Fig. 1. Relevant energy levels of ¹³³Cs 6S_1/2-6P_3/2-6D_5/2 ladder-type atomic system

Fig. 2. Schematic diagram of IDEALF experimental setup

Fig. 3. Typical IDEALF nonlinear optical filter spectral curve

Fig. 4. Changes of IDEALF signals with the temperature of cesium vapor cell. (a) Co-pumping configuration; (b) counter-pumping configuration

Fig. 5. Peak transmission of IDEALF signals with the temperature of Cs vapor cell

Fig. 6. Changes of IDEALF signals with the power of 852 nm pump laser. (a) Co-pumping configuration (temperature of Cs vapor cell is 50 ℃ ); (b) counter-pumping configuration (temperature of Cs vapor cell is 40 ℃)

Fig. 7. Changes of IDEALF signals from line-center filter to line-wing filter with the increase of 852 nm pump optical power by theoretical calculation

Fig. 8. Peak transmission of IDEALF signals with the power of 852 nm pump laser

Fig. 9. Equivalent noise bandwidth of IDEALF signal varies with the temperature of Cs vapor cell and pump light power. (a) Temperature of Cs vapor cell; (b) pump light power