Darmstadt 2008 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 43: Photonik III

Q 43.4: Talk

Thursday, March 13, 2008, 14:45–15:00, 2B/C

Time-domain investigation of backward-wave formation in negative index materials — •Ulrich Dobramysl and Kurt Hingerl — Christian Doppler Labor für Oberflächenoptische Methoden, Institut für Halbleiter- und Festkörperphysik, Johannes Kepler Universität Linz, Austria

We study the properties of negative index structures using the FDTD method by directly investigating the electromagnetic fields at the boundary between air and a region with negative µ and є. The material consists of split ring resonator (SRR) structures[1] with negative permeability. These SRRs are embedded in a material exhibiting a Lorenz resonance and thus negative є. The formation of a backward wave is studied. The FTDT simulation shows that it takes around 20-40 wavefronts until negative refraction is built up. During this initial time positive refraction exists and a damped wave propagates with a positive k-vector into the material.

The effective material parameters are extracted by means of the the Fresnel equations. Using the Fresnel formulas it is possible to extract the effective permeability and permittivity by investigating the wave pattern at an interface without relying on reflection and transmission measurements. The field summation method[2] is used to complement this method.

[1] J. B. Pendry, A. J. Holden, D. J. Robbins, and W. J. Stewart: IEEE Transactions on Microwave Theory and Techniques, 47, 2075 (1999)

[2] D. R. Smith, J. B. Pendry: J. Opt. Soc. Am. B, 23, 391 (2006)