Gap plasmon-based metasurfaces: From amplitude to phase control of reflected light

We demonstrate how metal-insulator-metal configurations, in which the upper metal layer is periodically structured, allow for efficient control of the amplitude and phase of the reflected light, emphasizing the presence of gap-surface plasmon resonances and their connection to the optical response. Furthermore, we discuss applications of inhomogeneous meta-surfaces, ranging from subwavelength plasmonic color printing to unidirectional polarization-controlled excitation of surface plasmon polaritons.