Astronomical Quantum Optics: Photon Correlations and Intensity Interferometry

Project funded by Swedish Research Council (Project grant), grant 2008-04092_VR. Participating organisations named by the source: Lund University. Funded amount: SEK 1,000,000, as stated by the source. Runs 2009-01-01 to 2011-12-31. Keywords: Oklassificerat, Unclassified. Source: OpenAIRE Graph, from the funder's project data (collected by OpenAIRE on 2025-12-05); national funding data, not CORDIS. Abstract given by the source: Quantum optics is exploited to expand parameter domains of optical astronomy. Ordinary imaging devices study spatial coherence of light while spectrometers measure the temporal one. However, light has further degrees of freedom in the statistics of photon arrival times, and in photon orbital angular momentum. Those may clarify emission processes in natural lasers and around compact objects, while high-speed photon-counting with digital signal handling enables multi-element and long-baseline intensity interferometry. Both individual photons and photon streams can be much more complex, and carry much more information than was commonly believed in the past. Being insensitive to atmospheric turbulence, intensity interferometry enables very long optical baselines for imaging stellar surfaces. Flux collectors are connected in software while electronic time delays track stars across the sky. Full-scale tests were made in 2007 with 12 m flux collectors, first optical telescopes ever real-time connected by digital software. Experiments are next planned at a dedicated test facility with the long-term vision of a diffraction-limited square-kilometer optical telescope. Photon-correlation spectroscopy measures intensity fluctuations as function of time delay, deducing temporal coherence, thus enabling spectroscopy with exceedingly high spectral resolution. Such is required to resolve predicted sharp-lined natural lasers, such as those in Eta Carinae, and other very luminous stars.

Original source.

Source: OpenAIRE Graph: projects of national funders, OpenAIRE, from the project data of Swedish Research Council. Retrieved 2026-10-22. Licence: Creative Commons Attribution 4.0 (OpenAIRE Graph). Selected metadata, adapted presentation; the publisher's record is authoritative. No endorsement by the source is implied. Licence: Creative Commons Attribution 4.0 (CC BY 4.0).

AI-assisted summary: The project "Astronomical Quantum Optics: Photon Correlations and Intensity Interferometry" was funded by the Swedish Research Council with SEK 1,000,000 from 2009 to 2011, involving Lund University. It explores quantum optics to enhance optical astronomy through advanced photon analysis. Suggested technology pillar: sensing. Generated by AI from the public source text; it may contain errors and the original source is authoritative.