The effect of self- and cross-phase modulation on photon-pairs generated by spontaneous four-wave mixing in integrated optical waveguides

TL;DR

This paper introduces a time-domain model for spontaneous four-wave mixing in nonlinear waveguides, analyzing how self- and cross-phase modulation influence photon-pair generation and purity, with implications for heralded single-photon sources.

Contribution

It presents a novel momentum-operator-based approach to model these effects and identifies conditions where modulation does not affect photon-pair properties.

Findings

Generation rate and purity are unaffected when only one photon in the pair is filtered.

Self- and cross-phase modulation effects are negligible in specific filtering scenarios.

The approach aids in designing efficient heralded single-photon sources.

Abstract

A novel time-domain approach using the momentum operator is used to model spontaneous four-wave mixing in a lossless nonlinear waveguide. The effects of self- and cross-phase modulation on the photon-pair production rate and heralded photon purity are investigated. We show that in the special case where only one half of the photon-pair state is filtered that the generation rate and purity of the heralded photons are unmodified by the presence of self- and cross-phase modulation. The significance of this special case arises when we consider heralded single-photon sources, where future schemes are likely to only filter the herald photon to ensure a high heralding efficiency is maintained.