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conference on algorithms and systems for optical information processing V

作者： Waddie, AJ Taghizadeh, MR Heriot Watt Univ Dept Phys Diffract Opt Grp Edinburgh EH14 4AS Midlothian Scotland

ISBN: (纸本)0819441856

It is generally accepted that diffractive optical elements provide the optimal flexibility for the implementation of free-space interconnections between arrays of optoelectronic components. In this paper we discuss the Hopfield neural network demonstrator based around a 2D array of Vertical-Cavity Surface-Emitting Users and an off-the-shelf Si photodetector array. The interconnection matrix between the optoelectronic arrays is provided by a diffractive optical element, the precise nature of which is determined by the problem to be solved by the network. In order to study the potential of the optoelectronic Hopfield network topology for both scalability and miniaturization, the design and micro-fabrication techniques used in the creation of diffractive optical elements will be analyzed. This analysis will allow estimates to be made of the maximum number of devices that may be interconnected using diffractive optical elements as well as outlining possible approaches to system miniaturization by the use of micro-optical elements.

关键词： optoelectronics diffractive optics neural networks scalability

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Universal Multimedia Access

Universal Multimedia Access

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conference on Multimedia systems and Applications iii

作者： Smith, JR IBM TJ Watson Res Ctr Hawthorne NY 10532 USA

ISBN: (纸本)081943874X

A growing diversity of pervasive devices such as wireless phones and hand-held computers is gaining access to the Internet and other information sources. However, much of the rich multimedia content cannot be easily handled by the terminal devices with limited communication, processing, storage and display capabilities. One of the driving applications of the MPEG-7 multimedia content description standard involves the concept of "Universal Multimedia Access." The basic idea of Universal Multimedia Access (UMA) is the allowance of scalable or adaptive delivery of multimedia to users and terminals regardless of conditions of communication bandwidth or capabilities of terminal devices and their support for media formats. In this paper, we describe how MPEG-7 enables UMA by providing tools for specification of Transcoding Hints, Content Variations, Space and Frequency Views, and Summaries.

关键词： Universal Multimedia Access MPEG-7 multimedia system support and delivery multimedia processing and coding universal access content adaptation pervasive computing.

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Quantum photonic informatics: an overview of theoretical development and implementation via integrated photonics

Quantum photonic informatics: an overview of theoretical dev...

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conference on Photonics Technology in the 21st Century

作者： Binh, LN Monash Univ Dept Elect & Comp Syst Engn Lab Opt Commun & Appl Photon Clayton Vic 3800 Australia

ISBN: (纸本)081944328X

Quantum photonic informatics involves manipulation and processing of information at a photon energy level. The qu-bit with optical modes containing one photon energy is described and photonic gates representing its quantum states are given and expanded into quantum systems and networks for computing and information processing. Integrated photonic devices are proposed for implementation of the quantum gates and networks and case studies are examined for further expansion and implementation of quantum algorithms.

关键词： quantum computing quantum information processing integrated photonics integrated optics informatics

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optical multi-token-ring networking using smart pixels with field programmable gate arrays (FPGAs)

Optical multi-token-ring networking using smart pixels with ...

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conference on Photonic devices and algorithms for Computing iii

作者： Zhang, LP Hong, SW Min, CK Alpaslan, ZY Sawchuk, AA Univ So Calif Inst Signal & Image Proc Los Angeles CA 90089 USA

ISBN: (纸本)0819441848

This research explores architectures and design principles for monolithic optoelectronic integrated circuits (OEICs) through the implementation of an optical multi-token-ring network testbed system. Monolithic smart pixel CMOS OEICs are of paramount importance to high performance networks, communication switches, computer interfaces, and parallel signal processing for demanding future multimedia applications. The general testbed system is called Reconfigurable Translucent Smart Pixel Array (R-Transpar) and includes a field programmable gate array (FPGA), a transimpedance receiver array, and an optoelectronic very large-scale integrated (OE-VLSI) smart pixel array. The FPGA is an Altera FLEX10K100E chip that performs logic functions and receives inputs from the transimpedance receiver array. A monolithic (OE-VLSI) smart pixel device containing an array of 4 x 4 vertical-cavity surface-emitting lasers (VCSELs) spatially interlaced with an array of 4 x 4 metal-semiconductor-metal (MSM) detectors connects to these devices and performs optical input-output functions. These components are mounted on a printed circuit board for testing and evaluation of integrated monolithic OEIC designs and various optical interconnection techniques. The system moves information between nodes by transferring 3-D optical packets in free space or through fiber image guides. The R-Transpar system is reconfigurable to test different network protocols and signal processing functions. In its operation as a 3-D multi-token-ring network, we use a specific version of the system called Transpar-Token-Ring (Transpar-TR) that uses novel time-division multiplexed (TDM) network node addressing to enhance channel utilization and throughput. Host computers interface with the system via a high-speed digital I/O board that sends commands for networking and application algorithm operations. We describe the system operation and experimental results in detail.

关键词： optical interconnections optical computing smart pixels optoelectronic integrated circuits vertical-cavity surface-emitting lasers

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Evaluation of the real time optical filter generation correlator

Evaluation of the real time optical filter generation correl...

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conference on algorithms and systems for optical information processing V

作者： Jones, BK Kirsch, JC US Army Aviat & Missile Command AMSAM RD WS PL Redstone Arsenal AL 35898 USA

ISBN: (纸本)0819441856

optical correlators using spatial light modulators in the filter plane have been discussed and presented for many years. In most cases, these devices are electrically addressed modulators and the filters are generated off-line in software. These filters can be tailored to fit the desired application but cannot be adjusted to account for real-time changes in the target appearance. In addition, building filters to account for all of the possible viewing configurations can strain the reference database and the memory storage capability of the system. Recently, a correlator architecture that used an optically addressed, multiple quantum well (MQW) spatial light modulator as the filter plane device was presented. The architecture is a modified Vander Lugt correlator with and additional input modulator. The filter formed by the interference of the reference image beam and the reference beam is recorded on the MQW spatial light modulator. The recorded filter retains the full complex information as high-resolution film did years ago. Additionally, the filter can be updated simply by changing the pattern on the reference input modulator. The second input modulator is used to address this stored filter in - a normal correlator read-out configuration. The correlator has been completed and results will be presented as part of this paper.

关键词： region of interest camera optical image correlation multiple quantum well modulator real-time filter generation

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Electrically addressed spatial light phase modulator

Electrically addressed spatial light phase modulator

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conference on Photonic devices and algorithms for Computing iii

作者： Hara, T Fukuchi, N Kobayashi, Y Yoshida, N Igasaki, Y Wu, MH Hamamatsu Photon KK Cent Res Lab Hamakita Shizuoka 4348601 Japan

ISBN: (纸本)0819441848

A nonpixelized electrically addressable spatial light phase-only modulator has been developed. The device consists of an optically addressed parallel aligned nematic liquid crystal spatial light modulator (PAL-SLM), coupling optics, an XGA liquid crystal display (LCD) which serves as an accurate addressable mask for the PAL-SLM, a laser diode (LD) for illuminating the LCD and collimating optics for the LD. The device has a phase modulation capability of over 2pi radians and a high diffraction efficiency of greater than 35% at a spatial frequency of 10 1p/mm of binary (0,pi) grating. Also when a multilevel (0, 0.5pi, pi, 1.5pi) grating was written in the device, a diffraction efficiency of greater than 70% at a spatial frequency of 10 1p/mm was obtained. Moreover, surplus diffraction light (diffraction noise) caused by the pixelized structure was reduced to less than 3% by the coupling optics, compared with almost 50% occurring in the LCD by itself.

关键词： spatial light modulator electrically addressed liquid crystal optical information processing phase modulation diffraction efficiency

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Protein-based optical transducer for mechatronic devices

Protein-based optical transducer for mechatronic devices

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conference on Optomechatronic systems iii

作者： Knopf, GK Bassi, AS Univ Western Ontario Fac Engn Sci Dept Mech & Mat Engn London ON N6A 5B9 Canada

ISBN: (纸本)0819442925

An optical transducer based on the light modulated transmission properties of bacteriorhodopsin (bR) film is described in this paper. The bR protein molecules undergo a complex photocycle when absorbing light energy that is characterized by several measurable states. The most relevant states in the photocycle for this application are the initial B state (lambda(max) = 570 nm) and the longest lived M intermediate state (lambda(max) = 410 nm). If a yellow light source with a wavelength of approximately 570 nm and a second deep blue source at 410 nm illuminate the same region of the thin bR film, the two beams will mutually suppress the optical transmission properties of the thin film and reduce the intensity of the light output. The suppression-modulated transmission mechanism of the bR polymeric film is, therefore, controlled by the intensity and wavelength of the two light sources. Based on this simple mechanism, a number of different protein-based optical devices have been proposed in the literature for optical signal and information processing. The focus of this research is to exploit the light transmission properties of the bR. film to develop efficient optical transducers that can be easily interfaced with micro-electro-mechanical systems (MEMs) for mechatronic applications. The proposed transducer design is activated by an external light source and free from electrical noise. Illustrations of how thin bR film can be used for the modulation of light intensity, optical switches, and logic gates are presented.

关键词： mechatronic system design optical transducers bacteriorhodopsin suppression-modulated transmission

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Nondestructive sensing technologies using micro optical elements for applications in the NIR-MIR spectral regions

Nondestructive sensing technologies using micro optical elem...

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3rd International conference on Subsurface and Surface Sensing Technologies and Applications

作者： Otto, T Saupe, R Bruch, R Fritzsch, U Stock, V Gessner, T Afanasyeva, N Fraunhofer-Institut fuer Zuverlaessigkeit und Mikrointegration (Germany) Univ. of Nevada/Reno (United States) Colour Control Farbmesstechnik GmbH (Germany) Technische Univ. Chemnitz (Germany) Fraunhofer-Institut fuer Zuverlaessigkeit und Mikrointegration and Chemnitz Univ. of Techn (Germany)

ISBN: (纸本)0819442054

The field of microtechnology is an important industrial and scientific resource for the 21st century. There is a great interest in spectroscopic sensors in the near and middle infrared (NIR-MIR) wavelength regions (1 - 2.5 mum;2.5 - 4.5 mum;4 - 6 gm). The potential for cheap and small devices for nondestructive, remote sensing techniques at a molecular level has stimulated the design and development of more compact analyzer systems. Therefore we will try to build analyzers using micro optical components such as micromirrors and embossed micro gratings optimized for the above mentioned spectral ranges. Potentially, infrared sensors can be used for rapid nondestructive diagnostics of surfaces, liquids, gases, polymers and complex biological systems including proteins, blood, cells and cellular debris as well as body tissue. Furthermore, NIR-MIR microsensing spectroscopy will be utilized to monitor the chemical composition of petrochemical products like gasoline and diesel. In addition, miniature analyzers will be used for rapid measuring of food, in particular oil, starch and meat. In this paper we will present an overview of several new approaches for subsurface and surface sensing technologies based on the integration of optical micro devices, the most promising sensors for biomedical, environmental and industrial applications, data processing and evaluation algorithms for classification of the results. Both scientific and industrial applications will be discussed.

关键词： NIR-MIR analyzer nondestructive sensing microtechnology

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Growth characterisation of In_xGa_1-xAs/GaAs/AlAs vertical-cavity surface-emitting laser structure using photomodulated reflectance

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IEE PROCEEDINGS-OPTOELECTRONICS 2001年第1期148卷 49-53页

作者： Choulis, SA Hosea, TJC Univ Surrey Dept Phys Guildford GU2 5XH Surrey England

Of crucial importance for vertical-cavity surface-emitting lasers (VCSELs) is the energy separation of the Fabry-Perot cavity mode and peak of the gain spectrum of the quantum-well (QW) active region. Since this is affected by growth variations, nondestructive characterisation of VCSEL wafers is usually required prior to full processing, to check that structures have been grown to specification. It is shown that photomodulated reflectance (PR) spectroscopy is useful for prefabrication testing of VCSEL wafers, for the example of a near-infrared ln(x)Ga(1-x)As/ GaAs/AlAs VCSEL. By varying either the probe position on the wafer or the temperature, PR was used to study the interaction between the cavity mode and both the ground-state QW exciton and all the higher-order QW transitions. Firstly, a growth-induced shift across the wafer was exploited to tune the cavity-mode wavelength through resonance with all the QW excitonic transitions at room temperature. Secondly, by cooling from room to liquid-helium temperatures, each QW transition was blue-shifted into resonance with the cavity mode. In both methods, the PR signal was enhanced at such resonances, which could provide a sensitive way of locating 'sweet spots' on a nonuniform VCSEL wafer (where operating devices might be fabricated). Since PR can detect all the QW transitions, it is able, by comparing the measured and predicted transition energies, to provide much information about the QW cavity and growth.

关键词： photoreflectance aluminium compounds prefabrication testing Vacuum deposition quantum well lasers Design of specific laser systems Laser resonators and cavities optical testing growth variations iii-V semiconductors growth characterisation gain spectrum temperature Materials testing Nondestructive testing: optical methods QW cavity optical fabrication InGaAs-GaAs-AlAs probe position Testing photomodulated reflectance nonuniform VCSEL wafer VCSEL Production facilities and engineering gallium arsenide optical testing techniques ground-state QW exciton nondestructive characterisation InxGa1-xAs/GaAs/AlAs vertical-cavity surface-emitting laser structure cavity mode near-infrared InxGa1-xAs/GaAs/AlAs VCSEL blue-shift growth-induced shift Fabry-Perot resonators resonance transition energies molecular beam epitaxial growth nondestructive testing excitons ground states 9 to 325 K QW excitonic transitions liquid-helium temperatures operating devices higher-order QW transitions sweet spots QW transitions spectral line shift semiconductor growth Other optical properties of condensed matter Surface treatment and coating techniques Fabry-Perot cavity mode Engineering materials semiconductor device testing Lasing action in semiconductors indium compounds Optoelectronics manufacturing Semiconductor lasers laser cavity resonators optical fabrication, surface grinding VCSEL wafers surface emitting lasers quantum-well active region energy separation cavity-mode wavelength room temperature

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Application of panoramic annular lens for motion analysis tasks: surveillance and smoke detection

Application of panoramic annular lens for motion analysis ta...

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International conference on Pattern Recognition

作者： I. Kopilovic B. Vagvolgyi T. Sziranyi Department of Image Processing and Neurocomputing University of Veszprém Veszprem Hungary Analogical and Neural Computing Laboratory Comp. and Aut. Institute Hungarian Academy of Sciences Budapest Hungary

ISBN: (纸本)0769507506

In this paper some applications of motion analysis are investigated for a compact panoramic optical system (panoramic annular lens). Panoramic image acquisition makes multiple or mechanically controlled camera systems needless for many applications. Panoramic annular lens' main advantage to other omnidirectional monitoring systems is that it is a cheap, small, compact device with no external hyperboloidal, spherical, conical or paraboloidal reflecting surface as in other panoramic optical devices. By converting the annular image captured with an NTSC camera to a rectangular one, we get a low-resolution (2.8 pixels/degrees horizontally and 3 pixels/degree vertically) image. We developed algorithms which can analyze this low-resolution image to yield motion information for surveillance and smoke detection.

关键词： Lenses Motion analysis Cameras Pixel Control systems Monitoring optical devices Image converters Image analysis Image motion analysis

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