High performance AlGaAs-based laser diodes: fabrication, characterisation and applications

Data are presented on low threshold (<5 mA) 810 nm AlGaAs/GaAs and 980 nm InGaAs/AlGaAs quantum well laser diodes fabricated by low temperature liquid phase mesa melt-etching and regrowth. The base laser structures were grown either by MBE or MOVPE. Native oxides were used as a mask in the melt-etching and regrowth processes. Characterization of mirror catastrophical degradation of single mode laser diodes using traditional electrooptical parameters as well as the parameters of internal second harmonic generation and measurements of excess mirror temperature were performed. First results on pumping Nd doped optical fibers and medical applications using these laser diodes are reported.