Numerical analysis of film‐loaded silicon nanowire optical rectangular waveguide: an effective optical sensing

Abstract

Subwavelength waveguide using silicon nanowires is investigated for its compatibility with silicon-on-insulator platform. A layer of silicon film over SiO2 substrate is employed to construct silicon nanowire waveguides that complies with standard 220 nm silicon height technology. The proposed structure is further investigated for its utility as an optical sensing element in photonic integrated circuits. Film-loaded silicon nanowire optical rectangular waveguide (SNORW) allows light to be guided inside low refractive indexed gapping region with optimised dimension. Fully numerical analysis is performed using finite-element method as evidence to support the guiding phenomena of this waveguide. Eventually, confinement factor and waveguide sensitivity is found to be linear with measurand refractive index. As a result, the purpose of this SNORW leads to an effective sensing in the new era of photonics.