Spectrally resolved Hong-Ou-Mandel interference between independent sources

TL;DR

This paper explores spectrally resolved Hong-Ou-Mandel interference between independent photon sources, revealing spectral information during interference and enabling improved visibility through spectral filtering, advancing quantum information processing.

Contribution

It introduces spectral domain analysis of HOM interference using a fast fiber spectrometer, providing new insights into spectral effects in HOMI-IPS.

Findings

Spectral distribution during HOM interference was successfully measured.

Spectral filtering can enhance interference visibility.

Demonstrated interference with both single-photon and thermal sources.

Abstract

Hong-Ou-Mandel (HOM) interference between independent photon sources (HOMI-IPS) is the fundamental block for quantum information processing, such as quantum gate, Shor's algorithm, Boson sampling, etc. All the previous HOMI-IPS experiments were carried out in time-domain, however, the spectral information during the interference was lost, due to technical difficulties. Here, we investigate the HOMI-IPS in spectral domain using the recently developed fast fiber spectrometer, and demonstrate the spectral distribution during the HOM interference between two heralded single-photon sources, and two thermal sources. This experiment can not only deepen our understanding of HOMI-IPS in the spectral domain, but also be utilized to improve the visibility by post-processing spectral filtering.