Observation of light localization in modulated Bessel optical lattices

Robert Fischer,Yuri S. Kivshar,Dragomir N. Neshev,Anton S. Desyatnikov,Andrey A. Sukhorukov,Servando Lopez-Aguayo,Wieslaw Krolikowski

doi:10.1364/oe.14.002825

Abstract

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.

Highlights

In recent decades, many studies have been devoted to the analysis and experimental observation of self-trapping and localization of light in different types of nonlinear media [1]
As was recently suggested theoretically [3] and demonstrated in experiments [4, 5, 6], a periodically modulated refractive index can be induced by imprinting an optical pattern in a photorefractive crystal, and nonlinear localized states can exist in different spectral bands of the periodic lattices
Perimental results are in a good agreement with numerical simulations of the nonlinear model accounting for a nonlocal anisotropic response of photorefractive nonlinear crystals [19, 20]

Summary

Introduction

Many studies have been devoted to the analysis and experimental observation of self-trapping and localization of light in different types of nonlinear media [1]. As was recently suggested theoretically [3] and demonstrated in experiments [4, 5, 6], a periodically modulated refractive index can be induced by imprinting an optical pattern in a photorefractive crystal, and nonlinear localized states can exist in different spectral bands of the periodic lattices. We use the nondiffracting nature of the Bessel beam to induce an optical lattice in a biased photorefractive crystal and study the nonlinear trapping of light in such lattices. We report on the first experimental observation of self-focusing and localization of light in azimuthally modulated Bessel lattices considered theoretically [18]. Perimental results are in a good agreement with numerical simulations of the nonlinear model accounting for a nonlocal anisotropic response of photorefractive nonlinear crystals [19, 20]

Generation of nondiffracting Bessel lattices

Light localization in a Bessel lattice

Numerical results for the anisotropic model

Conclusions