High-temperature operation (to 180  °C) of 0.98 μm strained single quantum well In0.2Ga0.8As/GaAs lasers

Graded refractive index In0.2Ga0.8As/GaAs strained single quantum well ridge lasers, emitting at 0.98 μm, have been grown by molecular beam epitaxy. For pulsed excitation, laser operation has been obtained up to 180 °C for 1016-μm-long lasers. This record high operating temperature results from a high T0=160 °C characteristic of these long lasers. Anomalous threshold current dependences on temperature are found for shorter lasers and are attributed to band filling at high current densities and a shift of the emission from the n=1 quantum level to the n=2 level.