Theory of four-wave-mixing in phonon polaritons

TL;DR

This paper develops a quantum theory for four-wave mixing in phonon polaritons, enabling the analysis of nonlinear optical processes like Kerr self-interaction and parametric scattering in complex environments.

Contribution

It introduces a comprehensive quantum framework for four-wave mixing in inhomogeneous phonon polariton systems, extending understanding of nonlinear interactions in these materials.

Findings

Kerr self-interaction of phonon polaritons is theoretically demonstrated.

Parametric scattering processes are shown to be experimentally feasible.

The theory applies to arbitrarily inhomogeneous photonic environments.

Abstract

Third order anharmonic scattering in light-matter systems can drive a wide variety of practical and physically interesting processes from lasing to polariton condensation. Motivated by recent experimental results in the nonlinear optics of localised phonon polaritons, in this Letter we develop a quantum theory capable of describing four-wave mixing in arbitrarily inhomogeneous photonic environments. Using it we investigate Kerr self-interaction and parametric scattering of surface and localised phonon polaritons, showing both processes to be within experimental reach.