We demonstrate that weak parametric interaction of a fundamental beam with
its harmonic field in a Kerr medium can drastically modify the beam dynamic
s, giving rise to very complex bifurcation phenomena and quasi solitons. Mo
st importantly, we reveal a novel physical mechanism of the collapse suppre
ssion in a bulk optical kerr: medium: parametric coupling to a weakly radia
ting harmonic field. (C) 1999 Optical Society of America OCIS codes: 190.44
10, 190.3270, 190.5530.