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ABSTRACT: The DARPA CORONET program is laying the foundations for a next generation IP-over-optical network that supports 100 Tbps of traffic and provides rapid, on-demand, switched wavelength services. The wavelength services are very dynamic, with setup times of 100 ms and holding times as short as a few seconds to a minute. A major management challenge is designing a provisioning protocol for the dynamic services. We describe in this paper a 3-way handshake (3WHS) protocol that meets the service requirements, and we provide simulation results of the performance of the 3WHS.
Military Communications Conference, 2009. MILCOM 2009. IEEE; 11/2009
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ABSTRACT: We present a method for impairment-aware routing in transparent networks that allows constraint dependencies and objectives minimizing regeneration cost. The method is guaranteed to identify impairment-feasible paths when they exist and uses transponder resources efficiently.
Optical Fiber Communication Conference, 2004. OFC 2004; 03/2004
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ABSTRACT: The choice of a storage technology for video-on-demand servers
depends on a variety of factors. The primary technical factor is the
number of video streams that the technologies can provide, while the
initial cost of the memory technologies will play a major role in the
final system price. This article compares various storage technologies
and storage architectures for video-on-demand servers and analyzes the
relative costs and performance of each
IEEE Transactions on Circuits and Systems for Video Technology 09/1995; · 1.65 Impact Factor
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ABSTRACT: The lateral definition of vertical‐cavity surface‐emitting lasers (VCSELs) using buried ion implantation and the optimization of this process are described. A VCSEL structure was grown, and lasers were laterally defined using deep proton implantation process. The buried implantation process created a funnel shape current path into the laser active region. By optimizing this process, a serial resistance of 50 Ω, 2.1 mW continuous wave output power and a 1 V lower ‘‘turn on’’ voltage were achieved for an optimum dose of 1×10<sup>1</sup><sup>3</sup> ions/cm<sup>2</sup> for 10×10 μm<sup>2</sup> lasers. These improvements were achieved, while retaining the same low threshold current level of fully confined VCSELs.
Applied Physics Letters 08/1991; · 3.84 Impact Factor
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ABSTRACT: The first successful hybrid integration of Si CMOS drivers with InGaAs-GaAs vertical cavity surface emitting (VCSE) laser arrays operating at bit rates up to 622 Mbit/s is described. This technology has potential for low cost, high-bandwidth communication links in optical interconnect and optical computing applications. The simple, power-efficient driver circuits were implemented in a standard 1.0 mu m CMOS process.
Electronics Letters 07/1991; · 0.96 Impact Factor
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ABSTRACT: The dynamic, polarization, and transverse mode characteristics of
strained InGaAs-GaAs quantum well vertical cavity surface emitting
lasers (VCSELs) emitting at 0.98 μm are investigated. The dynamic
behavior of VCSELs with high and low operating voltages and series
resistances is compared. A large wavelength chirp in the lasing spectrum
was observed for the lasers with high voltage/resistance, even under
low-duty-cycle pulse operation. This is thought to be due to resistive
heating close to the laser junction. It is observed that the transverse
mode structure of VCSELs and their dependence on laser dimensions and
drive current are highly analogous to those of edge emitting lasers,
whereas the polarization characteristics of the two types of lasers are
significantly different
IEEE Journal of Quantum Electronics 07/1991; · 1.88 Impact Factor
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ABSTRACT: We report a technique of integrating planar Fresnel microlenses with InGaAs/GaAs-based vertical-cavity surfacee-mitting laser arrays by selectively ion-beam milling the substrate. Depending on the application, one can focus, collimate, and bend the individual laser beams using such microlenses. An example is presented where a 32 x 32 array of microlenses, each with an aperture of 80microm and a focal length of 108 microm is integrated with a laser array. As expected, arrays of focused beams, each with a 2-microm spot size, are generated at a distance of approximately 110 microm.
Optics Letters 06/1991; 16(12):919-21. · 3.40 Impact Factor
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ABSTRACT: Vertical cavity surface‐emitting lasers are integrated with GaAs/AlGaAs heterojunction phototransistors to yield optically controlled lasers. The two‐terminal device operates in several modes: As an amplifier with a large signal, external optical gain of 5, as in optical logic gate, and as an optically or electrically triggerable latch. The optical AND gate has an output on‐to‐off ratio of 10:1. Although the device has no optical feedback, latching is achieved with appropriate biasing through impact ionization. The device structure is advantageous for forming large two‐dimensional arrays for optical signal processing.
Applied Physics Letters 06/1991; · 3.84 Impact Factor
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ABSTRACT: The design, fabrication and characterisation of 1024-element matrix addressable vertical cavity surface emitting laser (VCSEL) arrays are described. A strained InGaAs quantum well VCSEL structure was grown by molecular beam epitaxy and an array of 32*32 lasers was defined using a proton implantation process. A matrix addressing architecture was employed, which enables the individual addressing of each of the 1024 lasers using only 64 electrical contacts. All the lasers in the array, measured after the laser definition step, were operating with fairly homogeneous characteristics, threshold current of 6.8 mA and output quantum differential efficiency of about 8%.
Electronics Letters 03/1991; · 0.96 Impact Factor
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ABSTRACT: The basic issues involved in the growth by molecular beam epitaxy (MBE) of vertical-cavity surface-emitting lasers (VCSELs) are discussed. Successful VCSEL optical information processing applications demonstrated to date are discussed, including two-dimensional arrays, holographic memory retrieval, optical addressing, wavelength division multiplexing, and tunable VCSEL operation.
MRS Proceedings. 12/1990; 228.
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ABSTRACT: A planarity preserving method for the definition of vertical‐cavity surface‐emitting lasers (VC‐SEL) is described. A strained‐layer InGaAs quantum well VC‐SEL structure was grown and lasers were laterally defined using a tailored deep proton implantation process. In these lasers we obtained low threshold current densities of 1000 A/cm<sup>2</sup> and efficient cw operation. This method facilitates large‐scale integration of VC‐SEL devices.
Applied Physics Letters 07/1990; · 3.84 Impact Factor
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Lasers and Electro-Optics Society Annual Meeting, 1988. Conference Proceedings. LEOS '88.; 12/1988
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ABSTRACT: We present TE and TM waveguide loss measurements of partially disordered GaAs/AlGaAs quantum well separate confinement laser structures. Disordering is accomplished by silicon ion implanation and subsequent annealing. Propagation losses as low as 9 cm<sup>-</sup><sup>1</sup> are observed at the lasing wavelength of the corresponding untreated laser wafer. The waveguides are shown to be compatible with fabrication and dimensional requirements of high quality semiconductor lasers; ridge waveguide lasers fabricated in unimplanted portions of the same wafer exhibit threshold currents of only 8 mA. The results show that impurity‐induced quantum well disordering is suitable for monolithic integration of low‐threshold quantum well lasers and transparent optical waveguides.
Applied Physics Letters 11/1988; · 3.84 Impact Factor
