Weak magnetic sensor based on magneto-optical coupling and magnetic field measurement method

Abstract

The invention discloses a weak magnetic sensor based on magneto-optical coupling and a magnetic field measurement method and relates to the technical field of magnetic performance measurement devices. The sensor comprises a base, a magnetostrictor, a double-side Faraday reflector, an optical fiber collimation probe, a single mode fiber and a Michelson interference device, wherein one end of the magnetostrictor is mechanically and fixedly connected with the base, the other end of the magnetostrictor adheres to the double-side Faraday reflector, the optical fiber collimation probe is connected with the Michelson interference device through the single mode fiber, and the center of the optical fiber collimation probe and the center of the double-side Faraday reflector are located on the same axis. The external magnetic field is sensed through the magnetostrictor so that the reflector can be driven to make linear movement, displacement-phase photovoltaic conversion and detection are achieved through the Michelson optical interference device, and then the intensity of the magnetic field is obtained. According to the sensor, the complicated design of traditional magnetoelectricity sensors is avoided, the influence of temperature is effectively reduced, sensitivity is high, repeatability is high, and high-precision low-intensity magnetic field measurement in the complicated magnetoelectricity environment can be achieved.

Description

technical field [0001] The invention relates to the technical field of measuring devices for magnetic field characteristics, in particular to a magneto-optical coupling-based weak magnetic sensor and a magnetic field measuring method. Background technique [0002] Magnetic detection technology uses the method of measuring the magnetic field of magnetic targets or the earth's magnetic field, and obtains relevant information through signal processing and analysis, which is used for target detection and resource investigation, etc. There is a wide range of needs in defense technology. With the rapid development of the electronics industry, the application of various magnetic materials and magnetic devices has become more and more common, and higher requirements have been put forward for the measurement accuracy and environmental adaptability of weak magnetic fields. [0003] According to the working principle of the sensitive components of the measurement system, commercial ma...

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Problems solved by technology

The research results show that: the fiber optic magnetic field sensor based on the Fabry-Perot interferometer has poor temperature stability, high requirements for the detection of interference fringes, and relatively low precision; the fiber optic magnetic field sensor based on the Mach-Zehnder interferometer has poor anti-polarization fading performance and unstable stability. However, the fiber optic magnetic field sensor based on the Michelson interferometer is similar to the Mach-Zehnder interferometer and has good application prospects. The arm is stationary, and the measuring arm pulls a specific structure or device through the mechanical effect of the magnetostrictive material to change the optical parameter, thereby changing the optical path of the reflected signal, and realizing the coupling of the magneto-optical parameter

However, the solution of the above structure is easily affected by temperature, and the elongation of the magnetostrictive material is easily limited by the mechanical load, the repeatability is poor, the measurement accuracy is not high, and there are few application reports.

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