Photonic crystal fiber-based SPR sensor for broad range of refractive index sensing applications

• In this paper, a high-sensitivity surface plasmon resonance (SPR) sensor based on photonic crystal fibre (PCF) is designed and simulated for a wide range of applications involving refractive index (RI) sensing. • The outside surface of PCF is coated with gold (Au), and a small layer of titanium dioxide acts as an adhesive between the gold and silica. • Wavelength sensitivity of 10000 nm/RIU, sensor resolution of 2 × 10 −5 RIU and amplitude sensitivity of 1115 RIU −1 are achieved. • In the operating wavelength between 0.5 µm and 1.35 µm, the proposed sensor can detect the RI of the analyte from 1.35 to 1.40. • The proposed sensor is exceptional for biochemical sensing, medical testing, and environmental monitoring due to its extensive range of RI detection and sensing. Until now, the use of photonic crystal fiber (PCF) based sensors has been limited. Environmental monitoring, the chemical industry, the food industry, and biomedicine are merely some of the fields. In this work, a surface plasmon resonance (SPR) sensor based on PCF is designed and simulated for a wide range of refractive index (RI) sensing applications with high sensitivity. The outer surface of PCF is coated with gold (Au), and a thin coating of titanium dioxide serves as an adhesive between the Au and silica. Using the SPR interaction between the core mode and Surface Plasmon Polariton mode of the proposed sensor, the RI of the analyte is detected. The simulated sensor has shown wavelength sensitivity of 10000 nm/RIU, sensor resolution of 2 × 10 −5 RIU and amplitude sensitivity of 1115 RIU −1 . Its operating wavelength ranges from 0.5 µm to 1.35 µm and it can detect the RI ranges from 1.35 to 1.40. The proposed sensor is exceptional for biochemical sensing, medical testing, and environmental monitoring due to its extensive range of RI detection and sensing.