Dual-parameter Ag/SiC PCF-SPR sensor for RI and temperature in NIR

Abstract The sensitivity of near-infrared (NIR) band measurements is higher compared to that of visible light. Accurate NIR sensing of refractive index (RI) and temperature is thus of growing importance. Silicon carbide (SiC), due to its relatively high RI, enables red-shift the resonance wavelength to the NIR band. Therefore, a dual-parameter double-sided polished photonic crystal fiber (PCF) sensor suitable for the NIR band has been proposed. On one side of the fiber, a silver (Ag) film coated with silicon carbide (SiC) facilitates RI detection. The other side adopts a polydimethylsiloxane (PDMS) and Ag/SiC composite film, specifically engineered for temperature detection. The sensor was constructed and simulated using COMSOL software. Results demonstrate a maximum RI sensitivity of 17500 nm RIU −1 and temperature sensitivity of 15.8 nm °C −1 are achieved for RI between 1.31 and 1.41 and temperature range from 0 °C to 100 °C. This analysis confirms that the proposed sensor not only enables dual parameter sensing in the NIR band but also exhibits high sensitivity and a broad detection range.