2012 marked the 50th anniversary of the first published prediction of the self-focusing phenomenon in light beams. The recent revived interest in the subject is due to advances in high-power femtosecond laser technology and due to the possibility they provided of creating extended filaments of high light field intensity in gases and condensed media. This review shows in retrospect how our understanding of the self-action of light evolved from the self-focusing of laser beams in the 1960s to the filamentation of femtosecond laser pulses at present. We also describe the current status of this rapidly growing area of nonlinear optics and laser physics. Finally, we discuss, in general terms, what the phenomena of laser beam self-focusing and laser pulse filamentation have in common and how they differ.

https://iopscience.iop.org/article/10.3367/UFNe.0183.201302b.0133/pdf

From self-focusing light beams to femtosecond laser pulse filamentation

We demonstrate for the first time that input polarisation control inducing one single filamentation is a very robust technique to accurately control the filamentation dynamics enhancing throughput energy of the supercontinuum generation up to 1.2 millijoule. Reaching the above-millijoule regime opens the way to post-compression of multi-terawatt laser pulses.

Above-millijoule super-continuum generation using polarisation dependent filamentation in atoms and molecules.

Generation of polarization singularities in the self-focusing of an elliptically polarized laser beam in an isotropic Kerr medium

We present numerical simulations of interaction of bright transversely two-dimensional solitons with different topological indices in a homogenous transparent medium with saturable self-focusing nonlinearity of refraction index. We describe also the propagation and interaction of powerful light beams, including vortices, in such medium.

V. A. Gaponov

Papers

Self-focusing of wave beams with elliptical polarization

Self-focusing of elliptically polarized wave-beams