Observation of dark-line degradation sites in AlGaAs/GaAs DH laser material by etching and phase-contrast microscopy

Abstract

We have observed precise geometrical correlation between ``dark‐line''‐type defects characteristic of the rapid degradation mode of (optically pumped) AlGaAs DH laser material with etch pit features in the vicinity of the GaAs/p‐Al_x Ga_1−x As heteroboundary. The patterns observed strongly suggest that the degradation is associated with creation or possibly decoration of dislocation lines inclined to the {100} junction plane, and that the commonly observed 〈100〉 orientation of the dark lines is due to statistical aggregation of such inclined lines.