Light propagation in locally symmetric arrays of waveguides

• Applicants: Professor Dr. Peter Schmelcher; Professor Alexander Szameit, Ph.D.
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 314425454

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.

• DFG Programme: Research Grants