本文报道了一种用于镱原子光钟的759 nm光晶格激光频率锁定方法。759 nm激光通过Pound-Drever-Hall(PDH)技术锁定在一个腔长为10 cm的超低膨胀系数(ULE)的高细度Fabry-Perot(FP)腔上。激光频率被锁定后的测量结果表明,759 nm的光晶格激光线宽被压窄到小于200 kHz;运用频率锁定的759 nm激光和飞秒光梳拍频来监测超稳腔的长期漂移率,结果显示ULE超稳腔的漂移率为016 Hz／s。将锁定后的759 nm光晶格激光用于镱原子光钟光晶格的装载,实现了镱原子在光晶格场中的稳定装载以及对光晶格场频率的精确控制,从而为镱原子光钟的闭环运转做了必要的技术准备。

We report a locking method of the 759 nm laser for ytterbium(Yb) optical clock is realized experimentally.The 759 nm laser is locked to an ultra-low expansion(ULE) cavity with the Pound-Drever-Hall (PDH) technique.After the laser is locked,the linewidth of the 759nm laser decreases to less than 200 kHz; Beating with corresponding component of the femtosecond comb,the lattice laser show an excellent long term drift behavior,with the drift rate of 016 Hz／s.The frequency-stabilized 759 nm lattice laser is used to load the cold atoms into the optical lattice for the Yb optical clock,and the cold Yb atoms is steadily trapped in the optical lattice and the frequency of the lattice laser is accurately controlled.It paves the way for the closed-loop operation of the Yb lattice clock.