Fig. 1. Energy level diagram of cesium atom relevant to experiment

Fig. 2. Experimental setup for FADOF system based on commercial-type HCL

Fig. 3. Absorption spectra of 852 nm signal light passing through cesium HCL under different working currents

Fig. 4. Transmittance spectrum of FADOF varying with working current of cesium HCL

Fig. 5. Peak transmittance of FADOF varying with working current of cesium HCL and signal power. (a) Working current; (b) signal power

Fig. 6. Transmittance spectrum of FADOF varying with axial magnetic field

Fig. 7. Peak transmittance of FADOF varying with axial magnetic field

Fig. 8. ENBW varying with axial magnetic field