ELECTROMAGNETIC BEAM-BREAKUP - MULTIPLE FILAMENTS, SINGLE-BEAM EQUILIBRIA, AND RADIATION

In the framework of the nonlinear Schrodinger equation, the radiation aspect of self-focusing in two transverse dimensions appears to be (to gether with self-trapped propagation) an essential part of any self-fo cusing process; The final beamlets created in multiple filamentation a re shown to be very close to canonical solitonlike solutions. This fac t is used to establish an upper bound on the amount of radiation emitt ed. From this a parameter is defined which proves to be useful to char acterize the self-focusing behavior as a function of the initial condi tions.