Modeling of Refractive Index Sensing Using Au Aperture Arrays on a Bragg Fiber Facet

• Published in: Photonic sensors (Berlin) Vol. 9; no. 4; pp. 337 - 343
• Main Authors: Xiao, Gongli, Yang, Hongyan
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.12.2019; Springer Nature B.V; SpringerOpen
• Subjects: Apertures; Core loss; Figure of merit; Finite difference method; finite-difference time-domain; Lasers; Measurement Science and Instrumentation; Microwaves; Optical Devices; Optical fiber sensors; Optics; Parameter sensitivity; periodic array; Photonics; Physics; Physics and Astronomy; refractive index sensing; Refractivity; Regular; RF and Optical Engineering; Sensitivity analysis; Sensitivity enhancement; surface plasmon resonance; Optical fiber sensors; refractive index sensing; surface plasmon resonance; periodic array; finite-difference time-domain
• ISSN: 1674-9251; 2190-7439
• DOI: 10.1007/s13320-019-0542-0

A finite-difference-time-domain (FDTD) approach is undertaken to investigate the extraordinary optical transmission (EOT) phenomenon of Au circular aperture arrays deposited on a Bragg fiber facet for refractive index (RI) sensing. Investigation shows that the choice of effective indices and modal loss of the Bragg fiber core modes will affect the sensitivity enhancement by using a mode analysis approach. The critical parameters of Bragg fiber including the middle dielectric RI, as well as its gap between dielectric layers, which affect the EOT and RI sensitivity for the sensor, are discussed and optimized. It is demonstrated that a better sensitivity of 156 ± 5 nm per refractive index unit (RIU) and an averaged figure of merit exceeding 3.5 RIU −1 are achieved when RI is 1.5 and gap is 0.02 μm in this structure.