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Infrared Technology and Applications XXVII conference

作者： Horn, S Campbell, J Driggers, R Soyka, T Norton, P Perconti, P Ostromek, TE Estrera, JP Bacarella, A Beystrum, T Scribner, D Warren, P USA CECOM Night Vis & Elect Sensors Directorate Ft Belvoir VA 22060 USA

ISBN: (纸本)0819440647

Fusion of reflected/emitted radiation light sensors can provide significant advantages for target identification and detection. The two bands-0.6-0.9 or 1-2 mum reflected light and 8-12 gm emitted radiation-offer the greatest contrast since those bands have the lowest correlation, hence the greatest amount of combined information for infrared imaging. Data from fused imaging systems is presented for optical overlay as well as digital pixel fusion. Advantages of the digital fusion process are discussed as well as the advantages of having both bands present for military operations. Finally perception tests results are presented that show how color can significantly enhance target detection, A factor of two reduction in minimum resolvable temperature difference is postulated from perception tests in the chromaticity plane. Although initial results do not yet validate this finding, it is expected with the right fusion algorithms and displays that this important result will be proven shortly.

关键词： Sensors Target detection Image processing Long wavelength infrared Signal to noise ratio Cameras optical sensors Image fusion Imaging systems Infrared sensors

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Microphotonics:: Physics, technology, and an outlook toward 21^st Century

Microphotonics:: Physics, technology, and an outlook toward ...

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Asia-Pacific optical and Wireless Communications conference (APOC 2001)

作者： Lee, EH Lee, SG O, BH Kim, SK Inha Univ Microphoton Adv Res Ctr PARC Inchon 402751 South Korea Korea Elect Terminal Co Inchon 402751 South Korea

This paper presents an overview of our study on the subject that is categorically termed >. Microelectronics, as we define it here, is an area of scientific and technological study concerning the miniaturization, i... 详细信息

ISBN: (纸本)0819443107

This paper presents an overview of our study on the subject that is categorically termed <>. Microelectronics, as we define it here, is an area of scientific and technological study concerning the miniaturization, interconnection, and integration of photonic devices, circuits, and systems in micron or submicron scale. We examine the scientific and technological issues relating to these matters and discuss the challenges that the microphotonics faces toward the information technology in the 21st century. In the course of this study, we closely follow the experiences of microelectronics side by side, so that they can provide lessons, learnings, and insights that microphotonics can rightfully benefit from in a complementary form. Similarities, dissimilarities, advantages, and disadvantages, merits and demerits of the two technologies are explored in such a way that they can be more effectively utilized by mutual support. Directions for future studies are also discussed with particular emphasis on information technology.

关键词： photonics optoelectronics optical communication optical information processing optical interconnection optical integration quantum optics

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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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Capturing, processing and rendering real-world scenes

Capturing, processing and rendering real-world scenes

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conference on Videometrics and optical Methods for 3D Shape Measurement

作者： Nyland, LS Lastra, A McAllister, DK Popescu, V Mccue, C Fuchs, H Univ N Carolina Chapel Hill NC 27515 USA

ISBN: (纸本)0819439878

While photographs vividly capture a scene from a single viewpoint, it is our goal to capture a scene in such a way that a viewer can freely move to any viewpoint, just as he or she would in an actual scene. We have built a prototype system to quickly digitize a scene using a laser rangefinder and a high-resolution digital camera that accurately captures a panorama of high-resolution range and color information. With real-world scenes, we have provided data to fuel research in many areas, including representation, registration, data fusion, polygonization, rendering, simplification, and reillumination. The real-world scene data can be used for many purposes, including immersive environments, immersive training, re-engineering and engineering verification, renovation, crime-scene and accident capture and reconstruction, archaeology and historic preservation, sports and entertainment, surveillance, remote tourism and remote sales. We will describe our acquisition system, the necessary processing to merge data from the multiple input devices and positions. We will also describe (and show) high quality rendering using the data we have collected. Issues about specific rendering accelerators and algorithms will also be presented. We will conclude by describing future uses and methods of collection for real-world scene data.

关键词： Software prototyping

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Intelligent multi-fiber interface module for high bit-rate interprocessor data transfer

Intelligent multi-fiber interface module for high bit-rate i...

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European conference on optical Communication (ECOC)

作者： N.A. Riza Z. Yaqoob Photonic Information Processing Systems Laboratory Nuonics Inc. Orlando FL USA Photonic Information Processing Systems Laboratory School of Optics CREOL UCF Orlando FL USA

ISBN: (纸本)0780367057

An intelligent multi-fiber interface module (IMIM) is proposed for a multi-Gigabit inter-processor data transfer using wavelength division multiplexing (WDM). The IMIM features ultrafast nanosecond rate dataflow path reconfiguration speeds between multiple fibers of an optical data bus and parallel processors arranged in ring architecture. The IMIM exploits an arrayed-waveguide grating device and wavelength tuning in a compact non-coupler design.

关键词： optical transmitters High speed optical techniques Ultrafast optics Tunable circuits and devices optical fiber devices Laser tuning optical fiber cables Wavelength division multiplexing optical interconnections optical tuning

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Design of high-encryption wireless network with distributed host management and dynamic key generation

Design of high-encryption wireless network with distributed ...

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conference on Optoelectronic and Wireless Data Management, processing, Storage, and Retrieval

作者： Weber, R Univ Colorado Boulder CO 80309 USA

ISBN: (纸本)0819442585

The widespread deployment of wireless networks using the 802.11(b) standard across the country presents a rebirth of age-old network security problems along with a number of new ones. The wireless network, much like a shared network using broadcast devices such as network hubs, travels across a shared medium. Because of the structure any member of the wireless network can observe and intercept data being sent or received by other members. Unlike 'wired' networks there is no means to isolate traffic from other network members. The second security issue for wireless networks is the transmission of data 'clear text' so that if it is intercepted it can be read and used. Wireless networks bring about another problem that compounds the first two concerns that all shared networks must deal with, that is, anyone within the transmission range of the wireless network can join. No longer must a person enter a building to infiltrate a business network, they need only park across the street. The first implementation of network security for wireless was the WEP (Wired Equivalent Privacy) protocol. WEP attempts to make a wireless network at least as secure as a switched 'wired' network. The WEP protocol intends to secure the traffic integrity with the use of a RC4 cipher and a CSC-32 checksum. In the passphrase used for the RC4 encryption is also used as a form of access control. There are several critical faults in the WEP implementation that allow both passive data acquisition and active data modification. At 11 Mbit, capturing approximately 5 hours of clear text data can guarantee the capture of two packets with the same initialization vector (IV). Once the packets are used to get the clear text packet, that information can be used to decrypt any packets with the same IV. Since the IV's are only 24 bits the decryption of entire network becomes only an exercise in patience, with a 24 hours of continuous monitoring the WEP encryption can be defeated completely and a simple approx

关键词： Network security Standards development Error control coding information security Computer security Databases Local area networks Data acquisition Software development Operating systems

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Computing with interference: all-optical single-query 50-element database search

Computing with interference: all-optical single-query 50-ele...

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Quantum Electronics and Laser Science conference (QELS)

作者： C. Dorrer P. Londero M. Anderson S. Wallentowitz I.A. Walmsley The Institute of Optics University of Rochester Rochester NY United States

Summary form only given. Quantum information processing relies on interference and entanglement. Certain quantum algorithms have been demonstrated using interference alone. These have been criticized on the grounds that the number of resources they require does not scale favorably with the size of the database. Nonetheless it has been argued that algorithms implemented entirely using interference may be more efficient than algorithms implemented on classical particle-based machines.

关键词： Interference Databases optical computing Ultrafast optics optical signal processing optical solitons Adaptive optics Analog computers optical devices Quantum computing

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Perspectives and limits of optical information processing

Perspectives and limits of optical information processing

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Quantum Electronics and Laser Science conference (QELS)

作者： K. Wagner Department of ECE Optoelectronic Computing Systems Center University of Colorado Boulder CO USA

Summary form only given. . In this talk we will compare the development of the analog optical signal processing approaches to the Moore's law exponential growth of digital microelectronic techniques and show an example in array processing where optics will continue to have a substantial advantage in computational throughput for the foreseeable future.

关键词： information processing optical computing Ultrafast optics optical signal processing optical solitons Adaptive optics Analog computers optical devices Quantum computing optical fiber networks

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A portable device for optically recognizing Braille. I. Hardware development

A portable device for optically recognizing Braille. I. Hard...

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Australian and New Zealand conference on Intelligent information systems

作者： I. Murray T. Dias School of Electrical and Computer Engineering Curtin University of Technology Bentley WA Australia

This is the first of a pair of papers that describe a prototype portable device for optically scanning embossed Braille and conversion of the scanned text to binary Braille representation. This prototype has been developed in conjunction with the Association for the Blind (WA). An application to convert the literary Braille code to expanded text has also been implemented and is described in part II. The system developed utilises a hand held scanner that captures the embossed Braille image, in real time, via a linear 128-pixel CCD array. A Texas Instruments digital signal processor performs recognition processing.

关键词： optical devices Hardware optical films optical character recognition software Australia Employment Prototypes Real time systems Charge coupled devices Instruments

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Web-based multimedia information retrieval for clinical application research

Web-based multimedia information retrieval for clinical appl...

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Medical Imaging 2001 conference

作者： Cao, XH Hoo, KS Zhang, H Ching, W Zhang, M Wong, STC Univ Calif San Francisco Lab Radiol Informat San Francisco CA 94143 USA

ISBN: (纸本)0819440094

We described a web-based data warehousing method for retrieving and analyzing neurological multimedia information. The web-based method supports convenient access, effective search and retrieval of clinical textual and image data, and on-line analysis. To improve the flexibility and efficiency of multimedia information query and analysis, a three-tier, multimedia data warehouse for epilepsy research has been built. The data warehouse integrates clinical multimedia data related to epilepsy from disparate sources and archives them into a well-defined data model. The middle-ware consists of business logic components such web server, applets and active server page (ASP) scripts for dealing with user authentication and authorization, HTTP request, SQL data access from data warehouse and algorithms to support data analysis. At client side, a web-based graphical user interface (GUI) is used to receive user's query request and display the retrieved textual data. Client-side image processing and display for DICOM format was implemented by Java applets. An image query and display method based on 3D projections has been developed to retrieve and analyze MRI and PET.

关键词： medical multimedia information data warehouse information retrieval World Wide Web

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