Phase transitions of nonlinear waves in lithium niobate waveguide arrays

Abstract

We study two-color parametric nonlinear modes in waveguide arrays with quadratic nonlinear response. We predict theoretically and observe experimentally a new type of phase transition in nonlinear lattices accompanied by an abrupt power-controlled change of the staggered mode structure due to an interplay of localization and synchronization in para-metrically driven discrete systems.