A Plasmonic Biosensor Based on Dual D-Shaped Photonic Crystal Fiber

A symmetrical surface plasmon resonance (SPR)-based dual D-shaped photonic crystal fiber (PCF) biosensor has been proposed and investigated by finite element method (FEM) based mode solver. The fiber has a circular core based on ring of air holes on inner layer and an outer layer of hexagonal lattice. As plasmonic material, gold is applied to the surface that has been polished. The sensor exhibits a maximum sensitivity of 37900 nm/RIU in wavelength interrogation and a wavelength resolution of 2.64×10
⁻⁶
RIU in the sensing range of 1.36–1.42, which is a suitable range for biosensing applications, such as cancer detection. Maximum amplitude sensitivity obtained is 2570 RIU
⁻¹
. Due to high sensitivity in both wavelength and amplitude interrogation approaches, suitable range and ease of fabrication complexity, the proposed fiber can be considered as an optimum alternative for bio-molecular analyte detection.