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:0812.1516 · Optics Express

Entangled-photon coincidence fluorescence imaging

Giuliano Scarcelli, Seok Hyun Yun

Published Sep 26, 2008• 18 citations
arXivHTMLPDF

Abstract

We describe fluorescence imaging using the second-order correlation of entangled photon pairs. The proposed method is based on the principle that one photon of the pair carries information on where the other photon has been absorbed and has produced fluorescence in a sample. Because fluorescent molecules serve as "detectors" breaking the entanglement, multiply-scattered fluorescence photons within the sample do not cause image blur. We discuss experimental implementations.

DOI
10.1364/oe.16.016189

Related papers

Fluorescence ghost imaging

Giuliano Scarcelli, Seok Hyun Yun

We introduce a method of using the second-order correlation of entangled photon pairs for fluorescence imaging. The method relies on the fact that one photon of the pair carries information on where the other photon has been absorbed and has produced fluorescence in a sample. Because fluorescent molecules serve as "detectors" breaking the entanglement, multiply-scattered fluorescence photons within the sample do not cause image blur. We discuss practical implementations.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Aug 20, 2009•0 citations

Quantum holographic imaging by entangled photons

Jaewan Kim, Hai-Woong Lee

Principle of quantum holographic imaging is explained. While one of the entangled twin photons interacts with an object, the other one carries the holographic image of the object. While this scheme does not work for simple scattering objects, it works for absorbing objects with selective coincidence detection. Generalization of this scheme to state-transforming objects is also proposed.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Feb 3, 2004•0 citations

Entangled Photon Excited Fluorescence in Organic Materials: An Ultrafast Coincidence Detector

Oleg P. Varnavski, Brian Pinsky, Theodore G. Goodson III

We report the fluorescence emission from organic systems selectively excited by entangled pairs of photons. We have demonstrated a linear dependence of this two-photon excited fluorescence on the excitation intensity which is a unique nonclassical feature of two-photon interactions induced by entangled photons. The entangled photon (ETPA) excited fluorescence has been detected in several organic molecules possessing a high entangled photon absorption cross section. The ETPA fluorescence showed a nonmonotonic dependence on the delay between signal and idler beams. The fluorescence signal was detectable within the signal–idler relative delay time interval of ∼100 fs. This time is comparable with the estimated entanglement time, T E, making the ETPA-excited fluorescence in organic materials an ideal ultrafast coincidence detector. These results have widespread impact in applications ranging from spectroscopy to chemical and biological sensing, imaging, and microscopy.

The Journal of Physical Chemistry Letters•Dec 28, 2016•80 citations

Experimental test of the entanglement enhancement in two-photon fluorescence

Gewei Qian, Xiao Liu, Chenran Xu +2 more

Abstract Entangled photons with time-energy correlations are predicted to have improved sensitivity compared with classical light in two-photon fluorescence, which is promising for lowering the phototoxicity in biomedical imaging. While the mechanism has been demonstrated in atoms and crystals, the effectiveness in biological molecules has been under debate. Here we report the experimental results, including both positive and negative ones, in various samples. While entanglement induced enhancement in the sum frequency generation of a nonlinear crystal was confirmed, we observe no such enhancement in the two-photon nonlinear process of various molecules. However, we observed classical two-photon fluorescence excited by nW light in rare earth element doped core-shell structure nano-crystals, which can also be used in sensitive biomedical imaging. Our results provide guidance in characterizing the effect of entanglement in two-photon processes.

Quantum Frontiers•Feb 28, 2024•5 citations

Scanning Single Photon Detector Implementation of Quantum “Ghost Imaging”

Tao Jin, Minzhao Liu

Entangled photons can be exploited for single-photon imaging: photons are accumulated one by one to form an image on a camera. To improve the signal-to-noise ratio, one can use “heralded imaging,” where camera data is only accepted if a partner (entangled) photon is detected in coincidence, at a second detector. A secondary consequence of the strong correlations between entangled photons is that we can place the object into the path of the second detector, and yet still create an image on the original camera, using only photons that never interacted with the viewed object. This configuration is called “ghost imaging.” To reduce cost, we designed and implemented a modified version, replacing the fast-gated camera with single-photon sensitivity with a single-pixel detector that scans the image plane. Our design had to carefully preserve optical alignment so that the detector is always pointing at the source of entangled photons. Our next step will be to use ghost diffraction to demonstrate that entangled phone pairs are correlated in ways that extend beyond what is allowed by classical physics.

•Jan 1, 2019•0 citations

Quantum Phase Imaging using Spatial Entanglement

Chien-Hung Lu, Matthew C. Reichert, Sun, Xiaohang +1 more

Entangled photons have the remarkable ability to be more sensitive to signal and less sensitive to noise than classical light. Joint photons can sample an object collectively, resulting in faster phase accumulation and higher spatial resolution, while common components of noise can be subtracted. Even more, they can accomplish this while physically separate, due to the nonlocal properties of quantum mechanics. Indeed, nearly all quantum optics experiments rely on this separation, using individual point detectors that are scanned to measure coincidence counts and correlations. Scanning, however, is tedious, time consuming, and ill-suited for imaging. Moreover, the separation of beam paths adds complexity to the system while reducing the number of photons available for sampling, and the multiplicity of detectors does not scale well for greater numbers of photons and higher orders of entanglement. We bypass all of these problems here by directly imaging collinear photon pairs with an electron-multiplying CCD camera. We show explicitly the benefits of quantum nonlocality by engineering the spatial entanglement of the illuminating photons and introduce a new method of correlation measurement by converting time-domain coincidence counting into spatial-domain detection of selected pixels. We show that classical transport-of-intensity methods are applicable in the quantum domain and experimentally demonstrate nearly optimal (Heisenberg-limited) phase measurement for the given quantum illumination. The methods show the power of direct imaging and hold much potential for more general types of quantum information processing and control.

arXiv:1509.01227•Sep 3, 2015•1 citation
We describe fluorescence imaging using the second-order correlation of entangled photon pairs. The proposed method is based on the principle that one photon of the pair carries information on where the other photon has been absorbed and has produced fluorescence in a sample. Because fluorescent molecules serve as "detectors" breaking the entanglement, multiply-scattered fluorescence photons within the sample do not cause image blur. We discuss experimental implementations.
We report the fluorescence emission from organic systems selectively excited by entangled pairs of photons. We have demonstrated a linear dependence of this two-photon excited fluorescence on the excitation intensity which is a unique nonclassical feature of two-photon interactions induced by entangled photons. The entangled photon (ETPA) excited fluorescence has been detected in several organic molecules possessing a high entangled photon absorption cross section. The ETPA fluorescence showed a nonmonotonic dependence on the delay between signal and idler beams. The fluorescence signal was detectable within the signal–idler relative delay time interval of ∼100 fs. This time is comparable with the estimated entanglement time, T E, making the ETPA-excited fluorescence in organic materials an ideal ultrafast coincidence detector. These results have widespread impact in applications ranging from spectroscopy to chemical and biological sensing, imaging, and microscopy.
Abstract Entangled photons with time-energy correlations are predicted to have improved sensitivity compared with classical light in two-photon fluorescence, which is promising for lowering the phototoxicity in biomedical imaging. While the mechanism has been demonstrated in atoms and crystals, the effectiveness in biological molecules has been under debate. Here we report the experimental results, including both positive and negative ones, in various samples. While entanglement induced enhancement in the sum frequency generation of a nonlinear crystal was confirmed, we observe no such enhancement in the two-photon nonlinear process of various molecules. However, we observed classical two-photon fluorescence excited by nW light in rare earth element doped core-shell structure nano-crystals, which can also be used in sensitive biomedical imaging. Our results provide guidance in characterizing the effect of entanglement in two-photon processes.
Entangled photons can be exploited for single-photon imaging: photons are accumulated one by one to form an image on a camera. To improve the signal-to-noise ratio, one can use “heralded imaging,” where camera data is only accepted if a partner (entangled) photon is detected in coincidence, at a second detector. A secondary consequence of the strong correlations between entangled photons is that we can place the object into the path of the second detector, and yet still create an image on the original camera, using only photons that never interacted with the viewed object. This configuration is called “ghost imaging.” To reduce cost, we designed and implemented a modified version, replacing the fast-gated camera with single-photon sensitivity with a single-pixel detector that scans the image plane. Our design had to carefully preserve optical alignment so that the detector is always pointing at the source of entangled photons. Our next step will be to use ghost diffraction to demonstrate that entangled phone pairs are correlated in ways that extend beyond what is allowed by classical physics.
Entangled photons have the remarkable ability to be more sensitive to signal and less sensitive to noise than classical light. Joint photons can sample an object collectively, resulting in faster phase accumulation and higher spatial resolution, while common components of noise can be subtracted. Even more, they can accomplish this while physically separate, due to the nonlocal properties of quantum mechanics. Indeed, nearly all quantum optics experiments rely on this separation, using individual point detectors that are scanned to measure coincidence counts and correlations. Scanning, however, is tedious, time consuming, and ill-suited for imaging. Moreover, the separation of beam paths adds complexity to the system while reducing the number of photons available for sampling, and the multiplicity of detectors does not scale well for greater numbers of photons and higher orders of entanglement. We bypass all of these problems here by directly imaging collinear photon pairs with an electron-multiplying CCD camera. We show explicitly the benefits of quantum nonlocality by engineering the spatial entanglement of the illuminating photons and introduce a new method of correlation measurement by converting time-domain coincidence counting into spatial-domain detection of selected pixels. We show that classical transport-of-intensity methods are applicable in the quantum domain and experimentally demonstrate nearly optimal (Heisenberg-limited) phase measurement for the given quantum illumination. The methods show the power of direct imaging and hold much potential for more general types of quantum information processing and control.