Metasurfaces are planar arrangements of elements that are designed to present a particular response to an incident electromagnetic field. Due to their ability to control at will the phase, polarization and amplitude of the reflected and/or transmitted waves at a subwavelength scale they have gathered a great deal of attention among the research community.
Although the first metasurface proposals were realized with plasmonic particles, the focus is now turning into all-dielectric approaches, in order to mitigate losses and increase the device efficiencies. Besides the obvious advantage of loss reduction, when high-index, subwavelength particles are considered a whole new family of resonant, magnetic-like modes is accessible. This new set of modes, which cannot be excited in simple metallic particles, brings additional functionalities for these metasurfaces, as will be shown in this talk.
We will focus on the interesting effects that arise as a consequence of the far-field interference between electric and magnetic modes excited in the dielectric particles forming the metasurface and the strong modification of their scattering patterns as a consequence of this interference. In particular, we will show the possibility to realize so called ideal Huygens’ secondary sources to generate a perfectly transmissive metasurface with full phase control. We will also show that these metasurfaces support a generalized version of Brewster’s effect, in which the phenomenon is not restricted to a particular angle or polarization of incidence but can be tuned at will, and the different implications that this concept has.