Effects of Thermal Annealing on the Dynamic Characteristics of InAs/GaAs Quantum Dot Lasers

We investigated the effects of rapid thermal annealing (RTA) on the dynamic characteristics of the InAs/GaAs ten-layer quantum dot (QD) laser. Improvements in the temperature stability of bandwidth have been demonstrated upon annealing. We attribute the improvements to the following factors: 1) increase in internal quantum efficiency and 2) reduction in temperature dependency of differential gain. The increase in bandwidth at high temperature from the annealed QDs could be due to a reduction in the relaxation time on the order of 0.1 ps. More importantly, the RTA process resulted in better temperature stability in the differential gain and gain compression. This is beneficial for the development of uncooled high-speed QD lasers.