High-Sensitivity Two-Core Dual-Polarization Photonic-Crystal-Fiber Surface-Plasmon-Resonance Sensor Based on Indium Tin Oxid

In this paper, we propose a high-sensitivity two-core dual-polarization photonic-crystal-fiber surfaceplasmon-resonance (PCF-SPR) sensor based on Indium Tin oxide (ITO). ITO is a conductor material with adjustable photoelectric properties and low losses in the infrared range, and the two-core structure could better direct the incident light to the metal surface to enhance the coupling. According to numerical simulation results, the maximum wavelength sensitivities are 17,000 nm/RIU and 25,500 nm/RIU in the x-polarization mode and y-polarization mode. The maximum resolution of the x-polarization mode and y-polarization mode of the sensor can reach 5.88·10⁻⁶ RIU and 3.92·10⁻⁶ RIU, respectively, and the liquid refractive index detection range is 1.32 – 1.39. Taking into account the simple structure and excellent sensing performance, the sensor has wide application prospect and can accurately detect the refractive index of liquids, such as blood plasma, hemoglobin, etc.