Time-resolved spectroscopy of noise-driven collective states of light

TL;DR

This paper investigates how controlled temporal noise affects the collective states of light in a laser cavity, revealing regimes of extended, Gaussian, and localized lattice occupation with distinct transport dynamics.

Contribution

It introduces a novel approach to study noise-induced localization and transport in a synthetic frequency lattice of a laser cavity, highlighting the impact of noise on collective light states.

Findings

Noise creates three regimes: extended, Gaussian, and localized.

Transport persists in the Gaussian regime but is suppressed in the localized regime.

Noise reduces transport speed and confirms system ergodicity.

Abstract

We study a collective liquid state of light in a fast-gain laser. Controlled temporal noise on the cavity modulation creates a fluctuating linear potential along the synthetic frequency lattice of the cavity modes. We identify three regimes of lattice occupation as noise increases: an extended distribution, a Gaussian envelope, and exponential localization. Time-resolved spectroscopy on single realizations of noise reveals distinct dynamics in the latter two: transport persists in the Gaussian regime, modulated by the fluctuating potential, but is fully suppressed at all times in the localized regime. Averaging over many noise realizations shows that noise reduces the transport speed and confirms ergodicity of the system.