Berlin 2005 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 58: Poster IIb
HL 58.38: Poster
Dienstag, 8. März 2005, 16:30–19:00, Poster TU F
Negative refraction in 2d square lattice photonic crystals at millimetre waves — •Rados Gajic1, Ronald Meisels2, Friedemar Kuchar2, Javad Zarbakhsh3, and Kurt Hingerl3 — 1Institute of Physics, University of Belgrade, Yugoslavia — 2Institute of Physics, University of Leoben, Austria — 3Christian Doppler Laboratory, Institute for
We investigated the negative refraction of microwaves in a 2D photonic crystal (PhC) made of alumina rods in air. The experiments were performed in the 26 – 40 GHz range. Negative refraction was experimentally verified of the TM mode for the Gamma-M surface of the crystal in the range 35 to 37 GHz for an incidence of 45 degree. In addition we studied collimation and self-focusing effects in our PhC.
The refraction of an incident beam was determined by measuring the lateral displacement of the beam by a plane parallel slab made from the PhC. The beam was collimated using a pyramidal horn. The intensity distribution after the slab was scanned using an open-ended waveguide connected to a power meter.
Experimental findings are in agreement with calculations determining the direction of the beam as that of the group velocity which is obtained from the equifrequency contours (from band structure calculations). In addition real space FDTD simulations of the beam propagation were also found to validate the experiments.