A Circumvolution Phase of Metasurface Based on Rotational Circular Ring Configuration

Abstract In this study, a phase of metasurface is proposed based on rotational ring configuration, whose tuning principle is associated with its conversion between spin angular and orbital momentum. The focusing vortex beams could be obtained with steerable focal plane. The spin‐selection mechanisms of phase shifting process depend on the corresponding orbital momentums. To promote its practical application, the relationships between the mechanical performance, i.e., the limited circumvolution angle and the optical properties including the tuning range of focal length and the orbital momentum are analyzed and discussed, indicating that the demand on rotational ring implementation would be lower by increasing the converted orbital momentum. The optical sparse aperture is then proposed and demonstrated as an effective solution to implement the conversion involved with high orbital momentum. This work will pave the way for designing tunable metasurface based on circumvolution phase and facilitating their applications in areas of optical manipulation and vortex‐based communication.