Abstract
In this Letter, we propose an approach to generate high-purity orbital angular momentum (OAM) vortex waves using an amplitude-and-phase metasurface (APM). By varying the square split ring opening and orientation angles, the cross-polarized reflection response of the proposed structure can yield full phase and amplitude coverage. Based on the traditional phase-only metasurface (POM), the Chebyshev synthesis method (CSM) is applied to array the metasurface amplitude distribution. Metasurfaces with modes $l$ of 1, 2, 3, and 4 are designed. Compared with the POM, the APM can effectively improve the vortex beam quality and OAM mode purity. The measured results agree well with full-wave simulations. The presented method provides a new, to the best of our knowledge, way to design high-purity OAM generators based on metasurfaces.
© 2021 Optical Society of America
Full Article | PDF ArticleMore Like This
Xiangshuai Meng, Jiaji Wu, Zhensen Wu, Lin Yang, Li Huang, Xi Li, and Tan Qu
Opt. Lett. 44(6) 1452-1455 (2019)
Kunjian Dai, J. Keith Miller, Wenzhe Li, Richard J. Watkins, and Eric G. Johnson
Opt. Lett. 46(14) 3332-3335 (2021)
Shixing Yu, Long Li, and Na Kou
Opt. Mater. Express 7(9) 3312-3321 (2017)