Calibration device and method for measuring weak field of Hall magnetometer based on spin noise spectrum

Abstract

The invention belongs to the technical field of atomic measurement, and discloses a calibration device for weak field measurement of Hall magnetometer based on spin noise spectrum, comprising: a detection light source, the first detection light output by the detection light source passes through the first half After the wave plate, the first polarizer and the lens, it enters the atomic gas chamber along the X direction, and then is detected by the first balance detector after passing through the second half-wave plate and the first Wollaston prism; the atomic gas chamber is set In the magnetic shielding cylinder, the first Helmholtz coil for providing a magnetic field along the Y direction is arranged in the magnetic shielding cylinder; the output ends of the first balance detector are respectively connected to the first fast Fourier transform dynamic signal Analyzer; the first fast Fourier transform dynamic signal analyzer is used to analyze the detection signal to obtain the corresponding Larmor precession frequency. The invention can realize the calibration of the Hall magnetometer and can be widely used in the field of magnetometer calibration.

Description

technical field [0001] The invention belongs to the technical field of atomic measurement, and in particular relates to a calibration device and method for measuring a weak field of a Hall magnetometer based on a spin noise spectrum. Background technique [0002] Aleksandrov and Zapasskii demonstrated that the spin noise of alkali metal atoms can be detected by an unperturbed detuned probe laser. The basic principle of spin noise spectroscopy is to map the random spin fluctuations of atoms onto linearly polarized light, which is reflected by the rotation of the polarization plane. For an atomic system in thermal equilibrium, the mean value of the spin polarization m z = (N↑ − N↓) / (N↑ + N↓) is 0 after long-term average, where N↑ and N↓ represent the number of spin-up and spin-down particles respectively, and N↑ + N↓ represents The total number of spin particles detected by the laser. However, due to the existence of thermal fluctuations, there are random fluctuations in N...

AI Technical Summary

Problems solved by technology

However, the measurement accuracy of such sensors is limited by quantum polarization noise (photon shot noise), so the use of polarization-squeezed light can solve this problem to some extent

[0007] Although the high-pressure inert buffer gas in the atomic gas chamber slows down the diffusion speed of atoms to the inner wall of the gas chamber, at the same time, due to the introduction of the buffer gas, at a certain temperature, additional pressure expansion and collision frequency shift will occur inside the atomic gas chamber

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