Indirect measurement of three-photon correlation in nonclassical light sources

TL;DR

This paper introduces an indirect method to measure three-photon correlations in nonclassical light sources using detector dead time effects, validated through cavity-QED microlaser experiments, offering a more efficient measurement approach.

Contribution

The authors developed a general theory for extracting three-photon correlations from two-photon measurements with finite dead time detectors, reducing the number of detectors needed.

Findings

The measurement scheme accurately detects three-photon correlations.

Experimental results agree with theoretical predictions.

The method reduces measurement time compared to traditional schemes.

Abstract

We have observed the three-photon correlation in nonclassical light sources by using an indirect measurement scheme based on the dead time effect of photon-counting detectors. We first developed a general theory which enables us to extract the three-photon correlation from the two-photon correlation of an arbitrary light source measured with detectors with finite dead times. We then confirmed the validity of our measurement scheme in experiments done with the cavity-QED microlaser operating with a large intra-cavity mean photon number exhibiting both sub- and super-poissoniaq photon statistics. The experimental results were in a good agreement with the theoretical expectation. Our measurement scheme provides an alternative approach for N-photon correlation measurement employing (N-1) detectors and thus a reduced measurement time for a given signal-to-noise ratio, compared to the usual scheme requiring N detectors.