Thin anisotropic metasurfaces for simultaneous light focusing and polarization manipulation

The possibility of integration of two important categories of optical components, i.e., circular polarizer and lens, into a thin plasmonic metasurface is examined, for the realistic case when metal losses cannot be neglected, for example when operating in the visible spectrum, or at infrared when non-noble metals are used. We introduce a metasurface made of nanoantennas that offer enough degrees of freedom to control both amplitude and phase of the reflection coefficient. First a theoretical formulation is developed and then an optimal design for a polarizing lens atmid-infraredwavelengthsnear 4.3 μmispresented.A two-dimensional array ofY-shapednanoantennaswith polarization-dependent and spatially varying phase response offers the possibility of balancing the losses experienced by the xand y-polarized incident fields and is the basis for such a compact polarizing lens. © 2015Optical Society of America OCIS codes: (160.3918) Metamaterials; (250.5403) Plasmonics; (050.6624) Subwavelength structures. http://dx.doi.org/10.1364/JOSAB.32.000318