Near-infrared Sb2S3 metasurface with giant and tunable circular dichroism

Abstract

Abstract Tunable circular dichroism (CD) is crucial for the development of chiral imaging, biosensing, and optical communication etc Herein, by employing the ultralow loss reversible phase-change materials Sb2S3, we achieved the giant and tunable CD signal in a chiral double-L array. Numerical results show that CD strength of the Sb2S3 metasurface can be over 0.9 in both amorphous and crystalline states. Strikingly, the resonant wavelength shift induced by the phase change of Sb2S3 reaches 93 nm, proving that the proposed metasurface possesses excellent tunability. In addition, the physical mechanism of the giant CD response is explained via multipole analysis. The proposed Sb2S3 metasurface capable of giant and tunable CD effect will facilitate the design of tunable dichroic devices.