PRIN 2022 CALL. DECREE NO. 104 OF 2 FEBRUARY 2022
PROJECT TITLE: “Quantum imaging for exoplanet detection” (QUEXO)
CUP CODE: D53D23002850006
Budget: € 94.396
P.I.: Prof. Cosmo Lupo
Other Research Units or any Sub-Units: Italian Space Agency (Matera)
Brief project description
Quantum technologies for image acquisition and processing promise to achieve a resolution superior to that allowed by classical optics. The objective of QUEXO is to test a new technology based on the decomposition of the electromagnetic field into transverse modes (Spatial mode demultiplexing - SPADE), in combination with single-photon detectors, to obtain precision measurements well beyond the classical diffraction limit. In a controlled environment, we will characterize measurement protocols and hypothesis tests for exoplanet detection [Huang, Lupo, Phys. Rev. Lett. 127, 130502 (2021)]. Our vision is that this fundamental research will pave the way for new experimental methodologies and stimulate exoplanet research through direct imaging. We anticipate future advances in exoplanet detection well beyond the state of the art: in the photon-counting regime and for planets with lower mass and orbital radius, for example Earth-like planets and those in the habitable zone.
Purpose
Develop and test optical methodologies for high-precision measurements, to obtain experimental systems for observing space, and in particular exoplanets, with resolution below the diffraction limit.
Expected results
Theoretical modelling and experimental implementation, first on the optical table, and then with integration into the Cassegrain telescope at the Matera site of the Italian Space Agency. Demonstration of the experimental methodology to obtain high-precision measurements below the diffraction limit.
Achieved results
QUEXO completed 4 optical-table experiments, demonstrating precision measurements of lengths, frequencies, and time intervals. In [Santamaria, Sgobba, Lupo, Optica Quantum 2, 46 (2024)] we demonstrated the use of SPADE and single-photon detectors for precision measurement of the distance between two incoherent point sources, as well as the measurement of their relative intensity. In [Santamaria, Sgobba, Pallotti, Lupo, Photonics Res. 13, 865 (2025)] we demonstrated the use of SPADE for spectroscopy with resolution below the diffraction limit. Our work anticipated the first high-resolution Doppler spectroscopy measurement of a stellar source [Kim et al., Astrophys. J. Lett. 993, L3 (2025).
We developed theoretical models to describe and interpret the experimental data, generalizing our approach to the problem of discriminating between incoherent sources, not necessarily point-like [Triggiani, Lupo, Quantum Sci. Technol. 11, 015028 (2026)], also with the aid of artificial intelligence [Buonaiuto, Lupo, Quantum Mach. Intell. 7, 28 (2025)].
QUEXO has published 10 articles in international peer-reviewed journals, presented its results at 7 conferences (5 talks and 2 posters), also delivered 5 invited talks, and organized 2 workshops in Bari.
