# Solitary waves in three-dimensional crystal-like structures

## TL;DR

This paper investigates the behavior of 3D solitary waves in crystal-like structures, demonstrating their directional control and the influence of modulation instability, supported by analytical and numerical methods.

## Contribution

It introduces methods to control the movement of 3D solitary waves and analyzes the delay of modulation instability using lensing effects.

## Key findings

- Solitary waves can be directed in specific 3D crystal-like structures.
- Lensing factors can delay modulation instability in these systems.
- Analytical results align with numerical simulations.

## Abstract

The motion of three-dimensional (3D) solitary waves and solitons in nonlinear crystal-like structures, such as photonic materials, is studied. It is demonstrated that collective excitations in these systems can be tailored to move in particular directions of the 3D system. The effect of modulation instability is studied showing that in some cases it can be delayed by using a lensing factor. Analytical results supported by numerical simulations are presented.