Dual-Parameter Sensor for Temperature and Strain Measurement Based on Antiresonance Effect and Few-Mode Fiber

Abstract

A simple and novel hybrid interferometer based on the antiresonance (AR) effect and Mach–Zehnder interference (MZI), which enables simultaneous measurement of temperature and strain, is proposed and investigated. The sensor is made by cascading a 30 cm section of a few-mode fiber (FMF) and a 3.376 mm hollow-core fiber (HCF) through a single-mode fiber (SMF). The FMF and SMF are fused without misalignment to excite two stable modes, thereby forming a Mach–Zehnder interferometer. Concurrently, the introduction of HCF can effectively excite the AR effect, which is manifested in the transmission spectrum as two different dips at the same time caused by the difference in the two physical mechanisms, showing diverse responses to both external temperature and strain. This difference can be used to construct a cross-coefficient matrix to implement the simultaneous measurement of temperature and strain. The experimental results demonstrate that the AR effect and MZI correspond to strain sensitivities of –0.87 and –2.29 pm/µε, respectively, and temperature sensitivities of 15.68 and –13.93 pm/°C, respectively. Furthermore, the sensor is also tested for repeatability, and the results show that it has good repeatability and great potential in sensing applications.