Open AccessTerahertz vortex beam generator based on bound states in the continuum
Author(s) -
Tairong Bai,
Qian Li,
Yiqing Wang,
Yifan Chen,
Zheng-Da Hu,
Jicheng Wang
Publication year - 2021
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.431814
Subject(s) - vortex , physics , optical vortex , optics , resonator , photonic crystal , light beam , beam (structure) , terahertz radiation , thermodynamics
Vortex beams are playing an increasingly crucial role in wireless optical communications. Traditional vortex beam generators based on spiral phase plates and metasurfaces have a geometric center in real space, which limit their convenience in practical applications. In this work, we propose that the creation of a vortex beam can be achieved by using the bound state in the continuum (BIC) supported by a photonic crystal slab structure. Theoretical analysis shows that the proposed structure can be used as a kind of "momentum-space resonators" and thus can generate vortex beams. Moreover, higher-order vortex beams can also be achieved by changing the symmetry of photonic crystal slab, thus paving the way for the application of vortex beams in the fields of quantum information processing and micro optical micromanipulation.