Freiburg 2019 – wissenschaftliches Programm
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FM: Fall Meeting
FM 83: Poster: Enabling Technologies Sources of Quantum States of Light
FM 83.7: Poster
Donnerstag, 26. September 2019, 16:30–18:30, Tents
Exceptional points in optical anisotropic thin films — •Sebastian Henn1, Evgeny Krüger1, Chris Sturm1, Armin Dadgar2, Matthias Wieneke2, Marius Grundmann1, and Rüdiger Schmidt-Grund1,3 — 1Universität Leipzig, Felix-Bloch-Institut für Festkörperphysik, Linnéstr. 5, Leipzig — 2Otto-von-Guericke-Universität Magdeburg, Institut für Physik, Universitätsplatz 2, Magdeburg — 3now at: Technische Universität Ilmenau, Institut für Physik, Weimarerstr. 25, Ilmenau
We investigate exceptional points (EP) in optically anisotropic transparent thin films both experimentally and theoretically. Such points represent degeneracies in k-space and were already observed in absorptive biaxial crystals [1] and microcavities [2,3]. At the EP the eigenspace of the optical eigenmodes becomes one-dimensional, yielding degeneracy in the complex energy and polarization state. This is reflected by a complex square root topology of the eigenmode energies [1]. Promising systems for the realization of EP are optically anisotropic thin films, providing symmetry breaking and dissipation through losses at the interfaces. We demonstrate the presence of EP in GaN as well as ZnO thin films using spectroscopic ellipsometry and polarization resolved reflection measurements and present rigorous Maxwell-based calculations. We discuss ways to control the occurrence and direction of the EP by altering the design of the system.
[1] W. Voigt et al., Ann. Phys 314, 367 (1902)
[2] S. Richter et al., Phys. Rev. A 95, 023836 (2017)
[3] J. Wiersig, Phys. Rev. Lett. 112, 203901 (2014)