Birfringence Measurment of Magnetic Fluid Based on Tapered Hi-Bi Fiber in Fiber Loop Mirror

The linear birefringence (LB) is caused by the different phase retardation (retardance) of two linearly polarized eigenstates of light passing through the material. Birefringence was a significant parameter of an optical material in optical area. Compared with the traditional birefringence measurement method such as modulation technique, a novel birefringence measurement method of magnetic fluid (MF) using all optical fiber based on a Hi-Bi non-adiabatic tapered optical fiber (HBT) sensor in fiber loop mirror (FLM) was proposed in this letter. The sensitivity and detection limit of the sensor in this set up was enhanced. Moreover, it was stability, strong resistance to disturbance, easy assembly, and achievement.