The spatial second-order interference of two independent pseudothermal light beams in a Hong-Ou-Mandel interferometer is studied experimentally and theoretically. The similar cosine modulation in the second-order coherence function as the one with entangled-photon pairs in a Hong-Ou-Mandel interferometer is observed. Two-photon interference based on Feynman's path integral theory is employed to interpret the results. The experimental results and theoretical simulations agree with each other very well.The spatial second-order interference of two independent pseudothermal light beams in a Hong-Ou-Mandel interferometer is studied experimentally and theoretically. The similar cosine modulation in the second-order coherence function as the one with entangled-photon pairs in a Hong-Ou-Mandel interferometer is observed. Two-photon interference based on Feynman's path integral theory is employed to interpret the results. The experimental results and theoretical simulations agree with each other very well.

Optics ExpressAug 6, 201339 citations

Two-photon quantum interference in a Michelson interferometer (4 pages)

Satoru Odate, Toshiki Kobayashi, Haoyang Wang

Physical Review AJan 1, 20050 citations

The non-local Hong-Ou-Mandel effect

Yuki Kodama, Jonte R. Hance, Holger F. Hofmann

Two-photon interference effects arise because photons are indistinguishable particles. In the wellknown Hong-Ou-Mandel (HOM) effect, the transmission of two photons at a beam splitter interferes destructively with the reflection of both photons, requiring both photons to "bunch up" by leaving the beam splitter on the same side. Here, we show that the interference between locally propagating photons and photons exchanged by a mode swap can be implemented by post-selecting spatially separated photon outputs of a four-path interferometer. Even though the photons detected at spatially separated locations must have travelled along paths that never met up at the same beam splitter, the Hong-Ou-Mandel effect can be observed in correlations between the output ports that originate from the association of detection events with non-local output modes defined by the two single photon inputs. Local phase shifts can be used to map out non-classical correlations between the photons detected at different output locations, clarifying the role of linear optics in generating entanglement between spatially separated photons. Our work thus establishes a fundamental relation between multiphoton interference and entanglement, opening the door to new possibilities in optical quantum technologies.Two-photon interference effects arise because photons are indistinguishable particles. In the wellknown Hong-Ou-Mandel (HOM) effect, the transmission of two photons at a beam splitter interferes destructively with the reflection of both photons, requiring both photons to "bunch up" by leaving the beam splitter on the same side. Here, we show that the interference between locally propagating photons and photons exchanged by a mode swap can be implemented by post-selecting spatially separated photon outputs of a four-path interferometer. Even though the photons detected at spatially separated locations must have travelled along paths that never met up at the same beam splitter, the Hong-Ou-Mandel effect can be observed in correlations between the output ports that originate from the association of detection events with non-local output modes defined by the two single photon inputs. Local phase shifts can be used to map out non-classical correlations between the photons detected at different output locations, clarifying the role of linear optics in generating entanglement between spatially separated photons. Our work thus establishes a fundamental relation between multiphoton interference and entanglement, opening the door to new possibilities in optical quantum technologies.

quant-pharXiv:2604.10886Apr 14, 20260 citations

Spatial two-photon interference in a Hong-Ou-Mandel interferometer

Heonoh Kim, Osung Kwon, Wonsik Kim +1 more

We report the observation of the cosine modulation in the coincidence rates from a Hong-Ou-Mandel (HOM) interferometer. Spatial interference fringes are seen by minute rotations of one mirror about the vertical axis, while the beam splitter is fixed in the center position. The results show that the maximum visibility of the fringe is 0.81, and the photon pairs separated by less than $1.52\phantom{\rule{0.3em}{0ex}}\mathrm{mm}$ in the source plane are measured to be indistinguishable. It turns out that it is possible to invert the HOM dips to peaks by the rotation of the mirror.We report the observation of the cosine modulation in the coincidence rates from a Hong-Ou-Mandel (HOM) interferometer. Spatial interference fringes are seen by minute rotations of one mirror about the vertical axis, while the beam splitter is fixed in the center position. The results show that the maximum visibility of the fringe is 0.81, and the photon pairs separated by less than $1.52\phantom{\rule{0.3em}{0ex}}\mathrm{mm}$ in the source plane are measured to be indistinguishable. It turns out that it is possible to invert the HOM dips to peaks by the rotation of the mirror.

Physical Review AFeb 27, 200620 citations

Quantum interference of multimode two-photon pairs with a Michelson interferometer

Fuyuan Wang, Bao‐Sen Shi, Guang‐Can Guo

arXiv:0806.4260Optics CommunicationsNov 7, 20091 citation

1.52\phantom{\rule{0.3em}{0ex}}\mathrm{mm}

in the source plane are measured to be indistinguishable. It turns out that it is possible to invert the HOM dips to peaks by the rotation of the mirror.