SS Assass SXSYNXSYS says as als. Sa...Y. Navaraayaay R.A. Morgan, K. Kojima, T. Mullally, G.D. Guth, M.W. Focht, R.E. Leibenguth, and M. Asom, High-Power Coher ently Coupled 8x8 Vertical Cavity Surface Emitting Laser Array, Appl. Phys. Lett. 61, Sep. 7, 1992, pp. 1160–1162. D.G. Deppe, J.P. van der Ziel, Naresh Chand, G.J. Zydzik, and S.N.G. Chu, Phase-Coupled Two-Dimensional A1GaAS-GaAS Vertical–Cavity Surface-Emitting Laser Array, Appl. Phys. Lett. 56, May 21, 1990, pp. 2089–2091. Xuefei Tang, Jan P. van der Ziel, Fellow IEEE, Bing Chang, Ralph Johnson, Member IEEE, and Jim A. Tatum, Obser vation of Bistability in GaAs Quantum-Well Vertical-Cav ity Surface-Emitting Lasers, Journal of Antum Electronics, 3 pages. European Search Report for EP 99 123311, May 25, 2000, 3 pages.

We describe in-situ transmission electron microscope observations of the relaxation of strained layer GeSi/Si epitaxy. Dynamic observations of misfit dislocations in these structures reveal that dislocation nucleation and growth activation barriers, as well as interactions, limit the rate at which strain is relieved. The equivalence of threading and misfit dislocations in this system is demonstrated. Extension of the principles learnt from these single layer experiments to threading dislocation propagation through multilayer structures, enables us to understand the relative inefficiency of GeSi/Si strained layer superlattices in blocking threading dislocations.

In this letter, we have developed a tandem electroabsorption modulator with an integrated semiconductor optical amplifier that is capable of both nonreturn-to-zero and return-to-zero (RZ) data transmission at 40 Gb/s. The tandem modulator consists of a broad-band data encoder and a narrow-band pulse carver. The pulse carver is able to produce 5-ps pulses with more than 20 dB of extinction. The on-chip semiconductor optical amplifier provides up to 8.5 dB of fiber-to-fiber gain and enables the modulator to be operated with zero insertion loss. Devices have been realized with greater than 40-GHz bandwidth, and 13-dB dynamic extinction for a 2.5-V swing. For optimized designs bandwidths of nearly 60 GHz: have been realized. Using these devices penalty free RZ data transmission over a 100-kin dispersion compensated fiber link has been demonstrated with a received power sensitivity of -29 dBm.

NRZ and RZ data transmission at 40Gb/s are demonstrated for the first time using buried heterostructure tandem electro-absorption modulators monolithically integrated with a semiconductor optical amplifier and input/output spot-size converters. Zero penalty RZ transmission over a 100km dispersion managed link is achieved.

Electro-absorption modulated sources are likely to be key components in the evolution of optical communication line rates from 10Gb/s to 40Gb/s. Compared with the LiNbO3 alternative EA modulators are more compact, less expensive, compatible with monolithic integration, and offer lower drive voltages. However, fabrication complexity and open questions concerning the fidelity with which they transmit information make the exact role of 40Gb/s EA modulators in advanced tm systems somewhat unclear. In this talk we will describe the design, fabrication, and transmission, performance of 40Gb/s EA modulators configured for both NRZ and RZ operation. For NRZ transmission the device structure consists of a short MQW modulator with spot-size converters on the input and output ends. Tandem EA modulators for pulse carver and data encoder functions were monolithically integrated along with a semiconductor optical amplifier (SOA) and input / output spot-size converters to explore RZ transmission. Both single and tandem modulator designs are realized using semi-insulating InP current confined buried heterostructure technology. Modulation bandwidth of better than 50 GHz is demonstrated along with a fiber-to-fiber insertion loss of less than 6dB for the single modulator design. The carver / encoder configuration with onboard SOA yields better than 0dB insertion loss. Transmission impairments were studies using both designs.

We report on a fully functional 2.5-Gb/s electroabsorption (EA)-modulated wavelength-selectable laser module meeting all long-haul transmission requirements for stability, chirp, power, and linewidth over 20 channels on a 50-GHz grid. Based on a highly integrated InP chip comprising a distributed Bragg reflector (DBR) laser, semiconductor optical amplifier, power monitor, and EA-modulator, the compact transmitter module also contains optics and control circuits necessary to ensure simultaneous long-term wavelength and mode stability. We have achieved 2.5-Gb/s transmission on all 20 channels over 680 km of standard fiber.

We describe the design, fabrication, and performance of a five-element quarterwave-shifted distributed feedback laser array with monolithically integrated spot size converters intended for use as a multiple-wavelength source in dense wavelength-division telecommunications systems. Facet power in excess of 10 mW with less than 150 mA bias and longitudinal side mode suppression greater than 40 dB were routinely achieved. Narrow far-field full-width at half-maximum angles of 6.9/spl deg//spl times/16.3/spl deg/ provided 3.5-dB coupling loss into single-mode fiber with 1.0-dB misalignment tolerances of /spl plusmn/2.0 /spl mu/m. With /spl plusmn/10/spl deg/C thermal tuning, 22 1555-nm channels spaced by 50 GHz were accessed with this device. Thorough field evaluation indicates that such a device is consistent with manufacturing requirements.

We have fabricated vertical-cavity surface-emitting lasers (VCSELs) which, for the first time, effectively combine a shallow ion implanted aperture, for current confinement under a thin highly conducting lateral current injection layer, and an independent index guide for optical beam confinement (I/sup 2/-VCSELs). Both features are possible only because they are made before a top dielectric mirror is deposited and patterned, and are photolithographically defined for improved size reproducibility compared to oxide-confined designs. The devices emit near 980 nm and have optical power outputs of 1 mW at 2.5-mA input. The 12-VCSEL design also easily incorporates coplanar contacts allowing us to operate flip-chip bonded I/sup 2/-VCSEL's on silicon test chips at data rates of nearly 1 Gb/s.

We describe the first integration of vertical-cavity surface-emitting laser arrays with gigabit-per-second CMOS circuits via flip-chip bonding.

A method of wafer bonding is demonstrated which significantly reduces the thermal expansion mismatch stress, by removing the substrate before the high temperature anneal, thereby allowing elastic accommodation of the thin device layers. Record low dark current Si/InGaAs pin detectors have been realized

One of the principal advantages of Vertical-Cavity Surface-Emitting Lasers (VCSEL's) is their high power conversion efficiency (from electrical to optical) at low power levels, in the lmW regime.

Test results from a two-dimensional array of 50 CMOS smart-pixel receivers equipped with both optical and electrical outputs are reported. Parallel testing of the array at 311 Mbit/s indicates a /spl sim/2.5 dB penalty for operation of nearly the whole array as compared to a single element.

The use of fiber optic communication is becoming widespread in high-speed local area networks.

The optoelectronic multiplexing and demultiplexing of data is a common operation on optical communication links, and one that is becoming more important as these links become increasingly prevalent. These operations permit multiple electronic data streams to be combined onto and removed from a single optical link, taking advantage of the high link-bandwidth available. Demultiplexing places particularly stringent demands on optoelectronic components. In this paper, we describe a method for demultiplexing optical data that utilizes clocked-optical receivers. This method permits the extraction of signals without the need for optoelectronic circuits operating at the full multiplexed-data rate, provided synchronization and timing information are available.