DSP-based high-power semiconductor laser fully digital temperature control system

To eliminate the great influence of temperature variation on the high-power semiconductor laser, we propose an approach using digital temperature sensor to control the temperature of the laser. Compared to the traditional analog temperature sensor RTDS, the digital temperature sensor has an advantage of high sensitivity, linearity, fast response and easy use. This system contains a digital signal processing (DSP) device TMS320LF2407 as the central processor and a 12-bit D/A converter as high-precision converter. To regulate the laser temperature, we use Fuzzy-PID algorithm instead of conventional PID algorithm to control the output power of thermoelectric cooler (TEC). We perform the experiment of setting the characteristic temperature of the laser as 25.0 □ with the designed control system. The results show that the regulation time can be reduced to 50 s, and the stability of temperature is better than ±0.1 □.