High Performance Opening Up Dual-core Photonic Crystal Fiber Sensor Based on Surface Plasmon Resonance

Nowadays, plasmonic sensor based on photonic crystal fiber (PCF) attracted a great deal of attention in field of optical sensing. An opening up dual-core photonic crystal fiber based on surface plasmon resonance (SPR) are numerically demonstrated and analyzed for detecting wide refractive index (RI) range by Finite-Difference Time-Domain method (FDTD). The wavelength and amplitude integration methods, as well as figure of merit are used to investigate the sensor performance. For improving sensing performance, it is introduced a large hole between two cores in opening up section. The opening up section as a sensing channel is coated with gold film and a thin titanium dioxide (\({TiO}_{2}\)) layer. By surface engineering including imposing of grating on the gold film, specification of optimized values of different layers located near the surface, sensing performance are investigated. Next, the effect of the fiber structural parameters is analyzed to enhancing of SPR and fundamental core mode coupling. The proposed sensor revealed maximum wavelength and amplitude sensitivities of 15167 \(\left(\frac{nm}{RIU}\right)\) and 207.19 \(\left({RIU}^{-1}\right)\), respectively. Due to ease of infiltering analyte and gold coating and tanks to high wavelength and amplitude sensitivity, the sensors can be promising candidate of physical and chemical sensing.