Jamal Bouayad-Amine

Low-chirp highly linear 1.55 mu m strained-layer MQW DFB lasers for optical analog TV distribution systems

The design and realization of highly linear 1.5- mu m distributed-feedback (DFB) lasers for optical analog TV distribution systems based on dispersive single-mode fibers are reported. A simple and comprehensive model relating grating characteristics to laser chirp was developed and used for optimization of the DFB grating. The model predicts that lasers emitting at wavelengths located in the positive slope sections of the DFB-reflectivity-wavelength characteristic have higher resonance frequencies and reduced chirp. The lasers were realized by using strained-layer multiple quantum wells for high differential gain and low alpha factor, antireflection (AR) coating of one laser facet for reduction of internal photon density, and a special grating design for low spatial hole burning and chirp reduction. >

Mode-locked laser realized by selective area growth for short pulse generation and optical clock recovery in TDM systems

We report on monolithically integrated active/passive coupled cavity mode locked lasers for 1.55 micrometer realized by selective area growth technology of InGaAs(P) quantum wells. Mode locked FP or DBR lasers are fabricated with an integrated cavity comprising up to three different band gaps. The devices emit short light pulses at around 10 GHz repetition rate with pulse width down to 8.7 ps. A time-bandwidth product of 0.5 is achieved for mode locked DBR lasers. Active/passive integrated mode locked laser is used for generation of optical 10 GHz clock signal from optical 10 Gb/s PRBS RZ data stream injected into the laser cavity.

Monolithic mode locked DBR laser with multiple-bandgap MQW structure realized by selective area growth

The realization of novel monolithically integrated multiple-segment pulse laser sources in InGaAsP MQW technology is reported. The MQW layers for all functional sections of these devices, the modulator, the active (gain) and the passive waveguide, as well as the Bragg section were grown in a single selective area growth (SAG) step by LP-MOVPE on SiO/sub 2/ patterned 2 inch InP substrates. Due to a properly selected pattern geometry 3 different bandgap regions with smooth interfaces are thereby formed along the laser cavity. The more than 4 mm long DBR lasers which exhibit a threshold current as low as 30 mA were mode locked by an intra-cavity electroabsorption modulator applying a sinusoidal voltage at around 10 GHz. In this way an optical pulse train with pulse widths <13 ps (measured with a streak camera) and high extinction ratio was generated. A time-bandwidth product of 0.5 close to the Fourier limit is obtained. This device is very attractive for signal generation in 40 Gb/s OTDM transmission systems at 1.55 /spl mu/m wavelength.

Realization and wafer test of InGaAsP/InP DFB laser/monitor OEICs

Wafer-testable distributed feedback (DFB) lasers and monolithically integrated monitor diodes are realized to replace the time consuming and expensive single-chip test procedure in semiconductor laser fabrication process. Laser-end facets and integrated monitor diodes are defined on 1.5- mu m InGaAsP/InP multiple quantum well (MQW) DFB laser wafers by reactive ion beam etching (RIBE). Using terminal electrical noise (TEN) measurement, the lasers are characterized directly on the wafer with respect to threshold current and single mode operation. Threshold currents down to 10 mA have been achieved for the integrated devices.<<ETX>>

Wide temperature 1.55 /spl mu/m InGaAsP SL-MQW DFB lasers with high reliability

The introduction of customer access services require low cost laser modules capable for operation in a wide temperature range. We report on optimization of laser structures for wide temperature characteristics of 1.55 /spl mu/m DFB lasers. Single lasers conventionally mounted and laser arrays flip-chip mounted on silicon-motherboards by Au/Au thermo compression bonding show excellent reliability. Stability of the laser-fibre coupling was high in temperature cycling and burn-in.