High Quality Fano Resonance by Lattice Mode Coupling in Terahertz Metamaterials

Abstract

Fano resonance is the outcome of indirect excitation of EM wave leading to an asymmetric resonant response and having trade-off between Quality factor (Q) and Figure of merit (FOM). We investigated that this tradeoff can be reduced by the coupling of lattice modes with the Fano modes, resulting in high Q-factor and FOM simultaneously. In our study, we fixed the lattice mode by fixing the periodicity, and then engineered the resonator's position such that, the two characteristic frequencies overlap to yield the desired response, which can be utilized in the applications like narrowband filters, modulators, switches, and sensors.