With the recent development of the metasurface, generating an optical vortex in optical far or near fields is realized in various ways. However, to generate vortices in both the near and far fields simultaneously is still a challenge, although it has great potential in the future compact and versatile photonic system. Here, a bi-channel optical vortex generator in both the near and far fields is proposed and demonstrated within a single metasurface, where the surface plasmon vortex and the far-field optical vortex can be simultaneously generated under circularly polarized light. The ability of generating vortices with arbitrary topological charges is experimentally demonstrated, which agrees well with simulations. This approach provides great freedom to integrate different vortex generators in a single device and offers new opportunities for integrated optical communications, trapping, and other related fields.

中文翻译：

---

基于单等离子超表面的双通道近场和远场光学涡流发生器

随着超表面的最新发展，在光学远场或近场中产生光学涡流以多种方式实现。然而，同时在近场和远场同时产生涡流仍然是一个挑战，尽管它在未来紧凑且多功能的光子系统中具有巨大的潜力。在这里，近场和远场的双通道光学涡流发生器被提出并在单个超表面内进行演示，其中表面等离子体涡旋和远场光学涡旋可以在圆偏振光下同时产生。实验证明了产生具有任意拓扑电荷的涡流的能力，这与模拟非常吻合。