Evaluation of differential gain of 1.3 /spl mu/m AlGaInAs/InP strained MQW lasers

Differential gain (dg/dn) of AlGaInAs strained MQW lasers was estimated from relaxation oscillation frequency (fr), and compared with that of GaInAsP lasers. The estimated dg/dn of the AlGaInAs laser was 1.1/spl times/10/sup -15/ cm/sup 2/ at 25/spl deg/C, which was 1.4 times larger than that of the GaInAsP laser. The AlGaInAs laser also showed less temperature dependence of dg/dn. The degradation of dg/dn in 25-85/spl deg/C was only 28%, while that of the GaInAsP laser was 51%.