Yuce Cem, Ramezani Hamidreza
Opt Lett. 2021 Feb 15;46(4):765-768. doi: 10.1364/OL.411999.
We propose to use exceptional points (EPs) to construct diffraction-free beam propagation and localized power oscillation in lattices. We specifically consider two systems to utilize EPs for diffraction-free beam propagation, one in synthetic gauge lattices and the other in unidirectionally coupled resonators where each resonator individually is capable of creating orbital angular momentum (OAM) beams. In the second system, we introduce the concept of robust and tunable OAM beam propagation in discrete lattices. We show that one can create robust OAM beams in an arbitrary number of sites of a photonic lattice. Furthermore, we report power oscillation at the EP of a non-Hermitian lattice. Our research widens the study and application of EPs in different photonic systems including OAM beams and their associated dynamics in discrete lattices.
我们提议利用例外点（EPs）在晶格中构建无衍射光束传播和局域功率振荡。我们具体考虑了两个利用EPs实现无衍射光束传播的系统，一个是在合成规范晶格中，另一个是在单向耦合谐振器中，其中每个谐振器单独能够产生轨道角动量（OAM）光束。在第二个系统中，我们引入了离散晶格中稳健且可调谐的OAM光束传播的概念。我们表明，人们可以在光子晶格的任意数量的位点中创建稳健的OAM光束。此外，我们报告了非厄米晶格的例外点处的功率振荡。我们的研究拓宽了例外点在不同光子系统中的研究和应用，包括OAM光束及其在离散晶格中的相关动力学。
