Hollow‐Core Anti‐Resonance Sensing Fiber Based on SPR With Ultra‐Wide Detection Range

ABSTRACT To achieve ultra‐wide refractive index sensing, a single nested node‐less hollow core anti‐resonant fiber is proposed. A gold film is plated in one of the cladding tubes to obtain the surface plasmon resonance effect. The analyte is filled in the fiber core and the gold‐coated tube, which is conducive to expanding the range of refractive index sensing. The sensing structure's performance is investigated by the finite element method. The numerical simulations show that the sensing structure can work in the range of 1.16–1.43, with an average sensitivity of 6153 nm/RIU, a maximum sensitivity of 13 100 nm/RIU, and a resolution of 7.64 × 10 −6 . This provides a novel solution for ultra‐wide refractive index range sensing.