Highly sensitive refractive index sensor based on hybrid plasmonic waveguide microring resonator

Abstract

A refractive index (RI) sensor based on straight silicon strip waveguide and a hybrid plasmonic microring resonator is presented. The hybrid waveguide is made up of a Metal-Air-Silicon structure, where the electric field is significantly enhanced in the narrow air gap. The transmission spectrum and electric field distribution of this sensor structure are simulated using Finite Element Method (FEM). Due to a large overlap of the optical field in the hybrid microring resonator and the sensing medium, this sensor can be used for both gas and bio sensing applications. The best sensitivity of 690 nm/RIU and 401 nm/RIU is obtained for gas and bio sensing, respectively. The obtained values are relatively high as compared to conventional dielectric microring resonator sensors. Our proposed sensor design has a potential to find further applications in biomedical science and nanophotonic circuits.

KEYWORDS:

• Hybrid plasmonic waveguide
• ring resonator
• high sensitivity
• near infrared

Subject classification codes:

• include these here if the journal requires them

ORCID

M. A. Butt http://orcid.org/0000-0003-0829-4886

Additional information

Funding

This work was supported by Russian Foundation for Basic Research [grant number 16-29-09528] in part of design and analytical method and by the Ministry of Science and Higher Education within the State assignment FSRC «Crystallography and Photonics» RAS in part of simulation results.