An Antiinterference Temperature Sensor Based on Mach-Zehnder Interferometer Using Kagome Hollow-Core Photonic Crystal Fiber

An antiinterference temperature sensor based on the Mach-Zehnder interferometer (MZI) is proposed, which is formed by successively fusing a homemade Kagome hollow-core photonic crystal fiber (HC-PCF) with two no-core fibers (NCFs) and two single-mode fibers (SMFs). Because of the antiresonant reflection optical waveguide properties, the interference between hollow-core mode and glass mode is achieved in Kagome HC-PCF, which significantly simplifies the overall sensing architecture and maintains better stability of the sensing signal. Using a Kagome HC-PCF length of $497 \mu \text{m}$ , the maximum temperature sensitivity of the proposed sensor is obtained as 38.39 pm/°C. Meanwhile, it exhibits a low sensitivity of 0.5041 pm/ $\mu \varepsilon $ to ambient stress variation, −0.28 nm/ $\text{m}^{-{1}}$ to curvature change, and 9.35 nm/RIU to external refractive index (RI) change. This MZI temperature sensor has the advantages of compact structure, easy fabrication, low cost, small size, high sensitivity, and antiinterference capability, which can be expected to be applied to temperature sensing in complex environments.