Berlin 2005 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 42: Symposium: Photonic Crystals
HL 42.5: Vortrag
Montag, 7. März 2005, 17:00–17:30, TU P270
Interaction between Photonic Gaps and Material Excitations in 1- and 2-Dimensional Structures — •Carl G. Ribbing1, Herman Högström 2, and Andreas Rung1 — 1Dept. of Functional Materials, Swedish Defense Research Agency, Linköping, Sweden of Sensor Technology, Swedish Defence Research Agency, Linköping, Sweden — 2Department of Engineering Sciences, The Ångström Laboratory, Uppsala, University, Box 534, 751 21 Uppsala, Sweden
Photonic gaps in periodic dielectric structures originate from diffraction and interference, and can be observed phenomenologically as total reflectance and zero emittance. Mathematically, the appearance of a gap coincides with the occurrence of an imaginary wave vector. This is characteristic also for homogenous materials with a negative dielectric function – typical for metals in the visible and infrared spectral regions. Investigations of so called metallodielectric crystals with new and interesting features were published in the later part of the 90’s. In this contribution, the case of polaritonic, photonic crystals is discussed. In the infrared region, a group of compounds with ionic binding have Reststrahlen Bands within which the dielectric function is negative. This will give rise to the formation of polaritonic gaps that are narrow, in contrast to the metallodielectric case, and occur in a material that is an electric insulator. Depending on the detailed conditions, different features arise from the interaction between the polaritonic gap and the photonic gap (fixed by the choice of structure and lattice constant).