Transformation of Longitudinally Customizable Curved Vector Vortex Beams Using Dielectric Metasurface

In recent years, the emergence of metasurfaces has brought revolutionary changes to the generation and processing of vortex beams, triggering widespread research interest. Meanwhile, the longitudinally varying features of propagating beams provide new design freedom for realizing multi-dimensional optical manipulation and promote the advancements of related areas such as microscopic detection, microfabrication, and biomedical applications. In addition, self-accelerating Bessel beams are promising for a wide range of applications such as particle manipulation and medicine due to their nondiffracting, self-healing as well as obstacle avoidance properties. In this paper, a novel kind of curved transmitted high-order Bessel beams with longitudinally varying features based on form-birefringent metasurface, by simultaneously manipulating the phase profiles of output orthogonal polarization components is demonstrated. Multiple dimensions of the beam, including the propagation trajectory, polarization state, and orbital angular momentum, can be tailored arbitrarily. For verifying the feasibility of the demonstrated method, two samples with different propagation trajectories, as well as different variations of orbital angular momentum, are designed and experimentally demonstrated. Such a novel approach can open new doors for the manipulation of vortex beams and can be used for depth sensing and distance measurement in complex environments.