Highly sensitive curvature sensor based on single-mode fiber using core-offset splicing

•High resolution and wide measurement scale.•Simple fabrication process and low cost.•High sensitivity for small curvature measurement.

A highly sensitive curvature sensor based on core-offset splicing is proposed and demonstrated. The whole fabrication process is quite simple and the sensor head is cost effective. Measurement results show that it has a high sensitivity of −22.947 nm/m−1 in the range from 0.35312 m−1 to 2.8127 m−1. Temperature sensitivity of 77.6 pm/°C within the range of 20–80 °C has also been achieved, which implies the possibility for measurement of temperature. High sensitivity and low-cost make it a preferable candidate for small curvature sensing with high resolution in practical applications.