Dresden 2014 – wissenschaftliches Programm
O 71.1: Vortrag
Donnerstag, 3. April 2014, 10:30–10:45, GER 38
Photochromic switching of Fano resonances in metallic photonic crystals — •Felix Bleckmann1, Sandra Cordes2, Eduard Maibach2, Clayton Shallcross2, Klaus Meerholz2, and Stefan Linden1 — 1Physikalisches Institut, Universität Bonn, Nußallee 12, 53115 Bonn, Germany — 2Institut fürr Physikalische Chemie, Universität zu Köln, Luxemburger Str. 116, 50939 Köln, Germany
We study switchable metallic photonic crystals composed of a gold grating embedded in a photochromic waveguide. For that purpose we coated the gold grating on top of an ITO-covered glass substrate with the photochromic material XDTE. The interaction of localized plasmonic resonances and delocalized waveguide modes forms waveguide-plasmon polaritons (WPPs) and thus gives rise to a typical Fano line shape in the extinction spectra. The layer thicknesses as well as the shape and period of the gold grating were optimized for the design wavelength of the maximal switching efficiency of the XDTE layer (λ=610 nm). By illumination of the sample with UV light, XDTE becomes absorptive in the red part of the spectrum and the damping of the waveguide mode strongly increases. As a result, the Fano dip is strongly suppressed. The low absorpion state is recovered by illumination with orange light. Compared to a simple XDTE film of the same thickness, our approach doubles the switching efficiency at the design wavelength λ=610 nm.