High-temperature and continuous wave-operation of all-MOCVD grown InAs/GaAs quantum dot laser diodes with highly strained layer and low temperature p-AlGaAs cladding layer

Abstract

InAs/GaAs quantum dot laser diodes (QDLDs) on a GaAs substrate grown by utilizing all-metalorganic chemical vapor deposition (MOCVD) technology with a p-AlGaAs cladding layer are systematically investigated to produce 75 °C continuous-wave (CW) operation for the first time. First, the InAs quantum dots (QDs) in a dot-in-a-well (DWELL) structure formed by engineering the strained bottom InGaAs layer are successfully grown without detectable clusters, making it possible to increase the number of DWELL stacks effectively. To avoid degradation of the DWELL active layer during the high-temperature growth of the upper p-AlGaAs cladding layer, a detailed analysis of the p-AlGaAs cladding layer grown at low temperature is then carried out. The results of electron-channeling contrast imaging reveal that dislocations in the p-cladding layer are generated due to the accumulative strain of the DWELL and low-temperature growth. The fabricated InAs/GaAs QDLDs show good electrical and optical characteristics with O-band emission wavelength without high-reflection coating, indicating that the suggested growth technologies and the fabricated devices are promising options for future Si-photonic light source components.