Evolution of polarization properties in circular birefringent fiber Bragg gratings and application for magnetic field sensing

The transmission and polarization properties of Fiber Bragg Grating (FBG) with Faraday Effect are studied in this paper. The evolutions of transmission spectrum for different circular birefringence, grating parameter (physical length, index modulation) and input polarizations are simulated with Jones Matrix method. It is demonstrated that the monitoring of the 3rd normalized Stokes parameter peak values provide a new magnetic field measurement. The magnetic field strength sensitivity value is 1.482 × 10−5/Gs by using the optical vector analyzer whose precision is 10−5 in experiment and a very good agreement between theory and experience is reported.

► We review a new magnetic field sensor based on the polarization properties of FBG. ► The evolutions of transmission spectrum are simulated with Jones Matrix method. ► Simulation results proved the theoretical feasibility of the proposed method. ► The experimental results confirm the method can be used to measure magnetic field.