Article in AVS Quantum Science

Posted on 8/2/2021

Latest article published and entitled: 'Single germanium vacancy centers in nanodiamonds with bulk-like spectral stability.' by M. Nahra, D. Alshamaa, R. Deturche, V. Davydov, L. Kulikova, V. Agafonov, and C. Couteau in AVS Quantum Science 3, 012001 (2021).

Here is the abstract :

Motivated by the success of group IV color centers in nanodiamonds (NDs) for hybrid technology requiring a single photon source, the authors study single germanium-vacancy (GeV−) centers in NDs at room temperature with size ranging from 10 to 50 nm and with remarkable spectral properties. The authors characterize their zero-phonon line, study their internal population dynamics, and compare their emission properties in the framework of a three level model with intensity dependent de-shelving. Furthermore, the authors characterize their lifetime, polarization, and brightness. The authors find a maximum photon emission count rate of 1.6 MHz at saturation. The authors also report a polarization visibility of 92% from the fluorescence light, which potentially makes GeV− centers good candidates for quantum key distribution requiring polarized single photons. The authors show that GeV− centers in NDs presented in this work have a comparable spectral stability compared to their bulk counterpart, which is needed for future applications using nanodiamonds.

qnD is back...

Posted on 02/07/2021

qnD is definitely back online again!

Congratulations to Dr Xiaolun XU

Posted on 15/12/2020

Congratulations to Dr Xiaolun XU who successfully passed his PhD defence on “Integrated nanoemitters on glass-based waveguides by photopolymerization”. This was held at the UTT on the 15th of December 2020 and the jury was composed of :

  • Delphine MARRIS-MORINI (Université Paris-Saclay), jury president
  • Renaud BACHELOT (UTT, Troyes), jury member
  • Sylvain BLAIZE (UTT, Troyes), PhD supervisor
  • Christophe COUTEAU (UTT, Troyes), PhD supersivor
  • Stéphanie BUIL (Université Versailles Saint-Quentin, France), rapporteur
  • Ngoc-Diep LAI (ENS Université Paris-Saclay) rapporteur

Xiaolun is now looking for a post-doc position.

Congratulations to Dr Jean-Philippe Girard

Posted on 05/07/2018

Congratulations to Dr Jean-Philippe Girard who successfully passed his PhD defence on "Réalisation et caractérisation de photodétecteurs à base de nanofils de semiconducteur". This was held at the UTT on the 05th of July 2018 and the jury was composed of :

  • Jean-Michel GÉRARD (CEA, France), jury president
  • Renaud BACHELOT (Université de technologie de Troyes - Troyes), jury member
  • Louis GIRAUDET (Université de Reims, France), PhD supervisor
  • Christophe COUTEAU (Université de technologie de Troyes - Troyes), PhD supersivor
  • Jean-Sébastien LAURET (ENS Université Paris-Saclay, France), rapporteur
  • Robert TAYLOR (University of Oxford, UK) invited member
  • Maria TCHERNYCHEVA (C2N, CNRS, France), rapporteur

Jean-Philippe will start a post-doc position from September onwards at the University of Aalto in Finland

Champagne-Ardenne PhD Prize for N. Rahbany

Posted on 5/11/2017

Congratulations to Nancy Rahbany who obtained the Champagne-Ardenne PhD award. She passed her PhD in 2016 under the supervision of CC and Renaud Bachelot working on 'Towards integrated optics at the nanoscale: plasmon-emitter coupling using plasmonic structures'. She is now doing a post-doc at the Langevin Institute at the ESPCI in Paris.

Research habilitation for CC

Posted on 5/5/2017

Just passed my research habilitation (HdR) at the Université Pierre and Marie Curie, Sorbonne Université with the title 'Harnessing light-matter interaction: applications in nanophotonics and quantum technologies' with the jury composed of Jean-Michel Raimond (UPMC, ENS), Elisabeth Giacobino (CNRS, ENS), Carlo Sirtori (Paris Diderot), Rémi Carminati (ESPCI), John Rarity (University of Bristol) and Sébastien Tanzilli (CNRS and Université de Nice).

ITN project LIMQUET accepted!

Posted on 5/2/2017

We are part of a European Innovative Training Network (ITN) that has been accepted on Light-Matter Interface for Enabling Quantum Technologies (LIMQUET) with the University of Bourgogne (project coordinator), the University of Oxford, Darmstad University, EPFL Lausanne, the University of Sussex, the University of Sofia and the companies TeemPhotonics, Qubig and Qutools.

Single Photons Single Spins II workshop at the UTT

Posted on 4/18/2017

This is the first announcement for the Second Topical Meeting on Single Photons Single Spins (SPSS II), to be held in Troyes, France on August 29th to September 1st 2017. Save the date!

The goal of this meeting is to bring together academic and industrial European actors in the fields of

  • Spin-photon interfaces,
  • Nanoscale single-photon sources and detectors,
  • Quantum networks with nanoscale devices,
  • Applied quantum nanophotonics,
  • Single-spin quantum sensing,
  • Fundamental studies with nanoscale structures

Confirmed keynote speakers

  • Natalia Ates, University of Oxford
  • Christoph Becher, Saarland University
  • Sophia Economou, Virginia Tech
  • Chris Erven, KETS and University of Bristol
  • Patrick Maletinsky, University of Basel and Qnami
  • Boris Naydenov, University of Ulm
  • Ruth Oulton, University of Bristol

Please find more information at
Abstract submission deadline : May 27th
Registration deadline : July 29th

The meeting is organized by the COST Action on 'Nanoscale Quantum Optics' MP1403 and more specifically jointly by the Working Group 1 and Working Group 3 (see more information here We thank the support from the CNRS GdR IQFA on Quantum Engineering (see more information here

The organizing committee

  • Christophe Couteau - University of Technology of Troyes -
  • Félix Bussières - University of Geneva -
  • Thomas Durt - University of Marseille
  • Anna Fontcuberta i Morral - EPFL Lausanne
  • Peter Lodahl - Niels Bohr Institute
  • Jason Smith - Oxford University

Information :

Article in Nanotechnology

Posted on 3/6/2017

Latest article published and entitled: 'Plasmon–emitter interaction using integrated ring grating–nanoantenna structures.' by N. Rahbany, W. Geng, R. Bachelot, & C. Couteau in Nanotechnology 28, 185201 (2017).

Here is the abstract :

Overcoming the diffraction limit to achieve high optical resolution is one of the main challenges in the fields of plasmonics, nanooptics and nanophotonics. In this work, we introduce novel plasmonic structures consisting of nanoantennas (nanoprisms, single bowtie nanoantennas and double bowtie nanoantennas) integrated in the center of ring diffraction gratings. Propagating surface plasmon polaritons (SPPs) are generated by the ring grating and coupled with localized surface plasmons (LSPs) at the nanoantennas exciting emitters placed in their gap. SPPs are widely used for optical waveguiding but provide low resolution due to their weak spatial confinement. In contrast, LSPs provide excellent sub-wavelength confinement but induce large losses. The phenomenon of SPP–LSP coupling witnessed in our structures allows for achieving more precise focusing at the nanoscale, causing an increase in the fluorescence emission of the emitters. Finite-difference time-domain simulations as well as experimental fabrication and optical characterization results are presented to study plasmon–emitter coupling between an ensemble of dye molecules and our integrated plasmonic structures. A comparison is given to highlight the importance of each structure on the photoluminescence and radiative decay enhancement of the molecules.



2017 CLEO Pacific Rim Conference
in Singapore
31 July-04 August 2017

Single Photons Single Spins II
(SPSSII) Meeting, University of Technology of Troyes,
29 August-01 September 2017.

COST Nanoscale Quantum Optics (NQO)