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

arXiv:2102.01603 · Optics Express

Experimental demonstration of superresolution of partially coherent light sources using parity sorting

S. A. Wadood, Kevin Liang, Yiyu Zhou, Jing Yang, M. A. Alonso, X.-F. Qian, T. Malhotra, S. M. Hashemi Rafsanjani, Andrew N. Jordan, Robert W. Boyd, A. Nick Vamivakas

Published Jun 7, 2021• 41 citations
arXivHTMLPDF

Abstract

Analyses based on quantum metrology have shown that the ability to localize the positions of two incoherent point sources can be significantly enhanced over direct imaging through the use of mode sorting. Here we theoretically and experimentally investigate the effect of partial coherence on the sub-diffraction limit localization of two sources based on parity sorting. With the prior information of a negative and real-valued degree of coherence, higher Fisher information is obtained than that for the incoherent case. Our results pave the way to clarifying the role of coherence in quantum-limited metrology.

DOI
10.1364/oe.427734

Related papers

Superresolution using parity sorting with partially coherent light

S. A. Wadood, Julia Allen, Yiyu Zhou +5 more

We demonstrate supperresolution for incoherent sources using parity sorting. Simulations are performed for superresolution using parity sorting of partially coherent sources. We show that anti-correlation increases the measurement sensitivity.

Frontiers in Optics•Jan 1, 2019•1 citation

Superresolution of two unbalanced point sources assisted by the entangled partner

Abdelali Sajia, Xiao‐Feng Qian

Sub-diffraction-limit resolution, or superresolution, has been successfully demonstrated in recent theoretical and experimental studies for two equal-brightness and incoherent point sources. However, practical situations of either nonequal brightness (i.e., unbalancedness) or partial coherence are shown to have fatal effects on such superresolution. As a step towards resolving such issues, we consider the effects of both unbalancedness and a form of partial coherence (i.e., quantum state coherence) together by including an entangled degree of freedom of the two point sources. Unexpectedly, it is found that the two negative effects can counteraffect each other, thus permitting credible superresolution, when the measurement is analyzed in the entangled partner's rotated basis. The least resolvable non-zero two-source separation is also identified analytically. Our result represents useful guidance towards the realization of superresolution for practical point sources. The vector-structure analog of quantum and classical light sources also suggests that our analysis applies to both contexts.

arXiv:2112.01725•Physical Review Research•Sep 29, 2022•9 citations

Quantum-inspired superresolution for incoherent imaging

Xiaojie Tan, Qi Luo, Lianwei Chen +3 more

Optical measurements that can achieve the fundamental quantum limits have the potential to improve the imaging of subdiffraction objects in important applications, including optical astronomy and fluorescence microscopy. Working towards the goal of implementing such quantum-inspired measurements for real applications, we experimentally demonstrate the localization of two incoherent optical point sources and the semiparametric estimation of object moments in the subdiffraction regime via spatial-mode demultiplexing (SPADE). In the case of two sources, we are able to estimate both of their locations accurately, not just their separation, by exploiting the asymmetric response of our SPADE device. In the case of semiparametric estimation, we demonstrate that, even if the source number is unknown, the moments of the source distribution can still be estimated accurately. Our demonstration paves the way towards the use of SPADE for optical superresolution in practical scenarios, where adaptive measurements are difficult and many parameters are unknown.

Optica•Jul 27, 2023•33 citations

Passive optical superresolution at the quantum limit

A. I. Lvovsky, Michael R. Grace, Saikat Guha +3 more

For more than a century, the diffraction limit has defined the resolution achievable by passive optical imaging systems. Although some resolution improvement can be gained through classical data processing of the image, it is limited by the noise arising from quantum nature of light. Minimizing the effect of this noise requires quantum treatment of optical imaging. By reformulating imaging as a problem of quantum measurement and estimation, it becomes possible to identify optimal detection strategies that recover spatial information previously thought inaccessible. This review summarizes the theoretical framework that underpins this development, from the formulation of quantum Cramer-Rao bounds and Chernoff bounds to the construction of receivers that attain them, such as those based on spatial-mode demultiplexing. We show how these methods can beat conventional imaging in the classification, localization, and imaging of sub-Rayleigh incoherent sources. We then discuss extensions to multiparameter and partially coherent scenarios, and highlight the unifying connections between estimation and discrimination tasks. Finally, we survey recent experimental demonstrations that approach quantum-limited resolution and outline emerging applications in microscopy, astronomy, and optical sensing.

quant-pharXiv:2605.10767•Optica•May 12, 2026•0 citations

Quantum Fisher information for estimating N partially coherent point sources

Kevin Liang, S. A. Wadood, A. Nick Vamivakas

A partially coherent object's localization parameters are shown to be theoretically estimable with higher precision than those of an incoherent object, and the maximum number of independent parameters that have non-vanishing precision in the sub-Rayleigh regime is 3 (compared to 2 for an incoherent object). Normalization schemes, which are crucial in the proper interpretation of quantum Fisher information results in the presence of partial coherence, are introduced and detailed.

Optics Express•Dec 6, 2022•12 citations

Superresolution imaging of two incoherent optical sources with unequal brightnesses

Jiandong Zhang, Yiwen Fu, Lili Hou +1 more

Resolving the separation between two incoherent optical sources with high precision is of great significance for fluorescence imaging and astronomical observations. In this paper, we focus on a more general scenario where two sources have unequal brightnesses. We give the ultimate precision limit with respect to separation by using the quantum Fisher information. Through the calculation of the classical Fisher information, we analyze and compare several specific measurement schemes including direct measurement, Gaussian mode measurement and zero-photon measurement. The results indicate that Gaussian mode measurement is the nearly optimal for a small separation. On this basis, the effects of relative brightness fluctuation are addressed. Our work provides a positive complement to the aspect of superresolution imaging of incoherent sources.

arXiv:2404.17463•Optics Express•Jun 27, 2024•9 citations
Analyses based on quantum metrology have shown that the ability to localize the positions of two incoherent point sources can be significantly enhanced over direct imaging through the use of mode sorting. Here we theoretically and experimentally investigate the effect of partial coherence on the sub-diffraction limit localization of two sources based on parity sorting. With the prior information of a negative and real-valued degree of coherence, higher Fisher information is obtained than that for the incoherent case. Our results pave the way to clarifying the role of coherence in quantum-limited metrology.
Sub-diffraction-limit resolution, or superresolution, has been successfully demonstrated in recent theoretical and experimental studies for two equal-brightness and incoherent point sources. However, practical situations of either nonequal brightness (i.e., unbalancedness) or partial coherence are shown to have fatal effects on such superresolution. As a step towards resolving such issues, we consider the effects of both unbalancedness and a form of partial coherence (i.e., quantum state coherence) together by including an entangled degree of freedom of the two point sources. Unexpectedly, it is found that the two negative effects can counteraffect each other, thus permitting credible superresolution, when the measurement is analyzed in the entangled partner's rotated basis. The least resolvable non-zero two-source separation is also identified analytically. Our result represents useful guidance towards the realization of superresolution for practical point sources. The vector-structure analog of quantum and classical light sources also suggests that our analysis applies to both contexts.
Optical measurements that can achieve the fundamental quantum limits have the potential to improve the imaging of subdiffraction objects in important applications, including optical astronomy and fluorescence microscopy. Working towards the goal of implementing such quantum-inspired measurements for real applications, we experimentally demonstrate the localization of two incoherent optical point sources and the semiparametric estimation of object moments in the subdiffraction regime via spatial-mode demultiplexing (SPADE). In the case of two sources, we are able to estimate both of their locations accurately, not just their separation, by exploiting the asymmetric response of our SPADE device. In the case of semiparametric estimation, we demonstrate that, even if the source number is unknown, the moments of the source distribution can still be estimated accurately. Our demonstration paves the way towards the use of SPADE for optical superresolution in practical scenarios, where adaptive measurements are difficult and many parameters are unknown.
For more than a century, the diffraction limit has defined the resolution achievable by passive optical imaging systems. Although some resolution improvement can be gained through classical data processing of the image, it is limited by the noise arising from quantum nature of light. Minimizing the effect of this noise requires quantum treatment of optical imaging. By reformulating imaging as a problem of quantum measurement and estimation, it becomes possible to identify optimal detection strategies that recover spatial information previously thought inaccessible. This review summarizes the theoretical framework that underpins this development, from the formulation of quantum Cramer-Rao bounds and Chernoff bounds to the construction of receivers that attain them, such as those based on spatial-mode demultiplexing. We show how these methods can beat conventional imaging in the classification, localization, and imaging of sub-Rayleigh incoherent sources. We then discuss extensions to multiparameter and partially coherent scenarios, and highlight the unifying connections between estimation and discrimination tasks. Finally, we survey recent experimental demonstrations that approach quantum-limited resolution and outline emerging applications in microscopy, astronomy, and optical sensing.
Resolving the separation between two incoherent optical sources with high precision is of great significance for fluorescence imaging and astronomical observations. In this paper, we focus on a more general scenario where two sources have unequal brightnesses. We give the ultimate precision limit with respect to separation by using the quantum Fisher information. Through the calculation of the classical Fisher information, we analyze and compare several specific measurement schemes including direct measurement, Gaussian mode measurement and zero-photon measurement. The results indicate that Gaussian mode measurement is the nearly optimal for a small separation. On this basis, the effects of relative brightness fluctuation are addressed. Our work provides a positive complement to the aspect of superresolution imaging of incoherent sources.