Optical fiber current transformer for three-phase common super-fluorescence optical fiber light source

The embodiment of the invention provides an optical fiber current transformer for a three-phase common super-fluorescence optical fiber light source SFS; the current transformer comprises a super-fluorescence optical fiber light source SFS, a 1*3 single-mould coupler, a three-port single-module circulator, a Y waveguide integrated optical phase modulator, a polarization beam splitter, a polarization-maintaining delay line, a 1/4 wave plate, a sensing optical fiber, a reflection mirror, an optical-electric detector, a light source driving circuit and a signal processing unit, wherein the lightemitted by the super-fluorescence optical fiber light source is divided into three parts through the 1*3 single-mould coupler for respectively providing the light power input to each phase transformer; and the combination of the three-port single-mould circulator, the Y waveguide integrated optical phase modulator and the polarization beam splitter is adopted to realize the low consumption designof the optical path. The transformation ratio error of the transformer caused by the central wavelength shifting of the light source can be reduced through the current transformer, the demand for thelight source temperature control precision is reduced, and the service life of the transformer is prolonged; moreover, the optical fiber current transformer has small optical path consumption, high signal optical utilization ratio and relatively lower requirement for the light source output power with the same signal to noise ratio demand.