Observation of Dark Defects Related to Degradation in InGaAsP/InP DH Lasers under Accelerated Operation

Abstract
Generation and development of dark line and dark spot defects (DLD/DSDs), and related increases in room temperature pulse threshold current are investigated on InGaAsP/InP double heterostructure (DH) lasers under 10 kA/cm2 forward current density and (250±25)°C junction temperature operation. The average development speed of DLDs is estimated to be about 0.3 µm/h. Temperature rise is confirmed at DSDs with an infrared thermometer. These dark defects have geometrical correlation with etch pit features in the InGaAsP/InP heteroboundary. They are considered to be developed by carrier injection.