Physical system device of passive type CPT (Coherent Population Trapping) atomic clock

Abstract

The invention discloses a physical system device of a passive type CPT (Coherent Population Trapping) atomic clock, wherein after linearly-polarized circular divergent laser beams sent by a laser beam launcher pass through a lens, an attenuator and a first polarization beam splitter, first linearly-polarized parallel light beams are obtained; after the first linearly-polarized parallel light beams pass through a first Lambda / 4 wave plate, an air bubble and a second Lambda / 4 wave plate, second linearly-polarized parallel light beams are obtained; after being reflected by a second polarization beam splitter, a reflecting device and the first polarization beam splitter and then passing through the first Lambda / 4 wave plate, the air bubble and the second Lambda / 4 wave plate and the second polarization beam splitter again, the second linearly-polarized parallel light beams are output to a photoelectric detector; and the polarization direction of first linearly-polarized reflected parallel light beams is perpendicular to that of the linearly-polarized parallel light. The physical system device of the passive type CPT atomic clock can realize the effects that orthogonal circular-polarized light acts with atoms at the same time, so that CPT resonance is realized, and the atoms are centralized on the '0-0 energy level', and therefore, a CPT resonance signal is enhanced, and the signal noise ratio and the contrast ratio of the signal are improved. All the components in the device are useful for integration, and the miniature passive type CPT atomic clock can be realized.

Description

Technical field [0001] The technology of the present invention relates to the field of atomic clocks, and in particular to a passive CPT atomic clock physical system device, which is suitable for small and micro passive CPT atomic clocks. Background technique [0002] An atomic clock is a precision time measurement instrument. Bubble atomic clocks are widely used in global positioning systems, communications, scientific experiments and military aspects. The atomic clock's bubble contains alkali metal atoms and a buffer gas, and is heated above room temperature to produce a vapor of alkali metal atoms. Buffer gases are inert gases such as nitrogen, methane, and helium or their mixed gases, which are used to suppress narrow spectral line width, fluorescence quenching, energy level mixing, etc. The alkali metal atoms are cesium 133, rubidium 87 or rubidium 85, and the resonance between their ground state hyperfine levels is used to identify the frequency of the injected micro...

AI Technical Summary

Problems solved by technology

However, the short-term frequency stability of atomic clocks (called frequency stability in the professional field, actually refers to frequency instability) is inversely proportional to the contrast, so the short-term stability of atomic clocks manufactured by this scheme is not high

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