High output power operation of 1.3 μm strained MQW lasers with low threshold currents at high temperature

We have investigated the temperature dependencies of the output power and the threshold current for compressively strained InGaAsP MQW lasers on well number. Smaller well number means larger temperature dependencies of the slope efficiency as well as the threshold current due to enhanced carrier overflow, while greater well number means degradation in crystalline quality that lowers the reliability of the laser. The 1.3 μm strained MQW laser with a compressive strain of 1.0% and 7 wells shows the highest output power of 6.8 mW and the lowest threshold current of 5.5 mA at 85°C, and the lowest variation in output power of 2.0 dB from 25°C to 85°C at the injection current of 50 mA. These characteristics show that the optimized lasers are suitable for light sources of the optical access networks