Regensburg 2010 – scientific programme
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HL: Fachverband Halbleiterphysik
HL 58: Photonic Crystals: Experiment
HL 58.6: Talk
Thursday, March 25, 2010, 17:15–17:30, H13
Long living surface acoustiv wafes in a phononic-photonic crystal — Alexey S. Salasyuk1, Alexey V. Scherbakov1, Dmitriy R. Yakovlev1,3, Andrey V. Akimov1,3, 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.