Abstract-Double Fano resonance with externally driven subradiant mode

Y.U. Lee, J.W. Wu, 
http://ieeexplore.ieee.org/abstract/document/7746488/

In this study, we observe that a dark mode is not necessarily prerequisite for an asymmetric Fano resonance to take place in plasmonic structures. The characteristic asymmetry feature of Fano resonance is retained in a plasmonic structure when both superradiant and subradiant oscillators are externally driven. Double Fano resonances are experimentally and theoretically observed where a common subradiant driven oscillator is coupled with two superradiant oscillators. As a classical analogue of a four-level tripod atomic system, the extinction spectrum of the composite metamaterial exhibits a coherent effect based on double Fano resonances. Transfer of the absorbed power between two orthogonal superradiant oscillators is shown to be mediated by the common subradiant oscillator.

Abstract-Graphene based tunable terahertz sensor with double Fano resonances

Yuping Zhang,   Tongtong Li,   Beibei Zeng,   Huiyun Zhang,  Huanhuan Lv,   Xiaoyan Huang,   Weili Zhang and   Abul Azad  

Nanoscale, 2015, Accepted Manuscript

DOI: 10.1039/C5NR03044G
Received 09 May 2015, Accepted 20 Jun 2015
First published online 24 Jun 2015
http://pubs.rsc.org/en/content/articlelanding/2015/nr/c5nr03044g#!divAbstract

We propose an ultrasensitive terahertz (THz) sensor consisting of a subwavelength graphene disk and an annular gold ring within a unit cell. The interference between the resonances arising from the graphene disk and the gold ring gives rise to Fano type resonances and enables ultrasensitive sensing. Our full wave electromagnetic simulations show frequency sensitivity as high as 1.9082THz/refractive index unit (RIU) and a figure of merit (FOM) of 6.5662. Furthermore, the sensing range can be actively tuned by adjusting the Fermi level of graphene.