2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/165063This paper presents a tutorial review of nonlocal interferometry. The role of the Feynman propagator in optical coherence is also discussed, including the possibility of generating optical coherence and entanglement outside of the light cone.13 pages, 16 figures; proceedings of CQO9Quantum Physicstext