Refractive Index Sensor of V-Shaped Fiber Microstructure Fabricated by Femtosecond Laser

Abstract

The defect of fiber core or cladding near the core could result in imperfect total internal reflection (ATR) via multiple internal reflections along the fiber and attenuated light intensity of fiber. In this paper, V-shaped fiber microstructure was fabricated by femtosecond (fs) laser. The loss of light energy is sensitive to surrounding refractive index (RI), which is used to detect the refractive index of surrounding media. The depth of V-shaped microstructure is controlled by fabrication process, and it found that it has evident effect on RI sensitivity.