D-shaped surface plasmon photonic crystal fiber temperature sensor

This work presents a D-shaped photonic crystal fiber temperature sensor based on surface plasmon resonance with high sensitivity and high figure of merit. To enhance surface plasmon resonance, the gold film is deposited on the polished flat of D-shaped photonic crystal fiber. Ethanol and chloroform are employed as temperature-sensitive materials, which are placed on the outside of the fiber to detect temperature changes. When the phase-matching condition is met, the core mode couples with the surface plasma mode, resulting in energy transfer. The finite element method is used to perform all numerical simulations of sensor characteristics in the COMSOL software. The results show that the highest sensitivity of the sensor can reach 6.36 nm/°C, and the maximum figure of merit (FOM) is 0.3440/°C between − 5 ℃ and 60°C. To our knowledge, the achieved sensing characteristics are significantly better than those of the current PCF temperature sensors. Furthermore, excellent linearity with a polynomial fit R 2 of up to 0.9981. The proposed sensor has exceptional performance in terms of temperature detection range, sensitivity, FOM and fabrication, making it suitable for a wide variety of biochemical and medical applications.