Research on Dual-Channel High-Precision Laser Current and Temperature Control System

This study addresses the core challenge of output optical frequency and wavelength instability in semiconductor lasers within high-precision quantum sensing systems, which is caused by drive current fluctuations and operating temperature drift. A dual-channel, high-precision current drive and temperature control system was successfully developed. The drive circuit employs a Howland circuit, which integrates an adjustable current-limiting protection circuit based on a comparator and DAC. This effectively reduces circuit noise and allows for the flexible setting of current-limiting thresholds to accommodate different lasers. To address the poor stability and large steady-state error of traditional PID control systems caused by the nonlinear characteristics of NTC thermistors, a segmented adaptive PID control strategy was proposed. This achieved precise temperature regulation within ±0.005°C across the 20–40°C control range.