Role of intensity fluctuations in third-order correlation double-slit interference of thermal light

TL;DR

This study demonstrates that third-order correlation interactions in thermal light double-slit interference significantly enhance visibility, with negative correlation values observed, explained by classical statistical optics theory.

Contribution

It provides the first experimental demonstration of the influence of third-order correlation terms in thermal light interference, highlighting their role in visibility enhancement.

Findings

Visibility is dramatically enhanced in third-order interference.

Negative third-order correlation values can occur when detectors are scanned oppositely.

The phenomena are explained by classical statistical optics theory.

Abstract

A third-order double-slit interference experiment with pseudo-thermal light source in the high-intensity limit has been performed by actually recording the intensities in three optical paths. It is shown that not only can the visibil- ity be dramatically enhanced compared to the second-order case as previously theoretically predicted and shown experimentally, but also that the higher visi- bility is a consequence of the contribution of third-order correlation interaction terms, which is equal to the sum of all contributions from second-order cor- relation. It is interesting that, when the two reference detectors are scanned in opposite directions, negative values for the third-order correlation term of the intensity fluctuations may appear. The phenomenon can be completely explained by the theory of classical statistical optics, and is the first concrete demonstration of the influence of the third-order correlation terms.