High temperature operation of AlGaInAs/InP lasers

We discuss the design of uncooled lasers which minimizes the change in both threshold current and slope efficiency over the temperature range from -40 to 85°C. To prevent carrier overflow under high-temperature operation, the electron confinement energy is increased by using the Al_xGa_yIn_1-x-yAs/InP material system instead of the conventional Ga_xIn_1-xAs_yP_1-y/InP material system. Experimentally, the Al_xGa_yIn_1-x-y As/InP strained quantum well lasers show superior high temperature performances such as a small drop of 0.3 dB in slope efficiency when the heat sink temperature changes from 25 to 100°C, a maximum CW operation temperature of 185°C, a thermally-limited 3-dB bandwidth of 13.9 GHz at 85°C, and a mean-time-to-failure of 33 years at 100°C and 10 mW output power