A Vectorial Analysis of the Curvature Sensor Based on a Dual-Core Photonic Crystal Fiber

A novel curvature sensor was proposed based on a dual-core photonic crystal fiber (PCF) that was spliced between two single-mode fibers (SMFs). The sensor sensitivity was investigated both analytically and experimentally, and the influence of the PCF length and temperature on the sensor performance was also analyzed. The results showed the sensor had different sensitivity with different bending direction and its highest sensitivity can reach 10.14 nm/m
^-1
. It also showed great insensitivity to temperature interference. Being of simple structure and good mechanical strength, this curvature sensor has great application potential in various fields, such as architecture, machinery, robot, wearable sensor, and so on.