Chinese Academy of Sciences

Shougang Zhang

Chao Li

Enxue Yun

Fuyu Sun

Guobin Liu

Qinglin Li

Yuping Gao

Qiang Hao

Jie Liu

Xiaofeng Li

Xuwen Hu

Provided are an atomic beam magnetic resonance method and system based on combined separated oscillatory fields. The method includes: generating, by an atomic beam source, two identical atomic beams; performing atomic state purification treatment on the two identical atomic beams to generate two identical state-purified atomic beams; exciting, by zero-phase-difference SOFs, one identical state-purified atomic beam to perform atomic beam magnetic resonance to obtain a first atomic beam magnetic resonance signal; and exciting, by π-phase-difference SOFs, the other identical state-purified atomic beam to perform atomic beam magnetic resonance to thereby obtain a second atomic beam magnetic resonance signal, the zero-phase-difference SOFs and the π-phase-difference SOFs have the same interaction length, the same drift length, and the same oscillatory field strength; and performing subtraction operation on the first atomic beam magnetic resonance signal and the second atomic beam magnetic resonance signal to thereby generate a combined Ramsey magnetic resonance signal.

Atomic beam magnetic resonance method and system based on combined separated oscillatory fields

An optically pumped atomic beam apparatus based on curved four conductors includes a vacuum chamber; and a magnetic shielding chamber, a beam source device, a curved four-conductor static magnetic field generation structure, a microwave cavity, and a fluorescence collection device are disposed in the vacuum chamber. The curved four-conductor static magnetic field generation structure is composed of the curved four conductors with same shapes and sizes, and the curved four conductors are symmetrically arranged by taking an atomic beam as a center axis; a middle portion of each of the curved four conductors is a straight section, and two end portions of each of the curved four conductors are two curved sections bent towards the atomic beam; and a rectangle is formed by intersecting any plane perpendicular to the atomic beam with the curved four conductors, and a length-width ratio of each rectangle is the same.

Optically pumped atomic beam apparatus based on curved four conductors

The invention relates to a differential detection of double-modulation (DM) CPT method and a system for implementing the method of this invention. The method comprises the following steps: Generating a coherent bichromatic light, in which the polarization and the relative phase are synchronously modulated. The DM light interacts with a quantum resonance system and prepares it into a CPT state. Then the polarization of coherent bichromatic light is switched from circular polarization to linear polarization. After interacting with the CPT state prepared in the previous stage, the constructive and destructive quantum interference occur simultaneously. The polarization of the transmitted light from the quantum resonance system is converted and spatially separated. Then two CPT signals, detected by balanced photodetectors, are observed with constructive and destructive interference respectively. Finally, a differential CPT signal with high signal-to-noise ratio is obtained by subtracting the above-mentioned two CPT signals.

Double-modulation CPT differential detection method and system

The invention relates to a coherent population trapping (CPT) phase modulation and demodulation method and a system for implementing the method of this invention. The method comprises the following steps: Generating a coherent bichromatic light, in which the relative phase between the two frequency components is modulated with proper modulation depth. The phase modulated coherent bichromatic light interacts with a quantum resonance system, and prepares it alternately into two inverted CPT states. Detecting the transmitted light with a photodetector, two inverted dispersive CPT signals in two detection windows are observed. With synchronous phase demodulation, a CPT error signal is obtained, which is used for locking the local oscillator to implement a CPT atomic clock.

CPT phase modulation and demodulation method and system

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Xi'an, China

Shougang Zhang