Generation of achromatic perfect vortex beams based on fiber end-integrated meta-structures

Combined with the strong anti-interference ability of optical fiber in light transmission and the flexible light control ability of meta-structures, the integration of optical fiber with meta-structures offers an excellent platform for designing new kinds of highly integrated and robust light field control devices. However, compared with on-chip meta-structure devices, the influences of fiber structure on the design of fiber-end integrated meta-structures and the target beam quality are still a problem worth studying. In this paper, we systematically investigate this topic via an all-fiber achromatic perfect vortex beam generator. Firstly, via correcting chromatic aberration, an achromatic perfect vortex beam generator in the wavelength range of 580-690 nm is designed. Then, the impacts of the fiber structure on the meta-structures design are explored. It is found that the achromatic properties and annular intensity radius of the perfect vortex beam are mainly determined by the meta-structures, while the fiber structure has significant effects on the width and quality of the intensity ring. Finally, generators enable the generation of superimposition states, and elliptical achromatic perfect vortex beams are also designed. Our works may have promising applications in high-capacity communications, optical manipulation, and integrated photonic systems.