Low threshold current 1.61 mu m InGaAsP/InP tapered active layer multiquantum well laser with improved coupling to cleaved singlemode fibre

The authors report low threshold current large spot size MQW BH lasers. Coupling losses to 10 mu m core cleaved singlemode fibre down to 4.1 dB have been obtained for devices with threshold currents of 4.9 and 15 mA at 20 and 80 degrees C, respectively.