Ultra-narrow spectral response of a hybrid plasmonic-grating sensor Articles uri icon

publication date

  • April 2020

start page

  • 3520

end page

  • 3528

issue

  • 7

volume

  • 20

International Standard Serial Number (ISSN)

  • 1530-437X

Electronic International Standard Serial Number (EISSN)

  • 1558-1748

abstract

  • We configure and analyze a nanostructured device that hybridizes grating modes and surface plasmon resonances. The model uses an effective index of refraction that considers the volume fraction of the involved materials, and the propagation depth of the plasmon through the structure. Our geometry is an extruded low-order diffraction grating made of dielectric nano-triangles. Surface plasmon resonances are excited at a metal/dielectric interface, which is separated from the analyte by a high-index dielectric layer. The optical performance of the refractometric sensor is highly competitive in sensitivity and figure of merit (FOM) because of the the ultra-narrow spectral response (below 0.1 nm). Moreover, it is operative within a wide range of the index of refraction (from 1.3 till 1.56), and also works under normal incidence conditions.

keywords

  • nanophotonics; optical sensors; plasmonics