Thermal coefficient of InP-based quantum dot laser from cavity-mode measurements

The thermal coefficient of InP-based InAs quantum dot lasers covering its wavelength in the range of 1.55 μm were reported. The measurements were based on analyzing the junction temperature in the active region. Under continuous wave mode, a more than 24 °C junction temperature rise is obtained from the Fabry–Perot-cavity-mode shifts. The laser exhibits a coefficient of thermal resistance of 26.76 °C/W when the injection current increases from 90 to 500 mA. At the same time, a thermal resistivity of 8.62 °C cm/W with a thermal conductivity of 0.116 W/cm °C was also obtained from the thermal resistance. The thermal resistance might be a crucial factor of quantum dot laser diodes and has greatly impact on their performance.