Discrete solitons in waveguide arrays with long-range linearly coupled effect

TL;DR

This paper investigates how long-range linearly coupled interactions influence discrete solitons in waveguide arrays, revealing digital-like properties and stable flat-top solitons with potential applications in optical data processing.

Contribution

It introduces the effect of long-range nonlocal interactions into the discrete nonlinear Schrödinger equation, demonstrating new soliton behaviors and stable flat-top solutions.

Findings

Fundamental DS is narrowly confined to a single waveguide.

Dipole and double-monopole solitons are found in different nonlinear regimes.

Stable flat-top solitons occupying multiple waveguides are demonstrated.

Abstract

We study the influences to the discrete soliton (DS) by introducing linearly long-range nonlocal interactions, which give rise to the off-diagonal elements of the linearly coupled matrix in the discrete nonlinear schrodinger equation to be filled by non-zero terms. Theoretical analysis and numerical simulations find that the DS under this circumstance can exhibit strong digital effects: the fundamental DS is a narrow one, which occupies nearly only one waveguide, the dipole and double-monopole solitons, which occupy two waveguides, can be found in self-focusing and -defocusing nonlinearities, respectively. Stable flat-top solitons and their stagger counterparts, which occupy a controllable number of waveguides, can also be obtained through this system. Such digital properties may give rise to additional data processing applications and have potential in fabricating digital optical devices in all-optical networks.