D-shaped microstructure fiber temperature sensor based on surface plasmon resonance

In order to solve the problems of oxidation of the metal film coated on the outer surface of the photonic crystal fiber and the low sensitivity of the sensor, a side polishing temperature sensor based on surface plasmon resonance is proposed. First, the sensor is modelled with a metal coating on the side of the optical fiber of the sensor, using a temperature sensitive liquid as the temperature sensing substance. Then, simulations were carried out to calculate the structural parameters of the optical fiber and the effect of the metal material on the resonant wavelength of the loss spectrum. By comparing the sensitive sensing of different metal films, gold was chosen as the surface plasma sensing material. Finally, the sensing characteristics of the sensor are simulated using the finite element method. The results show that when gold is used as the surface plasmon material, the wavelength range is 675–1117 nm, and the high sensitivity sensing in the temperature range of 0 °C–60 °C can be realized. When the temperature is 0 °C, the maximum spectral sensitivity is 24.6 nm °C−1. The designed sensors have excellent performance and can be widely used for temperature sensing.