  Propagation of rays in 2D and 3D corrugated waveguides is performed in the
general framework of stability indicators. The analysis of stability is based
on the Lyapunov and Reversibility error. It is found that the error growth
follows a power law for regular orbits and an exponential law for chaotic
orbits. A relation with the Shannon channel capacity is devised and an
approximate scaling law found for the capacity increase with the corrugation
depth.
