Extremely stable temperature characteristics of 1550-nm band, p-doped, highly stacked quantum-dot laser diodes

We fabricated 1.55-mu m band, broad-area, p-doped, 30-layer stacked quantum-dot (QD) laser diodes (LDs) grown on an InP(311)B substrate via a delta-doping method employing a strain compensation technique. We doped Be atoms to a depth of 5 nm from the bottom of each QD layer. The concentration of Be atoms doped in the InGaAlAs spacer layer was 1 x 10-(18) cm(-3). We observed a strong photoluminescence emission and a relatively coherent surface of QDs using atomic force microscopy. In addition, we observed that the fabricated QD-LDs had extremely stable temperature characteristics, and a characteristic temperature T-0 of more than 2156K was obtained. (C) 2017 The Japan Society of Applied Physics