Frankfurt 2006 – wissenschaftliches Programm
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Q: Quantenoptik und Photonik
Q 47: Photonische Kristalle III
Q 47.3: Vortrag
Mittwoch, 15. März 2006, 18:00–18:15, HV
Geometrical Freedom for Negative Refraction-based Photonic Crystal Lenses — •Jozef Havran1, Javad Zarbakhsh1,2, and Kurt Hingerl1 — 1Christian Doppler Lab, Halbleiter und Festkoerperphysik, Johannes Kepler Universitaet Linz, AltenbergerStr 69, A-4040 Linz, Austria — 2Institut fuer Theoretische Festkoerperphysik, Universitaet Karlsruhe, 76128 Karlsruhe, Germany
Photonic band-gap materials are artificial structures with spatial variation of permittivity. Periodicity has been considered as an essential requirement for the formation of a photonic band gap. Investigations on photonic quasi-crystals, curvilinear photonic crystals, and circular photonic crystals (CPC) have changed this view. The negative refraction can be seen over a wide range of size changes in period array of air holes in Silicon wafers.
We calculate the geometrical freedom contour plot (GFCP) for Negative refraction by means of finite-difference time-domain simulations in order to determine the negative refraction range for different Period/Radius pairs. We present to which extent PC structures are flexible - still preserving negative refraction with favorable transmission. A goal function is defined to describe the rate of negative refraction. It is shown that GFCP can help us to design curvilinear PC lenses. The curvilinear negative refraction lens can focus electromagnetic waves better that PC flat lenses. We analyze the focusing effect theoretically and optimize the shape of lens in order to minimize the losses.