Observation of light localization in modulated Bessel optical lattices

We generate higher-order azimuthally modulated Bessel optical lattices in photorefractive crystals by employing a phase-imprinting technique. We report on the experimental observation of self-trapping and nonlinear localization of light in such segmented lattices in the form of ring-shaped and single-site states. The experimental results agree well with numerical simulations accounting for an anisotropic and spatially nonlocal nonlinear response of photorefractive crystals. (c) 2006 Optical Society of America.