Abstract
In this paper, the modal characteristics of silicon-based optical waveguides (hereafter represented as WGs) such as ridge,
rib, slot and the hybrid plasmonic WGs are discussed. For sensing applications, the geometric parameters of the WGs are
optimized to evaluate the mode sensitivity (Smode) and evanescent field ratio (EFR). For highly sensitive devices, these two
parameters should be as high as possible to facilitate strong light-matter interaction. The analysis is performed via the finite
element method (FEM) which demonstrate that EFR and Smode follow the following order: Hybrid WG ≥ Slot WG > Ridge WG
@ TE mode > Rib WG @ TE-mode > Ridge WG @ TM mode > Rib WG @ TM mode. Furthermore, refractive index sensor
established on a ridge, slot and hybrid plasmonic WGs are studied. The numerical calculations have revealed that the best
sensitivity of 167 nm/RIU, 233.3 nm/RIU and 333.3 nm/RIU is delivered by ring resonator designs constructed on ridge, slot
and the hybrid plasmonic WG, respectively. We believe that these findings are quite beneficial to have a detailed analysis of
different WG types to make a judicious selection of optical WG structure for sensing applications.
Keywords
Ridge waveguide, Rib waveguide, Slot waveguide, Hybrid plasmonic waveguide, Refractive index sensing application.
Citation
N. L. KAZANSKIY, A. KAŹMIERCZAK, M. A. BUTT, Why slot and hybrid plasmonic waveguides are ideal candidates for sensing applications?, Optoelectronics and Advanced Materials - Rapid Communications, 15, 5-6, May-June 2021, pp.195-206 (2021).
Submitted at: Dec. 8, 2020
Accepted at: June 11, 2021