The application provides an all-
fiber current sensor based on
linear measurement of sharp wedge interference,
linearly polarized light obtained through a
polarizer is divided into two mutually orthogonal linearly polarized lights through a coupler, a
delay line and a 45-degree fusion splice point, is modulated by an
initial phase modulator, is converted into left-handed and right-handed circularly polarized light through a first
lambda / 4 wave plate, enters a sensing
optical fiber, and a
phase difference of the two circularly polarized lights is generated through a Faraday
magneto-optic effect; the
phase difference is doubled after being reflected by a mirror, is combined into a
linearly polarized light through a first
lambda / 4 wave plate and a 45-degree fusion splice point, and the
phase difference of the circularly polarized light is converted into a rotation of a
polarization plane of the
linearly polarized light; the rotation of the
polarization plane of the linearly polarized light is converted into synchronous translation of a
light spot through a coupler, a second
lambda / 4 wave plate, a sharp wedge and a
polarizer after being twice phase-modulated by a modulator; and
linear measurement of a phase
delay angle is obtained through positioning of the
light spot by an
image sensor; the
demodulation result of the application is irrelevant to
optical power, and is beneficial to separation and compensation of
linear birefringence.