Three-parameter sensing characteristics of PCF based on surface plasmon resonance

In this study, a refractive index-temperature sensor based on surface plasmon resonance (SPR) in photonic crystal fiber (PCF) is proposed. Unlike conventional dual-parameter sensing research, this sensor features three sensing channels, offering the advantages of high-sensitivity measurements without cross-interference, utilizing three different plasmonic materials (Au, AZO, Ag), and enabling accurate measurement of temperature and refractive indices of two different analytes simultaneously. The finite element method is employed to investigate the influence of sensor structural parameters on sensing performance and optimize these parameters. In channel 1, analytes within the range of 1.37–1.43 can be detected, with maximum wavelength sensitivity (WS) of 31,500 nm/RIU and maximum amplitude sensitivity (AS) of 5690RIU −1 . The range of the SPR sensor in CH-2 is 1.25–1.40, with a max WS value of 5500 nm/RIU and peak AS of 10,845RIU −1 . Furthermore, the sensor obtains a higher figure of merit of 2357RIU −1 and a maximum wavelength resolution of 9.2208×10 −7 . Regarding temperature sensing, the proffered sensor has shown its ability to detect environmental temperature, with a wide detection range from 5°C to 95°C degrees and a maximum WS of 6.3 nm/°C. In summary, the proposed PCF-SPR sensor is capable of precise measurement of solution concentration and environmental temperature over a wide range, exhibiting high sensitivity and possessing potential applications in biosensing, environmental temperature detection, and more.