve as the trunk line for highly demanded Internet traffics. Most of them use soliton or soliton-like RZ (Return to Zero) format in fibers with properly managed (group velocity) dispersion. These formats are the only stable envelope waveforms of light waves in fibers in the presence of Kerr (cubic) nonlineariy and dispersion with loss compensated by periodic optical amplifications. In practice, the transmission systems utilize the all-optical transmission concept and the nonlinear Schrodinger equation assisted by the split step numerical solutions as the master equation to describe the information transfer in fibers. All these facts are the outcome of research on optical solitons in fibers. The talk presents a brief historical development of the soliton based high-speed communications followed by current status of ultra-high speed communications by means of solitons as well as by other formats. Although the talk may not be of a core interest of plasma physics community, it presents an interesting example of a useful by-product of plasma physics research.

  9. Quantum cryptography and applications in the optical fiber network

    NASA Astrophysics Data System (ADS)

    Luo, Yuhui

    2005-09-01

    Quantum cryptography, as part of quantum information and communications, can provide absolute security for information transmission because it is established on the fundamental laws of quantum theory, such as the principle of uncertainty, No-cloning theorem and quantum entanglement. In this thesis research, a novel scheme to implement quantum key distribution based on multiphoton entanglement with a new protocol is proposed. Its advantages are: a larger information capacity can be obtained with a longer transmission distance and the detection of multiple photons is easier than that of a single photon. The security and attacks pertaining to such a system are also studied. Next, a quantum key distribution over wavelength division multiplexed (WDM) optical fiber networks is realized. Quantum key distribution in networks is a long-standing problem for practical applications. Here we combine quantum cryptography and WDM to solve this problem because WDM technology is universally deployed in the current and next generation fiber networks. The ultimate target is to deploy quantum key distribution over commercial networks. The problems arising from the networks are also studied in this part. Then quantum key distribution in multi-access networks using wavelength routing technology is investigated in this research. For the first time, quantum cryptography for multiple individually targeted users has been successfully implemented in sharp contrast to that using the indiscriminating broadcasting structure. It overcomes the shortcoming that every user in the network can acquire the quantum key signals intended to be exchanged between only two users. Furthermore, a more efficient scheme of quantum key distribution is adopted, hence resulting in a higher key rate. Lastly, a quantum random number generator based on quantum optics has been experimentally demonstrated. This device is a key component for quantum key distribution as it can create truly random numbers, which is an

  10. ControlNet features high speed

    SciTech Connect

    McEldowney, D.

    1996-11-01

    ControlNet is a high-speed, high-capacity network providing a connection among controllers and I/O subsystems. It was designed for applications in which data integrity, determinism, high speeds, and high data capacities are required. ControlNet addresses applications needing tighter control over processes as well as demanding remote I/O or interlocked PLC applications, both discrete- and process-related. Some examples include high-speed conveyors, transfer lines, cut-to-length lines, high-speed assembly, bottling, and packaging. Process examples, or those typically requiring heavy remote analog I/O, include water/wastewater, test stands, chemical, beverage, food, marine control, and utility balance-of-plant.

  11. Lubrication and cooling for high speed gears

    NASA Technical Reports Server (NTRS)

    Townsend, D. P.

    1985-01-01

    The problems and failures occurring with the operation of high speed gears are discussed. The gearing losses associated with high speed gearing such as tooth mesh friction, bearing friction, churning, and windage are discussed with various ways shown to help reduce these losses and thereby improve efficiency. Several different methods of oil jet lubrication for high speed gearing are given such as into mesh, out of mesh, and radial jet lubrication. The experiments and analytical results for the various methods of oil jet lubrication are shown with the strengths and weaknesses of each method discussed. The analytical and experimental results of gear lubrication and cooling at various test conditions are presented. These results show the very definite need of improved methods of gear cooling at high speed and high load conditions.

  12. Damping Bearings In High-Speed Turbomachines

    NASA Technical Reports Server (NTRS)

    Von Pragenau, George L.

    1994-01-01

    Paper presents comparison of damping bearings with traditional ball, roller, and hydrostatic bearings in high-speed cryogenic turbopumps. Concept of damping bearings described in "Damping Seals and Bearings for a Turbomachine" (MFS-28345).

  13. Quantum receiver beyond the standard quantum limit of coherent optical communication.

    PubMed

    Tsujino, Kenji; Fukuda, Daiji; Fujii, Go; Inoue, Shuichiro; Fujiwara, Mikio; Takeoka, Masahiro; Sasaki, Masahide

    2011-06-24

    The most efficient modern optical communication is known as coherent communication, and its standard quantum limit is almost reachable with current technology. Though it has been predicted for a long time that this standard quantum limit could be overcome via quantum mechanically optimized receivers, such a performance has not been experimentally realized so far. Here we demonstrate the first unconditional evidence surpassing the standard quantum limit of coherent optical communication. We implement a quantum receiver with a simple linear optics configuration and achieve more than 90% of the total detection efficiency of the system. Such an efficient quantum receiver will provide a new way of extending the distance of amplification-free channels, as well as of realizing quantum information protocols based on coherent states and the loophole-free test of quantum mechanics.

  14. Block-free optical quantum Banyan network based on quantum state fusion and fission

    NASA Astrophysics Data System (ADS)

    Zhu, Chang-Hua; Meng, Yan-Hong; Quan, Dong-Xiao; Zhao, Nan; Pei, Chang-Xing

    2014-12-01

    Optical switch fabric plays an important role in building multiple-user optical quantum communication networks. Owing to its self-routing property and low complexity, a banyan network is widely used for building switch fabric. While, there is no efficient way to remove internal blocking in a banyan network in a classical way, quantum state fusion, by which the two-dimensional internal quantum states of two photons could be combined into a four-dimensional internal state of a single photon, makes it possible to solve this problem. In this paper, we convert the output mode of quantum state fusion from spatial-polarization mode into time-polarization mode. By combining modified quantum state fusion and quantum state fission with quantum Fredkin gate, we propose a practical scheme to build an optical quantum switch unit which is block free. The scheme can be extended to building more complex units, four of which are shown in this paper.

  15. A high-speed photonic clock and carrier regenerator

    NASA Technical Reports Server (NTRS)

    Yao, X. S.; Lutes, G.

    1995-01-01

    As data communications rates climb toward 10 Gbits/s, clock recovery and synchronization become more difficult, if not impossible, using conventional electronic circuits. The high-speed photonic clock regenerator described in this article may be more suitable for such use. This photonic regenerator is based on a previously reported photonic oscillator capable of fast acquisition and synchronization. With both electrical and optical clock inputs and outputs, the device is easily interfaced with fiber-optic systems. The recovered electrical clock can be used locally and the optical clock can be used anywhere within a several kilometer radius of the clock/carrier regenerator.

  16. Nonlinear and quantum optics near nanoparticles

    NASA Astrophysics Data System (ADS)

    Dhayal, Suman

    We study the behavior of electric fields in and around dielectric and metal nanoparticles, and prepare the ground for their applications to a variety of systems viz. photovoltaics, imaging and detection techniques, and molecular spectroscopy. We exploit the property of nanoparticles being able to focus the radiation field into small regions and study some of the interesting nonlinear, and quantum coherence and interference phenomena near them. The traditional approach to study the nonlinear light-matter interactions involves the use of the slowly varying amplitude approximation (SVAA) as it simplifies the theoretical analysis. However, SVVA cannot be used for systems which are of the order of the wavelength of the light. We use the exact solutions of the Maxwell's equations to obtain the fields created due to metal and dielectric nanoparticles, and study nonlinear and quantum optical phenomena near these nanoparticles. We begin with the theoretical description of the electromagnetic fields created due to the nonlinear wavemixing process, namely, second-order nonlinearity in an nonlinear sphere. The phase-matching condition has been revisited in such particles and we found that it is not satisfied in the sphere. We have suggested a way to obtain optimal conditions for any type and size of material medium. We have also studied the modifications of the electromagnetic fields in a collection of nanoparticles due to strong near field nonlinear interactions using the generalized Mie theory for the case of many particles applicable in photovoltaics (PV). We also consider quantum coherence phenomena such as modification of dark states, stimulated Raman adiabatic passage (STIRAP), optical pumping in 4-level atoms near nanoparticles by using rotating wave approximation to describe the Hamiltonian of the atomic system. We also considered the behavior of atomic and the averaged atomic polarization in 7-level atoms near nanoparticles. This could be used as a prototype to study

  17. The high speed interconnect system architecture and operation

    NASA Astrophysics Data System (ADS)

    Anderson, Steven C.

    The design and operation of a fiber-optic high-speed interconnect system (HSIS) being developed to meet the requirements of future avionics and flight-control hardware with distributed-system architectures are discussed. The HSIS is intended for 100-Mb/s operation of a local-area network with up to 256 stations. It comprises a bus transmission system (passive star couplers and linear media linked by active elements) and network interface units (NIUs). Each NIU is designed to perform the physical, data link, network, and transport functions defined by the ISO OSI Basic Reference Model (1982 and 1983) and incorporates a fiber-optic transceiver, a high-speed protocol based on the SAE AE-9B linear token-passing data bus (1986), and a specialized application interface unit. The operating modes and capabilities of HSIS are described in detail and illustrated with diagrams.

  18. Optical electronics

    NASA Technical Reports Server (NTRS)

    Javan, A.

    1976-01-01

    The development of an optical diode consisting of a metal-dielectric-metal junction in which the high-speed electric conduction process occurs due to quantum mechanical electron tunneling across the dielectric barrier is briefly reviewed. Potential applications of the diode are discussed.

  19. Ultracold Quantum Gases in Hexagonal Optical Lattices

    NASA Astrophysics Data System (ADS)

    Sengstock, Klaus

    2010-03-01

    Hexagonal structures occur in a vast variety of systems, ranging from honeycombs of bees in life sciences to carbon nanotubes in material sciences. The latter, in particular its unfolded two-dimensional layer -- Graphene -- has rapidly grown to one of the most discussed topics in condensed-matter physics. Not only does it show proximity to various carbon-based materials but also exceptional properties owing to its unusual energy spectrum. In quantum optics, ultracold quantum gases confined in periodic light fields have shown to be very general and versatile instruments to mimic solid state systems. However, so far nearly all experiments were performed in cubic lattice geometries only. Here we report on the first experimental realization of ultracold quantum gases in a state-dependent, two-dimensional, Graphene-like optical lattice with hexagonal symmetry. The lattice is realized via a spin-dependent optical lattice structure with alternating σ^+ and σ^- -sites and thus constitutes a so called `magnetic'-lattice with `antiferromagnetic'-structure. Atoms with different spin orientation can be loaded to specific lattice sites or -- depending on the parameters -- to the whole lattice. As a consequence e.g. superpositions of a superfluid spin component with a different spin component in the Mott-insulating phase can be realized as well as spin-dependent transport properties, disorder etc. After preparing an antiferromagnetically ordered state we e.g. measure sustainable changes of the transport properties of the atoms. This manifests in a significant reduction of the tunneling as compared to a single-component system. We attribute this observation to a partial tunneling blockade for one spin component induced by population in another spin component localized at alternating lattice sites. Within a Gutzwiller-Ansatz we calculate the phase diagrams for the mixed spin-states and find very good agreement with our experimental results. Moreover, by state-resolved recording

  20. Flow-Visualization Techniques Used at High Speed by Configuration Aerodynamics Wind-Tunnel-Test Team

    NASA Technical Reports Server (NTRS)

    Lamar, John E. (Editor)

    2001-01-01

    This paper summarizes a variety of optically based flow-visualization techniques used for high-speed research by the Configuration Aerodynamics Wind-Tunnel Test Team of the High-Speed Research Program during its tenure. The work of other national experts is included for completeness. Details of each technique with applications and status in various national wind tunnels are given.

  1. Recent advances in high speed photography and associated technologies in the USA

    SciTech Connect

    Paisley, D.L.

    1988-01-01

    In the past decade, high speed photography has been rapidly incorporating electro-optics. More recently, optoelectronics and digital recording of images for specialized laboratory cameras and commerically available systems have helped broaden the versatility and applications of high speed photography and photonics. This paper will highlight some of these technologies and specialized systems. 10 refs., 22 figs.

  2. Quantum optical random walk: Quantization rules and quantum simulation of asymptotics

    SciTech Connect

    Ellinas, Demosthenes; Smyrnakis, Ioannis

    2007-08-15

    Rules for quantizing the walker-coin parts of a classical random walk are provided by treating them as interacting quantum systems. A quantum optical walk (QOW) is introduced by means of a rule that treats the quantum or classical noise affecting the coin's state as a source of quantization. The long-term asymptotic statistics of the QO walker's position, which shows enhanced diffusion rates as compared to the classical case, is exactly solved. A quantum optical implementation of the walk provides a physical framework for quantum simulation of its asymptotic statistics. The simulation utilizes interacting two-level atoms and/or randomly pulsating laser fields with fluctuating parameters.

  3. Quantum optics and cavity QED Quantum network with individual atoms and photons

    NASA Astrophysics Data System (ADS)

    Rempe, G.

    2013-08-01

    Quantum physics allows a new approach to information processing. A grand challenge is the realization of a quantum network for long-distance quantum communication and large-scale quantum simulation. This paper highlights a first implementation of an elementary quantum network with two fibre-linked high-finesse optical resonators, each containing a single quasi-permanently trapped atom as a stationary quantum node. Reversible quantum state transfer between the two atoms and entanglement of the two atoms are achieved by the controlled exchange of a time-symmetric single photon. This approach to quantum networking is efficient and offers a clear perspective for scalability. It allows for arbitrary topologies and features controlled connectivity as well as, in principle, infinite-range interactions. Our system constitutes the largest man-made material quantum system to date and is an ideal test bed for fundamental investigations, e.g. quantum non-locality.

  4. Optical Fresnel transformation and quantum tomography

    NASA Astrophysics Data System (ADS)

    Fan, Hong-Yi; Hu, Li-yun

    2009-09-01

    Corresponding to optical Fresnel transformation characteristic of a ray transfer matrix (A,B,C,D),AD-BC=1, there exists Fresnel operator F(A,B,C,D) in quantum optics, we show that under the Fresnel transformation the pure-state position density ∣x>ss=. Similarly, we find F∣p>sp=∫∫-∞∞dp'dx'δp-Ax'-Cp')Δx',p', where ∣p>

  5. The impact of quantum dot filling on dual-band optical transitions via intermediate quantum states

    SciTech Connect

    Wu, Jiang; Passmore, Brandon; Manasreh, M. O.

    2015-08-28

    InAs/GaAs quantum dot infrared photodetectors with different doping levels were investigated to understand the effect of quantum dot filling on both intraband and interband optical transitions. The electron filling of self-assembled InAs quantum dots was varied by direct doping of quantum dots with different concentrations. Photoresponse in the near infrared and middle wavelength infrared spectral region was observed from samples with low quantum dot filling. Although undoped quantum dots were favored for interband transitions with the absence of a second optical excitation in the near infrared region, doped quantum dots were preferred to improve intraband transitions in the middle wavelength infrared region. As a result, partial filling of quantum dot was required, to the extent of maintaining a low dark current, to enhance the dual-band photoresponse through the confined electron states.

  6. Application of Optical Measurement Techniques During Stages of Pregnancy: Use of Phantom High Speed Cameras for Digital Image Correlation (D.I.C.) During Baby Kicking and Abdomen Movements

    NASA Technical Reports Server (NTRS)

    Gradl, Paul

    2016-01-01

    Paired images were collected using a projected pattern instead of standard painting of the speckle pattern on her abdomen. High Speed cameras were post triggered after movements felt. Data was collected at 120 fps -limited due to 60hz frequency of projector. To ensure that kicks and movement data was real a background test was conducted with no baby movement (to correct for breathing and body motion).

  7. Silicon quantum dots for optical applications

    NASA Astrophysics Data System (ADS)

    Wu, Jeslin J.

    Luminescent silicon quantum dots (SiQDs) are emerging as attractive materials for optoelectronic devices, third generation photovoltaics, and bioimaging. Their applicability in the real world is contingent on their optical properties and long-term environmental stability; and in biological applications, factors such as water solubility and toxicity must also be taken into consideration. The aforementioned properties are highly dependent on the QDs' surface chemistry. In this work, SiQDs were engineered for the respective applications using liquid-phase and gas-phase functionalization techniques. Preliminary work in luminescent downshifting for photovoltaic systems are also reported. Highly luminescent SiQDs were fabricated by grafting unsaturated hydrocarbons onto the surface of hydrogen-terminated SiQDs via thermal and photochemical hydrosilylation. An industrially attractive, all gas-phase, nonthermal plasma synthesis, passivation (aided by photochemical reactions), and deposition process was also developed to reduce solvent waste. With photoluminescence quantum yields (PLQYs) nearing 60 %, the alkyl-terminated QDs are attractive materials for optical applications. The functionalized SiQDs also exhibited enhanced thermal stability as compared to their unfunctionalized counterparts, and the photochemically-hydrosilylated QDs further displayed photostability under UV irradiation. These environmentally-stable SiQDs were used as luminescent downshifting layers in photovoltaic systems, which led to enhancements in the blue photoresponse of heterojunction solar cells. Furthermore, the QD films demonstrated antireflective properties, improving the coupling efficiency of sunlight into the cell. For biological applications, oxide, amine, or hydroxyl groups were grafted onto the surface to create water-soluble SiQDs. Luminescent, water-soluble SiQDs were produced in by microplasma treating the QDs in water. Stable QYs exceeding 50 % were obtained. Radical-based and

  8. Aerodynamics of High-Speed Trains

    NASA Astrophysics Data System (ADS)

    Schetz, Joseph A.

    This review highlights the differences between the aerodynamics of high-speed trains and other types of transportation vehicles. The emphasis is on modern, high-speed trains, including magnetic levitation (Maglev) trains. Some of the key differences are derived from the fact that trains operate near the ground or a track, have much greater length-to-diameter ratios than other vehicles, pass close to each other and to trackside structures, are more subject to crosswinds, and operate in tunnels with entry and exit events. The coverage includes experimental techniques and results and analytical and numerical methods, concentrating on the most recent information available.

  9. High speed databus evaluation - Further work

    NASA Astrophysics Data System (ADS)

    Lee, Andrew J.

    Communication elements of avionic architectures and tools for assessing their capabilities are discussed with emphasis placed on the most recent study aimed at understanding and using of high speed databuses. The latter include Linear Token Passing Bus, High Speed Ring Bus, and Fiber Distributed Data Interface. Simulation techniques for evaluating the performance of communication system elements provide a cost-effective and time efficient method of assessment. Further work is aimed at providing a unique capability capable of simulating the hardware and software functionality as well as communication elements. This tool will be used to assess complete avionic architectures.

  10. Gain and noise properties of InAs/InP quantum dash semiconductor optical amplifiers

    NASA Astrophysics Data System (ADS)

    Bilenca, A.; Hadass, D.; Alizon, R.; Dery, H.; Mikhelashvili, V.; Eisenstein, G.; Somers, A.; Kaiser, W.; Deubert, S.; Reithmaier, J. P.; Forchel, A.; Calligaro, M.; Bansropun, S.; Krakowski, M.

    2005-10-01

    Semiconductor optical amplifiers (SOAs) based on nanostructure gain media such as quantum dots (QD) and quantum dashes (QDASH) have several basic characteristics which offer significant performance improvements over commonly used quantum well (QW) or bulk amplifiers. Among these are broadband optical gain bandwidth (which is two to three times broader than that of QW/bulk gain media), fast gain dynamics, large saturation powers, and low α parameter and population inversion factor. Originally, these properties have been demonstrated for QD/QDASH SOAs operating at 1000 nm and 1300 nm. However, it is imperative that QD/QDASH SOAs operating at 1550 nm be materialized in order for them to have the expected impact on fiber-optic communication. Operation at 1550 nm has been achieved using InAs / InP QD and QDASH laser structures. In this paper the unique gain and noise properties of InAs / InP QDASH SOAs operating at 1550 nm will be presented. Specifically, cross-gain-modulation, four-wave-mixing and chirp measurements which explore the complex spectral cross relaxation dynamics of these SOAs will be described and highlighted in the context of simultaneous, distortionless, high bit-rate multiwavelength data amplification, as well as wideband / high-speed optical signal processing applications. Also, an experimental study of the gain and noise in saturated QDASH SOAs will be described together with a theoretical analysis comprising both coherent and incoherent gain phenomena. The impact of the partially inhomogeneously broadened gain spectrum, fast population pulsation dynamics, α parameter and wetting layer density of states on the noise characteristics will be discussed.

  11. Reconfigurable high-speed optoelectronic interconnect technology for multiprocessor computers

    NASA Astrophysics Data System (ADS)

    Cheng, Julian

    1995-06-01

    We describe a compact optoelectronic switching technology for interconnecting multiple computer processors and shared memory modules together through dynamically reconfigurable optical paths to provide simultaneous, high speed communication amongst different nodes. Each switch provides a optical link to other nodes as well as electrical access to an individual processor, and it can perform optical and optoelectronic switching to covert digital data between various electrical and optical input/output formats. This multifunctional switching technology is based on the monolithic integration of arrays of vertical-cavity surface-emitting lasers with photodetectors and heterojunction bipolar transistors. The various digital switching and routing functions, as well as optically cascaded multistage operation, have been experimentally demonstrated.

  12. High speed single- and dual-stage vertical positioners

    NASA Astrophysics Data System (ADS)

    Yong, Yuen K.; Wadikhaye, Sachin P.; Fleming, Andrew J.

    2016-08-01

    This article presents a high-speed single- and dual-stage vertical positioners for applications in optical systems. Each positioner employs a unique end-constraint method with orthogonal flexures to preload a piezoelectric stack actuator. This end-constraint method also significantly increases the first mechanical resonance frequency. The single-stage positioner has a displacement range of 7.6 μm and a first resonance frequency of 46.8 kHz. The dual-stage design consists of a long-range slow-stage and a short-range fast-stage. An inertial counterbalance technique was implemented on the fast-stage to cancel inertial forces resulting from high-speed motion. The dual-stage positioner has a combined travel range of approximately 10 μm and a first evident resonance frequency of 130 kHz.

  13. High speed single- and dual-stage vertical positioners.

    PubMed

    Yong, Yuen K; Wadikhaye, Sachin P; Fleming, Andrew J

    2016-08-01

    This article presents a high-speed single- and dual-stage vertical positioners for applications in optical systems. Each positioner employs a unique end-constraint method with orthogonal flexures to preload a piezoelectric stack actuator. This end-constraint method also significantly increases the first mechanical resonance frequency. The single-stage positioner has a displacement range of 7.6 μm and a first resonance frequency of 46.8 kHz. The dual-stage design consists of a long-range slow-stage and a short-range fast-stage. An inertial counterbalance technique was implemented on the fast-stage to cancel inertial forces resulting from high-speed motion. The dual-stage positioner has a combined travel range of approximately 10 μm and a first evident resonance frequency of 130 kHz. PMID:27587157

  14. High Speed and Slow Motion: The Technology of Modern High Speed Cameras

    ERIC Educational Resources Information Center

    Vollmer, Michael; Mollmann, Klaus-Peter

    2011-01-01

    The enormous progress in the fields of microsystem technology, microelectronics and computer science has led to the development of powerful high speed cameras. Recently a number of such cameras became available as low cost consumer products which can also be used for the teaching of physics. The technology of high speed cameras is discussed,…

  15. Multipolar radiation of quantum emitters with nanowire optical antennas.

    PubMed

    Curto, Alberto G; Taminiau, Tim H; Volpe, Giorgio; Kreuzer, Mark P; Quidant, Romain; van Hulst, Niek F

    2013-01-01

    Multipolar transitions other than electric dipoles are generally too weak to be observed at optical frequencies in single quantum emitters. For example, fluorescent molecules and quantum dots have dimensions much smaller than the wavelength of light and therefore emit predominantly as electric dipoles. Here we demonstrate controlled emission of a quantum dot into multipolar radiation through selective coupling to a linear nanowire antenna. The antenna resonance tailors the interaction of the quantum dot with light, effectively creating a hybrid nanoscale source beyond the simple Hertz dipole. Our findings establish a basis for the controlled driving of fundamental modes in nanoantennas and metamaterials, for the understanding of the coupling of quantum emitters to nanophotonic devices such as waveguides and nanolasers, and for the development of innovative quantum nano-optics components with properties not found in nature.

  16. A scheme for efficient quantum computation with linear optics

    NASA Astrophysics Data System (ADS)

    Knill, E.; Laflamme, R.; Milburn, G. J.

    2001-01-01

    Quantum computers promise to increase greatly the efficiency of solving problems such as factoring large integers, combinatorial optimization and quantum physics simulation. One of the greatest challenges now is to implement the basic quantum-computational elements in a physical system and to demonstrate that they can be reliably and scalably controlled. One of the earliest proposals for quantum computation is based on implementing a quantum bit with two optical modes containing one photon. The proposal is appealing because of the ease with which photon interference can be observed. Until now, it suffered from the requirement for non-linear couplings between optical modes containing few photons. Here we show that efficient quantum computation is possible using only beam splitters, phase shifters, single photon sources and photo-detectors. Our methods exploit feedback from photo-detectors and are robust against errors from photon loss and detector inefficiency. The basic elements are accessible to experimental investigation with current technology.

  17. A high-speed hydroplane accident.

    PubMed

    Flaherty, G N

    1975-03-29

    This report records the investigation into a high-speed hydroplane accident in which the driver died. He was ejected head first into the water at 117 to 126 ft/sec (80 to 85 mph), suffering brain damage and a fractured skull. Suggestions are made to minimize the effects of these inevitable crashes. PMID:1143139

  18. High speed hydrogen/graphite interaction

    NASA Technical Reports Server (NTRS)

    Kelly, A. J.; Hamman, R.; Sharma, O. P.; Harrje, D. T.

    1974-01-01

    Various aspects of a research program on high speed hydrogen/graphite interaction are presented. Major areas discussed are: (1) theoretical predictions of hydrogen/graphite erosion rates; (2) high temperature, nonequilibrium hydrogen flow in a nozzle; and (3) molecular beam studies of hydrogen/graphite erosion.

  19. Aerodynamic design on high-speed trains

    NASA Astrophysics Data System (ADS)

    Ding, San-San; Li, Qiang; Tian, Ai-Qin; Du, Jian; Liu, Jia-Li

    2016-04-01

    Compared with the traditional train, the operational speed of the high-speed train has largely improved, and the dynamic environment of the train has changed from one of mechanical domination to one of aerodynamic domination. The aerodynamic problem has become the key technological challenge of high-speed trains and significantly affects the economy, environment, safety, and comfort. In this paper, the relationships among the aerodynamic design principle, aerodynamic performance indexes, and design variables are first studied, and the research methods of train aerodynamics are proposed, including numerical simulation, a reduced-scale test, and a full-scale test. Technological schemes of train aerodynamics involve the optimization design of the streamlined head and the smooth design of the body surface. Optimization design of the streamlined head includes conception design, project design, numerical simulation, and a reduced-scale test. Smooth design of the body surface is mainly used for the key parts, such as electric-current collecting system, wheel truck compartment, and windshield. The aerodynamic design method established in this paper has been successfully applied to various high-speed trains (CRH380A, CRH380AM, CRH6, CRH2G, and the Standard electric multiple unit (EMU)) that have met expected design objectives. The research results can provide an effective guideline for the aerodynamic design of high-speed trains.

  20. Italian High-speed Airplane Engines

    NASA Technical Reports Server (NTRS)

    Bona, C F

    1940-01-01

    This paper presents an account of Italian high-speed engine designs. The tests were performed on the Fiat AS6 engine, and all components of that engine are discussed from cylinders to superchargers as well as the test set-up. The results of the bench tests are given along with the performance of the engines in various races.

  1. High-speed data word monitor

    NASA Technical Reports Server (NTRS)

    Wirth, M. N.

    1975-01-01

    Small, portable, self-contained device provides high-speed display of bit pattern or any selected portion of transmission, can suppress filler patterns so that display is not updated, and can freeze display so that specific event may be observed in detail.

  2. Robust and scalable optical one-way quantum computation

    SciTech Connect

    Wang Hefeng; Yang Chuiping; Nori, Franco

    2010-05-15

    We propose an efficient approach for deterministically generating scalable cluster states with photons. This approach involves unitary transformations performed on atoms coupled to optical cavities. Its operation cost scales linearly with the number of qubits in the cluster state, and photon qubits are encoded such that single-qubit operations can be easily implemented by using linear optics. Robust optical one-way quantum computation can be performed since cluster states can be stored in atoms and then transferred to photons that can be easily operated and measured. Therefore, this proposal could help in performing robust large-scale optical one-way quantum computation.

  3. Generalization of continuous-variable quantum cloning with linear optics

    NASA Astrophysics Data System (ADS)

    Zhai, Zehui; Guo, Juan; Gao, Jiangrui

    2006-05-01

    We propose an asymmetric quantum cloning scheme. Based on the proposal and experiment by Andersen [Phys. Rev. Lett. 94, 240503 (2005)], we generalize it to two asymmetric cases: quantum cloning with asymmetry between output clones and between quadrature variables. These optical implementations also employ linear elements and homodyne detection only. Finally, we also compare the utility of symmetric and asymmetric cloning in an analysis of a squeezed-state quantum key distribution protocol and find that the asymmetric one is more advantageous.

  4. Characterization of optical quantum circuits using resonant phase shifts

    NASA Astrophysics Data System (ADS)

    Poot, M.; Tang, H. X.

    2016-09-01

    We demonstrate that important information about linear optical circuits can be obtained through the phase shift induced by integrated optical resonators. As a proof of principle, the phase of an unbalanced Mach-Zehnder interferometer is determined. Then, the method is applied to a complex optical circuit designed for linear optical quantum computation. In this controlled-NOT gate with qubit initialization and tomography stages, the relative phases, as well as the coupling ratios of its directional couplers, are determined.

  5. Quantum mechanical features of optically pumped CW FIR lasers

    NASA Technical Reports Server (NTRS)

    Seligson, D.; Leite, J. R. R.; Sanchez, A.; Feld, M. S.; Ducloy, M.

    1977-01-01

    Quantum mechanical predictions for the gain of an optically pumped CW FIR laser are presented for cases in which one or both of the pump and FIR transitions are pressure or Doppler broadened. The results are compared to those based on the rate equation model. Some of the quantum mechanical predictions are verified in CH3OH.

  6. Quantum analysis of polarization properties of optical beams

    SciTech Connect

    Lahiri, Mayukh; Wolf, Emil

    2010-10-15

    We present a quantum treatment of polarization of optical beams and discuss some properties of beams of any state of polarization. The analysis is based on quantum-mechanical interpretation of a canonical experiment that is used to elucidate polarization properties of stochastic fields in classical optics. Our work shows how to apply some ideas and techniques, commonly used in the classical theory, for fields that cannot be treated classically.

  7. Optical levitation of a microdroplet containing a single quantum dot.

    PubMed

    Minowa, Yosuke; Kawai, Ryoichi; Ashida, Masaaki

    2015-03-15

    We demonstrate the optical levitation or trapping in helium gas of a single quantum dot (QD) within a liquid droplet. Bright single photon emission from the levitated QD in the droplet was observed for more than 200 s. The observed photon count rates are consistent with the value theoretically estimated from the two-photon-action cross section. This Letter presents the realization of an optically levitated solid-state quantum emitter. PMID:25768143

  8. Intrinsic stability of quantum cascade lasers against optical feedback.

    PubMed

    Mezzapesa, F P; Columbo, L L; Brambilla, M; Dabbicco, M; Borri, S; Vitiello, M S; Beere, H E; Ritchie, D A; Scamarcio, G

    2013-06-01

    We study the time dependence of the optical power emitted by terahertz and mid-IR quantum cascade lasers in presence of optical reinjection and demonstrate unprecedented continuous wave (CW) emission stability for strong feedback. We show that the absence of coherence collapse or other CW instabilities typical of diode lasers is inherently associated with the high value of the photon to carrier lifetime ratio and the negligible linewidth enhancement factor of quantum cascade lasers.

  9. Quantum analysis of polarization properties of optical beams

    NASA Astrophysics Data System (ADS)

    Lahiri, Mayukh; Wolf, Emil

    2010-10-01

    We present a quantum treatment of polarization of optical beams and discuss some properties of beams of any state of polarization. The analysis is based on quantum-mechanical interpretation of a canonical experiment that is used to elucidate polarization properties of stochastic fields in classical optics. Our work shows how to apply some ideas and techniques, commonly used in the classical theory, for fields that cannot be treated classically.

  10. High speed photography, videography, and photonics V; Proceedings of the Meeting, San Diego, CA, Aug. 17-19, 1987

    NASA Technical Reports Server (NTRS)

    Johnson, Howard C. (Editor)

    1988-01-01

    Recent advances in high-speed optical and electrooptic devices are discussed in reviews and reports. Topics examined include data quantification and related technologies, high-speed photographic applications and instruments, flash and cine radiography, and novel ultrafast methods. Also considered are optical streak technology, high-speed videographic and photographic equipment, and X-ray streak cameras. Extensive diagrams, drawings, graphs, sample images, and tables of numerical data are provided.

  11. Integrated superconducting detectors on semiconductors for quantum optics applications

    NASA Astrophysics Data System (ADS)

    Kaniber, M.; Flassig, F.; Reithmaier, G.; Gross, R.; Finley, J. J.

    2016-05-01

    Semiconductor quantum photonic circuits can be used to efficiently generate, manipulate, route and exploit nonclassical states of light for distributed photon-based quantum information technologies. In this article, we review our recent achievements on the growth, nanofabrication and integration of high-quality, superconducting niobium nitride thin films on optically active, semiconducting GaAs substrates and their patterning to realize highly efficient and ultra-fast superconducting detectors on semiconductor nanomaterials containing quantum dots. Our state-of-the-art detectors reach external detection quantum efficiencies up to 20 % for ~4 nm thin films and single-photon timing resolutions <72 ps. We discuss the integration of such detectors into quantum dot-loaded, semiconductor ridge waveguides, resulting in the on-chip, time-resolved detection of quantum dot luminescence. Furthermore, a prototype quantum optical circuit is demonstrated that enabled the on-chip generation of resonance fluorescence from an individual InGaAs quantum dot, with a linewidth <15 μeV displaced by 1 mm from the superconducting detector on the very same semiconductor chip. Thus, all key components required for prototype quantum photonic circuits with sources, optical components and detectors on the same chip are reported.

  12. Quantum-dot optical temperature probes

    NASA Astrophysics Data System (ADS)

    Walker, Glen W.; Sundar, Vikram C.; Rudzinski, Christina M.; Wun, Aetna W.; Bawendi, Moungi G.; Nocera, Daniel G.

    2003-10-01

    The steady-state photoluminescence (PL) properties of cadmium selenide quantum dots (QDs) with a zinc sulfide overlayer [(CdSe)ZnS] can be strongly dependent on temperature in the range from 100 to 315 K. The PL intensity from 50 to 55 Å (CdSe)ZnS QDs in poly(lauryl methacrylate) matrices increases by a factor of ˜5 when the temperature is decreased from 315 to 100 K, and the peak of the emission band is blueshifted by 20 nm over the same range. The change in PL intensity is appreciable, linear, and reversible (-1.3% per °C) for temperatures close to ambient conditions. These properties of (CdSe)ZnS dots are retained in a variety of matrices including polymer and sol-gel films, and they are independent of excitation wavelength above the band gap. The significant temperature dependence of the luminescence combined with its insensitivity to oxygen quenching establishes (CdSe)ZnS dots as optical temperature indicators for temperature-sensitive coatings.

  13. Bell inequalities for quantum optical fields

    NASA Astrophysics Data System (ADS)

    Żukowski, Marek; Wieśniak, Marcin; Laskowski, Wiesław

    2016-08-01

    The commonly used "practical" Bell inequalities for quantum optical fields, which use intensities as the observables, are derivable only if specific additional assumptions hold. This limits the range of local hidden variable theories, which are invalidated by their violation. We present alternative Bell inequalities, which do not suffer from any (theoretical) loophole. The inequalities are for correlations of averaged products of local rates. By rates we mean ratios of the measured intensity in the given local output channel to the total local measured intensity, in the given run of the experiment. Bell inequalities of this type detect entanglement in situations in which the "practical" ones fail. Thus, we have full consistency with Bell's theorem, and better device-independent entanglement indicators. Strongly driven type-II parametric down conversion (bright squeezed vacuum) is our working example. The approach can be used to modify many types of standard Bell inequalities, to the case of undefined particle numbers. The rule is to replace the usual probabilities by rates.

  14. Nonadiabatic approach to quantum optical information storage

    NASA Astrophysics Data System (ADS)

    Matsko, A. B.; Rostovtsev, Y. V.; Kocharovskaya, O.; Zibrov, A. S.; Scully, M. O.

    2001-10-01

    We show that there is no need for adiabatic passage in the storage and retrieval of information in the optically thick vapor of Lambda-type atoms. This information can be mapped into and retrieved out of long-lived atomic coherence with nearly perfect efficiency by strong writing and reading pulses with steep rising and falling edges. We elucidate similarities and differences between the ``adiabatic'' and ``instant'' light storage techniques, and conclude that for any switching time, an almost perfect information storage is possible if the group velocity of the signal pulse is much less than the speed of light in the vacuum c and the bandwidth of the signal pulse is much less then the width of the two-photon resonance. The maximum loss of the information appears in the case of instantaneous switching of the writing and reading fields compared with adiabatic switching, and is determined by the ratio of the initial group velocity of the signal pulse in the medium and speed of light in the vacuum c, which can be very small. Quantum restrictions to the storage efficiency are also discussed.

  15. Optical properties of quantum-dot-doped liquid scintillators

    PubMed Central

    Aberle, C.; Li, J.J.; Weiss, S.; Winslow, L.

    2014-01-01

    Semiconductor nanoparticles (quantum dots) were studied in the context of liquid scintillator development for upcoming neutrino experiments. The unique optical and chemical properties of quantum dots are particularly promising for the use in neutrinoless double-beta decay experiments. Liquid scintillators for large scale neutrino detectors have to meet specific requirements which are reviewed, highlighting the peculiarities of quantum-dot-doping. In this paper, we report results on laboratory-scale measurements of the attenuation length and the fluorescence properties of three commercial quantum dot samples. The results include absorbance and emission stability measurements, improvement in transparency due to filtering of the quantum dot samples, precipitation tests to isolate the quantum dots from solution and energy transfer studies with quantum dots and the fluorophore PPO. PMID:25392711

  16. Quantum interference and control of the optical response in quantum dot molecules

    SciTech Connect

    Borges, H. S.; Sanz, L.; Villas-Boas, J. M.; Alcalde, A. M.

    2013-11-25

    We discuss the optical response of a quantum molecule under the action of two lasers fields. Using a realistic model and parameters, we map the physical conditions to find three different phenomena reported in the literature: the tunneling induced transparency, the formation of Autler-Townes doublets, and the creation of a Mollow-like triplet. We found that the electron tunneling between quantum dots is responsible for the different optical regime. Our results not only explain the experimental results in the literature but also give insights for future experiments and applications in optics using quantum dots molecules.

  17. Active resonant subwavelength grating devices for high speed spectroscopic sensing

    NASA Astrophysics Data System (ADS)

    Gin, A. V.; Kemme, S. A.; Boye, R. R.; Peters, D. W.; Ihlefeld, J. F.; Briggs, R. D.; Wendt, J. R.; Marshall, L. H.; Carter, T. R.; Samora, S.

    2009-02-01

    In this paper, we describe progress towards a multi-color spectrometer and radiometer based upon an active resonant subwavelength grating (RSG). This active RSG component acts as a tunable high-speed optical filter that allows device miniaturization and ruggedization not realizable using current sensors with conventional bulk optics. Furthermore, the geometrical characteristics of the device allow for inherently high speed operation. Because of the small critical dimensions of the RSG devices, the fabrication of these sensors can prove challenging. However, we utilize the state-of-the-art capabilities at Sandia National Laboratories to realize these subwavelength grating devices. This work also leverages previous work on passive RSG devices with greater than 98% efficiency and ~1nm FWHM. Rigorous coupled wave analysis has been utilized to design RSG devices with PLZT, PMN-PT and BaTiO3 electrooptic thin films on sapphire substrates. The simulated interdigitated electrode configuration achieves field strengths around 3×107 V/m. This translates to an increase in the refractive index of 0.05 with a 40V bias potential resulting in a 90% contrast of the modulated optical signal. We have fabricated several active RSG devices on selected electro-optic materials and we discuss the latest experimental results on these devices with variable electrostatic bias and a tunable wavelength source around 1.5μm. Finally, we present the proposed data acquisition hardware and system integration plans.

  18. High-speed amplified lightwave receiver for time domain measurements

    NASA Astrophysics Data System (ADS)

    Faller, Don

    1994-05-01

    The current trend of increasing data rates for fiber optics communications systems has created a demand for high-speed lightwave measurement instrumentation. For time domain measurements, a key element is a lightwave receiver for converting the optical signal to an electrical signal which can then be analyzed by conventional methods. The requirements for a high-speed lightwave receiver include DC-coupling, sufficient bandwidth to accurately reproduce the optical signal, frequency response flatness, sensitivity for measuring low signal levels, and linearity to avoid signal distortion. A receiver has been designed within Hewlett-Packard to meet these requirements for data rates up to 2.5 Gb/s. The receiver design consists of a high-bandwidth InP/InGaAs/InP p-i-n photodiode and a GaAs transimpedance amplifier. The photodiode has a bandwidth of 32 GHz with a responsivity greater than 0.5 A/W. The transimpedance amplifier has a gain of 600 ohms, flat frequency response, and a bandwidth of over 7 GHz. The combination results in a DC-coupled receiver with a bandwidth of over 4 GHz and a conversion gain of 330 V/W. The receiver provides accurate measurement capability for optical transmitters for both SONET and fibre channel communications systems.

  19. Quantum Yield Heterogeneity among Single Nonblinking Quantum Dots Revealed by Atomic Structure-Quantum Optics Correlation.

    PubMed

    Orfield, Noah J; McBride, James R; Wang, Feng; Buck, Matthew R; Keene, Joseph D; Reid, Kemar R; Htoon, Han; Hollingsworth, Jennifer A; Rosenthal, Sandra J

    2016-02-23

    Physical variations in colloidal nanostructures give rise to heterogeneity in expressed optical behavior. This correlation between nanoscale structure and function demands interrogation of both atomic structure and photophysics at the level of single nanostructures to be fully understood. Herein, by conducting detailed analyses of fine atomic structure, chemical composition, and time-resolved single-photon photoluminescence data for the same individual nanocrystals, we reveal inhomogeneity in the quantum yields of single nonblinking "giant" CdSe/CdS core/shell quantum dots (g-QDs). We find that each g-QD possesses distinctive single exciton and biexciton quantum yields that result mainly from variations in the degree of charging, rather than from volume or structure inhomogeneity. We further establish that there is a very limited nonemissive "dark" fraction (<2%) among the studied g-QDs and present direct evidence that the g-QD core must lack inorganic passivation for the g-QD to be "dark". Therefore, in contrast to conventional QDs, ensemble photoluminescence quantum yield is principally defined by charging processes rather than the existence of dark g-QDs.

  20. Editorial . Quantum fluctuations and coherence in optical and atomic structures

    NASA Astrophysics Data System (ADS)

    Eschner, Jürgen; Gatti, Alessandra; Maître, Agnès; Morigi, Giovanna

    2003-03-01

    From simple interference fringes, over molecular wave packets, to nonlinear optical patterns - the fundamental interaction between light and matter leads to the formation of structures in many areas of atomic and optical physics. Sophisticated technology in experimental quantum optics, as well as modern computational tools available to theorists, have led to spectacular achievements in the investigation of quantum structures. This special issue is dedicated to recent developments in this area. It presents a selection of examples where quantum dynamics, fluctuations, and coherence generate structures in time or in space or where such structures are observed experimentally. The examples range from coherence phenomena in condensed matter, over atoms in optical structures, entanglement in light and matter, to quantum patterns in nonlinear optics and quantum imaging. The combination of such seemingly diverse subjects formed the basis of a successful European TMR network, "Quantum Structures" (visit http://cnqo.phys.strath.ac.uk/~gianluca/QSTRUCT/). This special issue partly re.ects the results and collaborations of the network, going however well beyond its scope by including contributions from a global community and from many related topics which were not addressed directly in the network. The aim of this issue is to present side by side these di.erent topics, all of which are loosely summarized under quantum structures, to highlight their common aspects, their di.erences, and the progress which resulted from the mutual exchange of results, methods, and knowledge. To guide the reader, we have organized the articles into subsections which follow a rough division into structures in material systems and structures in optical .elds. Nevertheless, in the following introduction we point out connections between the contributions which go beyond these usual criteria, thus highlighting the truly interdisciplinary nature of quantum structures. Much of the progress in atom optics

  1. Quantum Dots Microstructured Optical Fiber for X-Ray Detection

    NASA Technical Reports Server (NTRS)

    DeHaven, Stan; Williams, Phillip; Burke, Eric

    2015-01-01

    Microstructured optical fibers containing quantum dots scintillation material comprised of zinc sulfide nanocrystals doped with magnesium sulfide are presented. These quantum dots are applied inside the microstructured optical fibers using capillary action. The x-ray photon counts of these fibers are compared to the output of a collimated CdTe solid state detector over an energy range from 10 to 40 keV. The results of the fiber light output and associated effects of an acrylate coating and the quantum dot application technique are discussed.

  2. Atomic physics and quantum optics using superconducting circuits.

    PubMed

    You, J Q; Nori, Franco

    2011-06-29

    Superconducting circuits based on Josephson junctions exhibit macroscopic quantum coherence and can behave like artificial atoms. Recent technological advances have made it possible to implement atomic-physics and quantum-optics experiments on a chip using these artificial atoms. This Review presents a brief overview of the progress achieved so far in this rapidly advancing field. We not only discuss phenomena analogous to those in atomic physics and quantum optics with natural atoms, but also highlight those not occurring in natural atoms. In addition, we summarize several prospective directions in this emerging interdisciplinary field.

  3. A simulation-based study of HighSpeed TCP and its deployment

    SciTech Connect

    Souza, Evandro de

    2003-04-29

    The current congestion control mechanism used in TCP has difficulty reaching full utilization on high speed links, particularly on wide-area connections. For example, the packet drop rate needed to fill a Gigabit pipe using the present TCP protocol is below the currently achievable fiber optic error rates. HighSpeed TCP was recently proposed as a modification of TCP's congestion control mechanism to allow it to achieve reasonable performance in high speed wide-area links. In this research, simulation results showing the performance of HighSpeed TCP and the impact of its use on the present implementation of TCP are presented. Network conditions including different degrees of congestion, different levels of loss rate, different degrees of bursty traffic and two distinct router queue management policies were simulated. The performance and fairness of HighSpeed TCP were compared to the existing TCP and solutions for bulk-data transfer using parallel streams.

  4. Pulse Detonation Engines for High Speed Flight

    NASA Technical Reports Server (NTRS)

    Povinelli, Louis A.

    2002-01-01

    Revolutionary concepts in propulsion are required in order to achieve high-speed cruise capability in the atmosphere and for low cost reliable systems for earth to orbit missions. One of the advanced concepts under study is the air-breathing pulse detonation engine. Additional work remains in order to establish the role and performance of a PDE in flight applications, either as a stand-alone device or as part of a combined cycle system. In this paper, we shall offer a few remarks on some of these remaining issues, i.e., combined cycle systems, nozzles and exhaust systems and thrust per unit frontal area limitations. Currently, an intensive experimental and numerical effort is underway in order to quantify the propulsion performance characteristics of this device. In this paper, we shall highlight our recent efforts to elucidate the propulsion potential of pulse detonation engines and their possible application to high-speed or hypersonic systems.

  5. High Speed Research Program Sonic Fatigue

    NASA Technical Reports Server (NTRS)

    Rizzi, Stephen A. (Technical Monitor); Beier, Theodor H.; Heaton, Paul

    2005-01-01

    The objective of this sonic fatigue summary is to provide major findings and technical results of studies, initiated in 1994, to assess sonic fatigue behavior of structure that is being considered for the High Speed Civil Transport (HSCT). High Speed Research (HSR) program objectives in the area of sonic fatigue were to predict inlet, exhaust and boundary layer acoustic loads; measure high cycle fatigue data for materials developed during the HSR program; develop advanced sonic fatigue calculation methods to reduce required conservatism in airframe designs; develop damping techniques for sonic fatigue reduction where weight effective; develop wing and fuselage sonic fatigue design requirements; and perform sonic fatigue analyses on HSCT structural concepts to provide guidance to design teams. All goals were partially achieved, but none were completed due to the premature conclusion of the HSR program. A summary of major program findings and recommendations for continued effort are included in the report.

  6. Friction in high-speed impact experiments

    NASA Astrophysics Data System (ADS)

    Pelak, Robert A.; Rightley, Paul; Hammerberg, J. E.

    2000-04-01

    The physical interactions at the contact interface between two metals moving relative to one another are not well understood, particularly when the relative velocity between the bodies becomes a significant fraction of the sound speed in either material. Our goal is to characterize the interfacial dynamics occurring between two metal surfaces sliding at high loads (up to 300 kbar) and at high speeds (greater than 100 m/s). We are developing a technique where a high-speed spinning projectile is fired from a rifled gun at a rod instrumented with electrical resistance strain gauges for measuring both longitudinal and torsional strain waves. The observed traces, in conjunction with computer simulations, are used to estimate the normal and tangential force components at the interface to produce an estimate of the coefficient of friction. A preliminary estimate for a copper/steel interface is presented.

  7. High-speed massively parallel scanning

    DOEpatents

    Decker, Derek E.

    2010-07-06

    A new technique for recording a series of images of a high-speed event (such as, but not limited to: ballistics, explosives, laser induced changes in materials, etc.) is presented. Such technique(s) makes use of a lenslet array to take image picture elements (pixels) and concentrate light from each pixel into a spot that is much smaller than the pixel. This array of spots illuminates a detector region (e.g., film, as one embodiment) which is scanned transverse to the light, creating tracks of exposed regions. Each track is a time history of the light intensity for a single pixel. By appropriately configuring the array of concentrated spots with respect to the scanning direction of the detection material, different tracks fit between pixels and sufficient lengths are possible which can be of interest in several high-speed imaging applications.

  8. High speed printing with polygon scan heads

    NASA Astrophysics Data System (ADS)

    Stutz, Glenn

    2016-03-01

    To reduce and in many cases eliminate the costs associated with high volume printing of consumer and industrial products, this paper investigates and validates the use of the new generation of high speed pulse on demand (POD) lasers in concert with high speed (HS) polygon scan heads (PSH). Associated costs include consumables such as printing ink and nozzles, provisioning labor, maintenance and repair expense as well as reduction of printing lines due to high through put. Targets that are applicable and investigated include direct printing on plastics, printing on paper/cardboard as well as printing on labels. Market segments would include consumer products (CPG), medical and pharmaceutical products, universal ID (UID), and industrial products. In regards to the POD lasers employed, the wavelengths include UV(355nm), Green (532nm) and IR (1064nm) operating within the repetition range of 180 to 250 KHz.

  9. High speed receiver for capsule endoscope.

    PubMed

    Woo, S H; Yoon, K W; Moon, Y K; Lee, J H; Park, H J; Kim, T W; Choi, H C; Won, C H; Cho, J H

    2010-10-01

    In this study, a high-speed receiver for a capsule endoscope was proposed and implemented. The proposed receiver could receive 20 Mbps data that was sufficient to receive images with a higher resolution than conventional receivers. The receiver used a 1.2 GHz band to receive radio frequency (RF) signal, and demodulated the signal to an intermediate frequency (IF) stage (150 MHz). The demodulated signal was amplified, filtered, and under-sampled by a high-speed analog-to-digital converter (ADC). In order to decode the under-sampled data in real time, a simple frequency detection algorithm was selected and was implemented by using a FPGA. The implemented system could receive 20 Mbps data.

  10. High-Speed Granular Chute Flows

    NASA Astrophysics Data System (ADS)

    McElwaine, J.

    2014-12-01

    Accurate models for high speed granular flows are critical for understanding long runout landslides and rockfalls. However reproducible experimental data is extremely limited and is mostly only available for steady state flows on moderate inclinations. We report on experiments over a much greater range of slope angles 30-50 degrees and flow depths 4-130 particle diameters with upto 20kg/s of sand flowing steadily. The data suggests that friction can be much larger than the μ(I)mu(I) rheology or kinetic theories predict and suggest and that there may be constant velocity states above the angle of vanishing hstop. We show similar high speed steady flows at angles up to 50 degress in Discrete Element Simuations and discuss how these can be understood theoretically.

  11. Nuclear spin physics in quantum dots: An optical investigation

    NASA Astrophysics Data System (ADS)

    Urbaszek, Bernhard; Marie, Xavier; Amand, Thierry; Krebs, Olivier; Voisin, Paul; Maletinsky, Patrick; Högele, Alexander; Imamoglu, Atac

    2013-01-01

    The mesoscopic spin system formed by the 104-106 nuclear spins in a semiconductor quantum dot offers a unique setting for the study of many-body spin physics in the condensed matter. The dynamics of this system and its coupling to electron spins is fundamentally different from its bulk counterpart or the case of individual atoms due to increased fluctuations that result from reduced dimensions. In recent years, the interest in studying quantum-dot nuclear spin systems and their coupling to confined electron spins has been further fueled by its importance for possible quantum information processing applications. The fascinating nonlinear (quantum) dynamics of the coupled electron-nuclear spin system is universal in quantum dot optics and transport. In this article, experimental work performed over the last decade in studying this mesoscopic, coupled electron-nuclear spin system is reviewed. Here a special focus is on how optical addressing of electron spins can be exploited to manipulate and read out the quantum-dot nuclei. Particularly exciting recent developments in applying optical techniques to efficiently establish nonzero mean nuclear spin polarizations and using them to reduce intrinsic nuclear spin fluctuations are discussed. Both results critically influence the preservation of electron-spin coherence in quantum dots. This overall recently gained understanding of the quantum-dot nuclear spin system could enable exciting new research avenues such as experimental observations of spontaneous spin ordering or nonclassical behavior of the nuclear spin bath.

  12. Development of high-speed video cameras

    NASA Astrophysics Data System (ADS)

    Etoh, Takeharu G.; Takehara, Kohsei; Okinaka, Tomoo; Takano, Yasuhide; Ruckelshausen, Arno; Poggemann, Dirk

    2001-04-01

    Presented in this paper is an outline of the R and D activities on high-speed video cameras, which have been done in Kinki University since more than ten years ago, and are currently proceeded as an international cooperative project with University of Applied Sciences Osnabruck and other organizations. Extensive marketing researches have been done, (1) on user's requirements on high-speed multi-framing and video cameras by questionnaires and hearings, and (2) on current availability of the cameras of this sort by search of journals and websites. Both of them support necessity of development of a high-speed video camera of more than 1 million fps. A video camera of 4,500 fps with parallel readout was developed in 1991. A video camera with triple sensors was developed in 1996. The sensor is the same one as developed for the previous camera. The frame rate is 50 million fps for triple-framing and 4,500 fps for triple-light-wave framing, including color image capturing. Idea on a video camera of 1 million fps with an ISIS, In-situ Storage Image Sensor, was proposed in 1993 at first, and has been continuously improved. A test sensor was developed in early 2000, and successfully captured images at 62,500 fps. Currently, design of a prototype ISIS is going on, and, hopefully, will be fabricated in near future. Epoch-making cameras in history of development of high-speed video cameras by other persons are also briefly reviewed.

  13. Data Capture Technique for High Speed Signaling

    DOEpatents

    Barrett, Wayne Melvin; Chen, Dong; Coteus, Paul William; Gara, Alan Gene; Jackson, Rory; Kopcsay, Gerard Vincent; Nathanson, Ben Jesse; Vranas, Paylos Michael; Takken, Todd E.

    2008-08-26

    A data capture technique for high speed signaling to allow for optimal sampling of an asynchronous data stream. This technique allows for extremely high data rates and does not require that a clock be sent with the data as is done in source synchronous systems. The present invention also provides a hardware mechanism for automatically adjusting transmission delays for optimal two-bit simultaneous bi-directional (SiBiDi) signaling.

  14. Turbulence modeling for high speed compressible flows

    NASA Technical Reports Server (NTRS)

    Chandra, Suresh

    1993-01-01

    The following grant objectives were delineated in the proposal to NASA: to offer course work in computational fluid dynamics (CFD) and related areas to enable mechanical engineering students at North Carolina A&T State University (N.C. A&TSU) to pursue M.S. studies in CFD, and to enable students and faculty to engage in research in high speed compressible flows. Since no CFD-related activity existed at N.C. A&TSU before the start of the NASA grant period, training of students in the CFD area and initiation of research in high speed compressible flows were proposed as the key aspects of the project. To that end, graduate level courses in CFD, boundary layer theory, and fluid dynamics were offered. This effort included initiating a CFD course for graduate students. Also, research work was performed on studying compressibility effects in high speed flows. Specifically, a modified compressible dissipation model, which included a fourth order turbulent Mach number term, was incorporated into the SPARK code and verified for the air-air mixing layer case. The results obtained for this case were compared with a wide variety of experimental data to discern the trends in the mixing layer growth rates with varying convective Mach numbers. Comparison of the predictions of the study with the results of several analytical models was also carried out. The details of the research study are described in the publication entitled 'Compressibility Effects in Modeling Turbulent High Speed Mixing Layers,' which is attached to this report.

  15. Turbulence modeling for high speed compressible flows

    NASA Astrophysics Data System (ADS)

    Chandra, Suresh

    1993-08-01

    The following grant objectives were delineated in the proposal to NASA: to offer course work in computational fluid dynamics (CFD) and related areas to enable mechanical engineering students at North Carolina A&T State University (N.C. A&TSU) to pursue M.S. studies in CFD, and to enable students and faculty to engage in research in high speed compressible flows. Since no CFD-related activity existed at N.C. A&TSU before the start of the NASA grant period, training of students in the CFD area and initiation of research in high speed compressible flows were proposed as the key aspects of the project. To that end, graduate level courses in CFD, boundary layer theory, and fluid dynamics were offered. This effort included initiating a CFD course for graduate students. Also, research work was performed on studying compressibility effects in high speed flows. Specifically, a modified compressible dissipation model, which included a fourth order turbulent Mach number term, was incorporated into the SPARK code and verified for the air-air mixing layer case. The results obtained for this case were compared with a wide variety of experimental data to discern the trends in the mixing layer growth rates with varying convective Mach numbers. Comparison of the predictions of the study with the results of several analytical models was also carried out. The details of the research study are described in the publication entitled 'Compressibility Effects in Modeling Turbulent High Speed Mixing Layers,' which is attached to this report.

  16. Optical detection of brain tumors using quantum dots

    NASA Astrophysics Data System (ADS)

    Toms, Steven A.; Daneshvar, Hamid; Muhammad, Osman; Jackson, Heather; Vogelbaum, Michael A.; Bruchez, Marcel

    2005-11-01

    Introduction: Brain tumor margin detection remains a challenging problem in the operative resection of gliomas. A novel nanoparticle, a PEGylated quantum dot, has been shown to be phagocytized by macrophages in vivo. This feature may allow quantum dots to co-localize with brain tumors and serve as an optical aid in the surgical resection of brain tumors. Methods: Sprague-Daly rats were injected intracranially with C6 gliosarcoma cell lines to establish tumors. Two weeks after implantation of brain tumors, PEGylated quantum dots emitting at 705 nm (PEG-705 QD) were injected via the tail vein. Twenty-four hours post PEG-705 QD injection, the animals were sacrificed and their tissues examined. Results: PEGylated quantum dots are avidly phagocytized by macrophages and are taken up by liver, spleen and lymph nodes. Macrophages and microglia co-localize with glioma cells, carrying the optical nanoparticle, the quantum dot. Excitation of the PEG-705 quantum dots gives off a deep red fluorescence detectable with charge coupled device (CCD) cameras, optical spectroscopy units, and in dark field fluorescence microscopy. Conclusions: PEG-705QDs co-localize with brain tumors and may serve as an optical adjunct to aid in the operative resection of gliomas. The particles may be visualized in surgery with CCD cameras or detected by optical spectroscopy.

  17. Testing of high speed network components

    SciTech Connect

    Wing, W.R.

    1997-06-30

    At the time of the start of this project, a battle was being fought between the computer networking technologies and telephone networking technologies. The telecommunications industry wanted to standardize on Asynchronous Transfer Mode (ATM) as the technology of choice for carrying all cross-country traffic. The computer industry wanted to use Packet Transfer Mode (PTM). The project had several goals, some unspoken. At the highest, most obvious level, the project goals were to test the high-speed components being developed by the computer technology industry. However, in addition, both industrial partners were having trouble finding markets for the high-speed networking technology they were developing and deploying. Thus, a part of the project was to demonstrate applications developed at Oak Ridge which would stretch the limits of the network, and thus demonstrate the utility of high-speed networks. Finally, an unspoken goal of the computer technology industry was to convince the telecommunications industry that packet switching was superior to cell switching. Conversely, the telecommunications industry hoped to see the computer technology industry`s packet switch fail to perform in a real-world test. Project was terminated early due to failure of one of the CRADA partners to deliver needed component.

  18. Quantum optics. Quantum harmonic oscillator state synthesis by reservoir engineering.

    PubMed

    Kienzler, D; Lo, H-Y; Keitch, B; de Clercq, L; Leupold, F; Lindenfelser, F; Marinelli, M; Negnevitsky, V; Home, J P

    2015-01-01

    The robust generation of quantum states in the presence of decoherence is a primary challenge for explorations of quantum mechanics at larger scales. Using the mechanical motion of a single trapped ion, we utilize reservoir engineering to generate squeezed, coherent, and displaced-squeezed states as steady states in the presence of noise. We verify the created state by generating two-state correlated spin-motion Rabi oscillations, resulting in high-contrast measurements. For both cooling and measurement, we use spin-oscillator couplings that provide transitions between oscillator states in an engineered Fock state basis. Our approach should facilitate studies of entanglement, quantum computation, and open-system quantum simulations in a wide range of physical systems.

  19. Slightly anharmonic systems in quantum optics

    NASA Technical Reports Server (NTRS)

    Klimov, Andrey B.; Chumakov, Sergey M.

    1995-01-01

    We consider an arbitrary atomic system (n-level atom or many such atoms) interacting with a strong resonant quantum field. The approximate evolution operator for a quantum field case can be produced from the atomic evolution operator in an external classical field by a 'quantization prescription', passing the operator arguments to Wigner D-functions. Many important phenomena arising from the quantum nature of the field can be described by such a way.

  20. Synchronizing Photography For High-Speed-Engine Research

    NASA Technical Reports Server (NTRS)

    Chun, K. S.

    1989-01-01

    Light flashes when shaft reaches predetermined angle. Synchronization system facilitates visualization of flow in high-speed internal-combustion engines. Designed for cinematography and holographic interferometry, system synchronizes camera and light source with predetermined rotational angle of engine shaft. 10-bit resolution of absolute optical shaft encoder adapted, and 2 to tenth power combinations of 10-bit binary data computed to corresponding angle values. Pre-computed angle values programmed into EPROM's (erasable programmable read-only memories) to use as angle lookup table. Resolves shaft angle to within 0.35 degree at rotational speeds up to 73,240 revolutions per minute.