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Optical metasurfaces are thin-layer subwavelength patterned structures that interact strongly with light. Metasurfaces have become the subject of several rapidly growing areas of research, being a logical extension of the field of metamaterials towards their practical applications. Metasurfaces demonstrate many useful properties of metadevices with engineered resonant electric and magnetic optical responses combined with low losses of thin-layer structures. In this talk, we introduce the basic concepts of this rapidly growing research field and review the most interesting properties of photonic metasurfaces, demonstrating their useful functionalities such as frequency selectivity, wavefront shaping, tunability and polarization control.
More specifically, we demonstrate that all-dielectric metasurfaces provide a powerful platform for highly efficient flat optical metadevices, owing to their strong electric and magnetic dipolar response accompanied with negligible losses at near-infrared frequencies. In particular, we experimentally demonstrate several different types of planar metadevices, as well as realize dynamic tuning of electric and magnetic resonances in the telecom spectral range. Strongly different tuning rates are observed for the electric and the magnetic response, which allows for dynamically adjusting the spectral mode separation. Furthermore, we study the influence of the anisotropic (temperature-dependent) dielectric environment provided by the liquid crystal and demonstrate that the phase transition of the liquid crystal from nematic to isotropic phase can break the symmetry of the optical metasurface response.
In addition, we discuss our studies of the interaction between monolayer MoSe2 and plasmonic dipolar antennas, and demonstrate manipulation of the photoluminescence intensity from quenching to enhancement and its strong polarization dependence.
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