Spatial soliton evolution in nematic liquid crystals in the nonlinear local regime

Spatial solitons in nematic liquid crystals are considered in the regime of local response of the crystal, such solitons having been called nematicons in previous experimental studies. In the limit of low light intensity and local material response, it is shown that the full governing equations reduce to a single, higher-order nonlinear Schrodinger equation. Modulation equations are derived for the evolution of a nematiconlike pulse; these equations also include the dispersive radiation shed as the pulse evolves. The modulation equations show that a nematicon is (weakly) stable. Solutions of the modulation equations are compared with numerical solutions of the full governing equations, and good agreement is found when the light intensity is small. (c) 2006 Optical Society of America.