Polarisation-dependent gain-current relationship in InGaAs/InGaAlAs/InAlAs SCH-MQW laser diodes

The polarisation-dependent gain spectra were measured at −190 C for InGaAs InGaAlAs InAlAs SCH-MQW laser diodes. The peak gain for TE polarisation was much larger (>750 cm−1) than that for TM polarisation, while the peak gain difference for InGaAs InAlAs DH lasers was as small as 15 cm−1. This peak gain difference for SCH-MQW lasers is surprisingly larger than that for GaAs GaAlAs MQW lasers. This difference was explained by the polarisation-related selection rules for optical transition.