Certifying spatial entanglement between non-degenerate photon pairs with a camera

TL;DR

This paper demonstrates a camera-based method to certify spatial entanglement between non-degenerate photon pairs, emphasizing the importance of adapted analysis for accurate entanglement verification across different wavelengths.

Contribution

It introduces an adapted correlation measurement technique for non-degenerate photon pairs and highlights the necessity of tailored theoretical analysis for reliable entanglement certification.

Findings

Successful certification of entanglement via EPR violation

Influence of pump waist and crystal length on correlations

Differences from frequency-degenerate entanglement cases

Abstract

We investigate transverse spatial entanglement between photon pairs of different wavelengths using a camera-based coincidence technique. By adapting the correlation measurements to the photons frequencies, we certify the presence of entanglement between the pairs through violation of an Einstein-Podolsky-Rosen criterion. Additionally, we examine how parameters such as pump waist and crystal length influence these correlations. Our results highlight key differences from the frequency-degenerate case, showing that an adapted theoretical analysis is essential to avoid significant misestimations and to reliably certify entanglement.