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Discusses a study that fabricated and evaluated indium gallium arsenide/gallium arsenide/aluminum gallium arsenide quantum well lasers. Comparison of the lasers with (indium) gallium arsenide devices; Step-graded quantum well heterostructure indium gallium arsenide laser; Gradual degradation-limited lifetimes of the strained-layers.

Reports on the fabrication of an integrated manifold of quantum-well lasers by metalorganic chemical vapor deposition. Aluminum mole fraction profile for the quantum-well doublet structure; Performance comparison.

Describes the performance of graded-index separate-confinement heterostructure single quantum well lasers designed for optical pumping applications. Comparison between single quantum and double heterostructure devices; Production of laser structures; Investigation on the variation in lasing wavelength with active layer aluminum composition.

Presents information on a study which observed amplified spontaneous emission involving the n=1 and n=2 confined states at room temperature in gallium arsenide graded-barrier single quantum-well laser material grown by metalorganic chemical vapor deposition. Estimated maximum excitation power density coupled into the sample; Discussion on the graded-index separate confinement heterostructure single quantum-well; Use of photopumping.

The condition for the fundamental mode operation in a single quantum well laser with vertically integrated passive waveguides has been studied. With proper choice of parameters, transverse beam divergence as low as 19° has been achieved. [ABSTRACT FROM AUTHOR]

The degradation rates for continuously operated quantum well lasers with natural facets have been investigated. For most devices, a simple functional relationship exists between degradation rate and operating current density and the data suggest that the role of optical flux is secondary. For device configurations with high excess nonradiative current densities, however, exceptionally high degradation rates are observed and a correlation is proposed. [ABSTRACT FROM AUTHOR]

The carrier recombination rate in GaAs-AlGaAs single quantum well layers is investigated using a small-signal technique for carrier densities from 1017 to 1019/cm3. For carrier densities up to mid 1018/cm3, the inverse of the differential carrier lifetime, 1/τd, increases linearly with the carrier density. The differential rate, however, saturates at higher carrier densities and remains nearly constant for carrier densities higher than 1019/cm3. The deviation from the bulk recombination behavior is due to a portion of the injected carriers populating the semicontinuum states where the rate for the radiative transition is much smaller. The experimental data indicate that the runaway increase of threshold current with decreasing cavity length commonly observed in the short-cavity lasers is mainly due to the loss of carrier confinement at high carrier densities rather than due to fast carrier-depleting processes, such as Auger recombination. [ABSTRACT FROM AUTHOR]

Data are presented on the efficiency, reliability, and temperature dependence of wavelength and threshold for strained-layer InxGa1-xAs-GaAs (x∼0.25, λ>1.06 μm) separate confinement heterostructure lasers for several thicknesses near the critical thickness. Devices with well thicknesses of 100 Å exhibit excellent time-zero characteristics and reliability, while those with 143 Å wells have higher initial thresholds and degrade rapidly. [ABSTRACT FROM AUTHOR]

Degradation-induced dark line defect growth velocities have been found to be inversely proportional to the operating temperature in quantum well lasers under current injection. A model has been developed, which considers the differing band structure and role of deep levels in quantum well structures as opposed to conventional double-heterostructure lasers. Our findings have significant implications for device yield since they suggest nontraditional screening strategies that recognize temperature as a decelerant for the sudden failure mode. [ABSTRACT FROM AUTHOR]

Thermally induced threshold wavelength shifts of 50 nm have been observed in short cavity length diode lasers fabricated from thin quantum well AlGaAs. Analysis suggests that the high-energy radiation is generated by transitions between the n=2 level in the conduction band and the n=2 heavy hole level in the valence band. The threshold characteristic temperature (T0) of the laser material is found to be a strong function of cavity length. [ABSTRACT FROM AUTHOR]

AlGaAs quantum well lasers operating at 808 nm with cw lifetimes exceeding 30 000 h are reported. The devices, grown by metalorganic chemical vapor deposition, were driven at 200 mW total optical power and were not coated. A study of diode configuration shows that longevity is enhanced by using a long cavity and by junction-down mounting. [ABSTRACT FROM AUTHOR]

A single quantum well laser with a 2-mm-wide aperture has exhibited low threshold current density and nearly 100% packing fraction. The lateral structure relies on epitaxial growth on a corrugated substrate to frustrate radiative lateral processes and it thus eliminates the need for isolation at least for incoherent operation. Threshold current densities are comparable to those for low-power devices, and slope efficiencies remain undiminished to our current limit where 10.7 W per facet is attained. The aperture size is limited only by our fixturing arrangement. [ABSTRACT FROM AUTHOR]

Pseudomorphic InGaAs lasers with cw operating lifetimes exceeding 5000 h are reported for the first time. The device structure, grown by low-pressure metalorganic chemical vapor deposition, incorporates a single In0.37Ga0.63As strained-layer quantum well in a GaAs/AlGaAs graded-index separate confinement heterostructure. These devices are remarkable for their immunity to sudden failure and for their (gradual) degradation rates which are comparable to the best GaAs lasers. [ABSTRACT FROM AUTHOR]

The electron-beam-induced current technique has been used to disclose dark-line patterns in degraded AlxGa1-xAs quantum well lasers. At least four distinct types of pattern exist, each being characteristic of a particular device structure. [ABSTRACT FROM AUTHOR]

cw power conversion efficiencies of 57% have been obtained on uncoated diode lasers emitting nearly 300 mW per facet. This performance is achieved by using a low-resistance graded index separate confinement single quantum well AlGaAs/GaAs structure with high (84%) differential quantum efficiency and low threshold current. [ABSTRACT FROM AUTHOR]