Plasmonic metasurfaces, i.e., nanometer-thin surface metal nanostructures with subwavelength-sized lattice units, have recently attracted considerable attention due to their abilities to efficiently control both phase and amplitude of transmitted and reflected radiation. In this talk, it is demonstrated how metal-insulator-metal configurations in which the upper metal layer is periodically structured, thus supporting gap surface plasmon (GSP) resonances, allow for efficient control of the phase of the reflected light, independently shaping orthogonally polarized reflected fields. Starting with the underlying physics of GSP resonant elements, the concept of GSP-based metasurfaces is introduced, including the design of efficient, compact (i.e., subwavelength thick) and background-free (i.e., no diffraction and no scattering into other polarizations) wave plates in reflection and flat focusing mirrors - the latter functionality is obtained by gradient (i.e., inhomogeneous) metasurfaces that facilitate the independent control of reflection phases of orthogonal light polarizations. Finally, GSP-based gradient birefringent metasurfaces are shown to enable the design of efficient unidirectional polarization-controlled surface plasmon polariton couplers.


Seminar, November 12, 2013, 12:00. Seminar Room

Hosted by Prof. Romain Quidant