Investigation of degraded laser diodes by chemical preparation and luminescence microscopy

The gradual degradation of 808 nm InGaAlAs/AlGaAs and 940 nm InGaAs/AlGaAs high power laser diodes has been investigated by plane view photoluminescence microscopy of the active layer. 940 nm lasers degraded by long-term operation revealed broad dark bands. The defect pattern of intentionally overheated devices shows dark spots and lines for both laser systems.