Superradiance of a subwavelength array of independent classical nonlinear emitters

TL;DR

This paper proposes a mechanism where a non-uniform phase distribution among classical nonlinear emitters in a subwavelength array leads to a superradiance burst through collective envelope oscillations, despite lack of full synchronization.

Contribution

It introduces a novel superradiance mechanism driven by radiative response fields in classical nonlinear emitters with arbitrary phase distributions.

Findings

Superradiance occurs only with non-uniform phase distributions.

The superradiance intensity scales with the square of the number of emitters.

Constructive interference in envelope oscillations creates large dipole moments.

Abstract

We suggest a mechanism for the emergence of a superradiance burst in a subwavelength array of nonlinear classical emitters. We assume that the emitters interact via their common field of radiative response and that they may have an arbitrary distribution of initially phases. We show that only if this distribution is not uniform, a non-zero field of radiative response arises leading to a superradiance burst. Although this field cannot synchronize the emitters, it forces fast oscillations of a classical nonlinear emitter to have long-period envelopes. Constructive interference in the envelopes creates a large dipole moment of the array which results in a superradiance pulse. The intensity of the superradiance is proportional to the squared number of the emitters, which envelopes participate in the fluctuation.