Temperature-Insensitivity Bending Sensor Based on Cladding-Mode Resonance of Special Optical Fiber

Abstract

A temperature-insensitive fiber bending sensor is demonstrated by using a special optical fiber with cladding-mode resonance. The special fiber with a pure silica core and a fluorine-doped silica inner cladding shows strong cladding-mode resonance. The single-mode fiber (SMF)-special fiber-SMF is proposed as a sensor head to monitor the cladding-mode resonance. The response of the resonant spectrum exhibits high sensitivity to bending curvature and inherent insensitivity to temperature. The proposed special fiber bending sensor is simple and inexpensive.