Photon correlations in multi-mode waveguides

TL;DR

This paper studies how classical and quantum light propagate in multi-mode waveguides, revealing that correlation patterns can revive with periods longer than intensity patterns, especially for symmetric input states, supported by experimental demonstrations.

Contribution

It uncovers the phenomenon of correlation revival periods exceeding intensity revival periods in multi-mode waveguides, with experimental validation for classical and quantum light.

Findings

Correlation patterns revive periodically during propagation.

Symmetric input states can lead to longer correlation revival periods.

Experimental results match theoretical predictions for both classical and quantum light.

Abstract

We consider the propagation of classical and non-classical light in multi-mode optical waveguides. We focus on the evolution of the few-photon correlation functions, which, much like the light-intensity distribution in such systems, evolve in a periodic manner, culminating in the 'revival' of the initial correlation pattern at the end of each period. It is found that when the input state possesses non trivial symmetries, the correlation revival period can be longer than that of the intensity, and thus the same intensity pattern can display different correlation patterns. We experimentally demonstrate this effect for classical, pseudo-thermal light, and compare the results with the predictions for non-classical, quantum light.