High-Efficiency All-Dielectric Metasurfaces for the Generation and Detection of Focused Optical Vortex for the Ultraviolet Domain

Applied Sciences

Guofeng Song¹  Yun Xu¹  Ziheng Zhang¹  Xiaofei Jiao¹  Tong Li² 

[1] Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China;School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410004, China;

关键词: dielectric metasurface;    polarization conversion;    optical vortex;    niobium pentoxide;   

DOI  :  10.3390/app10165716

来源: DOAJ

【 摘 要 】

The optical vortex (OV) has drawn considerable attention owing to its tremendous advanced applications, such as optical communication, quantum entanglement, and on-chip detectors. However, traditional OV generators suffer from a bulky configuration and limited performance, especially in the ultraviolet range. In this paper, we utilize a large bandgap dielectric material, niobium pentoxide (Nb₂O₅), to construct ultra-thin and compact transmission-type metasurfaces to generate and detect the OV at a wavelength of 355 nm. The meta-atom, which operates as a miniature half-wave plate and demonstrates a large tolerance to fabrication error, manipulates the phase of an incident right-handed circular polarized wave with high cross-polarized conversion efficiency (around 86.9%). The phase delay of $\pi$ between the orthogonal electric field component is attributed to the anti-parallel magnetic dipoles induced in the nanobar. Besides, focused vortex generation (topological charge l from 1 to 3) and multichannel detection (l from −2 to 2) are demonstrated with high efficiency, up to 79.2%. We envision that our devices of high flexibility may have potential applications in high-performance micron-scale integrated ultraviolet nanophotonics and meta-optics.

【 授权许可】

Unknown