aiqbench analysis
This research presents a robust experimental method for distinguishing faint light sources near brighter ones using spatial-mode demultiplexing, a core technique in quantum optics and imaging. The study validates that this approach maintains superior detection accuracy over traditional diffraction-limited methods even when imperfect optical systems introduce modal crosstalk. These findings advance the practical limits of single-photon detection, which is fundamental to emerging quantum sensing and communication applications.
Experimental subdiffraction source discrimination enabled by spatial demultiplexing and single-photon detectors
arXiv:2605.15929v2 Announce Type: replace Abstract: We experimentally demonstrate a universal, parameter-independent test for asymmetric source discrimination below the diffraction limit. The test exploits spatial-mode demultiplexing (SPADE) and single-photon detection to discriminate the presence of a faint source in the vicinity of a brighter one. We develop a complete theory of the test in the presence of arbitrary modal crosstalk and show that the crosstalk-affected test retains a favorable error exponent over diffraction-limited direct imaging, provided that the crosstalk remains below a threshold $C_{\mathrm{max}}\simeq 1/9$. This establishes a quantitative condition under which the subdiffraction advantage of SPADE survives realistic imperfections. We experimentally test the scheme for a range of source separations and intensity ratios, without requiring prior knowledge of these parameters. The measured false-negative error rates are in good agreement with the theoretical model and systematically outperform direct imaging. These results demonstrate that SPADE provides a robust and experimentally accessible advantage for asymmetric subdiffraction hypothesis testing in the photon-starved regime, even in the presence of realistic modal crosstalk.
Abstract:We experimentally demonstrate a universal, parameter-independent test for asymmetric source discrimination below the diffraction limit. The test exploits spatial-mode demultiplexing (SPADE) and single-photon detection to discriminate the presence of a faint source in the vicinity of a brighter one. We develop a complete theory of the test in the presence of arbitrary modal crosstalk and show that the crosstalk-affected test retains a favorable error exponent over diffraction-limited direct imaging, provided that the crosstalk remains below a threshold $C_{\mathrm{max}}\simeq 1/9$. This establishes a quantitative condition under which the subdiffraction advantage of SPADE survives realistic imperfections. We experimentally test the scheme for a range of source separations and intensity ratios, without requiring prior knowledge of these parameters. The measured false-negative error rates are in good agreement with the theoretical model and systematically outperform direct imaging. These results demonstrate that SPADE provides a robust and experimentally accessible advantage for asymmetric subdiffraction hypothesis testing in the photon-starved regime, even in the presence of realistic modal crosstalk.
arXiv:2605.15929 [quant-ph]
(or arXiv:2605.15929v2 [quant-ph] for this version)
https://doi.org/10.48550/arXiv.2605.15929 Focus to learn more arXiv-issued DOI via DataCite
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Full text under the publisher's open licence · 251 words