Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Frontiers in Optics

Interferometry-Based Astronomical Imaging Using Nonlocal Interference with Single-Photon States

Matthew Brown, Valérian Thiel, Markus Allgaier, Michael G. Raymer, Brian J. Smith, Paul G. Kwiat, John D. Monnier

Published Jan 1, 2021• 3 citations
Publisher

Abstract

Recent proposals suggest that a distributed single-photon would outperform weak coherent or thermal states as a phase reference for long-baseline interferometry of dim sources. We demonstrate experimental results toward confirming this prediction.
DOI
10.1364/fio.2021.fth6d.4

Related papers

Long-baseline interferometry using single photon states as a non-local oscillator

Matthew Brown, Valérian Thiel, Markus Allgaier +4 more

Recent proposals suggest that distributed single photons serving as a ‘non-local oscillator’ can outperform coherent states as a phase reference for long-baseline interferometric imaging of weak sources [1,2]. Such nonlocal quantum states distributed between telescopes can, in-principle, surpass the limitations of conventional interferometric-based astronomical imaging approaches for very-long baselines such as: signal-to-noise, shot noise, signal loss, and faintness of the imaged objects. Here we demonstrate in a table-top experiment, interference between a nonlocal oscillator generated by equal-path splitting of an idler photon from a pulsed, separable, parametric down conversion process and a spectrally single-mode, quasi-thermal source. We compare the single-photon nonlocal oscillator to a more conventional local oscillator with uncertain photon number. Both methods enabled reconstruction of the source’s Gaussian spatial distribution by measurement of the interference visibility as a function of baseline separation and then applying the van Cittert-Zernike theorem [3,4]. In both cases, good qualitative agreement was found with the reconstructed source width and the known source width as measured using a camera. We also report an increase of signal-to-noise per ‘faux’ stellar photon detected when heralding the idler photon. 1593 heralded (non-local oscillator) detection events led to a maximum visibility of ~17% compared to the 10412 unheralded (classical local oscillator) detection events, which gave rise to a maximum visibility of ~10% – the first instance of quantum-enhanced sensing in this context.

Quantum Computing, Communication, and Simulation•Mar 2, 2022•6 citations

Proof-of-Principle Laboratory Demonstration of Long-Baseline Interferometric Imaging Using Distributed Single-Photons

Matthew Brown, Valérian Thiel, Markus Allgaier +4 more

We report results of very-long-baseline interferometric imaging using distributed single photons. We demonstrate source autocorrelation reconstruction, and increased signal-to-noise ratio per detected coincidence compared to using classical states as phase reference.

Quantum 2.0 Conference and Exhibition•Jan 1, 2022•0 citations

Comparing Weak References For Quantum Long-Baseline Telescopy

Matthew Brown, Markus Allgaier, Michael G. Raymer +1 more

We compare the signal-to-noise ratio for different measurements that could be used for stellar interferometry. We find that single-photon sources with number-resolved detection outperform other weak local oscillator states.

Quantum 2.0 Conference and Exhibition•Jan 1, 2024•0 citations

Towards quantum telescopes: demonstration of a two-photon interferometer for precision astrometry

Jesse Crawford, Denis Dolzhenko, Michael Keach +6 more

Classical optical interferometry requires maintaining live, phase-stable links between telescope stations. This requirement greatly adds to the cost of extending to long baseline separations and limits on baselines will in turn limit the achievable angular resolution. Here we describe a novel type of two-photon interferometer for astrometry, which uses photons from two separate sky sources and does not require an optical link between stations. Such techniques may make large increases in interferometric baselines practical, even by orders of magnitude, with a corresponding improvement in astrometric precision benefiting numerous fields in astrophysics. We tested a benchtop analogue version of the two-source interferometer and unambiguously observe correlated behavior in detections of photon pairs from two thermal light sources, in agreement with theoretical predictions. This work opens new possibilities in future astronomical measurements.

arXiv:2301.07042•Optics Express•Sep 13, 2023•13 citations

Quantum entanglement as a tool to image distant astronomical objects

Particles entangled over long distances can, in theory, improve the sensitivity of long-baseline interferometers that are observing weak thermal light sources. A proof-of-concept experiment now demonstrates entanglement-assisted interferometry, paving the way for entanglement-enhanced non‑local sensing techniques. The resolution of telescope arrays detecting faint light signals could be improved using a quantum trick.

Nature•Mar 11, 2026•0 citations

Increasing baselines and precision of optical interferometers using two-photon interference effects

Michael Keach, Steve Bellavia, Zhi Chen +10 more

Observations using interferometers provide sensitivity to features of images on angular scales much smaller than any single telescope, on the order of Δθ ∼ λ/b where b is the interferometric baseline. Present-day optical interferometers are essentially classical, interfering single photons with themselves. However, there is a new wave of interest in interferometry using multiple photons, whose mechanisms are inherently quantum mechanical, which offer the prospects of increased baselines and finer resolutions among other advantages. We will discuss recent ideas and results for quantum-assisted interferometry using the resource of entangled pairs, and specifically a two-photon amplitude technique aimed at improved precision in astrometry.

SPIE Optical and Infrared Interferometry and Imaging•Jul 15, 2022•2 citations
Recent proposals suggest that distributed single photons serving as a ‘non-local oscillator’ can outperform coherent states as a phase reference for long-baseline interferometric imaging of weak sources [1,2]. Such nonlocal quantum states distributed between telescopes can, in-principle, surpass the limitations of conventional interferometric-based astronomical imaging approaches for very-long baselines such as: signal-to-noise, shot noise, signal loss, and faintness of the imaged objects. Here we demonstrate in a table-top experiment, interference between a nonlocal oscillator generated by equal-path splitting of an idler photon from a pulsed, separable, parametric down conversion process and a spectrally single-mode, quasi-thermal source. We compare the single-photon nonlocal oscillator to a more conventional local oscillator with uncertain photon number. Both methods enabled reconstruction of the source’s Gaussian spatial distribution by measurement of the interference visibility as a function of baseline separation and then applying the van Cittert-Zernike theorem [3,4]. In both cases, good qualitative agreement was found with the reconstructed source width and the known source width as measured using a camera. We also report an increase of signal-to-noise per ‘faux’ stellar photon detected when heralding the idler photon. 1593 heralded (non-local oscillator) detection events led to a maximum visibility of ~17% compared to the 10412 unheralded (classical local oscillator) detection events, which gave rise to a maximum visibility of ~10% – the first instance of quantum-enhanced sensing in this context.
Classical optical interferometry requires maintaining live, phase-stable links between telescope stations. This requirement greatly adds to the cost of extending to long baseline separations and limits on baselines will in turn limit the achievable angular resolution. Here we describe a novel type of two-photon interferometer for astrometry, which uses photons from two separate sky sources and does not require an optical link between stations. Such techniques may make large increases in interferometric baselines practical, even by orders of magnitude, with a corresponding improvement in astrometric precision benefiting numerous fields in astrophysics. We tested a benchtop analogue version of the two-source interferometer and unambiguously observe correlated behavior in detections of photon pairs from two thermal light sources, in agreement with theoretical predictions. This work opens new possibilities in future astronomical measurements.
Observations using interferometers provide sensitivity to features of images on angular scales much smaller than any single telescope, on the order of Δθ ∼ λ/b where b is the interferometric baseline. Present-day optical interferometers are essentially classical, interfering single photons with themselves. However, there is a new wave of interest in interferometry using multiple photons, whose mechanisms are inherently quantum mechanical, which offer the prospects of increased baselines and finer resolutions among other advantages. We will discuss recent ideas and results for quantum-assisted interferometry using the resource of entangled pairs, and specifically a two-photon amplitude technique aimed at improved precision in astrometry.