Towards superresolution surface metrology: quantum estimation of angular and axial separations

Napoli, Carmine; Piano, Samanta; Leach, Richard; Adesso, Gerardo; Tufarelli, Tommaso

Abstract

We investigate the localization of two incoherent point sources with arbitrary angular and axial separations in the paraxial approximation. By using quantum metrology techniques, we show that a simultaneous estimation of the two separations is achievable by a single quantum measurement, with a precision saturating the ultimate limit stemming from the quantum Cramér-Rao bound. Such a precision is not degraded in the subwavelength regime, thus overcoming the traditional limitations of classical direct imaging derived from Rayleigh’s criterion. Our results are qualitatively independent of the point spread function of the imaging system, and quantitatively illustrated in detail for the Gaussian instance. This analysis may have relevant applications in three-dimensional surface measurements.

Citation

Napoli, C., Piano, S., Leach, R., Adesso, G., & Tufarelli, T. (2019). Towards superresolution surface metrology: quantum estimation of angular and axial separations. Physical Review Letters, 122(14), Article 140505. https://doi.org/10.1103/physrevlett.122.140505

• Journal Article Type: Article
• Acceptance Date: Mar 22, 2019
• Online Publication Date: Apr 12, 2019
• Publication Date: Apr 12, 2019
• Deposit Date: Apr 29, 2019
• Publicly Available Date: Apr 29, 2019
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 122
• Issue: 14
• Article Number: 140505
• DOI: https://doi.org/10.1103/physrevlett.122.140505
• Keywords: Quantum Physics; Mesoscale and Nanoscale Physics; Instrumentation and Detectors; Optics
• Public URL: https://nottingham-repository.worktribe.com/output/1849350
• Publisher URL: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.140505
• Contract Date: Apr 29, 2019