Method for outputting standard frequency of coherent population beat-frequency atomic clock

Abstract

The invention discloses a method for outputting the standard frequency of a coherent population beat-frequency atomic clock. The method drives a semiconductor laser through a driving current signal, and the driving current signal is modulated by a microwave signal which is produced by a crystal oscillator and locked in the crystal oscillator, so as to produce two pumping lasers of which the frequency difference equals to the frequency of the microwave signal, and act with the atoms with Lambada three-level system so as to produce a relaxation oscillating signal of which the center frequency equals to the beat frequency of the microwave signal and the hyperfine energy level; then the relaxation oscillating signal is photo-electrically converted and FFT-transformed with DSP chips so as to get an oscillating center frequency; finally, the oscillating center frequency is taken as the control signal of an FPGA to change the frequency-controlled word of the DDS chips and get the standard frequency output. The method simplifies the circuit design of an atomic clock system, improves the stability and reliability of the atomic clock, and benefits the digitalization and miniaturization of the atomic clock.

Description

Technical field [0001] The invention relates to the technical field of atomic clocks and frequency standards, and in particular to a method for outputting a standard frequency from a coherent population beat (CPB) atomic clock. Background technique [0002] At present, atomic clocks have been widely used in many fields. For example, in basic scientific research fields such as communications and navigation, different types of atomic clocks have been developed and applied. The principle of traditional atomic clocks is to detect the reference spectrum line of the atomic energy level and lock the frequency output by the atomic clock with the reference spectrum line to obtain a stable atomic clock frequency. Traditional atomic clocks use the frequency spectrum line absorbed or emitted by the transition of a certain energy level of an atom as a benchmark (because it has relatively high stability), and use a phase-locked circuit or similar technology to combine a microwave signal o...

AI Technical Summary

Problems solved by technology

Therefore, the locking of the output frequency and the reference spectral line is an important technology of the traditional atomic clock, which leads to high requirements for the locking circuit of the traditional atomic clock, increasing its instability factors

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