Abstract
A rapid degradation mode is observed for most of our long‐life lasers (⩾5000 h) within the first 100 h of cw operation at room temperature. This degradation saturates thereafter and can be recovered by annealing at temperatures below 150 °C. It is shown that the reduction of gain as a result of decrease in recombination efficiency is the cause for the degradation. Addition of Al(⩾6%) in the active region is found to eliminate the degradation.