Bichromatic laser frequency stabilization system and method based on differential detection of coexisting lamb-dips and lamb-peaks with multiple interactions

A bichromatic laser frequency stabilization method based on differential detection of coexisting Lamb-dips and Lamb-peaks, comprising the steps of:

• providing a multichromatic laser beam having frequency component f1 and f2 with frequency difference close to the two ground states splitting;
• setting the multiple interactions between the laser beam and quantum resonance system in a Doppler-free configuration, in which the laser beam is split into a pump light and a probe light which propagate in opposite directions and overlap in space and act on the quantum resonance system simultaneously;
• setting the relative polarization directions of the pump and probe light using wave plate, and setting the relative Raman phases between the pump and probe light using mirrors;
• this allows the dark state created by the pump light and the two dark states created by the two polarization components of the probe light to have constructive interference and destructive interference respectively, then coexisting Lamb-dips and Lamb-peaks are generated;
• separating spatially the transmitted probe light from the pump light, and then separating and detecting the orthogonal polarization components of the probe transmitted light after its interactions with the quantum resonance system, the Lamb-dip signal and Lamb-peak signal are then obtained simultaneously;
• and
• subtracting the Lamb-peak signal from Lamb-dip signal to generate a differential signal.