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