Self-action of Bessel light beams in medium with large nonlinearity

The modifications of an angular spectrum of the intense Bessel J0 and J1 beams caused by self-action in the medium with large cubic nonlinearity are investigated. The appearance of an outer ring of triple radius was observed. The phenomenon can be explained as Bragg diffraction of Bessel beam on Bessel lattice in nonlinear medium. Experimental results are in qualitative agreement with the theoretical predictions.