Epitaxie und Chiptechnologie von GaAlAs-Halbleiterstrukturen fuer Diodenlaser hoher Leistung bei 808 nm Schlussbericht

The industrial application of diode pumped YAG-Lasers will importantly depend of the availability of proper laser diodes. Beside the necessary technical data as efficiency, optical output power and lifetime the aspect of the costs and therefore homogenity and reproducibility of the laser characteristics, will be of great importance. The project target was to realize high power laser diodes which fulfill the above requirements. Different quantum-well structures in the materialsystem GaAlAs/GaAs, InGaAs/GaAs and InGaAlAs/GaAs were realized, tested and processed into chip- and bar-structures with different lateral geometrie. The fabrication technology was improved. The degradation-behaviour of mounted chips (Siemens) and bars (Jenoptik Laserdiode) was investigated. In the GaAlAs/GaAs material system, the achieved homogenity and photolumineszence is #<=##+-#1 nm at 98% of all wafers from 60 epitaxial runs in one sequenz. Laserdiodes with 200 #mu#m active width and with (NH_4)_2S_x-treated laser facets give values for catastrophic optical mirror damage > 4,8 W CW. At 2 W optical output power the total conversion efficiency is 40%. The behaviour of degradation was drastically improved by using strained-layer structures. On account of the actual testresults lifetimes of > 10.000 h with InGaAs/GaAs-quantum-well structures at 1 W CW are expected. The realized quantum-well structures and the improved fabrication process are the fundamentals for the present fabrication of samples as well as the basic for further research and optimization work. (orig.)Available from TIB Hannover: F95B1352+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman