Phase-reversed structures in superlattice of nonlinear materials

TL;DR

This paper introduces phase-reversed superlattice structures with dual grating vectors enabling simultaneous phase-matching of multiple nonlinear processes, advancing the design of photon triplet and four-photon generation.

Contribution

It provides a detailed theoretical model of phase-reversed structures as assemblies of nonlinear segments for cascaded three-photon processes, validated by experimental data.

Findings

Successful modeling of cascaded three-photon processes in structured nonlinear materials

Enhanced quasi-phase-matching for photon triplet and four-photon generation

Agreement between theoretical predictions and experimental results

Abstract

We present detailed description of so-called phase-reversed structures that are characterized by two grating wave vectors allowing simultaneously phase-match two parametric three-wave processes. The novelty is that the structure is realized as a definite assembly of nonlinear segments leading to detailed description of cascaded three-photon processes with the parameters of realistic structured nonlinear materials of finite length. We apply these results for analysis of the quasi-phase-matching in production of both photon triplet and four-photon states in cascaded down-conversion. The received results are matched with the experimental data.