Asymmetry of microwave spectrum in an optically-pumped Cs atomic beam frequency standard

The asymmetry of microwave spectrum was investigated in an optically pumped Cs atomic beam frequency standard. The asymmetry was measured with the polarization state and the detuning of the pumping beam, and analyzed by the master equation based on the density matrix for the D2 transition line. It was found that the pumping transition, F=4-Fʹ=5 can offer a most sensitive detection scheme for the asymmetry. Finally, it was showed that the asymmetry could be compensated by adjusting the state of polarization of the pumping beam as well as the frequency of pumping laser