Momentum-resolved two photon interference of weak coherent states
Abstract
We demonstrate an experimental scheme for high-precision position measurements based on transverse-momentum-resolved two-photon interferometry with independent photons and single photon avalanche diode (SPAD) arrays. Our scheme extends the operative range of Hong-Ou-Mandel interferometry beyond its intrinsic constraints due to photons indistinguishability, paving the way to applications in high-resolution imaging. We assess the experimental results against the ultimate precision bounds as determined by quantum estimation theory. Our experiment ultimately proves that transverse-momentum resolved measurements of fourth-order correlations in the fields can be employed to overcome spatial distinguishability between independent photons. The relevance of our results extends beyond sensing and imaging towards quantum information processing, as we show that partial photon distinguishability and entanglement impurity are not necessarily a nuisance in a technique that relies on two-photon interference.
Cite
@article{arxiv.2508.19978,
title = {Momentum-resolved two photon interference of weak coherent states},
author = {Fabrizio Sgobba and Francesco Di Lena and Danilo Triggiani and Deborah Katia Pallotti and Cosmo Lupo and Piergiorgio Daniele and Gennaro Fratta and Giulia Acconcia and Ivan Rech and Luigi Santamaria Amato},
journal= {arXiv preprint arXiv:2508.19978},
year = {2025}
}
Comments
10 pages, 4 figures