Regensburg 2010 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 58: Photonic Crystals: Experiment

HL 58.6: Vortrag

Donnerstag, 25. März 2010, 17:15–17:30, H13

Long living surface acoustiv wafes in a phononic-photonic crystal — Alexey S. Salasyuk¹, Alexey V. Scherbakov¹, Dmitriy R. Yakovlev^1,3, Andrey V. Akimov^1,3, Alexander A. Kaplyanskii¹, Saveliy F. Kaplan¹, Sergey A. Grudinkin¹, Alexey V. Nashekin¹, Alexander B. Pevtsov¹, Valeriy G. Golubev¹, Thorsten Berstermann², Christian Brüggemann², •Michael Bombeck², and Manfred Bayer² — ¹Ioffe Physical-Technical Institute of the Russian Academy of Sciences, 194021 St.Petersburg, Russia — ²Experimentelle Physik 2, Technische Universität Dortmund, D-44227 Dortmund, Germany — ³School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK

The time evolution of bulk and surface acoustic wafes in synthetic opals with different sintering is detected by the changes of reflectivity. The opal system is a three dimensional array of close packed silica spheres with approximately 350nm diameter. It is known to provide a photonic stopband in the near infra red and also posses a full three dimensional phononic band gap in the GHz range. An acoustic puls is injected into the opal by a thermo-elastic transducer from a 800nm 150fs Ti:Sa laser puls. The changes of the reflectivity due to acoustic excitation of the opal are sampled by a probe pulse from the same laser. The main result of our measurments is the observation of a long-living acoustic mode corresponding to the first band gap of the phononic crystal with weak sintering. There is no observation of a long living mode in an opal with stronger sintering according to theory predictions.