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HL: Halbleiterphysik

HL 58: Poster IIb

HL 58.33: Poster

Tuesday, March 8, 2005, 16:30–19:00, Poster TU F

Photonic bandgap in two-dimensional octagonal quasi-periodic lattice — •Dmitry Chigrin and Johann Kroha — Physikalisches Institut, Universität Bonn, Nussallee 12, 53155 Bonn

A systematic study of a photonic bandgap formation in two-dimensional octagonal quasi-periodic lattice of dielectric rods is presented. Photonic bandgap maps are obtained for different dielectric constants and radiuses of rods for both fundamental polarizations. It is shown that for fairly high dielectric constant of rods, complete photonic bandgaps in both fundamental polarizations can overlap leading to a full bandgap. It is also shown, that in the case of TM polarization the first complete photonic bandgap remains open down to very small dielectric constants. The threshold dielectric constant can be as small as ε=1.6. Possible optoelectronic applications of two-dimensional octagonal photonic quasi-crystals are discussed. The physical mechanisms of the photonic bandgap formation in a quasi-periodic lattice are addressed. Finite-difference time-domain and plane wave expansion methods were used for density of states and band structure calculations, respectively.