Open AccessFano-like coupling between two oppositely enhanced processes by diffraction in a dielectric grating
Author(s) -
Jian Zhang,
Xinping Zhang
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.23.030429
Subject(s) - fano resonance , guided mode resonance , optics , materials science , plasmon , waveguide , grating , diffraction grating , diffraction , dielectric , optoelectronics , coupling (piping) , resonance (particle physics) , physics , particle physics , metallurgy
Fano-like coupling was investigated extensively in plasmonic nanostructures, which is based on the interaction between the photonic and plasmonic resonance modes. Metallic photonic crystals consisting of waveguide metallic gratings are typical devices exhibiting strong Fano-coupling between waveguide and plasmon resonance modes. However, we demonstrate here that similar effects can also be achieved in waveguide dielectric grating structures. In this case, the broad-band strong optical extinction results from multifold diffraction processes, instead of the plasmonic absorption and scattering of light. The diffraction efficiency of the waveguide dielectric gratings was tuned by changing the duty cycle through adjusting the exposure time in interference lithography. Enhanced diffraction efficiency reduces the direct transmission while enhances the waveguide resonance mode, leading to a Fano-like coupling process.