Compact Non-Chiral Dielectric Metasurfaces to Manifest Enormous Chirality based Optical Responses

Abstract

The chiro-optical effects are commonly linked with the chiral structures, which simultaneously break rotational and mirror symmetries. In recent years, the chiral metasurfaces (2D equivalent of metamaterials) emerged due to their exceptional ability to manipulate electromagnetic (EM) waves. Although many efforts have been made for highly efficient chiral meta-devices yet the realization of compact all-dielectric meta-devices at optical wavelengths is still challenging. In this work, we have demonstrated a non-chiral all-dielectric meta-device permitting enormous chirality based optical responses. The basic building block of the proposed meta-device comprises a pair of distinct subwavelength meta-atoms with a relative rotation angle of 45 degrees. The novel design strategy leads to a compact all-dielectric meta-device that offers a giant chiro-optical effect in terms of asymmetric transmission and optical activity at a wide-angle of the incident light. In our opinion, the proposed meta-device can find application in integrated chiral optical systems, polarization rotators, optical displays, and chiral sensing.