Observation of nonlocal interference in separated photon channels
Z. Y. Ou, X. Y. Zou, L. J. Wang, L. Mandeļ · Physical Review Letters · 1990
A two-photon coincidence experiment of the kind recently proposed by J. D. Franson [Phys. Rev. Lett. 62, 2205 (1989)] has been carried out with signal and idelr photons produced in the process of parametric down-conversion. The coincidence rate registered by the two detectors is found to exhibit a cosine variation with the optical path difference, with periodicity equal to the wavelength.