Shenbo Zhu, Yuan Li, Fengmin Cheng, Shuman Liu, Junqi Liu, Lijun Wang, Ning Zhuo, Shenqiang Zhai, Yonghai Chen, Jinchuan Zhang, Fengqi Liu. "Measurement of active region temperature in THz quantum cascade lasers by micro-photocurrent spectroscopy." Applied Physics Letters, 2025. doi:10.1063/5.0255489