Degradation Analysis of InP Buried Heterostructure Layers in Lasers Using Optical-Beam-Induced-Current Technique

The degradation of InP buried heterostructure layers in lasers during constant-power aging is investigated by using the optical-beam-induced-current (OBIC) technique. An increase in OBIC intensity after aging is detected in the InP layer, and it is shown that the carrier concentration around the p-type InP buried layer of the mesa sidewall is decreased by aging. This technique is useful for detecting changes in the carrier concentration in InP areas of several micrometers in lasers by using an incident light absorbed in an InP layer.