Discrete solitons in optically-induced photonic lattices

Abstract

Nonlinear wave propagation in photonic lattices is becoming ever more important, both for technological applications and from a basic science perspective. Scientifically, localized excitations (solitons) in periodic potentials are fundamental, appearing in a range of disciplines from biology to solid-state physics to optics. In the optical case, such solitons can be useful for information processing and signal routing applications. Thus far, however, experiments with diffraction and solitons in photonic lattices have been restricted to 1D topologies due to the difficulties of fabricating 2D periodic waveguide arrays [1]. In a series of recent papers, we have used our optical induction technique [2,3] to create (in real time) 2D nonlinear photonic lattices in a photorefractive crystal [4]. In these lattices, we study diffraction and the two families of discrete self-trapped wavepackets: the in-phase and the staggered 2D lattice solitons. These are the first observations of 2D lattice solitons in any physical system. General properties of these structures, analogies with other disciplines (e.g. matter waves in Bose-Einstein condensates), and potential applications will be discussed.