Coherent backscattering enhancement in cavities The simple-shape cavity revisited

Coherent backscattering enhancement (CBE) was introduced in disordered, random or chaotic media. In this study, our attention is focused on simple parallelepipedic cavities, as contrary to the widespread opinion, CBE can also be observed for a pure-tone source in a one-dimensional (1-D) cavity. This approach is of two-fold interest. First, analytical calculus predicts a dimensional dependence of the CBE according to a R = (3/2)(d) law, with d = 1,2,3 as the dimensionality of the cavity; these computations have not yet been compared to experiments. Secondly, a ray approach in simple-shape cavities confirms the modal theory and opens new ballistic interpretations, for which each multiply reverberated path is not necessarily associated with one single reciprocal counterpart. The number of associated equal length paths ranges from zero to four in rectangular cavities. (C) 2010 Elsevier B.V. All rights reserved.