Single-beam atom magnetometer bias and noise suppression device and method based on light intensity difference

Abstract

The invention discloses a single-beam atom magnetometer bias and noise suppression device and method based on light intensity difference, wherein the method comprises the steps: light generated by a laser is shaped by a first cylindrical lens and a second cylindrical lens in sequence and then is split after passing through a lambda / 2 wave plate and a polarization light splitting prism, one beam passes through an optical filter to make light intensity attenuated, and the attenuated light reaches a first photoelectric detector; the other beam sequentially enters a lambda / 4 wave plate and a diaphragm in a magnetic shielding barrel through an optical fiber coupling head after passing through a polarizer and then irradiates an atomic gas chamber, the light beam transmitted out of the gas chamber is influenced by atomic spin precession, and the polarization axis of linearly polarized light deflects; the light is outputted and reaches a second photoelectric detector; and the two beams of light are amplified by a photodiode amplifier after passing through the first photoelectric detector and the second photoelectric detector, and a lock-in amplifier is used for extracting frequency information in output signals of the amplifier. By differentiating the light intensities of the light beams in front of and behind an atom air chamber, the bias of the background light intensity in an atom non-polarized state and the light intensity noise before and after detection are eliminated, and the sensitivity of an atom magnetometer is improved.

Description

Technical field[0001]The present invention belongs to the field of magnetic sensors, and more particularly to a single beam atom magnetometer bias and noise suppression apparatus and method based on a light intensity differential.Background technique[0002]With the in-depth development of biological and medical and other technical fields, people put forward higher requirements for the measurement of extremely weak magnetic fields, but not only the sensitivity is higher, the noise is lower, but also lowers the magnetic sensor power, and can achieve chipping. At present, the magnetic sensor of the measured micro-magnetic field that has been commercially used is superconducting quantum interferometer (Squid), but due to expensive cost, it requires low temperature cooling, limiting its application in a broader field. The atomic magnetic strength of quantum technology is increasingly focused, especially the SERF (Spin-Exchange-Relaxation-Free, no self-exchange relaxation) status atom magn...

AI Technical Summary

Problems solved by technology

This method is easily affected by light intensity fluctuations, and there is a large output photoelectric signal bias, so that there is a strong background bias signal before the signal enters the photoelectric amplifier, which affects the amplification ability of the photoelectric amplifier.

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