Analysis of photon triplet generation in pulsed cascaded parametric down-conversion sources

TL;DR

This paper analyzes photon triplet generation in pulsed cascaded parametric down-conversion sources, focusing on realistic experimental conditions, noise contributions, and achievable rates, providing insights for optimizing quantum photon sources.

Contribution

It offers a detailed model of photon triplet generation in integrated PDC systems, including noise analysis and impact of higher-order effects, which advances understanding of practical quantum photon sources.

Findings

Approximately 4 photon triplets per hour at mean photon number 0.25

Noise contributions and higher-order effects significantly impact triplet rates

Identifies fundamental limitations and potential improvements for triplet generation

Abstract

We analyze the generation rates and preparation fidelities of photon triplet states in pulsed cascaded parametric down-conversion (PDC) under realistic experimental circumstances. As a model system, we assume a monolithically integrated device with negligible interface loss between the two consecutive PDC stages. We model the secondary down-conversion process in terms of a lossy channel and provide a detailed analysis of noise contributions. Taking variable pump powers into account, we estimate the impact of higher-order photon contributions and conversion processes on the achievable coincidence probabilities. At mean photon numbers of $\langle m\rangle\sim0.25$ photons per pulse behind the first PDC stage, we expect around $4.0$ genuine photon triplets per hour. Additionally, we discuss fundamental limitations of our model system as well as feasible improvements to the detectable photon triplet rate.