REFRACTION OF NONLINEAR LIGHT BEAMS IN NEMATIC LIQUID CRYSTALS.

We use modulation theory to analyze the interaction of optical solitons and vortices with a dielectric interface between two regions of nematic liquid crystals. In the analysis we consider the role of nonlocality, anisotropy and nonlinear reorientation and compare modulation theory results with numerical results. Upon interacting with the interface, nematicons undergo transverse distortion but remain stable and eventually return to a steady state, whereas vortices experience an enhanced instability and can break up into bright beams or solitary waves. [ABSTRACT FROM AUTHOR]