Open AccessHigh-efficiency broadband vortex beam generator based on transmissive metasurface
Author(s) -
Shiwei Tang,
Xike Li,
Wenfeng Pan,
Jun Zhou,
Tao Jiang,
Fei Ding
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.004281
Subject(s) - optics , broadband , vortex , bandwidth (computing) , beam (structure) , vortex generator , generator (circuit theory) , physics , telecommunications , power (physics) , computer science , quantum mechanics , thermodynamics
Vortex beam has attracted growing attention in recent years due to its remarkable abilities in the communication system since it is believed to be an effective way to improve the channel capacity efficiency. However, available vortex beam generators suffer from the issues of complex configurations, low efficiency as well as narrow bandwidths, especially for the transmissive case. Here, we proposed a broadband transmissive metasurface to generate vortex beam with l=1 in a broad band ranging from 8GHz to 13 GHz. We enhance the working bandwidth by carefully designing the meta-atoms which provide high transmittances along with similar slopes of the phase responses within a large frequency interval. More importantly, the designed vortex beam generator exhibits very high working efficiencies (more than 83% within the whole working band). Our finding opens a door for the design of high-efficiency broadband transmissive vortex beam generators and operating at other frequency domains.