D-shaped photonic crystal fiber based on surface plasmon resonance for low refractive index applications

Here, a fresh D-type photonic crystal fiber has been developed by us, relying on the surface plasmon resonance effect. Differing from conventional D-type photonic crystal fiber, this model coats gold film on an open-loop channel for excitation. Through the finite element method analysis, this sensor exhibits an effective scope of 1.20 to 1.30 for the refractive index of analyte. As the RI of the analyte rises, the loss peak within the spectrum gradually intensifies and then remains stable. At an RI value of 1.30, achieving a resolution of 9.52×10-6 RIU, this sensor exhibits excellent performance with a maximum sensitivity of 10500 nm/RIU. Its simple structure adds to its overall appeal. The outstanding sensing performance demonstrates enhanced competitiveness in sectors with lower refractive indices. Farther, to enhance the sensor's sensing capabilities, we conducted an analysis of how structural parameters impact the resonance spectrum with the goal of optimization.