High Power Laser Diode Fiber Coupling Module Temperature Control Technology

Laser diode (LD) is a new compact light source, it has many of the advantages of small volume, light weight, high conversion efficiency, low power consumption, power supply is simple and can be directly modulated, the structure is simple, safe, and their use wide range of areas. Its application areas including beauty, medical, material handling, aerospace technology, and military supplies. In recent years, the technology has been rapid development, in all directions have been an unprecedented increase, including high-power, high brightness fiber-coupled laser diode modules people’s attention more and more. The material of the semiconductor laser and its structure determined by the great influence of temperature, temperature output from the semiconductor laser wavelength and the output power change, thus affecting the normal use of the semiconductor laser, so that the working life of the semiconductor laser also because of the impact of high temperature and shortening. Influence of temperature on the semiconductor laser is more and more important to get attention. Semiconductor lasers for a stable and constant temperature is important, to get the semiconductor laser to achieve steady state operation, a stable operating temperature of the semiconductor laser is stable premise, the study of high power semiconductor laser having a temperature control extremely important.In this thesis, the output power of10W for high-power Laser diode optical coupling module based on research, the heat generated by Laser diode as the basis for many semiconductor cooling device selection, and then use the selected semiconductor refrigeration for the main refrigeration devices and fiber-coupled semiconductor laser design module temperature control system hardware circuit, including temperature measurement circuit, control circuit, monitoring circuit of three parts. Part of the main grounds of the temperature acquisition module is encapsulated in the coupling PT100thermistor inside and outside16high-precision serial A/D converter LTC1864and other components. The temperature control section includes DSP controller TMS320LF2407and D/A converter LTC1655and its peripheral circuits, and a bi-directional current control function for easy operation highly integrated thermoelectric cooler driver module MAX1968. Temperature monitoring component, mainly through the serial communications chip temperature of the collected data is sent to the computer through the temperature data received thereby that fiber-coupled Laser diode module internal temperature of the change process, and ultimately completed a temperature control system hardware circuit the overall design.Application of Matlab Simulink component establishes Laser diode PID algorithm temperature control system model and fuzzy adaptive PID algorithm model, maybe a model by comparison and analysis led to the conclusion proved theoretically that fuzzy adaptive PID algorithm in theory the feasibility of the design process. From the traditional PID and fuzzy PID algorithm comparative analysis, fuzzy adaptive PID (FAPID) algorithm model than traditional PID algorithm model control accuracy, control the temperature overshoot, the time required to reach steady state and other aspects, have certain advantages. Through experimental results, we know that the accuracy of the fuzzy PID algorithm is much higher than traditional, control accuracy of±0.05℃, to stabilize in less than65s, the temperature control can achieve the purpose and requirements.