A scalar magnetic field gradient measurement device and method based on optical field amplitude modulation

Abstract

The invention discloses a scalar magnetic field gradient measuring device and method based on optical field amplitude modulation. A circuit is controlled by a processor through a laser device to makethe laser device output a laser, the frequency of the laser is transitionally resonated with atoms, the amplitude changes periodically, the laser output by the laser device enters a first atomic gas chamber and a second atomic gas chamber passing through an optical fiber beam splitting device respectively, the laser is received by a first detector and a second detector respectively after the laseris acted with the atoms, and voltage signals output by the detectors are transmitted to the processor. The atoms are polarized by the laser, polarization axes process around a magnetic field in a Larmor frequency, the modulation frequency of the amplitude of the laser is changed by the processor, when the frequency value is the same as the atomic Larmor frequency, the laser spectrum emitted out from the atomic gas chamber reaches the maximum value, a magnetic field value is obtained by calculation through the Larmor frequency, and a magnetic field gradient value can be obtained by measuring the magnetic field at the positions of the first and second atomic gas chambers before conducting differential calculation. According to the method, a full optical structure is adopted by a magnetic sensitive part, and therefore the measuring precision of the magnetic field gradient is improved.

Description

technical field [0001] The invention relates to a scalar magnetic field gradient measurement device and method based on light field amplitude modulation, belonging to the field of magnetic field precision measurement. Background technique [0002] Magnetic field widely exists in space. Magnetic field measurement can be used in geological exploration, underground pipeline detection, non-destructive testing, geomagnetic navigation, medical diagnosis and other fields. Magnetic field includes information such as magnetic field amplitude, direction, and magnetic field gradient. Accurate measurement of magnetic field gradient can improve the performance of underground pipelines. Accuracy of detection, geomagnetic navigation, and biomagnetic field measurement. [0003] The traditional scalar magnetic field gradient measurement uses two independent magnetometer probes. The traditional magnetometer probe has a large volume, which limits the baseline length of the magnetic gradient me...

AI Technical Summary

Problems solved by technology

[0003] The traditional scalar magnetic field gradient measurement uses two independent magnetometer probes. The traditional magnetometer probe is large in size, which limits the baseline length of the magnetic gradient measurement.

Moreover, the traditional magnetometer probe contains electronic components such as lasers and photodetectors. The inherent magnetism of electronic components and the magnetic field interference generated by the corresponding current in the circuit will affect the measurement accuracy of the magnetic field gradient.

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