Energy shedding during nonlinear self-focusing of laser pulses

With the development of lasers, self-trapping and self-focusing of intense light due to the intensity-dependent change in the refractive index of certain media was predicted. For a medium with a sufficiently large, negative Kerr coefficient (n₂), self-focusing of the incident light takes place when the power exceeds a critical value. For cw and short pulse regimes (~100fs) the phenomenon is well modelled by the nonlinear Schrödinger equation (NLS). We presnt results of numerical simulations of NLS using a diffraction-limited input pulse with a Gaussian spatial profile and address the energy shedding that takes place when entering a nonlinear medium and during propagation.