Optical phase dynamics in mutually coupled diode laser systems exhibiting power synchronization

TL;DR

This study investigates how optical phase dynamics, influenced by the linewidth enhancement factor, drive power synchronization in mutually coupled diode lasers, revealing phase-driven amplitude death and universal correlation behaviors.

Contribution

It uncovers the role of optical phases and the linewidth enhancement factor in power synchronization and amplitude death in coupled diode lasers, providing new insights into their phase-amplitude interplay.

Findings

Optical phase synchronization leads to power synchronization and amplitude death.

Varying $\alpha$ causes a sequence of in-phase amplitude-death states.

Cross-correlation exhibits universal power-law behavior with respect to $\alpha$.

Abstract

We probe the physical mechanism behind the known phenomenon of power synchronization of two diode lasers that are mutually coupled via their delayed optical fields. In a diode laser, the amplitude and the phase of the optical field are coupled by the so-called linewidth enhancement factor, $\alpha$. In this work, we explore the role of optical phases of the electric fields in amplitude (and hence power) synchronization through $\alpha$ in such mutually delay-coupled diode laser systems. Our numerical results show that the synchronization of optical phases drives the powers of lasers to synchronized death regimes. We also find that as $\alpha$ varies for different diode lasers, the system goes through a sequence of in-phase amplitude-death states. Within the windows between successive amplitude-death regions, the cross-correlation between the field amplitudes exhibits a universal power-law behaviour with respect to $\alpha$.