Frequency Stability of Atomic Clocks Based on Coherent Population Trapping Resonance in ^85Rb

An atomic clock system based on coherent population trapping （CPT） resonance in 85Rb is reported, while most past works about the CPT clock are in ST Rb. A new modulation method （full-hyperfine-frequency-splitting modulation） is presented to reduce the effect of light shift to improve the frequency stability of the CPT clock in SSRb. The experimental results show that the short-term frequency stability of the CPT clock in SSRb is in the order of 10^-10/s and the long-term frequency stability can achieve 1.5 × 10^-11/80000s, which performs as well as 87 Rb in CPT resonance. This very good frequency stability performance associated with the low-cost and low-power properties of SSRb indicates that an atomic clock based on CPT in SSRb should be a promising candidate for making the chip scale atomic clock.

Frequency Stability of Atomic Clocks Based on Coherent Population Trapping Resonance in 85Rb

An atomic clock system based on coherent population trapping (CPT) resonance in ⁸⁵Rb is reported, while most past works about the CPT clock are in 87Rb. A new modulation method (full-hyperfine-frequency-splitting modulation) is presented to reduce the effect of light shift to improve the frequency stability of the CPT clock in ⁸⁵Rb. The experimental results show that the short-term frequency stability of the CPT clock in ⁸⁵Rb is in the order of 10^-10/s and the long-term frequency stability can achieve 1.5×10^-11/80000s, which performs as well as ⁸⁷Rb in CPT resonance. This very good frequency stability performance associated with the low-cost and low-power properties of ⁸⁵Rb indicates that an atomic clock based on CPT in ⁸⁵Rb should be a promising candidate for making the chip scale atomic clock.