Abstract
Next-generation sensing technologies require high-performance sensors that can offer ultra-low loss while achieving enhanced sensitivity. To achieve this goal, we propose a hollow-core anti-resonant fiber (HC-ARF) refractive index (RI) sensor that leverages the surface plasmon resonance (SPR) detection mechanism for superior optical sensing performance. The proposed design features a simplified geometry with a single ring of uniformly arranged cladding tubes, each coated with a thin gold layer on both the tube and jacket surfaces to enable strong plasmonic interactions. Using rigorous finite element modeling (FEM) simulations, the fiber structure is precisely optimized to achieve ultra-low loss and high detection sensitivity through wavelength interrogation. The numerical results show that the proposed HC-ARF sensor exhibits losses that are up to two orders of magnitude lower than those of conventional solid-core fiber sensors. Remarkably, it is also maintaining outstanding wavelength sensitivity (WS) of 6500 and 11500 nm/RIU for analyte RIs of 1.33 and 1.43, respectively, effectively covering the RI range from 1.25 to 1.44. In addition, the sensor exhibits stable performance under tight bending conditions with an 80 cm bend radius and 4% variations in geometric parameters. Its high sensitivity and low loss property make the sensor a strong candidate for precise and real-time RI monitoring in diverse applications, including glucose and sucrose concentration analysis, cancer cell detection, and SARS-CoV-2 identification.
Md Selim Habib
Assistant Professor of Electrical Engineering
Hollow-core fibers; Fiber sensors; Ultrafast nonlinear optics