Abstract

An important issue related to the propagation of spatial solitons is their interaction with interfaces between media differing in linear and also nonlinear properties. When a beam strikes a smoothinterface propagating from a denser into a rarer material, above a critical angle of incidence it will be subject to total irternal reflection (TIR) with a penetration depth hence a Goos-Hänchen shift dependent on the index gradient. If the media differ in nonlinear response, the index mismatch changes with power and a nonlinear Goos-Hänchen (NGS) shift can occur. The latter is usually limited to a fraction of the spot-size even at grazing incidence. [1] In nematic liquid crystals (NLC), field induced molecular reorientation at optical frequencies provides a giant self-focusing non resonant no nlinearity for extraordinarily-polarized eigenwaves, supporting the propagation of stable (2D+1) spatial solitons or Nematicons.[2]

© 2007 IEEE