High-power optically pumped type-II quantum well lasers

Stimulated emission in InAs/InGaSb/InAs/AlSb type-II quantum- well (QW) lasers was observed up to room temperature at 4.5 micrometer, optically pumped by a pulsed 2-micrometer Tm:YAG laser. The absorbed threshold peak pump intensity was only 1.1 kW/cm2 at 300 K, with a characteristic temperature T0 of 61.6 K for temperatures up to 300 K. We have also studied another type-II QW laser using 0.808-micrometer pumping sources with a much longer pulse length of 50 microseconds. The devices demonstrated a maximum output power of 1.6 W per facet at 83 K, with a corresponding differential external quantum efficiency of 24.8%.