Self-Sustained Pulsation Appearance in InGaAsP/InP DH Lasers during Accelerated Operation

Self-sustained pulsation (SSP) has been observed in InGaAsP/InP double heterostructure (DH) lasers during accelerated operation. The development of SSP depends on the number and absorption coefficient magnitude of dark defects associated with degradation. The absorption coefficient of a dark defect that induces SSP is experimentally estimated to be from 300 to 600 cm -1 . The frequency of the SSP is a linear function of the square root of the current density. The fact that dark defects in the active region are one origin of SSP in InGaAsP/InP lasers, as well as AlGaAs/GaAs lasers, is made clear.