Point source in a phononic grating: stop bands give rise to phonon-focusing caustics
We use locally-excited gigahertz surface phonon wavepackets in microscopic line structures of different pitches to reveal profound anisotropy in the radiation pattern of a point source in a grating. Time-domain data obtained by an ultrafast optical imaging technique and by numerical simulations are...
Main Authors: | , , , , , |
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Format: | Article |
Language: | English |
Published: |
IOP Publishing
2012-01-01
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Series: | New Journal of Physics |
Online Access: | https://doi.org/10.1088/1367-2630/14/12/123015 |