title: Peakon profiles and collapse-bounce cycles in self-focusing spatial beams.
abstract: We study the over-focusing of spatial light beams due to self-focusing nonlinearity, in both local and nonlocal nonlinear media. Numerical simulation of both cases reveals a peaked profile, with a near-cusp at the center surrounded by exponentially-decaying tails, at a critical self-focusing power. The profile is a local effect, occurring as diffraction counteracts nonlinearity. Nonlocality, however, is needed to prevent modulation instability of the initial beam and to prevent catastrophic collapse in 2D. The peaked profile remains for weak nonlocality but disappears for wide nonlocal responses. Beyond the critical power for a peaked solution, or for longer propagation distances, competition between nonlinearity and diffraction causes oscillatory collapse-bounce behavior. The numerical results are confirmed by observing these dynamics in a self-focusing glass with a nonlocal, thermal response.
authors.affiliation: Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Can
authors.initials: C
authors.lastname: Sun
authors.forename: Christopher
authors.initials: C
authors.lastname: Barsi
authors.forename: Jason W
authors.initials: JW
authors.lastname: Fleischer
mesh_terms: D003198:Computer Simulation; D008027:Light; D008962:Models, Theoretical; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D012542:Scattering, Radiation