Phase Synchronization between Two Superradiant Lasers

TL;DR

This paper experimentally demonstrates phase synchronization between two superradiant lasers using cold atom ensembles, analyzing re-synchronization dynamics and steady state behavior, with implications for quantum phase transitions and ultra-narrow linewidth lasers.

Contribution

It presents the first experimental observation of phase synchronization between two superradiant lasers with cold atoms, exploring both dynamic and steady state regimes.

Findings

Successful synchronization of two superradiant lasers demonstrated.

Re-synchronization dynamics characterized after phase disruption.

Steady state frequency variation studied across the lasers.

Abstract

We experimentally demonstrate synchronization between two distinct ensembles of cold atoms undergoing steady state superradiance within a single longitudinal and transverse mode of the same optical cavity. The synchronization process is studied first in terms of the time dynamics of re-synchronization when the phase alignment of the two oscillators is abruptly broken. We also observe the steady state behavior of the lasers as their relative frequency is continuously varied. This system has the potential to realize a non-equilibrium quantum phase transition and could inform future implementations of milliHertz linewidth lasers.