This manuscript reviews our efforts in demonstrating state-of-the-art planar, batch-fabricable, high-performance vertical-cavity surface-emitting lasers (VCSELs). All performance requirements for short-haul data commu...
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ISBN:
(纸本)0819420573
This manuscript reviews our efforts in demonstrating state-of-the-art planar, batch-fabricable, high-performance vertical-cavity surface-emitting lasers (VCSELs). All performance requirements for short-haul data communication applications are clearly established. We concentrate on the flexibility of the established proton-implanted AlGaAs-based (emitting near 850 nm) technology platform, focusing on a standard device design. This structure is shown to meet or exceed performance and producibility requirements. These include > 99% device yield across 3-in-dia. metal-organic vapor phase epitaxy (MOVPE)-grown wafers and wavelength operation across a > 100-nm range. Recent progress in device performance [low threshold voltage (Vth equals 1.53 V); threshold current (Ith equals 0.68 mA); continuous wave (CW) power (Pcw equals 59 mW); maximum and minimum CW lasing temperature (T equals 200 degree(s)C, 10 K); and wall-plug efficiencies ((eta) wp equals 28%)] should enable great advances in VCSEL-based technologies. We also discuss the viability of VCSELs in cryogenic and avionic/military environments. Also reviewed is a novel technique, modifying this established platform, to engineer low-threshold, high-speed, single- mode VCSELs.
The DO-SAR system consists of an airborne SAR sensor unit and ground-based image processing equipment. It has been built in the late eighties. In order to study algorithms, there was the need to generate dual frequenc...
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ISBN:
(纸本)0819421294
The DO-SAR system consists of an airborne SAR sensor unit and ground-based image processing equipment. It has been built in the late eighties. In order to study algorithms, there was the need to generate dual frequency multipolarization data simultaneously. The DO-SAR images allow a comparison on a pixel by pixel basis. The system has been enhanced to along track and across track interferometry. The across track modes are used to generate height profiles with high accuracy. The along track interferometry can be used to estimate the velocity of targets on ground and the velocity of the aircraft. The system has been operating since 1989. It has been used overall in Europe for maritime and oceanic missions. It was used to fly over flooded areas and it provides simultaneous images together with SIRC, in Denmark and Germany. Presently, it is used to generate interferometric single path images in tropic areas in order to classify the tropical forests.
Multiplexing of ATM networks requires flexible switches that efficiently handle data at Gb/s speed. The CellRAM is a single-chip solution implementing a low-cost, low-power ATM multiplexing and switching system. The C...
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ISBN:
(纸本)0780331370
Multiplexing of ATM networks requires flexible switches that efficiently handle data at Gb/s speed. The CellRAM is a single-chip solution implementing a low-cost, low-power ATM multiplexing and switching system. The CellRAM uses a shared memory architecture with 8 input and 8 output, double-buffered, serial accessible, memory ports and a 4Mb DRAM memory core. The CellRAM is in a 0.54μm, 3V double-metal, triple-poly process and is packaged in a 184-pin, quad-flat pack. The CellRAM delivers 1.391Gb/s net ATM cell bandwidth operating at a 43.5MHz clock rate. Supporting unicast and multicasting functions, the CellRAM has all the necessary features for implementing a switch. This architecture anticipates evolutionary increases in memory density with advances in DRAM technology.
The proceedings contains 360 papers. Topics discussed include near field optical microscopy, datastorage and display technology, high order harmonic generations, condensed phase cavity quantum electrodynamics, guided...
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The proceedings contains 360 papers. Topics discussed include near field optical microscopy, datastorage and display technology, high order harmonic generations, condensed phase cavity quantum electrodynamics, guided wave frequency division, ultrafast dynamics, Bose-Einstein condensation, semiconductor lasers, second harmonic generation, vertical cavity surface emitting lasers, solitons, self-trapping in quadratic media and instabilities, semiconductor quantum wells, atomic and molecular physics, strong field physics, atomic beam control, nonlinear optical materials, excitation dynamics in semiconductors, photorefractive materials, amplification without inversion, quantum theory and measurement, coherent atomic beams, quantum optics and noise, and multiphoton spectroscopy.
The impressive growth of the opticalstorage market is largely due to the success of the compact disc (CD) system. Initially positioned as a new audio carrier, it now also finds widespread application as CD-ROM. New s...
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The impressive growth of the opticalstorage market is largely due to the success of the compact disc (CD) system. Initially positioned as a new audio carrier, it now also finds widespread application as CD-ROM. New systems are expected to further strengthen opticalstorage as a cost-effective and robust technology for data exchange. This paper elucidates more on these CD trends.
This paper details the main considerations to be addressed when specifying a swivel for a Floating Production, storage and Off-loading (FPSO) system or other offshore terminal requiring rotational freedom. The followi...
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This paper details the main considerations to be addressed when specifying a swivel for a Floating Production, storage and Off-loading (FPSO) system or other offshore terminal requiring rotational freedom. The following types of swivels are discussed: electrical swivels for power and control, optical swivels for control/data, hydraulic/pneumatic swivels for control or actuation, and combination units. The detailed design of product swivels is not within the scope of this paper. From the design perspective, typical specifications are discussed for each swivel type, including considerations of capacity, materials, terminations, sealing, weight, torque and position in the swivel stack. Testing and certification for hazardous locations is addressed. The information presented in this paper can be used primarily by designers and systems engineers in specifying swivels, which are used in various FPSO moorings allowing the vessel to weathervane about the mooring point. Several existing swivels are described to demonstrate the functionality available. These include hollow-bore units for systems with product swivels above the electrical or hydraulic swivel. There are a number of tradeoffs to be made when specifying a swivel for FPSO applications. This paper highlights these, enabling the buyer to specify a configuration completely, thus minimizing program changes and cost.
Large form factor is popular in the growth markets of regulated or access intensive application of imaging, banking, medical, financial and insurance. This popularity is attributed to its large storage capacity. Howev...
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Large form factor is popular in the growth markets of regulated or access intensive application of imaging, banking, medical, financial and insurance. This popularity is attributed to its large storage capacity. However, large form factor, including optical, is just starting to mature. But as opticaladvances, many great things are expected. Large form factor is expected to continue to lead in capacity-with-performance economies of scale.
Nondestructive evaluation (NDE) using X-rays is becoming indispensable for detecting microdefects in new materials currently used in aerospace and other engineering disciplines. Existing X-ray sensors pose limitations...
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Nondestructive evaluation (NDE) using X-rays is becoming indispensable for detecting microdefects in new materials currently used in aerospace and other engineering disciplines. Existing X-ray sensors pose limitations on the speed of operation due to persistence of the sensor and a problematic tradeoff between the sensor thickness and spatial resolution. To address these limitations we are developing a large area structured CsI(TI) imaging sensor for NDE using CCD based radiographic and computed tomographic systems. The sensor is formed by vapor deposition of CsI(TI) onto a specially designed fiberoptic substrate. Our work has produced X-ray sensors with a factor of 4.5 greater light output, at least three orders of magnitude faster decay time response, and greater spatial resolution (16% modulation transfer function, MTF(f), at 14 linepairs per millimeter (lp/mm)) compared to the currently used high density Tb2O3 doped fiberoptic glass scintillators. These performance advances will address the limitations of existing detector technology by producing high quality images and fast scan times required for real-time NDE inspection. Performance measurements for prototype CsI(TI) scintillator converters are presented. With these new sensors the development of larger area fiberoptic taper based CCD detectors with millisecond data acquisition capabilities and high spatial resolution suitable for NDE applications will be possible.
The author explains the present status and the future trends in the digital video datastorage and computer datastorage markets. Secondly, he briefly discusses the role of opticaldatastorage devices for storing the...
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The author explains the present status and the future trends in the digital video datastorage and computer datastorage markets. Secondly, he briefly discusses the role of opticaldatastorage devices for storing the digital video data and computer data, and compare with several other storage devices. After he describes the present status of opticaldatastorage for digital video and computer applications, he explains the future prospects for DVD (Digita1 Video Disc) and relating technologies.
The background section of "A Media Maniac's Answer to Where storage Will be in 2000" provides a rich history that applies to this paper. This paper addresses at a high level, the many individual technolo...
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The background section of "A Media Maniac's Answer to Where storage Will be in 2000" provides a rich history that applies to this paper. This paper addresses at a high level, the many individual technologies available today in the removable storage arena. It discusses recording data on removable magnetic tapes, magnetic floppies, optical disks and optical tape.
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