Optical vortex optical fiber current sensor based on single slit detection

Abstract

The invention provides an optical vortex optical fiber current sensor based on single slit detection. The sensor includes a linear polarization laser, a single mode fiber, a polarization controller, an optical vortex optical fiber, a fiber grating, a line detection polarizer, a single slit diaphragm, and a photodetector. The fiber grating achieves excitation of composite optical vortex modes in anannular core of the optical vortex optical fiber, a double-lobe light intensity distribution can be formed by the line detection polarizer, a current magnetic field is applied on the optical vortex optical fiber after the fiber grating, based on a Faraday magneto-optical effect, a phase difference is produced between the composite optical vortex modes, output lobe light spots rotate, light intensity passing through the single slit diaphragm changes, the amount of change of the light intensity is in direct proportion to the magnitude of current, the magnitude of the applied current can be measured according to a change of the light intensity, a suitable single slit width is selected through a parameter of the single slit width and a light spot diameter ratio, so that the sensing sensitivity is optimal. The optical fiber current sensor has the characteristics of high sensitivity, simple structure, easy practicality, and the like, and has important application value in the field of current measurement.

Description

technical field [0001] The invention relates to the field of optical fiber sensing, in particular to an optical vortex optical fiber current sensor based on single-slit detection. Background technique [0002] Optical fiber current sensors have important applications in power systems, because of their natural insulation, strong anti-interference ability, small size, light weight, large measurement dynamic range, and no magnetic saturation have been research and application hotspots at home and abroad. In recent years, optical vortex, as a kind of beam with special structure, has attracted more and more attention, and has been widely used in optical multiplexing communication, optical micro-manipulation, super-resolution optical detection and other fields. The optical vortex beam has a helical phase distribution, which combined with its polarization distribution characteristics has gained new applications in the field of current and magnetic field detection. In a typical res...

AI Technical Summary

Problems solved by technology

In view of the problems in the application of spatial optical vortex beams in current and magnetic field detection, Pang Fufei of Shanghai University and others proposed a fiber-based composite optical vortex fiber-optic current sensor. In the vortex mode, the infrared CCD is used as the output to observe the rotation of the lobe-shaped spot. The main problems of this scheme are the complexity of the composite optical vortex excitation device, the high cost of the infrared detection device, and the low sensitivity of detecting the rotation parameter of the spot (reference: Pang Fufei. Optical vortex mode all-fiber current sensor: China, CN201711426275.1[P]. 2017-12-26)

Images