Broadband quarter-wave plate based on dielectric-embedded plasmonic metasurface

Abstract

High transmission plasmonic and all-dielectric metasurface wave plates have been reported in recent studies. However, narrow bandwidth and low polarization conversion need to be addressed to attain even better operation requirements. In this work, we numerically demonstrate the concept of an ultrathin single layer plasmonic metasurface embedded with dielectric resonators. Our design is based on the transmission line theory and surface plasmon excitation to realize a quarter-wave plate with controllable birefringence. The controllability is achieved through manipulating relative permittivity of a non-dispersive dielectric material-embedded in a perforated silver film, and the surface dimensions of silver. We have also achieved higher degrees of linear-to-circular and circular-to-linear polarization conversions at broadband wavelengths in the near infrared compared with other conventional plasmonic metasurfaces. Moreover, the functioning of the wave plate is demonstrated on a compact and ultrathin metasurface showing great potential of integration into photonic sensors.