Fig. 1. D₂ line energy level structure of cesium atom

Fig. 2. Saturated absorption spectral peak diagram of

Fig. 3. Saturated absorption spectrum optical path system

Fig. 4. Single saturated absorption spectral peak line and its first-order derivative curve

Fig. 5. Saturated absorption spectrum and frequency discrimination curve of cesium D₂ line

Fig. 6. Two-photon optical path system

Fig. 7. EIT spectrum of cesium atom D state

Fig. 8. EIT-Stark spectra and error of 48D_5/2 state under external field. (a) EIT-Stark spectra after frequency calibration;(b) Measured results under different field strength