Coherent backscattering enhancement in cavities. Simple shape cavity revisited

Coherent backscattering effect (CBE) is classically introduced in disordered, random, or chaotic media. In this work, the attention is focused on simple parallepipedic cavities since, contrarily to a widespread idea, 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 computations predict a dimensional dependence of the coherent backscattering enhancement according to a (3/2)d law, d being the dimensionality of the cavity, that have not yet been compared to experiments. Second, it opens a new ballistic interpretations for which each multiply reverberated path is associated with more (rectangle and parallelepipedic cavities) or less (1D cavity) than one single reciprocal counterpart. This paper is the first of two, the second paper dealing with some impacts of symmetry on CBE.