Hybrid optical pumping-based accurate atomic density measurement method

Abstract

The invention relates to a hybrid optical pumping-based accurate atomic density measurement method. The method comprises the steps of heating an alkali metal gas chamber filled with K and Rb up to starting temperature, and measuring to obtain laser absorption spectrums of the K and the Rb to obtain densities of the K and the Rb at the starting temperature, and associating Raoult's law to obtain the starting temperature as well as ratios of saturated vapor pressures to molar fractions of the K and the Rb at the starting temperature; heating the gas chamber up to working temperature, wherein the density of the Rb is very high and the absorption is very strong near a resonance point in an SERF state, carrying out curve fitting to obtain a greater deviation of the density of the Rb, and accordingly obtaining the density of the K by means of a spectral absorbing method; combining the known molar fraction of the K, and calculating to obtain the working temperature; combining the molar fraction of the Rb to obtain the saturated vapor pressure of the Rb at the working temperature, and further obtaining the density of the Rb at the working temperature. The hybrid optical pumping-based accurate atomic density measurement method is suitable for the situation that during hybrid optical pumping, the saturation absorption spectrum is very high in atomic number density and is very strong in absorption at the both sides of a resonant peak, so that the density is difficult to obtain by means of a fitted curve.

Description

technical field [0001] The invention relates to an accurate measurement method of atomic density based on mixed light pumping, which can be applied to the density of alkali metal atoms in alkali metal gas chambers used in instruments such as atomic magnetometers and atomic spin gyroscopes based on mixed light pumping precise measurement. Background technique [0002] Alkali metal gas cells are the core sensitive devices of quantum measuring instruments such as atomic magnetometers and atomic gyroscopes. The measurement of the atomic density of alkali metals can provide support for the closed-loop polarizability of SERF atomic gyroscopes and magnetometers; provide a basic guarantee for the relaxation mechanism of SERF inertial and magnetic field measurement devices; provide a research basis for SERF devices, prototype sensitivity and drift optimization. Therefore, it is of great significance to propose an accurate measurement method of atomic density based on hybrid optical ...

AI Technical Summary

Problems solved by technology

[0003] The existing empirical formula method is based on the temperature of the alkali metal gas chamber to calculate the atomic density of the alkali metal vapor. Calculating the atomic density is relatively simple and has high precision, but the measurement accuracy of the absorbed light intensity near the resonance frequency in the SERF state is poor; the optical rotation angle method calculates the atomic density of the alkali metal vapor according to the optical deflection angle generated when the laser passes through the alkali metal vapor, and the accuracy Higher, but requires an external magnetic field and cannot be measured

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