Two-photon interference with two (and only two) independent photons

Lifeng Duan, Aojie Xu, Yun Zhang

Z. Y. Ou

Yanhua Zhai, Xi-Hao Chen, Ling-An Wu

The nature of two-photon interference is a subject that has aroused renewed interest in recent years and is still under debate. In this paper we report the observation of two-photon interference with independent pseudothermal sources in which subwavelength interference is observed. The phenomenon may be described in terms of optical transfer functions and the classical statistical distribution of the two sources.

Paul G. Kwiat

Jianbin Liu, Yu Zhou, Huaibin Zheng +3 more

Z. Y. Ou, June‐Koo Kevin Rhee, L. J. Wang

A number of multiphoton interference schemes involving independent fields from parametric down-conversion are analyzed. They include fourth-order (two-photon) interference between two fields from two independent parametric down-conversion processes, interference with two independent single photon Fock states (produced by gated parametric down-conversion), and quantum state teleportation and entanglement swapping. It is shown that the visibility in these interference experiments is related to a quantity that is responsible for the photon bunching effect in one of the fields (signal or idler) from the parametric down-conversion process. Besides the two-photon interference schemes, a four-photon interference scheme is discussed where we consider four-photon partition at a beamsplitter. It is found that probability distribution of the partition is dramatically changed by four-photon interference of six paths and the four-photon effect also depends on the same quantity responsible for photon bunching. We will discuss the difference between two-photon interference and four-photon interference.