铯原子气室中相干布居俘获的参数依赖关系研究

Investigation of experimental parameters of coherent population trapping with cesium vapor cell

基于铯原子基态6S_(1/2)的两个超精细能级(F=3与F=4)与激发态6P_(3/2)的超精细能级(F′=4)构成的Λ型三能级系统,采用室温下的未充缓冲气体和充有分压为266.6 Pa的氖气作为缓冲气体的铯原子气室对于相干布居俘获(CPT)的参数依赖关系进行了实验研究和理论分析.主要研究了CPT信号的半高全宽和幅度对于频率差为铯原子基态6S_(1/2)的超精细分裂(9.19263177 GHz)且位相锁定的两激光束的功率、光强比值、光斑直径、磁屏蔽之后的剩余磁场以及是否充缓冲气体等实验参数的依赖关系.在优化的实验参数条件下获得了约340 Hz的CPT信号半高全宽.

According to the A-type three-level system consisting of cesium 6S1/2 （F = 3 and F= 4） long-lived ground states and 6P312 （Fp = 4） excited state, we experimentally investigate and theoretically analyze the parameters of coherent population trapping （CPT） spectra in a cesium atomic vapor cell with or without neon as buffer gas. The CPT of the full width at half maximum （FWHM）, the signal amplitude as a function of optical intensity of the two phased-locked laser beams with a frequency difference of 9.19263177 GHz （the hyperfine splitting in the cesium ground state 6S1/2）, relative intensity ratio, beam spot size, residual magnetic field of the magnetic shielding, and the influence of with and without the cesium vapor cell containing neon as buffer gas are investigated experimentally. With the optimized parameters, we obtain the CPT signal FWHM to be as narrow as -340 Hz.