Spectral characterization of weak coherent state sources based on two-photon interference

TL;DR

This paper introduces a method to characterize the coherence of weak coherent light sources using two-photon interference in a Hong-Ou-Mandel setup, demonstrating equivalence with classical optical beat measurements.

Contribution

It presents a novel quantum interference-based technique for coherence characterization that aligns with classical methods, enhancing quantum optics analysis.

Findings

Quantum beat fitting matches classical optical beat results.

Two-photon interference effectively characterizes coherence.

Method confirms equivalence of quantum and classical measurements.

Abstract

We demonstrate a method for characterizing the coherence function of coherent states based on two-photon interference. Two states from frequency mismatched faint laser sources are fed into a Hong-Ou-Mandel interferometer and the interference pattern is fitted with the presented theoretical model for the quantum beat. The fitting parameters are compared to the classical optical beat when bright versions of the sources are used. The results show the equivalence between both techniques.