Abstract
The low-frequency eigenmodes of a fractal drum are studied through experimental observation of the acoustical resonances of a fractal-shaped liquid crystal film. The resonance frequencies agree with the numerical predictions for the Laplacian eigenvalues in the fractal domain with Dirichlet boundary conditions. The amplitude distribution of the modes is detected by scanning the excitation position. Several modes are found to be localized in agreement with numerical predictions. Two types of localization related to “strong” and “weak” localization mechanisms are observed in this system. This Letter presents the first direct experimental study of localized modes in fractal geometries.
- Received 30 March 1999
DOI:https://doi.org/10.1103/PhysRevLett.83.726
©1999 American Physical Society