SPR sensor based on D-type coreless fiber for measuring refractive index and temperature

This paper proposes a dual-parameter sensor based on surface plasmon resonance (SPR) utilizing a D-type coreless fiber. The proposed sensor is comprised of a D-type polished surface and a mixed liquid layer. In particular, the silver film deposited on the outer surface of the coreless fiber is responsible for measuring the refractive index. The silver film on the polished surface and the ethanol-chloroform mixed liquid layer are integrated to measure temperature features. The research results indicate that the proposed sensor achieves a maximum wavelength sensitivity of 12,400 nm/RIU with a refractive index range from 1.35 to 1.41, and a maximum temperature sensitivity of 13.7 nm/°C in the temperature range of 0°C to 40°C. More importantly, thanks to the simple structure, ease of fabrication, and high sensitivity, the proposed sensor exhibits promising application prospects in the fields of biomedical science and environmental monitoring.