Abstract

Metasurfaces, acting as arrays of perfect nano-polarizers, provide a promising approach to manipulate the amplitude of an incident light at the sub-wavelength scale. In this Letter, we design and demonstrate continuous amplitude-modulated meta-fork gratings to generate optical vortex beams. More importantly, benefiting from the unique negative amplitude modulation, the unavoidable zero-order light that conventional amplitude-only elements always suffer disappears by carefully adjusting the orientation of each nanobrick. The dramatically dropped zero-order light with only 3% leakage energy verifies our design. With the advantages of continuous amplitude modulation, zero-order extinction, and super-high resolution, the proposed meta-fork grating will have a widespread application in integrated optical vortex manipulation and promote the emergence of many other amplitude-modulated nano-optical devices.

© 2020 Optical Society of America

Single-size nanostructured metasurface for dual-channel vortex beam generation

Qi Dai, Zile Li, Liangui Deng, Nan Zhou, Juan Deng, Jin Tao, and Guoxing Zheng
Opt. Lett. 45(13) 3773-3776 (2020)

Zero-order-free meta-holograms in a broadband visible range

Rao Fu, Liangui Deng, Zhiqiang Guan, Sheng Chang, Jin Tao, Zile Li, and Guoxing Zheng
Photon. Res. 8(5) 723-728 (2020)

Toward generalized forked gratings via deep learning

Yue Zhao, Enliang Wang, Fulin Cao, and Changqing Xie
Opt. Lett. 46(24) 6059-6062 (2021)

On-axis three-dimensional meta-holography enabled with continuous-amplitude modulation of light

Guoxing Zheng, Rao Fu, Liangui Deng, Gongfa Li, and Zile Li
Opt. Express 29(4) 6147-6157 (2021)

Highly efficient nonlinear vortex beam generation by using a compact nonlinear fork grating

Yangfeifei Yang, Hao Li, Haigang Liu, and Xianfeng Chen
Opt. Lett. 48(24) 6376-6379 (2023)