Reseach On Temperature Control System Of High-power Laser Diode

The output power of high-power semiconductor lasers is greatly influenced by the temperature change, small temperature change can cause large fluctuation in output power and wavelength, threshold current and life will be affected. Therefore, the operating temperature is very important for semiconductor lasers. Stable operating temperature has to be provided to the semiconductor lasers and its control is extremely significant.Thermoelectric cooler is a solid pump based on Peltier effect which has small size, light weight and no noise. Temperature control using thermoelectric cooler has incomparable advantages, which can ensure high temperature stability. At a given ambient temperature condition, the selection of thermoelectric cooler is a key to the effective temperature control. This paper particularly analyzes the mathematical model of thermoelectric cooler and establishes the corresponding spice model. Before an effective method of selection is presented, working characteristics under different working conditions is analyzed using the simulation model.Different working characteristics under heating and cooling conditions require sub-control to obtain the best control effect. As the temperature control system is a first order lag element of inertia, this paper adopts theoretical analysis and experimental testing method to determine the transfer function under the heating and cooling conditions. For determining the transfer function, this paper determines the parameters of heating and cooling control in SIMULINK simulation and parameter tuning method. Sub-control can guarantee good temperature stability in both heating and cooling cases.Traditional temperature control circuit is not suitable for high power-driven , this paper gives an improved H-bridge circuit. Using H bridge driver IC IR2110 can make H bridge achieve a high power drive with the bridge arm bootstrap charge. Programmable logic device implements the drive signal distribution and dead-time control.A detailed theoretical analysis, simulation and test verification is carried out to semiconductor laser temperature control system from the device selection, control method, and software and hardware design. Device selection method, temperature control method and hardware for high-power drive system can effectively achieve stable temperature control of semiconductor lasers, which has good guidance and practical value for laser diode temperature control systems'development.