Temperature dependent optoelectronic properties of a non-intentionally created cleaved-coupled-cavity laser

A 1300 nm InGaAsP laser diode, degraded after the application of high voltage ESD pulses in forward direction, showed after degradation a strong longitudinal mode suppression, resulting in a single mode emission spectrum identical to the one of a cleaved-coupled-cavity laser. The room temperature threshold current after ESD induced degradation increased by about 50% and the differential quantum efficiency dropped substantially. However, even after degradation in a wide temperature range stable single mode laser operation has been achieved.