Double Fano resonance in a plasmonic double grating structure

It is shown theoretically and numerically that a simple gratings-based plasmonic structure can support a nearly-degenerate double Fano resonance which can lead to a relatively narrow spectral line shape. The double-resonance spectral location and line-shape are controllable by either adjusting the periodicity and unit-cell of the gratings or by adjusting the angle of incidence of the incoming radiation. (C) 2016 Optical Society of America