High-Sensitivity Temperature Sensor Based on Surface Plasmon Resonance Photonic Crystal Fiber

A high-sensitivity photonic crystal fiber (PCF) temperature sensor based on surface plasmon resonance (SPR) with a high figure of merit (FOM) is proposed. Compared with most optical fiber inner air holes coated with metal or placed with metal nanowires, owing to the plasma material directly contacting the analyte, the annular channel outside the cladding is convenient for analyte detection, and the sensor is easier to manufacture. The temperature-sensitive liquid is a mixed solution of ethanol and chloroform with a volume ratio of 1 : 1. The results indicate that the highest sensitivity of this sensor can reach 15.4 nm/degrees C, and the maximum FOM is 0.2829/degrees C between -10 degrees C and 60 degrees C. Furthermore, the influence of photonic crystal fiber air hole size, gold film thickness, and other parameters on the performance of the sensor is analyzed.