Author(s): Zhang, ZH (Zhang, Ziheng); Li, T (Li, Tong); Jiao, XF (Jiao, Xiaofei); Song, GF (Song, Guofeng); Xu, Y (Xu, Yun)

Source: APPLIED SCIENCES-BASEL Volume: 10 Issue: 16 Article Number: 5716 DOI: 10.3390/app10165716 Published: AUG 2020

Abstract: Featured Application Optics and Lasers, Integrated Ultraviolet Nanophotonics, Meta-optics. 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 chargelfrom 1 to 3) and multichannel detection(lfrom -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.

Accession Number: WOS:000564652800001

eISSN: 2076-3417

Full Text: https://www.mdpi.com/2076-3417/10/16/5716