Open AccessSpatial mapping of refractive index based on a plasmonic tapered channel waveguide
Author(s) -
Da Eun Lee,
TaeWoo Lee,
Soon-Hong Kwon
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.005907
Subject(s) - optics , refractive index , waveguide , scattering , plasmon , materials science , surface plasmon , light scattering , total internal reflection , forward scatter , physics
A tapered plasmonic channel waveguide can be used for index sensing by spatial mapping of the scattering field intensity. A numerical simulation shows that this waveguide reflects the plasmonic channel waveguide mode at various points as the refractive index of an analyte changes, and a strong outgoing scattering wave appears at the reflection point. One can measure the index change by detecting variations in the scattering point. In the case of a unit index change, the scattering point moved 2670 nm, which can be observed by an imaging system. Detection limit of the index change is estimated as 0.12. However, the limit can be further reduced by increasing the tapered length or decreasing the tapered angle of the structure.