Design Precise Temperature Control Circuit for Laser

Laser Diode is greatly influenced by temperature.If a stable output wavelength is required,the temperature of the Laser Diode must be precisely controlled.In this paper,a microprocessor is taken as con-troller core,then,a high accuracy Negative Temperature Coefficient resistance(NTC) combined with Thermal Electronic Cooler(TEC) are used.The TEC is driven by Pulse Width Modulation(PWM) and realized by H-bridge circuit.Finally,a precise temperature control circuit of a 2A Laser Diode is developed with a tem-perature accuracy of ±0.1℃.