Development of temperature control system of DFB laser using analog PID control

The control precision and stability of emitting wavelength of distributed feedback laser directly determines the measurement accuracy of detection system that uses infrared distributed feedback laser excitation light source as the core section. A temperature control system of distributed feedback laser was developed utilizing analog PID control. Simulated proportional-integral-differential temperature forward control module and real-time temperature backward acquisition module were adopted to control temperature. Emitting wavelength of 2 049 nm DFB laser was used in temperature control experiment. Results show that system temperature control stability is 0.05℃, and the stability time is less than 30 s. Meanwhile, spectrum test experiment was conducted using the developed temperature control system to control the proposed distributed feedback laser. The results show that the emitting wavelength of laser is linear with its working temperature while the laser drive current is fixed.