用于汞原子激光冷却的深紫外激光调谐和锁频系统（英文）

A Frequency Tuning and Locking System of a Deep UV Laser for Laser Cooling of Mercury Atoms

开发了一种用于253.7nm深紫外激光器的低功耗频率调谐和锁频系统,这种锁频系统将在中性汞原子磁光阱中起到重要作用。该系统用两个级联的声光调制器分别做频率调谐和频率调制。利用该系统可将深紫外激光器的频率锁定在汞原子的1S0-3P1的能级跃迁上,并为汞原子的激光冷却节约了功率。同时通过解调频率调制激光的饱和吸收光谱观测了汞原子的调频光谱。采用该技术将紫外激光锁定在200 Hg的1S0-3P1共振跃迁上,并且频率不稳定度低于0.1MHz。

We develop a power saving frequency tuning and locking system of a deep ultraviolet （UV） laser at 253.7 nm, which will play an important role in a magneto-optical trap for neutral mercury atoms. Combined with two cascade acousto-optical modulators （AOMs） and frequency modulation （FM） spectroscopy in a mercury vapour cell, the deep UV laser can be locked and tuned on 1S0-3P1 transition of Hg atoms, and the power for laser cooling can be saved. FM spectroscopy is also observed by demodulating the saturated absorption spectroscopy （SAS） of the FM laser. The UV laser is well locked on 1S0-3P1 transition of 200Hg atoms with the instability less than 0.1 MHz.