We report implementation and modelling of an efficient photon-triplets generation experiment based on a difference-frequency-mixing of two picosecond beams at 532 nm and 1491 nm in a type II phase-matched KTP crystal. The photon-triplets flux was measured as a function of the energy of the two incident beams using a coincidence protocol. A maximal flux of 11.6 photon-triplets per second was achieved. These experimental data were satisfactorily described by a semiclassical model based on the quantum fluctuations of vacuum and the classical equations of nonlinear optics.
@article{arxiv.2603.28519,
title = {Photon-triplets for quantum optics generated by a phase-matched third-order difference-frequency mixing in a KTiOPO4 bulk crystal pumped at 532 nm},
author = {Gaspar Mougin-Trichon and Veronique Boutou and Corinne Felix and David Jegouso and Benoit Boulanger},
journal= {arXiv preprint arXiv:2603.28519},
year = {2026}
}