Dark and bright modes, and their coherent control in dipolar metasurface bilayers

The authors derive a semianalytical model describing the reflection and absorption spectra of dipolar bilayer metasurfaces, showing how radiative coupling between the layers can result in the formation of nonradiative dark modes which can contribute significantly to the optical response of the system. The ability to vary the reflection and absorption spectra of such bilayers by changing the material and geometrical parameters, and to selectively excite the modes by adjusting the phase between two counter-propagating normally incident fields, promises numerous applications.