Intensity distribution of modes in surface corrugated waveguides

Exact calculations of transmission and reflection coefficients in surface randomly corrugated optical waveguides are presented. As the length of the corrugated part of the waveguide increases, there is a strong preference to forward coupling through the lowest mode. An oscillating behavior of the enhanced backscattering as a function of the wavelength is predicted. Although the transport is strongly nonisotropic, the analysis of the probability distributions of the transmitted waves confirms in this configuration distributions predicted by random matrix theory for volume disorder.