Research And Design Of Temperature-Contr System Based On Laser Diode

This paper introduce the research and improvement of SLD-type of middle-small power laser diode temperature control system, its performance and experiment of software and hardware.Semiconductor laser have been applied to many fields, we except it can work stable for a long time. In addition to the function factor of the semi-conductor laser, many influence factor such as the environment temperature unsteady and drive the electric current motion and multifarious wave to flow out pound at and spread hot etc. problem, for the stable character of laser, precision temperature control of inner crystal component has important effect. Therefore, the stable and constant control of semiconductor laser diode is rather important. A little part on content of this paper is to introduce and analyze the research of driver part of mode constant temperature controller.The small power laser diode can adopt in brief passive spread the heat. If requests the laser diode to have the high stability, then need to use to make use of the TEC as the performance piece of temperature control system. When the direct current passes the TEC, driving the direction of the electric current of TEC from the change to carry out to make cold or hearing; the nicety regulate with the current sizes of the TEC, can carry out precise temperatures control, this is the papers core part --the intelligence temperature control part.A control algorithm of combining the fuzzy theory with digital PID parameters self-tuning is adopted in the system. The process of control algorithm is as follows: First, the method of critical proportional band is used to get the parameters of digital PID control at certain temperature. Then, the digital PID parameters at some temperature and Lagrange quadratic interpolation are employed to obtain the interpolation equations of P, I and D. Finally, the system is able to self-tune the digital PID parameters of a certain temperature, and produces properly controlled quantum to control the temperature of LD.Some verification experiments have been performed using the whole temperature control system. The results of experiment indicate that within the temperature range of 10℃～40℃, the resolution of the temperature measurement is 0.03℃, and the accuracy of temperature control is 0.2℃and the establishing time is about 180 seconds. This temperature control system is an economical and practical system, and provides a good temperature control solution for the small or middle power LD temperature control.