Fig. 1. Microscopic photo of micro-fiber structure and Comsol simulated mode field of micro-fiber. (a) Microscopic photo of micro-fiber structure; (b) Comsol simulated mode field of micro-fiber

Fig. 2. Schematic diagram of experimental device

Fig. 3. Transmission spectrum of single-mode micro-fiber structure before and after magnetic fluid encapsulation

Fig. 4. Transmission spectrum whit the applied magnetic field intensity changes

Fig. 5. Relationship between interference peak wavelength shift and external magnetic field

Fig. 6. Magnetic field intensity sensitivity of interference peak versus its corresponding wavelength