Sub-Poissonian Photon Gun by Coherent Diffusive Photonics

EU Flagship Quantum Technologies

PhoG key image

The goal of the project is to deliver deterministic and compact sources of highly non-classical states, from sub-Poissonian light to multi-mode entanglement, all using a single technological platform.
The consortium PhoG will build working prototypes and develop the technological foundation for the applications of these sources in advanced optical imaging and metrology.
The proposed sources will be based on a novel paradigm in photonic devices: coherent diffusive photonics operating with dissipatively coupled optical waveguides. The project will demonstrate that light can flow diffusively while retaining coherence and even entanglement, can be effectively equalized and distributed in a controlled way by means of dissipative coupling. Such unique light propagation regimes will be realized with the help of a photonic analogue of a tight-binding lattice using coupled waveguide networks in linear and non-linear glass materials. The decisive role is played by the linear and nonlinear engineered loss. These coherent photonic devices will be fabricated by ultrafast laser inscription. The dissipative coupling will be realised by coupling each pair of the waveguides carrying optical signal to a linear chain of waveguides that act as a dissipative reservoir. Efficient quantum diagnostic methods will be developed to verify the source characteristics and to assess their technological readiness. We expect coherent diffusive photonic devices to find applications in photonic networks and in a range of metrology tasks, potentially also for simulations of complex quantum dynamics. The specific project goals are:
(1)   to implement a family of compact sub-Poissonian photon guns, capable of robust generation of mesoscopic non-classical and entangled states at 1550 nm and at 852/894 nm;
(2)   to perform a feasibility study of their applications in entanglement-enhanced imaging and atomic clocks aiming at the 2-4 times better clock frequency stability.


Natalia Korolkova

Natalia Korolkova

Theoretical Quantum Information Group, University of St Andrews, United Kingdom

Our group combines different fundamental aspects of quantum optics with more application-oriented research in practical quantum communication. Our main field is quantum information using continuous variables of light and its applications in experimental quantum communication including secure quantum signatures and coherent signal transport.
A large focus lies on the theory of quantum correlations in and beyond entanglement for Gaussian states. We further work on new settings for quantum computation over continuous variables, like measurement-based schemes, ancilla-driven quantum computation (ADQC), topological quantum computation (TQC) and some other, novel paradigms. On the more fundamental side, we are interested in engineered dissipation, physics of open quantum systems and in quantum state characterisation.

Dmitri Mogilevtsev

Dmitri Mogilevtsev

Theory Quantum Optics Group, Institute of Physics, Minsk, Belarus

The B. I. Stepanov Institute of Physics (IPNASB) was founded in 1955 and is at present one of the leading scientific institutions in Belarus, comprising about 530 academic staff. Its area of research is mainly connected to laser physics, quantum optics and spectroscopy. The Institute closely collaborates with a number of the Belarusian small and medium enterprises producing laser and spectroscopic equipment for the Belarusian and world markets. The scientists of the Institute are world leaders in such areas as dye lasers and dynamic holography. Directly involved with PhoG is the Center for Quantum Optics and Information 2015, specializing, in particular, in the research on non-classical states of light, super-resolution imaging, and quantum tomography. Researchers of the Center have extensive experience in theoretical methods of quantum state/process inference, open system dynamics.

Christine Silberhorn

Christine Silberhorn

Integrated Quantum Optics Group, University of Paderborn, Germany

The IQO group develops novel optical devices and methods for possible future applications in quantum information processing, quantum communication and for fundamental quantum experiments. Exploiting the potential of integrated optical devices enables on the one hand the realization of compact, miniaturized and rugged quantum lights sources and converters. Moreover, on the other hand, integrated quantum optics enables the implementation of quantum optic experiments with high complexity. Both aspects can be considered to be an important milestone towards the development of quantum technologies. These promise exciting novel applications by exploiting specific quantum properties which are not accessible with classical resources.

Robert Thomson

Robert Thomson

Photonic Instrumentation Group, Heriot-Watt University, Edinburgh, UK

The HWU team is part of the Institute of Photonics and Quantum Sciences (IPaQS) which carries out a broad range of world-leading research in photonics, engineering photonics and quantum sciences. IPaQS builds on Heriot-Watt's 40+ years of history in world-leading research in photonics. The diverse research topics within IPaQS include lasers and optical sensing approaches, future manufacturing methods, and the fundamentals of quantum information. A key area of expertise lies in quantum sciences and their close relationship with photonics-based technology. The broad research base encourages cross-fertilisation of ideas across the theoretical and experimental topics of photonics and quantum sciences, giving the Institute a strong capability to manage the challenges of contemporary academic research. IPaQS has strong links to industry and other collaborative partner laboratories and currently has formal strategic alliances with SELEX ES, Renishaw and AWE. The depth and quality of photonics research in IPaQS has led to the formation of a number of successful spin-out companies including Edinburgh Instruments, Helia Photonics, Optoscribe and PowerPhotonic.

Dmitri Boiko

Dmitri Boiko

CSEM, Switzerland

CSEM is a private, non-profit Swiss research and technology organization focused on generating value for a sustainable world.


  • N. Prasannan, J. Sperling, B. Brecht, Ch. Silberhorn: "Direct Measurement of Higher-Order Nonlinear Polarization Squeezing"arXiv:2204.07083v1 [quant-ph].
  • I. Peshko, D. Pustakhod, D. Mogilevtsev: "Breaking reciprocity by designed loss"arXiv:2204.02730 [quant-ph].
  • A.B. Mikhalychev, P.I. Novik, I.L. Karuseichyk, D.A. Lyakhov, D.L. Michels, D.S. Mogilevtsev: "Lost photon enhances superresolution"npj Quantum Information 7, 125 (2021).
  • A. Mikhalychev, Y.S. Teo, H. Jeong, A. Stefanov, D. Mogilevtsev: "Classical emulation of quantum states with coherent mixtures"arXiv:2104.15014 [quant-ph].
  • N. Prasannan, S. De, S. Barkhofen, B. Brecht, Ch. Silberhorn, J. Sperling: "Experimental entanglement characterization of two-rebit states"Phys. Rev. A 103, L040402 (2021).
  • J. Tiedau, M. Engelkemeier, B. Brecht, J. Sperling, Ch. Silberhorn: "Statistical Benchmarking of Scalable Photonic Quantum Systems"Phys. Rev. Lett. 126, 023601 (2021).
  • S. Vlasenko, A. B. Mikhalychev, I. L. Karuseichyk, D. A. Lyakhov, D. L. Michels, D. Mogilevtsev: "Optimal correlation order in superresolution optical fluctuation microscopy"Phys. Rev. A 102, 063507 (2020).
  • P. de la Hoz, A. Sakovich, A. Mikhalychev, M. Thornton, N. Korolkova, D. Mogilevtsev: "Integrated source of path-entangled photon pairs with efficient pump self-rejection"Nanomaterials 10(10), 1952 (2020).
  • V. Mitev, L. Balet, N. Torcheboeuf, Ph. Renevey, D.L. Boiko: "Discrimination of entangled photon pair from classical photons by de Broglie wavelength"Scientific Reports 10, 7087 (2020).
  • G.Ya. Slepyan, S. Vlasenko, D. Mogilevtsev: "Quantum Antennas"Advanced Quantum Technologies 3, 1900120 (2020).
  • V. Mitev, N. Torcheboeuf, ..., D.L. Boiko: "Novel ultra-short light pulse emitters utilizing multiple wide quantum wells"SPIE Proceedings 11301, Novel In-Plane Semiconductor Lasers XIX, 113010P (2020).
  • J. Tiedau, T. Schapeler, V. Anant, H. Fedder, Ch. Silberhorn, T. J. Bartley: "Single-channel electronic readout of a multipixel superconducting nanowire single photon detector"Optics Express 28, 5528-5537 (2020).
  • M. Thornton, A. Sakovich, A. Mikhalychev, J.D. Ferrer, P. de la Hoz, N. Korolkova, D. Mogilevtsev: "Coherent diffusive photon gun for generating non-classical states"Phys. Rev. Applied 12, 064051 (2019).
  • J. Tiedau, T. J. Bartley, G. Harder, A. E. Lita, S. W. Nam, T. Gerrits, Ch. Silberhorn: "Scalability of parametric down-conversion for generating higher-order Fock states"Phys. Rev. A 100, 041802(R) (2019).
  • I. Peshko, D. Mogilevtsev, I. Karuseichyk, A. Mikhalychev, A.P. Nizovtsev, G.Ya. Slepyan, A. Boag: "Quantum noise radar: superresolution with quantum antennas by accessing spatiotemporal correlations"Optics Express 27, 29217-29231 (2019).
  • S. Mukherjee, D. Mogilevtsev, G. Ya. Slepyan, T. H. Doherty, R. R. Thomson, N. Korolkova: "Dissipatively coupled waveguide networks for coherent diffusive photonics"Nature Communications 8, 1909 (2017).

Collaborations with other Quantum Flagship projects

    PhoG – CiViQ:

  • S. Richter, M. Thornton, I. Khan, H. Scott, K. Jaksch, U. Vogl, B. Stiller, G. Leuchs, C. Marquardt, N. Korolkova: "Agile and versatile quantum communication: signatures and secrets"Phys. Rev. X 11, 011038 (2021).

    PhoG – QMiCS:

  • "Remote state preparation with CV variables and resource states for Quantum Secret Sharing",  current theory work by C. Wilkinson, M. Thornton, N. Korolkova, manuscript in preparation, discussion regarding mw implementations are in progress with Qmics project.

    PhoG – UNIQORN:

  • "Robust and versatile directional couplers/beamsplitters based on Coherent diffusive photonics – miniturized and production-line adapted implementation on In-P platform",  D. Pustakhod, D. Mogilevtsev, N. Korolkova; first samples produced by Smart Photonics.

Latest News

  • 17 May 2022   PhoG Final Review Meeting, online
  • 13 May 2022   Cluster Day, Paris (agenda)
    The Cluster Review of 15 projects from the Ramp-up Phase of the QT Flagship will be preceded by a Cluster Day, which will be attended by up to three representatives from 21 projects' consortia (15 projects of the review and some of those finishing soon), the CSAs QFlag, QTEdu and InCoQFlag, the expert reviewers, and EC representatives. The Cluster Day will take place at Campus des Cordeliers, Sorbonne Université, Paris.
  • 9 Dec 2021   Biannual Project Meeting 6, online   (agenda, photo)
  • 14 Jun 2021   Biannual Project Meeting 5, online   (agenda, photo)
  • 11 Mar 2021   The article "Agile and versatile quantum communication: signatures and secrets"  resulting from our collaboration with CiViC has been a News item on the Quantum Flagship website.
    "As part of the Quantum Flagship’s projects PhoG and CiviQ, researchers from the Max Planck Institute for the Science of Light in Germany and the University of St Andrews in the United Kingdom, present the first proof-of-principle demonstration of an agile and versatile quantum communication system, using signatures and secret sharing protocols in the same hardware sender and receiver platform. In their work, published in the journal Physical Review X, the team has defined the concepts of quantum crypto-agility and quantum crypto-versatility by showing a layer-based description of a cryptosystem, and how its modular components can be moved around and recombined similar to the pieces of a puzzle."
  • 7 Dec 2020   Biannual Project Meeting 4, online   (agenda, photo)
  • 2-6 Nov 2020   European Quantum Week, Berlin + Online
    Organized by the European Quantum Flagship, with the collaboration of the European Commission, in the context of the Berlin Science Week, it included outreach activities for the general public, talks and presentations by the quantum community as well as European policy-making and institutional visions for the future of Europe within the field of Quantum Technologies.
    In a more specialized ambience and for the quantum community, it featured presentations and talks by quantum experts and coordinators of the 19 research projects running within the Quantum Flagship initiative, who showed the latest results obtained and progress accomplished by their projects in their first 18 months of life.   (PhoG presentation)
  • 31 May 2020   Video published introducing the quantum technologies and the science behind the quantum source PhoG.   (Available in English and in Russian.)
  • 14 May 2020   Mid-term review meeting  
  • 4-5 Dec 2019   Biannual Project Meeting 2, Heriot Watt University, Edinburgh, UK   (agenda, photo)
  • Oct 2019   First PhoG article published:  J.Tiedau et al. "Scalability of parametric down-conversion for generating higher-order Fock states"   Phys. Rev. A 100, 041802 (R) (2019)
  • 7 June 2019   Biannual Project Meeting 1, University of Paderborn, Germany   (agenda, photo)
  • 18-22 February 2019   The first European Quantum Technology Conference (EQTC 2019), initiated by the European funding initiative Quantum Flagship, took place in Grenoble, France.   (programme, photo)
  • 22 November 2018   PhoG [820365] Kick-off meeting, University of St Andrews, UK   (agenda)
  • 2 November 2018   Press releases published by the University of St Andrews (link) and University of Paderborn (link)
  • 29-30 October 2018   Kick-off meeting for the Quantum Flagship in Vienna, Austria   (poster presentation)

PhoG Photo Gallery

Biannual Project Meeting 6
Biannual Project Meeting 5
Biannual Project Meeting 6

online, 9 Dec 2021

Biannual Project Meeting 5

online, 14 Jun 2021

Biannual Project Meeting 4
presentation cover page
European Quantum Week
Biannual Project Meeting 4

online, 7 Dec 2020

PhoG mid-term progress report

at the European Quantum Week.   (video)

European Quantum Week

2-6 Nov 2020, Berlin + online

Promotional video
Biannual Project Meeting 2
Biannual Project Meeting 1
Fabrication of Integrated Quantum Devices

Promotional video made by Uni Paderborn.

Biannual Project Meeting 2

Edinburgh, 4 Dec 2019

Biannual Project Meeting 1

Paderborn, 7 Jun 2019

EQTC Grenoble Feb 2019
group photo
EQTC 2019

European Quantum Technologies Conference. Grenoble, 18 Feb 2019

PhoG Kick-off meeting

Agenda for the meeting held on 22 Nov 2018 in St Andrews.

PhoG Group Photo

St Andrews, 22 Nov 2018

PhoG Project 820365
Quantum Simulation Projects
PhoG - Project 820365

Aim of the project. Expected deliverables. The Consortium. Presentation for the Vienna Kick-off Meeting on 29-30 Oct 2018.

Quantum Simulation Projects

Information on other projects in the Quantum Simulation pillar of the Quantum Technologies Flagship.

PhoG poster for Vienna meeting

Vienna, 29-30 October 2018. Why? How? Physics. Expected Deliverables for PhoG.


  • In these videos produced for the general public we introduce the quantum technologies and the science behind our quantum source PhoG.

    If you want to watch for 2 to 5 min at most: The first 4 videos are brief and introduce the specific aspects of Quantum Optics and Quantum Information in relation to the PhoG project.
    If you are prepared to spend around 10 min: The fifth video covers all that is contained in the previous videos in a single coherent story about our project PhoG and the physics behind it.

    PhoG video

    This video is available in English and in Russian.

  • PhoG device in an asymmetric configuration

    PhoG key image
    Generation of strongly sub-Poissonian light from a coherent input using a waveguide network with engineered nonlinear loss. The two top (magenta) waveguides are the signal modes, that are coupled only through the reservoir, which is realised as an array of evanescently coupled waveguides (blue).
    We refer to the linear arrangement of waveguides (blue) implementing a common bath as "tail". The waveguides are laser inscribed in a bulk glass with high third order nonlinearity.
    Phase space insets show contours of the Wigner function of coherent states (left, input) and photon number squeezed states (right, output).

  • Controlling light with light – Tailored nonlinear photonics

    University Paderborn   


    The Collaborative Research Center TRR142 from Paderborn University and TU Dortmund University introduces their research.  How to design light with light?  The research area of tailored nonlinear photonics wants to find answers to this question and thus better understand the properties of light. The researchers involved provide insights into their work.

  • PhoG: presentation of results at European Quantum Week 2020

    Project PhoG gives an overview at mid-term on their project progress at the European Quantum Week, 2-6 November 2020, Berlin + online.

    PhoG results at mid-term, November 2020 Link to the video on YouTube.

  • Three examples of how Belarusian science is involved in solving shared European problems, bringing results also to their own country

    With regard to the metrology activities (superresolution imaging), WP4 of the PhoG project directly profits from the expertise developed by IPNASB in Horizon 2020 project SUPERTWIN, 2016-2019. The goal of the projects is to develop the technology foundation for an advanced optical microscope imaging at the resolution beyond the Rayleigh limit, which is set by the photon wavelength. The role of IPNASB is to develop ways of diagnosing non-classical input states used to perform the imaging, and develop a description of the superradiant source of entangled photons. This research is closely connected with the task of IPNASB in PhoG.
    For more information see the webpage of EU Neighbours.

    video For one of the applications, super resolution imaging, PhoG is building on the expertise gained in a past EU-funded project SUPERTWIN. Two of the SUPERTWIN partners, IPNASB (theory) and CSEM (experiment), are members of our current consortium. For an illuminating video on use of quantum light in imaging see a promotional video from the SUPERTWIN project.

  • Technology: Fabrication of Integrated Quantum Devices

    University Paderborn   

    The video on the "Fabrication of Integrated Quantum Devices" (at the bottom of the page the link goes to) takes you on a tour through the UPB clean rooms, where we fabricate our nonlinear waveguides. It all seems so simple: You place an order in our in-house procurement system, you wait a couple days and you get your sample delivered to your desk. Behind the scenes, however, there is a gazillion of individual processes and steps that all have to mesh like cogwheels in a machine. It takes experienced people to fabricate the best samples in the world. In the Integrated Quantum Optics group at UPB, we are lucky to have them!

  • 5 November 2018   Press release published by the University of Paderborn:   "EU-Initiative Quantum Flagship fördert Paderborner Forschung"

  • 2 November 2018   Press release published by the University of St Andrews:   "St Andrews-led project receives €2.6m boost"


Prof Natalia Korolkova
School of Physics & Astronomy,   University of St Andrews,
North Haugh,   St Andrews,   KY16 9SS,   Scotland,   UK

About the Quantum Flagship

Quantum Techology logo

The Quantum Flagship was launched in 2018 as one of the largest and most ambitious research initiatives of the European Union. With a budget of €1 billion and a duration of 10 years, the flagship brings together research institutions, academia, industry, enterprises, and policy makers, in a joint and collaborative initiative on an unprecedented scale.
The main objective of the Flagship is to consolidate and expand European scientific leadership and excellence in this research area as well as to transfer quantum physics research from the lab to the market by means of commercial applications and disruptive technologies. With over 5000 researchers from academia and industry involved in this initiative throughout its lifetime, it aims to create the next generation of disruptive technologies that will impact Europe's society, placing the region as a worldwide knowledge-based industry and technological leader in this field.

Our project PhoG is part of the European Union's Quantum Flagship research and innovation initiative, and is funded under project agreement [820365].