Elliptic gaussian beam self-focusing in nonlinear media

Abstract

A semi-analytical treatment of elliptic gaussian beam propagation in a nonlinear medium, in the WKB, paraxial approximation is presented. It is shown that the self-trapping threshold increases with ellipticity. This suggests the possibility of controlling diffraction and self-focusing collapse by varying the beam geometry. It is also shown that, at fixed wavelength and intensity, four intervals of ellipticity, in which the propagation properties show marked differences in the longitudinal intensity profile of the beam, can be identified.