Two-photon interference of multimode two-photon pairs produced by an optical parametric oscillator has been observed for the first time with an unbalanced interferometer. The time correlation between the multimode two photons has a multi-peaked structure. This property of the multimode two-photon state induces two-photon interference depending on delay time. The nonclassicality of this interference is also discussed.
@article{arxiv.quant-ph/0303150,
title = {Two-photon interference of multimode two-photon pairs with an unbalanced interferometer},
author = {Hayato Goto and Haibo Wang and Tomoyuki Horikiri and Yasuo Yanagihara and Takayoshi Kobayashi},
journal= {arXiv preprint arXiv:quant-ph/0303150},
year = {2007}
}