Fiber-optic curvature and temperature sensor based on the lateral-offset spliced SMF-FCF-SMF interference structure

Abstract Based on the Mach-Zehnder interference principle, a optic-fiber curvature and temperature sensor consisting of a lateral-offset spliced single-mode fiber-four-core fiber-single-mode fiber (SMF-FCF-SMF) interference structure has been proposed and demonstrated. The curvature and temperature characteristics of the sensor with different offset distances are studied in detail. Within the curvature range of 0.042–0.163 m−1, the maximum curvature sensitivity can reach −18.75 nm/m−1. Besides, the temperature sensitivity of the sensor is as high as 74 pm/°C in the range of 30–80 °C. The sensor has good linearity in measuring curvature and temperature with a simple structure, expected to be applied in industrial production, building monitoring, etc.