Structured vortices generated by metasurface holography

Highly customized and miniaturized structured light is expected in many application fields.A kind of structured vortex generators is proposed based on a metasurface consisting of rectangular nanoholes etched in a silver film,and the generated vortices with the same or different topological charges are distributed along the radial direction.The geometric metasurface is completed with the help of optical holography technology,and the structured vortex generator possesses high working efficiency and large information capacity.The proposed vortex generators work under circularly polarized light illumination,and the reproduced vortices of multiplexing vortex generator depend on the handedness of the circularly polarized light.This work paves a way to generate new structured light fields.The radially distributed vortices may be utilized to simultaneously screen or separate microparticles.The compact design of the structured vortex generator and the convenient switch of different structured vortices will be a benefit to expand the applications of structured vortex fields.