Open AccessActive switching and tuning of sharp Fano resonances in the mid-infrared spectral region
Author(s) -
Eunsongyi Lee,
In Cheol Seo,
Sung Chan Lim,
Hoon Yeub Jeong,
Young Chul Jun
Publication year - 2016
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.24.025684
Subject(s) - fano resonance , fano plane , resonator , resonance (particle physics) , optics , dielectric , infrared , scattering , physics , semiconductor , optical switch , optoelectronics , materials science , atomic physics , plasmon , mathematics , pure mathematics
We propose and analyze a scheme for active switching and spectral tuning of mid-infrared Fano resonances. We consider dielectric resonators made of semiconductor cylinder arrays and block pairs, and theoretically investigate their optical response change due to carrier generation. Owing to sharp optical resonances in these structures and large dielectric constant variations with carrier densities, the significant spectral tuning of Fano resonances is achievable. Furthermore, selective optical pumping in coupled semiconductor structures can even enable dynamic switching of Fano resonances. This leads to a drastic change in the scattering spectra as well as in the near-field intensity. We also observe a stark difference between Fano resonances in cylinder arrays and block pairs. To understand this unusual behavior, we adopt the two coupled oscillator model, and extract the relevant Fano resonance parameters that explain this difference. Our findings and in-depth analyses can be useful for molecular sensors and switching devices in the technologically important mid-infrared spectral region.