Berlin 2012 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 93: Poster Session: Metal-Semiconductor Hybrid Systems, Plasmonic Systems / Photonic Crystals / Carbon: Diamond & CNT / Quantum Information Systems

HL 93.16: Poster

Donnerstag, 29. März 2012, 16:00–19:00, Poster D

Deterministic aperiodic photonic structures based on woodpiles — •Michael Renner and Georg von Freymann — Department of Physics and Research Center OPTIMAS, University of Kaiserslautern, Erwin-Schrödinger-Str. 56, 67663 Kaiserslautern, Germany

Unlike most random photonic structures deterministic aperiodic structures (DAS) offer the possibility to reproducibly create specific potential landscapes whose Fourier components are determined by the underlying aperiodic sequence. In accordance with Lebesgue's spectral theorem the Fibonacci, Thue-Morse and Rudin-Shapiro sequences are examples of the three basic spectral measures, namely pure-point, singularly-continuous and absolutely-continuous, respectively.

We choose the woodpile structure as a starting point which can be routinely produced with a very small degree of structural imperfections. Minimizing these is crucial since intrinsic and extrinsic sample properties are often inseparable. Two layers of a fcc woodpile are grouped (bi-layer) and their rods are modulated in size by varying the laser power according to a binary deterministic aperiodic sequence. Rods which represent element 1 are written with raised laser power compared to the periodic case, rods representing element -1 were consequently lowered in power. Along the stacking direction the original bi-layer and its inverse are also arranged following the sequence in order to introduce aperiodicity in three dimensions. Structures derived from the above mentioned sequences are fabricated with increasing modulation depth and thickness. The transition from order to disorder is investigated in their optical transmission and reflection spectra.