Direct influence of chip design and material composition on GaAs/GaAlAs laser diodes reliability

GaAs/GaAlAs laser diodes with the same overall structure, but with different aluminum contents in their respective active layer are submitted to accelerated aging tests. The two types of devices have drastically different behaviors during aging. Devices with the higher x sub Al (lambda = 825 nm) age fairly well, while devices with the lower x sub Al (lambda = 875 nm) degrade very fast. The failure mechanisms responsible for fast degradation of 875 nm lasers are investigated by scanning electron microscope experiments with the Electron Beam Induced Current (EBIC) mode. The results obtained show that the degradation primarily occurs close to the mirror facets and then propagates throughout the laser stripe.