Highly Sensitive Wide Detection Range Semicircular Convex Slot PCF Temperature Sensor Based on Surface Plasmon Resonance

In this study, a novel semicircular convex groove photonic crystal fiber (PCF) sensor based on surface plasmon resonance (SPR) is designed to achieve high-precision temperature measurements in the near-infrared (NIR) range using gold as the plasmon material. Finite element numerical simulations show that the PCF-SPR sensor can obtain a temperature detection range of 16 °C–130 °C when the y-polarization (Y-pol) fundamental mode is coupled with the surface plasmon polariton (SPP) mode. The maximum wavelength sensitivity (WS) obtained is 41.5 nm/°C, the optimum resolution is
$2.4\times \,\, 10^{-{3}}~^{\circ }$
C, and the maximum figure of merit (FOM) is 0.1663 °C−1. When the x-polarization (X-pol) fundamental mode is coupled with the SPP mode. The PCF-SPR sensor achieves a temperature detection range of −25 °C to 80 °C. The maximum WS obtained is 2.74 nm/°C, the optimum resolution is
$3.65\times \,\, 10^{-{2}}~^{\circ }$
C, and the maximum FOM is 0.05007 °C−1. Thus, the sensor is highly competitive in the aerospace industry for temperature monitoring of cooling systems and cabin environments, as well as chemical reactions such as polymerization, solvent evaporation, and crystallization.