System and method for testing alkali metal atom number density spatial distribution uniformity of atom magnetometer

Abstract

The invention discloses a system and a method for testing alkali metal atom number density spatial distribution uniformity of an atom magnetometer. The system comprises a detection laser, a laser beam expanding system, a polarization element, a magnetic shielding system, an alkali metal atom gas chamber, a light beam contour camera, a beam splitter prism and the like which are sequentially arranged in a light advancing direction. The method is based on an optical absorption principle, light intensity attenuation of linear polarized light before and after passing through an alkali metal air chamber is tested by using a light beam profile camera with a pixel at a um level, a two-dimensional distribution matrix of atomic number density in space is calculated, and the uniformity of atomic number density distribution is analyzed by using a discrete coefficient. The system is simple to operate, easy to implement and extremely high in resolution ratio, direct measurement can be carried out on the basis of not changing the optical path of the atom magnetometer, the uniformity of the atomic number density in spatial distribution can be tested with high precision, the measurement sensitivity can be improved, and particularly the common-mode interference of a multi-channel differential magnetometer can be inhibited.

Description

technical field [0001] The invention belongs to the technical field of precision measurement, in particular to a test system and method for the uniformity of spatial distribution of alkali metal atomic number density of an atomic magnetometer. Background technique [0002] The alkali metal atomic magnetometer without spin exchange relaxation effect has extremely high magnetic field measurement sensitivity, and has been widely used in basic physics research, biomedicine, geomagnetic detection and other fields. The alkali metal atomic gas chamber is the core device of the atomic magnetometer. It needs to be heated to increase the atomic number density of the alkali metal vapor during use. This is because the atomic number density is proportional to the sum of the strength of the output signal and the square of the basic sensitivity Inversely proportional, so the greater the atomic number density, the stronger the output signal, and the smaller the minimum magnetic field that c...

AI Technical Summary

Problems solved by technology

If the temperature distribution of the heating oven is uneven, it will lead to uneven distribution of atomic number density, and the common mode noise of gradient differential detection will become larger

[0003] At present, the commonly used methods for testing the atomic number density include the Faraday optical rotation effect method, the magnetic resonance linewidth method, and the spectral absorption method: the Faraday optical rotation angle method needs to apply a large magnetic field, which cannot make the magnetometer work without spin exchange. In the relaxed state; the magnetic resonance linewidth method requires very low atomic polarizability, otherwise the magnetic resonance linewidth is also affected by the spin destruction rate

The spectral absorption method is more commonly used, but it can only measure the overall value of the atomic number density of the gas cell, and cannot measure the spatial distribution of the atomic number density

Therefore it is not possible to analyze the homogeneity

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