Two-photon coherent effects: theory and experiment (A)

M. M. Sushchinskiǐ

The general theory of stimulated radiation is applied to four-photon coherent Raman scattering. A comparison with the theory of the two-photon scattering is presented. Some peculiarities of the stimulated Raman scattering such as radiation asymmetry, replication effects, rings of the Raman components are considered based on the theory for coherent processes. Copyright © 2000 John Wiley & Sons, Ltd.

M. M. T. Loy

X. Y. Zou, Timothy P. Grayson, L. J. Wang +1 more

According to the de Broglie pilot wave theory, a pilot wave which is empty of photons is still capable of physical effects like induced coherence. We have carried out an experiment to test this prediction. The experiment involves interference of photons produced by down-conversion in two nonlinear crystals and depends on the mutual coherence induced between the two signal beams by an idler. When the photon is removed from the idler by a beam splitter, it is found that the resulting ``empty pilot wave'' no longer induces coherence. This violates at least the Selleri-Croca version of the de Broglie pilot wave theory makes the physical reality of the corresponding pilot wave doubtful.

NILOY KUMAR DUTTA

Bin Bai, Yu Zhou, Ruifeng Liu +4 more

From quantum point of view, Hanbury Brown-Twiss effect is a result of constructive-destructive two-photon interference. There should be no Hanbury Brown-Twiss effect if there was no two-photon interference. In this paper, we observed Hanbury Brown- Twiss effect in a specially designed experiment, in which two-photon interference is impossible by keeping only one two-photon probability amplitude in the experimental scheme. However, our experimental results can still be interpreted by Glauber's quantum optical coherence theory. The researches in our paper are helpful to understand the physics of the second-order coherence of light, especially the physics of Hanbury Brown-Twiss effect.

E. Gaižauskas, G. Gedvilas