Digital Laser Power Achieved Through Control of Temperature and Optical Feedback

摘要

A 144mW high stability output power laser diode (LD) pumped Nd:YVO_4 green laser digital power supply has been developed and we achieved the double closed loop feedback control with LD/KTP temperature feedback and optical feedback control. The accuracy of temperature controlling in LD and KTP crystal are respectively controlled less than ±0.1℃ by driving on thermoelectric coolers (TEC). Meanwhile, according to the error variety linearity curve of which LD output power varied with LD current by Si-photo sampling, PI control algorithm is realized to adjust LD controlled current source so as to reduce error amends in closed-loop control. Based on temperature control we further adopted laser optical feedback control; consequently, we can more best monitor the operational characteristics and states of laser output power by communication interface. A high stability laser less than ±3‰(σ) laser output power is achieved in our digital laser power supply. At last, it is applied in many different lasers by switching laser control mode and displayed the laser output power parameters.