Properties of the signal mode in the polariton OPO regime

TL;DR

This paper investigates the properties of the signal mode in the polariton OPO regime, revealing how the system's signal momentum can be predicted from pump-only analysis and depends on drive characteristics.

Contribution

It introduces a simple method to estimate the signal momentum in polariton OPOs based on pump-only configurations, addressing limitations of the three-mode mean field approximation.

Findings

Signal momentum can be predicted from pump-only analysis.

The chosen signal momentum depends on the properties of the drive.

The approach aligns with numerical simulations and experimental observations.

Abstract

Theoretical analyses of the polariton optical parametric oscillator (OPO) regime often rely on a mean field approach based on the complex Gross-Pitaevskii equations in a three-mode approximation, where only three momentum states, the signal, pump and idler, are assumed to be significantly occupied. This approximation, however, lacks a constraint to uniquely determine the signal and idler momenta. In contrast, multimode numerical simulations and experiments show a unique momentum structure for the OPO states. In this work we show that an estimate for the signal momentum chosen by the system can be found from a simple analysis of the pump-only configuration. We use this estimate to investigate how the chosen signal momentum depends on the properties of the drive.