Directional emission of down-converted photons from a dielectric nano-resonator

TL;DR

This paper theoretically demonstrates that dielectric nano-resonators can generate highly directional correlated photon pairs via spontaneous parametric down-conversion, leveraging Mie resonances and nonlinear Kerker effects for improved quantum optics applications.

Contribution

It introduces a novel approach to generate directional photon pairs using dielectric nanoparticles with resonant modes and nonlinear effects, advancing quantum light source design.

Findings

Directional photon-pair emission achieved through nonlinear Kerker effect.

Resonant Mie modes enhance photon-pair generation efficiency.

Polarization correlations are maintained in the directional emission regime.

Abstract

Creation of correlated photon pairs is one of the key topics in contemporary quantum optics. Here, we theoretically describe the generation of photon pairs in the process of spontaneous parametric down-conversion in a resonant spherical nanoparticle made of a dielectric material with bulk $\chi^{(2)}$ nonlinearity. We pick the nanoparticle size that satisfies the condition of resonant eigenmodes described by Mie theory. We reveal that highly directional photon-pair generation can be observed utilising the nonlinear Kerker-type effect, and that this regime provides useful polarisation correlations.