Couston Louis-Alexandre, Guo Qiuchen, Chamanzar Maysamreza, Alam Mohammad-Reza
Department of Mechanical Engineering, University of California, Berkeley, California 94720, USA.
Department of Electrical Engineering & Computer Sciences, University of California, Berkeley, California 94720, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2015 Oct;92(4):043015. doi: 10.1103/PhysRevE.92.043015. Epub 2015 Oct 22.
We show that significant water wave amplification is obtained in a water resonator consisting of two spatially separated patches of small-amplitude sinusoidal corrugations on an otherwise flat seabed. The corrugations reflect the incident waves according to the so-called Bragg reflection mechanism, and the distance between the two sets controls whether the trapped reflected waves experience constructive or destructive interference within the resonator. The resulting amplification or suppression is enhanced with increasing number of ripples and is most effective for specific resonator lengths and at the Bragg frequency, which is determined by the corrugation period. Our analysis draws on the analogous mechanism that occurs between two partially reflecting mirrors in optics, a phenomenon named after its discoverers Charles Fabry and Alfred Perot.
