Noise suppression in coherent population-trapping atomic clock by differential magneto-optic rotation detection.

We propose and investigate a scheme for differential detection of the magneto-optic rotation (MOR) effect, where a linearly polarized bichromatic laser field is coherent population-trapping (CPT)-resonant with alkali atoms, and discuss the application of this effect to CPT-based atomic clocks. The results of our study indicate that laser noise in a vertical cavity surface-emitting laser-based CPT atomic clock can be effectively suppressed by the proposed scheme. The proposed scheme promises to realize a packaged MOR-CPT atomic clock that has significantly better frequency stability coupled with similar power consumption, volume, and cost when compared with currently available packaged CPT atomic clocks.