We propose an experiment that permits observation of the de Broglie two-photon wave packet behavior for a pair of photons, using a Mach-Zehnder interferometer. It is based on the use of pulsed lasers to generate pairs of photons via spontaneous parametric down-conversion and the post-selection of events. It differs from previous realizations by the use of a third time-correlated photon to engineer the state of the photons. The same technique can give us which-path information via an ``interaction-free'' experiment and can be used in other experiments on the foundations of quantum mechanics related to wave-particle duality and to nonlocality.
@article{arxiv.quant-ph/0010016,
title = {A Mach-Zehnder Interferometer for a Two-Photon Wave Packet},
author = {Luiz Carlos Ryff and P. H. Souto Ribeiro},
journal= {arXiv preprint arXiv:quant-ph/0010016},
year = {2009}
}