Open AccessFano resonances in a multimode waveguide coupled to a high-Q silicon nitride ring resonator
Author(s) -
Dapeng Ding,
M. J. A. de Dood,
Jared F. Bauters,
Martijn J. R. Heck,
John E. Bowers,
Dirk Bouwmeester
Publication year - 2014
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.22.006778
Subject(s) - fano resonance , resonator , waveguide , optics , coupled mode theory , physics , resonance (particle physics) , optoelectronics , coupling (piping) , multi mode optical fiber , materials science , optical fiber , refractive index , plasmon , atomic physics , metallurgy
Silicon nitride (Si3N4) optical ring resonators provide exceptional opportunities for low-loss integrated optics. Here we study the transmission through a multimode waveguide coupled to a Si3N4 ring resonator. By coupling single-mode fibers to both input and output ports of the waveguide we selectively excite and probe combinations of modes in the waveguide. Strong asymmetric Fano resonances are observed and the degree of asymmetry can be tuned through the positions of the input and output fibers. The Fano resonance results from the interference between modes of the waveguide and light that couples resonantly to the ring resonator. We develop a theoretical model based on the coupled mode theory to describe the experimental results. The large extension of the optical modes out of the Si3N4 core makes this system promising for sensing applications.