Crystal current sensor based on composite optical vortex

Abstract

The invention discloses a crystal current sensor based on composite optical vortex. A laser emission unit is used to emit a linear polarization state fundamental mode Gaussian beam, and a composite beam generating unit is used to divide the linear polarization state fundamental mode Gaussian beam into two beams, and is used to modulate the two beams into optical vortex beams, which are combined together, and are converted into circular polarization type composite optical vortex beams. A crystal sensing unit is used to transmit the composite optical vortex beams into a crystal along the optical axis of the crystal, and is used to apply the current to the crystal to generate a magnetic field along the direction of the optical axis of the crystal. A detection unit is used to detect the light intensity distributions of the composite optical vortex beams before and after the application of the magnetic field, and the deflection of the composite optical vortex beams occurs, and the current is calculated by calculating the deflection degree, and therefore a current sensing function is realized. The circular polarization state characteristic of the optical vortex during a transmission process is maintained, and the change of the beam polarization state by using Faraday magneto-optic effect can be directly displayed in composite spots, and therefore a problem of reduction of sensitivity of an optical fiber current sensor caused by linear birefringence is effectively solved.

Description

technical field [0001] The invention relates to a crystal current sensor, in particular to a Sagnac interferometer type crystal current sensor, which is applied to the technical fields of magnetic field measurement and current sensing. Background technique [0002] At present, the principle of most optical current transformers is based on the Faraday magneto-optic effect, which encountered a pair of contradictions in the process of practical application: on the one hand, the Verdet constant of the silica fiber is low, and in order to improve the sensitivity, the winding turns of the fiber ring need to be increased On the other hand, the increase in the number of fiber turns will additionally introduce linear birefringence, which will reduce the sensitivity of the fiber optic current transformer, and excessive linear birefringence will even inhibit the Faraday effect. [0003] Optical vortex beams can have infinitely many eigenstates, and the eigenstates are mutually orthogon...

AI Technical Summary

Problems solved by technology

The invention makes full use of the characteristic that the optical vortex can maintain a good circular polarization state during the transmission process, and utilizes the principle that the change of the polarization state of the light beam caused by the Faraday magneto-optic effect can be directly reflected in the compound spot, effectively solving the problem caused by linear birefringence. The problem of reducing the sensitivity of fiber optic current transformers, so as to realize the function of current sensing

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