光学频率合成器可在激光波长宽调谐范围内按指定的频率高精度地输出赫兹线宽稳频激光。在实现700~990 nm光学频率合成器原理验证的基础上,研究了光学频率合成器自动化控制的方法。通过实时比较波长计读数与目标输出光频的差别,自动设定输出激光的波长和数字可控光栅转台,自动获得输出激光与飞秒光梳之间的拍频信号并进行自动信号处理,以获得输出激光与参考激光之间的锁相控制信号。采用计算机控制后,可在1 min内获得输出激光频率控制误差信号,这为实现全自动的光学频率合成器打下基础。

An optical frequency synthesizer can output single-frequency Hz-linewidth laser with high frequency stability at a specified optical frequency within a wide spectral range. Based on a prototype of optical frequency synthesizer at 700-990 nm, we make a step towards its automatic control. The wavelength of output laser and a motorized rotation stage of a grating are set automatically after comparing the reading of a wavemeter with the target output frequency. The beat frequency signal between the output laser and femtosecond optical comb can be obtained, and automatic signal processing can be realized, obtaining phase-locked control signal between the output laser and reference laser. An error signal for laser frequency control can be obtained within one minute. This study lays a foundation for the realizing the fully automatic optical frequency synthesizer.