# Rotating solitons supported by a spiral waveguide

## TL;DR

This paper demonstrates the existence of stable, rotating solitons in spiral waveguides within nonlinear photorefractive media, providing analytical and numerical methods to find and characterize these solitons.

## Contribution

It introduces a general procedure and variational approach for finding and analyzing solitons in spiral waveguides, highlighting their stable rotational motion without decay.

## Key findings

- Solitons exhibit robust stable rotational oscillations.
- No wave radiation or decay observed over many periods.
- Analytical predictions match numerical simulations.

## Abstract

We investigate numerically light propagation in a single spiral waveguide formed in a nonlinear photorefractive medium for a low spatial frequency of the waveguide rotation. We present the general procedure for finding solitonic solutions in spiral waveguiding structures, as well as the variational approach to calculate soliton parameters analytically. Solitons supported by the spiral waveguide perform robust stable rotational oscillatory motion, with the period predicted by their static characteristics, without any signatures of wave radiation or soliton decay over many rotation periods and diffraction lengths.