All-fibre temperature sensor employing photonic crystal fibre-based Mach-Zehnder interferometer structure

In this study, an all-fibre temperature sensor employing a photonic crystal fibre (PCF)-based Mach-Zehnder interferometer was manufactured by cascading single-mode fibre-multimode fibre (MMF)-PCF-MMF fusion splicing structure. For the sensor, the PCF length was 3 cm, and an interferometer comb spectrum free spectral range of 5.8 nm were realised. In the experiment, the temperature sensing characteristics during heating and cooling were measured; the sensitivity and linearity were 36 pm/degrees C within 30-60 degrees C and >0.9715, respectively. Moreover, the sensor exhibited good stability and repeatability. The results demonstrate the satisfactory performance of the proposed sensor for temperature sensor applications.