Quasimodes of a chaotic elastic cavity with increasing local losses.
We report noninvasive measurements of the complex field of elastic quasimodes of a silicon wafer with chaotic shape. The amplitude and phase spatial distribution of the flexural modes are directly obtained by Fourier transform of time measurements. We investigate the crossover from real mode to complex-valued quasimode, when absorption is progressively increased on one edge of the wafer. The complexness parameter, which characterizes the degree to which a resonance state is complex valued, is measured for nonoverlapping resonances, and is found to be proportional to the nonhomogeneous contribution to the line broadening of the resonance. A simple two-level model based on the effective Hamiltonian formalism supports our experimental results.
Xeridat
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Laboratoire de Physique de la Matière Condensée, CNRS UMR 6622, Université de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 02, France.
Poli
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C
Legrand
O
O
Mortessagne
F
F
Sebbah
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P
D003198:Computer Simulation; D055119:Elastic Modulus; D008956:Models, Chemical; D017711:Nonlinear Dynamics; D012825:Silicon / Q000737:chemistry*
D012825:Silicon