Spontaneous down conversion of surface plasmon polaritons: strong-field consideration

TL;DR

This paper presents a non-perturbative theory of spontaneous down conversion of surface plasmon polaritons at metal-dielectric interfaces, highlighting resonance enhancement and limitations at high excitation powers, with implications for quantum communication sources.

Contribution

It introduces a new non-perturbative theoretical framework for SDC of surface plasmon polaritons, accounting for strong-field effects and power-dependent yield behavior.

Findings

SDC is resonantly enhanced at characteristic excitation powers.

High laser fields rapidly decrease SDC yield due to surface plasmon dynamics.

Results suggest potential for miniaturized entangled photon sources.

Abstract

A non-perturbative theory of the spontaneous down conversion (SDC) of surface plasmon polaritons at a metal-dielectric interface is presented. It is shown that the process is resonantly enhanced for the characteristic power of excitation, typically of the order of tens of watts. At a stronger excitation the yield of SDC decreases rapidly. At a stronger excitation the yield of SDC decreases rapidly. The reason for this decrease is the high rate of the change of surface plasmon polaritons by the laser field, exceeding the rate of the zero-point fluctuations responsible for the SDC process. The obtained results may help one to construct miniature sources of entangled photons for quantum communication.