Compact Anisotropic Metasurface for Full Range and Arbitrary Complex-Amplitude Control

A novel method for complex amplitude manipulation of spin light is proposed based on a double-layer compact anisotropic metasurface. A new degree of freedom (DOF) is introduced through independently rotating the two layers to achieve a full range control of the amplitude. Then additional full range phase shift is further imparted independently based on the traditional Pancharatnam-Berry (PB) phase mechanism by the global rotation of the meta-atom. As a result, the ability of full range and arbitrary complex amplitude manipulation is achieved on meta-atom level. Time consuming massive geometric parameter searching is avoided in the proposed method, which is beneficial to the complicated metadevice design. Based on this theory, two devices for multi-beam generation and Airy beam deflection are designed and experimentally verified, respectively. The good agreement between the calculated and measured results confirms the advantage of the proposed method. Our findings may trigger great interest in high-performance functional metaoptics devices with compact size in integrated systems.