A high-sensitivity optical fiber temperature sensor with composite materials

An arc-shaped misaligned structure interferometer based on a single-mode fiber is proposed herein, in which a layer of composite material is coated onto the structure to improve its temperature sensitivity. Experiments show that the sensor has high sensitivity and linearity with respect to temperature, and the response to strain can be ignored. The temperature sensitivity reaches approximately −0.953 nm/°C, which is ∼79.4 times higher than that of the uncoated sensor. Owing to the advantages of a simple preparation method, low cost, and compact structure, this inter-mode interference-based fiber sensor is expected to be an ideal instrument for high-precision temperature sensing fields.