Multiphoton interference outperforms pairwise overlaps for distinguishability characterization

TL;DR

This paper introduces a multiphoton interference protocol that more efficiently characterizes photon distinguishability than traditional pairwise Hong-Ou-Mandel experiments, demonstrated through experimental results with three photons.

Contribution

The paper presents a novel multiphoton interference protocol that outperforms pairwise methods in characterizing photon overlaps, validated by experimental implementation.

Findings

Multiphoton interference provides higher Fisher information than pairwise methods.

The protocol is more efficient even in ideal noiseless conditions.

Experimental results confirm the protocol's superior performance.

Abstract

We propose a protocol that characterizes the pairwise overlaps of the internal modes of single photons more efficiently than pairwise Hong-Ou-Mandel characterization experiments. This protocol exploits multiphoton interference. We experimentally implement this protocol to characterize three photons. We show that our implementation of the characterization protocol outperforms the pairwise Hong-Ou-Mandel characterization, even if the Hong-Ou-Mandel characterization would have been performed in a noiseless, perfect experiment. We demonstrate this via the Fisher information matrix.