Mesoscopic Cooperative Emission From a Disordered System

TL;DR

This paper theoretically investigates how disorder affects cooperative light emission in a dense system of classical oscillators, revealing a transition from a single subradiant peak to multiple narrow peaks as disorder increases.

Contribution

It introduces a model for mesoscopic cooperative emission in disordered systems, showing the splitting of subradiant peaks into multiple narrow peaks under certain conditions.

Findings

Subradiant peak splits into multiple narrow peaks with disorder.

Spectral width of peaks depends on system parameters.

Mesoscopic structure amplitude can be estimated.

Abstract

We study theoretically the cooperative light emission from a system of $N\gg 1$ classical oscillators confined within a volume with spatial scale, $L$, much smaller than the radiation wavelength, $\lambda_0=2\pi c/\omega_0$. We assume that the oscillators frequencies are randomly distributed around a central frequency, $\omega_0$, with some characteristic width, $\Omega\ll\omega_0$. In the absence of disorder, that is $\Omega=0$, the cooperative emission spectrum is composed of a narrow subradiant peak superimposed on a wide superradiant band. When $\Omega\neq 0$, we demonstrate that if $N$ is large enough, the subradiant peak is not simply broadened by the disorder but rather splits into a system of random narrow peaks. We estimate the spectral width of these peaks as a function of $N, L, \Omega$, and $\lambda_0$. We also estimate the amplitude of this mesoscopic structure in the emission spectrum.