Theory of Interferometric Photon-Correlation Measurements: Differentiating Coherent from Chaotic Light

TL;DR

This paper develops a theoretical framework for interferometric photon-correlation measurements, enabling clear differentiation between coherent light with fluctuations and chaotic light, useful for characterizing nanolasers and coherent emission onset.

Contribution

The paper introduces a theoretical approach to interpret interferometric photon-correlation measurements for distinguishing coherent from chaotic light.

Findings

The framework unambiguously differentiates coherent and chaotic light.

It can characterize nanolaser outputs.

It monitors the onset of coherent emission.

Abstract

Interferometric photon-correlation measurements, which correspond to the second-order intensity cross-correlations between the two output ports of an unbalanced Michelson interferometer, are sensitive to both amplitude and phase fluctuations of an incoming beam of light. Here, we present the theoretical framework behind these measurements and show that they can be used to unambiguously differentiate a coherent wave undergoing dynamical amplitude and phase fluctuations from a chaotic state of light. This technique may thus be used to characterize the output of nanolasers and monitor the onset of coherent emission.