Very low threshold operation of quantum cascade lasers*
Yan Fang-Liang, Zhang Jin-Chuan†, Yao Dan-Yang, Liu Feng-Qi‡, Wang Li-Jun, Liu Jun-Qi, Wang Zhan-Guo
       
Peak power versus current of the QCL operated in pulsed mode at different heat sink temperatures between 20 °C and 50 °C. Inset shows the temperature dependence of the threshold. The dotted line denotes an exponential fit to the experimental data.