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

Journal of Physics Conference Series

High-brightness single-crystal approach in quantum imaging with undetected photons

Dmitry Tabakaev

Published Nov 1, 2017• 0 citations
Publisher

Abstract

Quantum imaging with undetected photons is recently appeared promising brunch of quantum optics. Due to properties of photon pairs (signal and idler), generated via spontaneous down-conversion (SPDC) process and phenomenon of induced coherence, one can obtain phase or intensity image of object without detecting of the photon, interacting with it. The theoretical treatment and limitations of such a system with an only crystal and increased brightness are given.

DOI
10.1088/1742-6596/917/6/062016

Related papers

New progress in quantum imaging with undetected photons (Conference Presentation)

Markus Gräfe, Marta Gilaberte Basset, Josué R. León Torres

Since the second quantum revolution, the growing exploitation of quantum states led to many sophisticated and novel applications [Phil. Trans. R. Soc. Lond. A 361, 1655 (2003). Former, mainly academic research is more and more transferred into real-world quantum technology ready to serve practical tasks. Today, the quantum computer is within reach, satellite based quantum communication already started, and the field of sensing and imaging was revolutionized, too. Non-classical states of light promise a phase sensitivity beyond any classical possibility [PRL 112, 103604 (2014)] and super-resolution capability [Nature Commun. 8, 14786 (2017)]. Moreover, based on quantum correlations, which are rooted in the very heart of quantum mechanics, the imaging of samples with photons that have never interacted with the object is feasible. This science fiction like phenomenon was first investigated by Mandel [PRA 44, 4614 (1991)] and later implemented for actual imaging purposes in the Zeilinger group [Nature 512, 409 (2014)]. We are going to present the transfer of this approach into applicable quantum technology within the realm of the Fraunhofer Key Research Initiative Quantum Methods for Advanced Imaging Solutions (QUILT). The method itself is based on induced coherence without induced emission [PRA 44, 4614 (1991)]. We built a novel compact implementation of this scheme based on only one nonlinear crystal. The crystal is coherently pumped by a laser from two sides such that signal and idler photon pairs can be collinearly emitted in either of two opposite directions (to the right or to the left). On the right side the idler beam will be separated by a dichroic mirror (DM) and interacts with an object (directly placed in front of a mirror or reflective object). On the left side the signal beam will be separated by another dichroic mirror and hit the camera, which is either a sCMOS or an EMCCD. Additional lenses provide the particular imaging. Sine the two possibilities for the idler beam – going right and interact with the object or going left from the nonlinear crystal – interfere the object could be observed by idler detection. However, the same interference can be observed for the signal beams although the never interacted with the object. Hence, the object can be imaged by detecting the signal light only. The crucial point here is the lack of wich-path information of the idler beams in this type of Michelson interferometric setup. The following points should be emphasized: (i) the signal channels never interact with the object, (ii) there is no induced emission due to the idler beam that interacted with the object, and (iii) there is no coincidence detection involved in this scheme. The obvious advantage of this technique is that the wavelength of the idler photons can be tailored to match the interesting spectral range for interaction with the object. At the same time, the signal photons, which are actually detected, can stay in the VIS range where, e.g., Si-based detectors are optimized. Besides the application for life science imaging, we are comparing the quantum imaging properties utilizing momentum correlations or spatial correlations, where the ladder is a modus that was never investigated before. As an outlook we work on significantly enhance SPDC sources in scope of quantum performance and wavelength separation. Obviously, pushing the short-wavelength idler photons further into the deep UV or XUV broadens the range of applications, but must be implemented by non-SPDC photon pair sources.

Quantum Communications and Quantum Imaging•Sep 10, 2019•0 citations

Fundamental resolution limit of quantum imaging with undetected photons

Andres Vega, Elkin A. Santos, Jorge Fuenzalida +5 more

Quantum imaging with undetected photons relies on the principle of induced coherence without induced emission and uses two sources of photon pairs with a signal- and an idler photon. Each pair shares strong quantum correlations in both position and momentum, which allows us to image an object illuminated with idler photons by just measuring signal photons that never interact with the object. In this work, we theoretically investigate the transverse resolution of this nonlocal imaging scheme through a general formalism that treats propagating photons beyond the commonly used paraxial approximation. We hereby prove that the resolution of quantum imaging with undetected photons is fundamentally diffraction limited to the longer wavelength of the signal and idler pairs. Moreover, we conclude that this result is also valid for other nonlocal two-photon imaging schemes.

arXiv:2203.06106•Physical Review Research•Sep 30, 2022•28 citations

Quantum optical measurements with undetected photons through vacuum field indistinguishability

Sun Kyung Lee, Tai Hyun Yoon, Minhaeng Cho

Quantum spectroscopy and imaging with undetected idler photons have been demonstrated by measuring one-photon interference between the corresponding entangled signal fields from two spontaneous parametric down conversion (SPDC) crystals. In this Report, we present a new quantum optical measurement scheme utilizing three SPDC crystals in a cascading arrangement; here, neither the detection of the idler photons which interact with materials of interest nor their conjugate signal photons which do not interact with the sample is required. The coherence of signal beams in a single photon W-type path-entangled state is induced and modulated by indistinguishabilities of the idler beams and crucially the quantum vacuum fields. As a result, the optical properties of materials or objects interacting with the idler beam from the first SPDC crystal can be measured by detecting second-order interference between the signal beams generated by the other two SPDC crystals further down the set-up. This gedankenexperiment illustrates the fundamental importance of vacuum fields in generating an optical tripartite entangled state and thus its crucial role in quantum optical measurements.

Scientific Reports•Jul 20, 2017•12 citations

Quantum imaging with undetected photons

Filip Krajinić, J.R. Leon-Tores, M. Kumar +3 more

We present principles of quantum imaging with undetected photons (QIUP) and show modifications we made to the nonlinear interferometer for QUIP in order to use off-axes holography for faster image reconstruction. We present images made by off-axes quantum holography (OAQH) and discuss image capabilities of the system. In this work we use a pair of quantum correlated photons, generated by spontaneous parametric down-conversion in a non-linear crystal; one photon form a pair interacts with object, and another is detected. In our system both photons are in near infra-red, but by slight modifications they will be in different spectral regions, interacting photons in mid infra-red, detected photons in visible or near infra-ed. This opens very useful applications of QIUP for imaging and sensing in MIR.

International Conference on Transparent Optical Networks•Jul 14, 2024•1 citation

Sub-Diffraction Near-Field Imaging with Undetected Photons using Thin Sources of Photon Pairs

Elkin A. Santos, Sina Saravi, Andres Vega +2 more

Quantum imaging with undetected photons allows for imaging an object by detecting photons that never interacted with it, using the correlation between photon pairs generated in the process of spontaneous parametric down conversion (SPDC) [1] . Through SPDC in a χ (2) material, a pump (P) photon of wavelength λ P can split into a pair of signal (S) and idler (I) photons, such that 1/ λ P = 1/ λ S + 1/ λ I . In such imaging schemes, the object’s optical properties at λ I , such as its absorption profile, can be inferred by only imaging the signal photons. Thus, one can image in challenging spectral ranges, such as mid-IR for λ I , using detectors in the visible for λ S [1] . In this scheme, the resolution is fundamentally diffraction-limited to the wavelength that interacts with the object, λ I [2] . We show that one can go beyond this diffraction limit by placing the object in the near-field of a subwavelength thin SPDC source, as shown schematically in Fig. 1(a) , through transferring the near-field information at λ I into propagating modes at λ S that can be detected in the far field. In this scheme, the resolution of imaging the object at λ I is determined by the detected signal wavelength λ S . As an application, we numerically demonstrate how two closely-spaced small scatterers at mid-IR can be resolved with a visible-range resolution.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 21, 2021•0 citations

Quantum Imaging: Perspectives for Applications of Quantum Imaging (Laser Photonics Rev. 13(10)/2019)

Marta Gilaberte Basset, Frank Setzpfandt, Fabian Steinlechner +3 more

In article number 1900097, Markus Gräfe and co-workers discuss one of the most fascinating quantum-enhanced imaging techniques, “quantum imaging with undetected photons”. This technique is based on induced coherence and, in addition, utilizes correlations between signal and idler photons; furthermore, it allows illumination of an object with the idler wavelength and then detection of only the signal wavelength with a camera, still capturing the object.

Laser & Photonics Review•Oct 1, 2019•6 citations
Quantum imaging with undetected photons is recently appeared promising brunch of quantum optics. Due to properties of photon pairs (signal and idler), generated via spontaneous down-conversion (SPDC) process and phenomenon of induced coherence, one can obtain phase or intensity image of object without detecting of the photon, interacting with it. The theoretical treatment and limitations of such a system with an only crystal and increased brightness are given.
Since the second quantum revolution, the growing exploitation of quantum states led to many sophisticated and novel applications [Phil. Trans. R. Soc. Lond. A 361, 1655 (2003). Former, mainly academic research is more and more transferred into real-world quantum technology ready to serve practical tasks. Today, the quantum computer is within reach, satellite based quantum communication already started, and the field of sensing and imaging was revolutionized, too. Non-classical states of light promise a phase sensitivity beyond any classical possibility [PRL 112, 103604 (2014)] and super-resolution capability [Nature Commun. 8, 14786 (2017)]. Moreover, based on quantum correlations, which are rooted in the very heart of quantum mechanics, the imaging of samples with photons that have never interacted with the object is feasible. This science fiction like phenomenon was first investigated by Mandel [PRA 44, 4614 (1991)] and later implemented for actual imaging purposes in the Zeilinger group [Nature 512, 409 (2014)]. We are going to present the transfer of this approach into applicable quantum technology within the realm of the Fraunhofer Key Research Initiative Quantum Methods for Advanced Imaging Solutions (QUILT). The method itself is based on induced coherence without induced emission [PRA 44, 4614 (1991)]. We built a novel compact implementation of this scheme based on only one nonlinear crystal. The crystal is coherently pumped by a laser from two sides such that signal and idler photon pairs can be collinearly emitted in either of two opposite directions (to the right or to the left). On the right side the idler beam will be separated by a dichroic mirror (DM) and interacts with an object (directly placed in front of a mirror or reflective object). On the left side the signal beam will be separated by another dichroic mirror and hit the camera, which is either a sCMOS or an EMCCD. Additional lenses provide the particular imaging. Sine the two possibilities for the idler beam – going right and interact with the object or going left from the nonlinear crystal – interfere the object could be observed by idler detection. However, the same interference can be observed for the signal beams although the never interacted with the object. Hence, the object can be imaged by detecting the signal light only. The crucial point here is the lack of wich-path information of the idler beams in this type of Michelson interferometric setup. The following points should be emphasized: (i) the signal channels never interact with the object, (ii) there is no induced emission due to the idler beam that interacted with the object, and (iii) there is no coincidence detection involved in this scheme. The obvious advantage of this technique is that the wavelength of the idler photons can be tailored to match the interesting spectral range for interaction with the object. At the same time, the signal photons, which are actually detected, can stay in the VIS range where, e.g., Si-based detectors are optimized. Besides the application for life science imaging, we are comparing the quantum imaging properties utilizing momentum correlations or spatial correlations, where the ladder is a modus that was never investigated before. As an outlook we work on significantly enhance SPDC sources in scope of quantum performance and wavelength separation. Obviously, pushing the short-wavelength idler photons further into the deep UV or XUV broadens the range of applications, but must be implemented by non-SPDC photon pair sources.
Quantum imaging with undetected photons relies on the principle of induced coherence without induced emission and uses two sources of photon pairs with a signal- and an idler photon. Each pair shares strong quantum correlations in both position and momentum, which allows us to image an object illuminated with idler photons by just measuring signal photons that never interact with the object. In this work, we theoretically investigate the transverse resolution of this nonlocal imaging scheme through a general formalism that treats propagating photons beyond the commonly used paraxial approximation. We hereby prove that the resolution of quantum imaging with undetected photons is fundamentally diffraction limited to the longer wavelength of the signal and idler pairs. Moreover, we conclude that this result is also valid for other nonlocal two-photon imaging schemes.
Quantum spectroscopy and imaging with undetected idler photons have been demonstrated by measuring one-photon interference between the corresponding entangled signal fields from two spontaneous parametric down conversion (SPDC) crystals. In this Report, we present a new quantum optical measurement scheme utilizing three SPDC crystals in a cascading arrangement; here, neither the detection of the idler photons which interact with materials of interest nor their conjugate signal photons which do not interact with the sample is required. The coherence of signal beams in a single photon W-type path-entangled state is induced and modulated by indistinguishabilities of the idler beams and crucially the quantum vacuum fields. As a result, the optical properties of materials or objects interacting with the idler beam from the first SPDC crystal can be measured by detecting second-order interference between the signal beams generated by the other two SPDC crystals further down the set-up. This gedankenexperiment illustrates the fundamental importance of vacuum fields in generating an optical tripartite entangled state and thus its crucial role in quantum optical measurements.
We present principles of quantum imaging with undetected photons (QIUP) and show modifications we made to the nonlinear interferometer for QUIP in order to use off-axes holography for faster image reconstruction. We present images made by off-axes quantum holography (OAQH) and discuss image capabilities of the system. In this work we use a pair of quantum correlated photons, generated by spontaneous parametric down-conversion in a non-linear crystal; one photon form a pair interacts with object, and another is detected. In our system both photons are in near infra-red, but by slight modifications they will be in different spectral regions, interacting photons in mid infra-red, detected photons in visible or near infra-ed. This opens very useful applications of QIUP for imaging and sensing in MIR.
Quantum imaging with undetected photons allows for imaging an object by detecting photons that never interacted with it, using the correlation between photon pairs generated in the process of spontaneous parametric down conversion (SPDC) [1] . Through SPDC in a χ (2) material, a pump (P) photon of wavelength λ P can split into a pair of signal (S) and idler (I) photons, such that 1/ λ P = 1/ λ S + 1/ λ I . In such imaging schemes, the object’s optical properties at λ I , such as its absorption profile, can be inferred by only imaging the signal photons. Thus, one can image in challenging spectral ranges, such as mid-IR for λ I , using detectors in the visible for λ S [1] . In this scheme, the resolution is fundamentally diffraction-limited to the wavelength that interacts with the object, λ I [2] . We show that one can go beyond this diffraction limit by placing the object in the near-field of a subwavelength thin SPDC source, as shown schematically in Fig. 1(a) , through transferring the near-field information at λ I into propagating modes at λ S that can be detected in the far field. In this scheme, the resolution of imaging the object at λ I is determined by the detected signal wavelength λ S . As an application, we numerically demonstrate how two closely-spaced small scatterers at mid-IR can be resolved with a visible-range resolution.