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

Contagem de fótons únicos com CCD em experimentos de óptica quântica

Lucas Paresqui Berruezo

Published Aug 4, 2017• 0 citations
OpenAlex

Abstract

In this work we discuss topics such as the theory of photon detectors, showing its operation mode, characteristics and types. In addition, we also study the quantum detection theory, how photons interact with the detector's atoms, and how the process of single and coincidences counting mode works. We look into the theory of parametric down conversion in order to create a correlated photon source and a single photon source. We also discuss about ghost imaging theory and experiments, since it shows us in a very clear way a direct appplication for a single photons camera. I present the results obtained so far with the camera we have in our laboratory. We detected the photon's cones generated by the parametric down conversion type I and type II. We recorded interference patterns, multiple slit images, and amplitude masks images with few photons. We used the CCD for photon counting in an experiment where an image of an object is obtained through photons that have not interacted with the object, but is part of one of the beams in the stimulated parametric down conversion. One of the great motivators of working with a camera is performing quantum optics experiments where spatial patterns are detected. In this aspect a camera has a greater robustness than single photon APD since it allows us to observe the whole transverse profile of a beam simultaneously, something that is possible only with a set of detectors APDs.

Related papers

A model for the detection of spatially correlated biphotons using a photon-counting camera

Ermes Toninelli, Paul‐Antoine Moreau, Thomas Gregory +1 more

Spontaneous downconversion is a versatile source for correlated biphotons that has been employed in many quantum sensing and imaging experiments. Spatially-resolved photon-counting detectors allow to access a large number of modes, posing the challenge of an accurate description of such systems. We propose a simple model to generate images as though acquired by a photon-counting camera, and allow to simulate and characterise the detection of quantum correlations. We derive quantitative parameters characteristic of the spatial correlations for a given experiment, comparing the images produced by our model to the frames acquired by an electron-multiplying CCD camera. Moreover we accurately predict the decreased detection of spatially correlated biphotons caused by introducing a variable amount of optical loss after the nonlinear crystal, even though the total number of detected events is kept constant, showing excellent agreement between model and experiment.

arXiv:1911.10562•Nov 24, 2019•2 citations

Quantum imaging with a photon counting camera

Osian Wolley, Thomas Gregory, Sebastian M. J. Beer +2 more

Classical light sources emit a randomly-timed stream of individual photons, the spatial distribution of which can be detected with a camera to form an image. Quantum light sources, based on parametric down conversion, emit photons as correlated photon-pairs. The spatial correlations between the photons enables imaging systems where the preferential selection of photon-pairs allows for enhancements in the noise performance over what is possible using classical light sources. However, until now the technical challenge of measuring, and correlating both photons has led to system complexity. Here we show that a camera capable of resolving the number of individual photons in each pixel of the detector array can be used to record an image formed from these photon-pair events and hence achieve a greater contrast than possible using a classical light source. We achieve an enhancement in the ratio of two-photon events compared to one-photon events using spatially correlated SPDC light compared to uncorrelated illumination by a LED. These results indicate the potential advantages of using photon counting cameras in quantum imaging schemes and these advantages will further increase as the technology is developed. Operating in photon sparse regimes such systems have potential applications in low-light microscopy and covert imaging.

Scientific Reports•May 18, 2022•47 citations

Heralded single-photon ghost imaging

Reuben S. Aspden, D. S. Tasca, Robert W. Boyd +1 more

Correlated-photon imaging, popularly known as ghost imaging, is a technique whereby an image is formed from light that has never interacted with the object. In ghost imaging experiments two correlated light fields are produced. One of these fields illuminates the object, and the other field is measured by a spatially resolving detector. In the quantum regime, these correlated light fields are produced by entangled photons created by spontaneous parametric down-conversion. To date, all correlated-photon ghost-imaging experiments have scanned a single-pixel detector through the field of view to obtain the spatial information. However, scanning leads to a poor sampling efficiency, which scales inversely with the number of pixels, N, in the image. In this work we overcome this limitation by using a time-gated camera to record the single-photon events across the full scene. We obtain high-contrast images, 90%, in either the image plane or the far-field of the photon pair source, taking advantage of the EPR-like correlations in position and momentum of the photon pairs. Our images contain a large number of modes, >500, creating opportunities in low-light-level imaging and in quantum information processing.

•Dec 20, 2012•1 citation

Quantum Characterization of Single Photon Detectors

M. G. Mingolla

The research activities described in this thesis have basically an experimental profile, and were realized in the Quantum Optics Laboratories of the Optic Division in the Istituto Nazionale di Ricerca Metrologica (I.N.Ri.M.). The experiments presented here are oriented to the characterization of single- and few-photon detectors calibration, exploiting quantum properties. The first chapter has an introductory character, oriented to the study of nonlinear optics phenomena and focused in the spontaneous parametric down conversion (PDC) process. After the quantization of the free electromagnetic field, we recall the quantum theory of PDC. In the second chapter the Klyshko's two-photon calibration technique is presented and applied to an Avalanche Photo Diode (APD) based single photon counting module. Chapter three is an introduction to quantum measurements and quantum operation theories where the concept of positive-operator valued measurement (POVM) is presented. In chapter four, the quantum characterization of a true photon-number resolving detector (PNRD) based on a transition edge sensor (TES) is presented. In this experiment, the POVM of the TES is reconstructed by realizing a tomography of the detection process's quantum operation, using as a probe a set of known coherent states. In the fifth and last chapter, the POVM of a tree type PNRD is reconstructed exploiting strong quantum correlations of PDC twin beams

•Jan 1, 2014•0 citations

Video recording true single-photon double-slit interference

Reuben S. Aspden, Miles J. Padgett, Gabriel C. Spalding

Commercially available cameras do not have a low-enough dark noise to directly capture double-slit interference at the single photon level. In this work, camera noise levels are significantly reduced by activating the camera only when the presence of a photon has been detected by the independent detection of a time-correlated photon produced via parametric down-conversion. This triggering scheme provides the improvement required for direct video imaging of Young's double-slit experiment with single photons, allowing clarified versions of this foundational demonstration. We present video data of the evolving interference patterns. Also, we introduce variations on this experiment aimed at promoting discussion of the role spatial coherence plays in such a measurement, emphasizing complementary aspects of single-photon measurement and highlighting the roles of transverse position and momentum correlations between down-converted photons, including examples of “ghost” imaging and diffraction.

arXiv:1602.05987•American Journal of Physics•Aug 19, 2016•84 citations

A comparison between the measurement of quantum spatial correlations using qCMOS photon-number resolving and electron multiplying CCD camera technologies

K. Roberts, Osian Wolley, Thomas Gregory +1 more

Cameras with single-photon sensitivities can be used to measure the spatial correlations between the photon-pairs that are produced by parametric down-conversion. Even when pumped by a single-mode laser, the signal and idler photons are typically distributed over several thousand spatial modes yet strongly correlated with each other in their position and anti-correlated in their transverse momentum. These spatial correlations enable applications in imaging, sensing, communication, and optical processing. Here we show that, using a photon-number resolving camera, spatial correlations can be observed after only a few 10s of seconds of measurement time, thereby demonstrating comparable performance with previous single photon sensitive camera technologies but with the additional capability to resolve photon-number. Consequently, these photon-number resolving technologies are likely to find wide use in quantum, low-light, imaging systems.

Scientific Reports•Jun 26, 2024•11 citations
In this work we discuss topics such as the theory of photon detectors, showing its operation mode, characteristics and types. In addition, we also study the quantum detection theory, how photons interact with the detector's atoms, and how the process of single and coincidences counting mode works. We look into the theory of parametric down conversion in order to create a correlated photon source and a single photon source. We also discuss about ghost imaging theory and experiments, since it shows us in a very clear way a direct appplication for a single photons camera. I present the results obtained so far with the camera we have in our laboratory. We detected the photon's cones generated by the parametric down conversion type I and type II. We recorded interference patterns, multiple slit images, and amplitude masks images with few photons. We used the CCD for photon counting in an experiment where an image of an object is obtained through photons that have not interacted with the object, but is part of one of the beams in the stimulated parametric down conversion. One of the great motivators of working with a camera is performing quantum optics experiments where spatial patterns are detected. In this aspect a camera has a greater robustness than single photon APD since it allows us to observe the whole transverse profile of a beam simultaneously, something that is possible only with a set of detectors APDs.
Spontaneous downconversion is a versatile source for correlated biphotons that has been employed in many quantum sensing and imaging experiments. Spatially-resolved photon-counting detectors allow to access a large number of modes, posing the challenge of an accurate description of such systems. We propose a simple model to generate images as though acquired by a photon-counting camera, and allow to simulate and characterise the detection of quantum correlations. We derive quantitative parameters characteristic of the spatial correlations for a given experiment, comparing the images produced by our model to the frames acquired by an electron-multiplying CCD camera. Moreover we accurately predict the decreased detection of spatially correlated biphotons caused by introducing a variable amount of optical loss after the nonlinear crystal, even though the total number of detected events is kept constant, showing excellent agreement between model and experiment.
Classical light sources emit a randomly-timed stream of individual photons, the spatial distribution of which can be detected with a camera to form an image. Quantum light sources, based on parametric down conversion, emit photons as correlated photon-pairs. The spatial correlations between the photons enables imaging systems where the preferential selection of photon-pairs allows for enhancements in the noise performance over what is possible using classical light sources. However, until now the technical challenge of measuring, and correlating both photons has led to system complexity. Here we show that a camera capable of resolving the number of individual photons in each pixel of the detector array can be used to record an image formed from these photon-pair events and hence achieve a greater contrast than possible using a classical light source. We achieve an enhancement in the ratio of two-photon events compared to one-photon events using spatially correlated SPDC light compared to uncorrelated illumination by a LED. These results indicate the potential advantages of using photon counting cameras in quantum imaging schemes and these advantages will further increase as the technology is developed. Operating in photon sparse regimes such systems have potential applications in low-light microscopy and covert imaging.
Correlated-photon imaging, popularly known as ghost imaging, is a technique whereby an image is formed from light that has never interacted with the object. In ghost imaging experiments two correlated light fields are produced. One of these fields illuminates the object, and the other field is measured by a spatially resolving detector. In the quantum regime, these correlated light fields are produced by entangled photons created by spontaneous parametric down-conversion. To date, all correlated-photon ghost-imaging experiments have scanned a single-pixel detector through the field of view to obtain the spatial information. However, scanning leads to a poor sampling efficiency, which scales inversely with the number of pixels, N, in the image. In this work we overcome this limitation by using a time-gated camera to record the single-photon events across the full scene. We obtain high-contrast images, 90%, in either the image plane or the far-field of the photon pair source, taking advantage of the EPR-like correlations in position and momentum of the photon pairs. Our images contain a large number of modes, >500, creating opportunities in low-light-level imaging and in quantum information processing.
The research activities described in this thesis have basically an experimental profile, and were realized in the Quantum Optics Laboratories of the Optic Division in the Istituto Nazionale di Ricerca Metrologica (I.N.Ri.M.). The experiments presented here are oriented to the characterization of single- and few-photon detectors calibration, exploiting quantum properties. The first chapter has an introductory character, oriented to the study of nonlinear optics phenomena and focused in the spontaneous parametric down conversion (PDC) process. After the quantization of the free electromagnetic field, we recall the quantum theory of PDC. In the second chapter the Klyshko's two-photon calibration technique is presented and applied to an Avalanche Photo Diode (APD) based single photon counting module. Chapter three is an introduction to quantum measurements and quantum operation theories where the concept of positive-operator valued measurement (POVM) is presented. In chapter four, the quantum characterization of a true photon-number resolving detector (PNRD) based on a transition edge sensor (TES) is presented. In this experiment, the POVM of the TES is reconstructed by realizing a tomography of the detection process's quantum operation, using as a probe a set of known coherent states. In the fifth and last chapter, the POVM of a tree type PNRD is reconstructed exploiting strong quantum correlations of PDC twin beams
Commercially available cameras do not have a low-enough dark noise to directly capture double-slit interference at the single photon level. In this work, camera noise levels are significantly reduced by activating the camera only when the presence of a photon has been detected by the independent detection of a time-correlated photon produced via parametric down-conversion. This triggering scheme provides the improvement required for direct video imaging of Young's double-slit experiment with single photons, allowing clarified versions of this foundational demonstration. We present video data of the evolving interference patterns. Also, we introduce variations on this experiment aimed at promoting discussion of the role spatial coherence plays in such a measurement, emphasizing complementary aspects of single-photon measurement and highlighting the roles of transverse position and momentum correlations between down-converted photons, including examples of “ghost” imaging and diffraction.
Cameras with single-photon sensitivities can be used to measure the spatial correlations between the photon-pairs that are produced by parametric down-conversion. Even when pumped by a single-mode laser, the signal and idler photons are typically distributed over several thousand spatial modes yet strongly correlated with each other in their position and anti-correlated in their transverse momentum. These spatial correlations enable applications in imaging, sensing, communication, and optical processing. Here we show that, using a photon-number resolving camera, spatial correlations can be observed after only a few 10s of seconds of measurement time, thereby demonstrating comparable performance with previous single photon sensitive camera technologies but with the additional capability to resolve photon-number. Consequently, these photon-number resolving technologies are likely to find wide use in quantum, low-light, imaging systems.