title: Conical refraction and nonlinearity.
abstract: We study conical refraction in crystals where both diffraction and nonlinearity are present. We develop a new set of evolution equations. We find that nonlinearity induces a modulational instability when it is defocussing as well as focussing. We also examine the evolution of incident beams which contain analytic singularities, and in particular optical vortices, which do not feel the effect of conical refraction.
authors.affiliation: Department of Mathematics, University of Arizona, Tucson, Arizona 85721, USA. indik@math.arizona.edu
authors.forename: R A
authors.initials: RA
authors.lastname: Indik
authors.forename: A C
authors.initials: AC
authors.lastname: Newell