Separate confinement heterostructure wafers grown by gas source molecular beam epitaxy have been used to prepare ridge waveguide lasers operating up to 50 °C. Laser threshold currents varied from 45 to 65 mA at room temperature and output powers up to 9 mW have been obtained with the external quantum efficiency of ∼36%. Gain profile measurements indicate excellent material uniformity. Frequency response flat to at least 2 GHz is consistent with the material free of interfacial traps or any capacitive shunt paths.