Pulsed beams in a nonlinear nematic fiber

A model for a cylindrical fiber whose cladding is an initially homogeneous nematic liquid crystal is presented. We construct a narrow wavepacket of tr ansverse magnetic modes propagating through the fiber taking into account t he dispersion, self-focusing and diffraction in the nematic. Then a nonline ar Schrodinger equation for the time evolution of its envelope is derived. The speed, time- and length-scales and nonlinear index of refraction of the optical solitons are estimated by using typical experimental values for so me of the parameters. (C) 2000 Elsevier Science B.V. All rights reserved.