cw narrow beam (AlGa)As multiquantum-well heterostructure lasers grown by molecular beam epitaxy

Proton-bombarded stripe-geometry (12×380 mm) lasers have been fabricated from multiquantum-well (MQW) heterostructure wafers grown by molecular beam epitaxy (MBE). cw current thresholds as low as 76 mA were obtained in spite of the reduced optical confinement factor G in these lasers. Such values are comparable with the lowest values obtained from similar stripe-geometry proton-bombarded double-heterostructure (DH) lasers. There also appears to be an improvement in the linearity and ’’tracking’’ of the output powers from the end mirrors in these MQW lasers over DH lasers using the same proton-irradiated stripe-geometry for current injection. Such improvements are results of a better lateral mode stabilization with injection currents. Significant beam width reduction in the direction perpendicular to the junction plane was obtained. The half-power full-width q⊥ as narrow as 25° was obtained. For the stripe-geometry lasers fabricated from some MQW wafers, the characteristic temperature T0 in the current threshold-temperature dependence can be as high as 293 °C in the temperature range of 10–70 °C.