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Chinese Physics Letters

Development of an Integrating Sphere Cold Atom Clock

Ben-Chang Zheng, Hua-Dong Cheng, Yan-Ling Meng, Ling Xiao, Jinyin Wan, Liang Liu

Published Dec 1, 2013• 9 citations
Publisher

Abstract

The Ramsey fringes with a linewidth of 45 Hz and a signal-to-noise ratio of 120 are demonstrated for a integrating sphere atom clock. The cycle time of the atom clock is reduced to 80 ms with the help of a pulsed cooling method. This result indicates that the short-term stability of the clock is in the order of 10 −12 .
DOI
10.1088/0256-307x/30/12/123701

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In the Ramsey scheme, if one modulates two microwave pulses at the same frequency but with pi/2 phase differences, the Ramsey fringes with zero amplitude at the central frequency can be obtained. By monitoring the variance of probe light absorption by atoms at the central frequency, one can get the error signals which feedbacks to the local oscillator. Theoretically, this method doubles the absorption signal intensity, compared with the case of Ramsey fringes with the same phase. Experimentally, the phase modulated Ramsey pattern in the integrating sphere cold atom clock system is the same with that from theoretical calculation. Moreover, the Ramsey fringe oscillation amplitude here is 1.6 times of that of Ramsey fringes with the same phase.