Modulational instability of discrete solitons in coupled waveguides with group velocity dispersion

A Yulin,Dmitry V Skryabin,A Vladimirov

doi:10.1364/oe.14.012347

Abstract

We study temporal modulational instability of spatial discrete solitons in waveguide arrays with group velocity dispersion (GVD). For normal GVD we report existence of the strong 'neck'-type instability specific for the discrete solitons. For anomalous GVD the instability leads to formation of the mixed discrete-continuous spatio-temporal quasi-solitons. Feasibility of experimental observation of these effects in the arrays of silicon-on-insulator waveguides is discussed.

Highlights

Interplay between nonlinear effects and diffraction control in planar arrays of optical waveguides and in the light induced lattices in photorefractive materials have recently attracted substantial interest, see, e.g., [1] for a review
Despite numerous interesting effects, which interplay of controllable diffraction and group velocity dispersion (GVD) can bring into nonlinear optics, the experimental efforts devoted to these problems in recent years have been limited [3]
Photonic crystal fibers could be considered as a notable exception [4], which allows large degree of the GVD engineering by periodic variations of the refractive index, but on the other hand it most often enforces geometrical suppression of the diffraction, rather than allowing exploration of the functionality of the diffraction control as it has been done in planar structures [1]

Summary

Introduction

Interplay between nonlinear effects and diffraction control in planar arrays of optical waveguides and in the light induced lattices in photorefractive materials have recently attracted substantial interest, see, e.g., [1] for a review. Despite numerous interesting effects, which interplay of controllable diffraction and GVD can bring into nonlinear optics, the experimental efforts devoted to these problems in recent years have been limited [3]. This is most likely because limitations imposed by the material and structure parameters. This problem becomes relevant because of the advances in fabrication of low loss planar silicon-on-insulator (SOI) structures with strong and controllable GVD and short coupling length, see, e.g., [16, 17, 18].

Stability analysis

Physical estimates

Summary