Entangled Photon-pair Generation in Nonlinear Thin-films
Abstract
We develop a fully vectorial and non-paraxial formalism to describe spontaneous parametric down-conversion in nonlinear thin films. The formalism is capable of treating slabs with a sub-wavelength thickness, describe the associated Fabry-P\'erot effects, and even treat absorptive nonlinear materials. With this formalism, we perform an in-depth study of the dynamics of entangled photon-pair generation in nonlinear thin films, to provide a needed theoretical understanding for such systems that have recently attracted much experimental attention as sources of photon pairs. As an important example, we study the far-field radiation properties of photon pairs generated from a high-refractive-index nonlinear thin-film with Zinc-Blende structure, that is deposited on a linear low-refractive-index substrate. In particular, we study the thickness-dependent effect of Fabry-P\'erot interferences on the far-field radiation pattern of the photon pairs. We also pay special attention to study of entanglement generation, and find the conditions under which maximally polarization-entangled photon pairs can be generated and detected in such nonlinear thin-films.
Keywords
Cite
@article{arxiv.2403.08633,
title = {Entangled Photon-pair Generation in Nonlinear Thin-films},
author = {Elkin A. Santos and Maximilian A. Weissflog and Thomas Pertsch and Frank Setzpfandt and Sina Saravi},
journal= {arXiv preprint arXiv:2403.08633},
year = {2024}
}