Quantum modeling of semiconductor gain materials and vertical-external-cavity surface-emitting laser systems

This article gives an,overview of the microscopic theory,theory used to quantitatively model a wide range of semiconductor laser gain materials. As a snapshot of the current state of research, applications to a variety of actual quantum-well systems are presented. Detailed theory experiment comparisons are shown and it is analyze how the theory can be used to extract poorly known material parameters. The intrinsic laser loss processes due to radiative and nonradiative Auger recombination are evaluated microscopically. The results are used for realistic simulations of vertical-external-cavity surface-emitting laser systems. To account for nonequilibrium effects, a simplified model is presented using pre-computed microscopic scattering and dephasing rates. Prominent deviations from quasi-equilibrium carrier distributions are obtained under strong in-well pumping conditions

Optically pumped semiconductor vertical external cavity surface emitting lasers

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Efficient coupling of several broad area laser diodes into an optical fiber

A high brightness, fiber coupled optical pumping system is described based on readily available optical components. Operating at a wavelength of 670 nm we have achieved an output of 1.25 W from a 50 mu m core diameter fiber (0.22 NA) and 3.5 W from a 100 mu m core diameter fiber (0.22 NA). This represents a six- to eightfold increase over commercially available systems at that wavelength. The design is generic and can immediately be implemented at other wavelengths, where high brightness pumping systems are not commercially available. The design and implementation are detailed

Novel GaIn medium design for short-wavelength vertical external-cavity surface-emitting laser

We report on a novel material developed as the gain medium for a vertical-external-cavity surface-emitting laser (VECSEL) operating around 850 nm. The new material departs from the conventional approach of using GaAs as the quantum-well (QW) material and expands the previously reported concept of using InAlGaAs QWs. The inclusion of indium pins dislocation propagation into the active region of the VECSEL. Crucial for the success of this design is also the development of indium and phosphorous containing quinternary strain-compensating layers. These surround the QWs and provide a more substantial resistance to defect propagation. Results are presented for stable high-power single spatial mode operation of a laser based on this material together with measurements of the unsaturated gain of the device and the characteristic temperature for the threshold power