Wide-temperature-range operation of quantum-dot LC-DFB lasers from -40°C to 110°C

By optimizing the grating period and adopting a high-temperature-tolerant p-doped quantum-dot (QD) laser structure, we demonstrate an O-band laterally coupled distributed feedback (LC-DFB) laser exhibiting stable single-longitudinal-mode operation over an extended temperature range. The device maintains an SMSR greater than 50 dB and shows a threshold current variation of only 7.7 mA from -40°C to 90°C. Single-mode lasing is further sustained up to 110°C, highlighting the excellent thermal robustness of the proposed QD LC-DFB design.