High temperature and very low threshold current operation of a separate confinement heterostructure (SCH) AlGaInP/GaxIn1−xP (x=0.43) strained multiple quantum well (SMQW) lasers has been achieved. Continuous wave (cw) operation was observed up to at least 150 °C with an output power of more than 7 mW, which is the highest cw operating temperature ever reported for devices operating in the visible wavelength region. The characteristic temperature between 20 and 80 °C was 130 K. The threshold current and threshold current density at 25 °C were 13.9 mA for a 5×160 &mgr;m device and 430 A/cm2for a 80×770 &mgr;m device.