# Extreme events induced by collisions in a forced semiconductor laser

## TL;DR

This paper experimentally and numerically investigates extreme intensity peaks in a forced semiconductor laser, attributing these events to collisions between phase solitons and transient structures, revealing new insights into laser dynamics.

## Contribution

It provides the first detailed experimental observation and numerical analysis of extreme events caused by soliton collisions in a multimode semiconductor laser.

## Key findings

- High intensity peaks are linked to collisions of opposite chirality structures.
- Heavy-tailed statistics indicate the presence of extreme events.
- Numerical models replicate the observed dynamical behavior.

## Abstract

We report on the experimental study of an optically driven multimode semiconductor laser with 1~m cavity length. We observed a spatiotemporal regime where real time measurements reveal very high intensity peaks in the laser field. Such a regime, which coexists with the locked state and with stable phase solitons, is characterized by the emergence of extreme events which produce a heavy tail statistics in the probability density function. We interpret the extreme events as collisions of spatiotemporal structures with opposite chirality. Numerical simulations of the semiconductor laser model, showing very similar dynamical behavior, substantiate our evidences and corroborate the description of such interactions as collisions between phase solitons and transient structures with different phase rotations.