光学频率梳恒温控制及泵浦驱动电路设计

Design on temperature control and pump driving circuit in an optical frequency comb system

针对光学频率梳中载波包络偏移频率(f0)的噪声抑制设计了高精度泵浦驱动电路和温控电路。采用功率MOS管作为调整管,通过结合集成运放的深度负反馈设计恒流电路;利用温控芯片LTC1923,以脉冲宽度调制方式驱动半导体制冷器实现温控电路。实现了泵浦源输出光功率稳定度达0.05%,对光梳核心光路温度控制误差达±0.01℃,在此基础上,f0的自由线宽窄至5 kHz,频率偏移速率降低至4.8 MHz/h。结果表明,该电路设计对于抑制f0噪声,提高f0短期稳定性有显著效果。

Aiming at the noise suppression of the carrier envelope offset frequency(f0)in the optical frequency comb,a high-precision pump driving circuit and a temperature control circuit are designed.The constant current power supply is realized by adjusting a MOSFET with the depth negative feedback processed from an integrated operational amplifier.The temperature control is achieved by tuning the thermo electric cooler(TEC)in pulse width modulation(PWM)with a chip called LTC1923.In this design,the output power stability of the pump source is 0.05%and the error of temperature control is±0.01℃.On this basis,the free linewidth of f0 is narrowed to 5 kHz and the frequency offset rate is reduced to 4.8 MHz/h.The results show that the circuit design has a significant effect on suppressing the f0 noise and improving the short-term stability of f0.