Microstructure fiber optic magnetic field sensor filled with magnetic ionic liquid

Abstract

The invention relates to a magnetic ion liquid-filled micro-structure optical fiber magnetic field sensor. The working principle of the sensor includes that a fiber core mode and an ion liquid columnmode are coupled by the aid of a refractive index matching and coupling principle, the transmission light attenuation coefficient of ion liquid is changed along with increase of the strength of an external magnetic field when the transmission direction of transmission light is perpendicular to the direction of the magnetic field, the attenuation coefficient of the magnetic ion liquid is changed under different magnetic field strengths, spectrum harmonic peak strength is obviously changed, and the strength change of the external magnetic field can be accurately measured. The sensor can be usedfor implementation of novel optical fiber magnetic field sensor research work. Compared with a past reported optical fiber magnetic field sensor, the sensor has the advantages that the property of themagnetic ion liquid is more stable than that of magnetic fluids, measuring results cannot be affected by base fluid property fluctuation, and the sensor has higher accuracy.

Description

technical field [0001] The invention belongs to the field of optical fiber sensing, and in particular relates to a test method for changes in an external magnetic field and functional reassembly of a microstructure optical fiber magnetic field sensor based on magnetic ionic liquid filling. Background technique [0002] The magnetic field is an objectively existing field that transmits the magnetic force between magnetic objects, and is a basic physical quantity in physics. Due to the importance of the magnetic field in the field of navigation, geophysics and modern safety monitoring, the measurement of the external magnetic field has become a research hotspot in recent years. Researchers have proposed various measurement methods of the magnetic field, including: planar fluxgate, Ho Hall effect, superconducting magnets, nuclear magnetic resonance, thermoelectric spin valves, and fiber optic magnetic field sensors gradually developed in recent years. Compared with traditional...

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Problems solved by technology

The magnetic response of ferrofluid is mainly due to the magnetic nanoparticles dispersed in it, but the response of the base fluid to the external environment will affect the measurement accuracy of the magnetic field, which also limits its application field.

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