The possibility of accelerating the self-focusing dynamics of light be
ams in nonlinear and dispersive media with either a constant or a weak
ly oscillating parabolic density profile is investigated. It is shown
that the self-compression of wave packets, that freely self-focus in h
omogeneous media, can be enhanced by the action of appropriate parabol
ic inhomogeneities, whose lensing influence shortens the focal time of
the wave. A similar property also occurs when the scalar envelope of
a nonlinear waveform interacts with a uniform external magnetic field.
The motion of light beamlets, originating from the filamentation inst
ability of an incident beam, is analytically described for inhomogeneo
us media with focusing and defocusing density profiles. (C) 1997 Ameri
can Institute of Physics.