Continuous CPT state preparation and differential detection method and system

Abstract

The invention provides a continuous CPT state preparation and differential detection method and system. Coherent two-color light is converted into continuous circularly polarized light and linearly polarized light, the circularly polarized light is taken as preparation light, the circularly polarized light interacts with 87Rb atoms in a quantum resonance system, and the CPT state preparation of a first stage is completed; linearly polarized light serves as probe light and is decomposed into left-hand circularly polarized light and right-hand circularly polarized light, the left-hand circularly polarized light and the right-hand circularly polarized light interact with 87Rb atoms in a quantum resonance system at the same time, the left-hand circularly polarized light and the right-hand circularly polarized light and CPT states prepared by preparation light generate coherent phase long and coherent phase destructive quantum interference effects respectively, and coherent phase long and coherent phase destructive CPT signals are obtained, and the two signals aresubtracted to obtain a differential CPT signal. The stability of the CPT atomic clock can be improved, the structure of the device is more compact, and the reliability of the system is improved.

Description

technical field [0001] The invention relates to precision measurement fields such as atomic clocks, magnetometers, and quantum precision spectroscopy, in particular to a method and system for CPT state preparation and differential detection. Background technique [0002] Coherent layout trapping (CPT) is a quantum interference effect. The two ground states are coupled to the same excited state through the interaction of the coherent two-color light and the quantum resonance system. When the frequency difference of the coherent two-color light is strictly equal to the transition frequency of the two ground states, the quantum resonance system is prepared to the CPT state. The quantum resonance system in the CPT state becomes transparent to incident light and no longer absorbs light. At this time, when detecting the intensity of the transmitted light, an extremely narrow CPT resonance line will appear, which can be used in precision measurement fields such as atomic clocks, m...

AI Technical Summary

Problems solved by technology

Even so, there is a large common-mode noise due to the light intensity change detection method, such as laser intensity noise (AM noise), amplitude noise caused by amplitude jitter converted by laser frequency jitter through absorption line conversion (FM-AM noise), Microwave power noise, etc., limit the further improvement of the frequency stability of the CPT clock, and have not yet reached the E-14τ predicted by the shot noise limit of the CPT atomic clock -1 / 2 s level

In addition, due to the relatively complex configuration and devices, the biggest advantage of the CPT clock - miniaturization is sacrificed.

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