Quantum interference with distinguishable photons through indistinguishable pathways
Yoon-Ho Kim, Warren P. Grice · Journal of the Optical Society of America B · 2005
We report a two-photon quantum interference experiment in which the detected individual photons have quite different properties. The interference is observed even when no effort is made to mask the distinguishing features before the photons are detected. The results can be explained only in terms of indistinguishable two-photon amplitudes.