Ramsey-coherent population trapping Cs atomic clock based on lin∥lin optical pumping with dispersion detection

A Cs vapor cell-based atomic clock that uses a lin∥lin pumping scheme with dispersion detection is reported. This atomic clock shows potential for high performance because of its high contrast pumping scheme, and for miniaturization because of its simple architecture. The experimental setup and optimal operating parameters for the clock are introduced. The current fractional frequency stability is measured to be $1.3\times {10}^{-12}/\sqrt{\tau }$ up to 20 s and reaches $3.1\times {10}^{-13}$ at 200 s. We have thoroughly investigated the related noise sources that affect clock frequency stability at the 1 s and 100 s levels. The investigation shows that the laser frequency noise limits the clock frequency stability significantly. The clock performance can be further improved by technically upgrading the laser frequency stabilization setup. (paper)