Delay of the stimulated emission in GaAs laser diodes near room temperature

Abstract

Specific experiments were conducted to investigate the validity of various models designed to explain the long time delay between the application of a current pulse and the generation of coherent oscillations in certain GaAs junction lasers near room temperature. A particular model is developed which leads to good quantitative agreement with a number of different experiments performed in the temperature range between 200 and 300°K. It is found that all facets of the delay can be explained by assuming that a moderate number of optical absorbing centers (> 10 16 cm -3) causes optical losses which are sufficient to prevent the diode from lasing until these centers are filled by electrons injected into the p-side of the junction. It is postulated that the relatively long filling time of these traps is caused by a coulomb barrier such as is displayed by double acceptors in II–VI compounds.