Improved performance of 1.3 μm multilayer InAs quantum-dot lasers using a high-growth-temperature GaAs spacer layer

The use of high-growth-temperature GaAs spacer layer (HGTSL) to inhibit threading dislocation formation in long wavelength InAs/InGaAs DWELL lasers was demonstrated. The use of these HGTSLs was found to be particularly important for multi-DWELL devices designed for single channel operation in the 1.3 μm telecommunications band with wavelength requirements of 1.31±0.02 μm. The HGTSL inhibits threading dislocation formation resulting in enhanced electrical and optical characteristics. The results show that incorporation of these spacer layers allows the fabrication of multilayer quantum-dot devices emitting above 1.3μm, with extremely low room-temperature threshold current densities and with operation up to 105°C.