Abstract We fabricated 1.55-µm 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× 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 …

… Abstract In this study, we fabricated 1.55 µm band p-doped 30 layers stacked quantum-dot
laser diodes (QD-LDs) using a strain-compensation technique on an InP(311)B substrate,
and we showed that the fabricated QD-LDs exhibit extremely stable temperature
characteristics. … So far, high characteristic temperature (T0) of more than 227 K [2] around
room temperature has hardly been reported at a 1.5 µm band, even though extremely high
T0, such as 320 K [3] and almost infinity (around room temperature) [4-5], has been reported …