Giant Intrinsic Chirality in Curled Metasurfaces
Chao Wang, Zhancheng Li, Ruhao Pan, Wenwei Liu, Hua Cheng, Junjie Li, Wenyuan Zhou, Jianguo Tian, Shuqi Chen
Abstract
Artificial nanostructures, whose spatial symmetry can be arbitrarily designed, play an ever more critical role for the realization of giant chiral optical responses. In order to break the mirror symmetry of the whole structure to realize a chiral optical response, there-dimensional geometries or multilayers of nanostructures were involved in the previous designs of chiral nanostructures, which may not be appealing from an application perspective due to their complexities and fabrication challenges. Here, we theoretically and experimentally demonstrate the use of curled metasurfaces for the implementation of giant intrinsic chiral optical responses in the near-infrared regime. Different from previous approaches, the giant chiral optical responses in the proposed curled metasurfaces are mainly attributed to the breaking of the mirror symmetry of the whole structure by involving curled nanostructures standing along horizontal rectangular apertures. Spin-selective transmission with over 60% efficiency has been experimentally proved with L-shaped curled metasurfaces. The proposed curled metasurfaces provide a new strategy for the realization of giant intrinsic chirality, which shows a great potential for practical application in spin optics and chiral sensing.