Thermal characterization of mid-infrared quantum cascade lasers based on emitting spectra measurements

A mid-infrared laser characterization system has been developed, including a GPIB programmable I-P and I-V set-up based on direct waveform measurement with extraordinary wide pulse duration and duty cycle tuning range, in conjunction with a Fourier transform infrared spectroscopy system adopting double modulation technique. Based on this characterization system, the characteristics of gas-source MBE grown InAlAs/IngaAs/InP quantum cascade lasers, especially on their thermal property, have been evaluated. The results show that in the combination of I-P, I-V and spectral measurements at various driving pulse parameters, the thermal resistance, lasing conditions as well as spectral characteristics of the mid-infrared quantum cascade lasers could be deduced in successive. This characterization system is also a useful tool for the evaluation of other type diode lasers in the mid-infrared band.