Some experiments on interference of photons

N. I. Kaliteevskii, O. M. Marchenko, S.N. Pen'kov

Z. Y. Ou

A number of recent interference experiments involving multiple photons are reviewed. These experiments include generalized photon bunching effects, generalized Hong-Ou-Mandel interference effects and multi-photon interferometry for demonstrations of multi-photon de Broglie wavelength. The multi-photon states used in these experiments are from two pairs of photons in parametric down-conversion. We find that the size of the interference effect in these experiments, characterized by the visibility of the interference pattern, is governed by the degree of distinguishability among different pairs of photons. Based on this discovery, we generalize the concept of multi-photon temporal distinguishability and relate it to a number of multi-photon interference effects. Finally, we make an attempt to interpret the coherence theory by multi-photon interference via the concept of temporal distinguishability of photons.

John Gordon King, Malcolm Correll

Dmitry Strekalov, T. B. Pittman, Morton H. Rubin +1 more

What is the difference between two-photon phenomena and phenomena involving two photons? We address this question by reporting two two-photon interference experiments. In the first experiment we show that two-photon interference does not require the “indistinguishability” of two photons, and hence is not interference of two photons.

Varun S Bhatta

Manpreet Kaur, Mandip Singh

Double-double-slit thought experiment provides profound insight on interference of quantum entangled particles. This paper presents a detailed experimental realisation of quantum double-double-slit thought experiment with momentum entangled photons and theoretical analysis of the experiment. Experiment is configured in such a way that photons are path entangled and each photon can reveal the which-slit path information of the other photon. As a consequence, single photon interference is suppressed. However, two-photon interference pattern appears if locations of detection of photons are correlated without revealing the which-slit path information. It is also shown experimentally and theoretically that two-photon quantum interference disappears when the which-slit path of a photon in the double-double-slit is detected.