# Collective dynamics of evanescently coupled excitable lasers with saturable absorber

## TL;DR

This paper numerically investigates how evanescently coupled excitable lasers with saturable absorbers synchronize more efficiently than lossy coupling and explores disorder-induced localization effects.

## Contribution

It introduces a detailed numerical analysis of purely imaginary (evanescent) coupling in excitable lasers, highlighting differences from previous lossy coupling studies.

## Key findings

- Evanescent coupling leads to more efficient synchronization.
- Disorder-induced localization occurs with imaginary coupling.
- Linewidth enhancement factor can suppress localization.

## Abstract

We present a numerical study of the collective dynamics in a population of coupled excitable lasers with saturable absorber. At variance with previous studies where real-valued (lossy) coupling was considered, we focus here on the purely imaginary coupling (evanescent wave coupling). We show that evanescently coupled excitable lasers synchronize in a more efficient way compared to the lossy coupled ones. Furthermore we show that out-of-diagonal disorder-induced localization of excitability takes place for imaginary coupling too, but it can be frustrated by nonvanishing linewidth enhancement factor.