Scattering of reorientational optical solitary waves at dielectric perturbations

We discuss the interaction of spatial solitary waves in nematic liquid crystals, termed nematicons, with localized inhomogeneities in the distribution of the optic axis. For beam waists small compared with the defect width, self-localization is preserved; in the opposite limit the spatial solitary waves undergo significant attenuation due to diffractive losses, to the extent that nematicons are essentially destroyed. Owing to their power-waist dependence spatial solitary waves interacting with defects in nematic liquid crystals are subject to an excitation-dependent transition from particlelike to wavelike behavior. In the latter regime their trajectory varies with input power, leading to novel approaches to the design and realization of all-optical circuits.