Abstract

The reliability and lifetime of AlGaAs single quantum well (SQW) lasers are critical to technologies such as optical recording and communications. The presence of defects and imperfections at the facets of semiconductor lasers is known to have detrimental effects on laser reliability. The occurrence or catastrophic optical damage (COD) in SQW lasers has been demonstrated to be tied to high laser facet temperature. In order to increase the reliability of lasers, it is important to reduce the defect density at the facet. Annealing (heat treatment) of the laser structure is a possible way to reduce the facet defect density. Unfortunately, annealing of the whole structure could induce unwanted dopant diffusion in the laser cavity, possibly causing problems in the control of the laser's characteristics. The process of localized burn-in described here utilises the heat generated at the facets intrinsically by the laser diode operation, It involves operating uncoated SQW lasers at high power in an inert environment (such as He or N₂) for a short period of time. Such a procedure generates heat locally at the facets without significant heating at the bulk laser cavity. Subsequent operation of these burnt-in laser's in air shows a substantial improvement of their lifetime when compared to lasers without the treatment. These results suggest an increase in stability of laser facets after burn-in which has been verified by Raman microprobe measurements of the facet temperature.

© 1993 Optical Society of America