Birefringence Measurement for Magnetic Fluid Film Using Optical Fiber System

Birefringence was a significant parameter of an optical material in optical area. Compared with the traditional birefringence measurement method, a novel birefringence measurement method of magnetic fluid using optical fiber was proposed in this letter. The measurement error induced by the alignment and the optical loss over the space optical path was effectively reduced. Moreover, it was stability, strong resistance to disturbance, easy assembly, and achievement. Simulation and experiment were carried out to prove the effective of the novel measurement system, and the magnetic fluid birefringence induced by an external magnetic field was measured. In addition, the birefringence of magnetic fluid was from 0 to 1.2 × 10^-3 in the range of 0-600 Gs. In addition, when the magnetic field was from 0 to 200 Gs, the sensitivity of magnetic fluid birefringence was 1.25 × 10^-6/Gs; when the magnetic field was from 200 to 500 Gs, the sensitivity downgraded to 0.26 × 10^-6/Gs. It has a great potential for the application of magnetic fluid birefringence in the optical sensing area.