Design and implementation of high precision temperature control system for semiconductor lasers

To solve the problem that stability of radiation wavelength and luminous intensity of a laser diode were affected easily by temperature, a high precision laser diode temperature control system was designed. Temperature acquisition circuit was designed by means of AD620 and LTC1864 and temperature control circuit by MAX1968 and LTC1655. The whole system was controlled accurately by a TMS320F2812 controller. Adaptive fuzzy proportion-integration-differentiation control strategy was proposed and the software was achieved. At the environmental temperature around 15℃, control precision of temperature was up to ±0.05℃ when the target temperature was set to 25℃ and 20℃ respectively. Experimental results show that the temperature control system has the advantages of fast response and high stability.