Purcell Enhancement of Parametric Luminescence: Bright and Broadband Nonlinear Light Emission in Metamaterials

TL;DR

This paper introduces a theoretical framework demonstrating that metamaterials can significantly enhance nonlinear light emission processes like parametric downconversion, enabling brighter, broadband, and phase-mismatch-free quantum light sources.

Contribution

It generalizes the Purcell effect to nonlinear emission in complex media and predicts a 1000-fold enhancement in photon pair generation rates.

Findings

Hyperbolic dispersion media enable broadband, phase-mismatch-free downconversion.

Predicted 1000-fold increase in photon pair emission rates.

Framework applicable to quantum nonlinear phenomena in nanostructures.

Abstract

Single-photon and correlated two-photon sources are important elements for optical information systems. Nonlinear downconversion light sources are robust and stable emitters of single photons and entangled photon pairs. However, the rate of downconverted light emission, dictated by the properties of low-symmetry nonlinear crystals, is typically very small, leading to significant constrains in device design and integration. In this paper, we show that the principles for spontaneous emission control (i.e. Purcell effect) of isolated emitters in nanoscale structures, such as metamaterials, can be generalized to describe the enhancement of nonlinear light generation processes such as parametric down conversion. We develop a novel theoretical framework for quantum nonlinear emission in a general anisotropic, dispersive and lossy media. We further find that spontaneous parametric downconversion in media with hyperbolic dispersion is broadband and phase-mismatch-free. We predict a 1000-fold enhancement of the downconverted emission rate with up to 105 photon pairs per second in experimentally realistic nanostructures. Our theoretical formalism and approach to Purcell enhancement of nonlinear optical processes, provides a framework for description of quantum nonlinear optical phenomena in complex nanophotonic structures.