Fiber optic faraday flux transformer sensor and system

摘要

A fiber optic Faraday flux transformer sensor is disclosed which comprises: a closed loop of wire being responsive to a first time- varying magnetic field from a remote source for producing a secondary time- varying magnetic field which varies as a function of the first time- varying magnetic field, and an optical fiber loop having a plurality of turns arranged in a preselected configuration adjacent to the closed loop of wire and adapted to receive and pass therethrough input light having a fixed state of linear polarization. The optical fiber loop is responsive to the secondary time-varying magnetic field and to the input light for producing light having a polarization state which changes as a function of the secondary time-varying magnetic field applied thereto. In a system implentation, an optical source transmits light having a linear state of polarization to a first polarizer, which selects and sends a fixed predetermined state of polarization to the fiber optic Faraday flux transformer sensor. A second polarizer converts the resultant light from the fiber optic Faraday flux transformer sensor into an output light which changes in intensity as a function of the changing polarization state of the resultant light. A photodetector converts this output light into an electrical signal which varies in amplitude as a function of the time-varying magnetic field from the remote source.