Light propagation in locally symmetric arrays of waveguides

在理论和实验的密切合作下，该项目将解决一类新型材料，其特点是它们由具有局部对称性的组件组合而成。这些可以是离散反射或平移对称。作为实验平台，我们采用倏逝耦合波导阵列，它在实现各种不同的结构参数方面表现出高度的灵活性，从而产生大量的局部对称性。该项目的主要目标是系统地探索局部对称材料的波动力学特性，从而深入了解相应的光波在波导阵列中的传播机制。由于局部对称性的影响和结合它们的多种可能性，对波传播特性的分类是至关重要的。通过发展离散局部对称光子结构的理论框架，我们将推导出将在实验中观察到的不变非局部电流。基于局部对称诱导不变量的系统模态展开和分类是探索所有结果现象的基石。后者包括由于局部对称性的存在而对波局域化的新颖控制，以及在完全局部对称阵列中完美传输共振的设计，这些将在理论和实验上进行探索。尽管我们的研究具有深刻的基础性，我们从理论上和实验上阐述了一种在波动动力学方面具有独特特征的新型材料，它最终将具有重大的应用导向影响，因为局部对称性和光操纵的新创新途径必须得到预期。

In a close collaboration of theory and experiment this project will address a novel class of materials which are characterized by the fact that they consist of a combination of components exhibiting local symmetries. These could be either discrete reflection or translation symmetries. As an experimental platform we employ arrays of evanescently coupled waveguides, which exhibit a high degree of flexibility in realizing various different structural parameters and consequently a plethora of local symmetries. The main objective of this project is the systematic exploration of the wave mechanical properties of locally symmetric materials thereby aiming at a deep understanding of the corresponding light wave propagation mechanisms in the array of waveguides. Due to the proven impact of local symmetries and the multitude of possibilities for combining them a classification of the characteristics of the wave propagation is of utmost importance. By developing the theoretical framework of discrete locally symmetric photonicstructures we will derive invariant non-local currents which will be observed experimentally. A systematic mode expansion and classification relying on the local symmetry induced invariants represents a cornerstone for the exploration for all resulting phenomena. The latter include novel control of wave localization due to the presence of local symmetries and the design of perfectly transmitting resonances in completely locally symmetric arrays which will be explored both theoretically and experimentally. Although our research is of deeply fundamental character, ie. we elaborate theoretically and experimentally on a new class of material with unique characteristics in terms of wave dynamics, it eventually will have significant application-oriented impact as with local symmetries new and innovative pathways to light manipulation have to be expected.