Professor Alain Aspect

Senior Fellow of Hong Kong Institute for Advanced Study, City University of Hong Kong

Professor at the Institut d’Optique Graduate School, France

Member of the French Academy of Sciences

Foreign Member of the Royal Society, UK

Nobel Laureate in Physics (2022)

Professor Alain Aspect
Professor Alain Aspect is known for his experiments illuminating the most intriguing properties of quantum mechanics. His Bell's inequalities tests with pairs of entangled photons (1982) have contributed to settle a debate between Albert Einstein and Niels Bohr, started in 1935. He has also, with Philippe Grangier, given a striking demonstration of wave-particle duality for a single photon, and realized the Wheeler's delayed choice experiment.

After his contribution to the development of laser cooling of atoms, with Claude Cohen-Tannoudji (1985-1992), he has switched to atom optics, where the group he has established revisits landmarks in quantum optics and develops quantum simulators of disordered materials.

A professor at the Institut d'Optique graduate school and at Ecole Polytechnique (University Paris-Saclay), he is a member of several academies (France, USA, Austria). Among the awards he has received: the CNRS gold medal (2005), the Wolf prize in Physics (2010), the Niels Bohr Gold medal and the Albert Einstein medal (2012), the Ives medal/Quinn prize of the OSA (2013), the Balzan prize in quantum information (2014).


  • 1965-69 : Studies at Ecole Normale Supérieure de Cachan and Université d’Orsay.
  • 1969 : ‘Agrégation’ in Physics (national French ranking exam)
  • 1969-1971 : Master thesis (Thèse 3ème cycle), Orsay: “Fourier spectroscopy by holography”
  • 1974-1983 :  PhD, Orsay: “Three experimental tests of Bell’s inequalities with entangled photons”

Positions Held

  • 1969-71 : Assistant lecturer, Orsay University
  • 1971-74 : Teacher as voluntary service overseas in Yaoundé (Cameroon)
  • 1974-85 : Lecturer (Maître assistant), Ecole Normale Supérieure de Cachan
  • 1985-92 : Collège de France scientist (sous-directeur de laboratoire), associated with the chair of atomic physics held by C. Cohen-Tannoudji
  • 1992-2012 : CNRS Senior scientist (directeur de recherche), at Laboratoire Charles Fabry de l’Institut d'Optique: head of the Atom Optics group.  Professor at Institut d’Optique and Ecole Polytechnique, Palaiseau

Research Topics (Main Results)

  • 1969-1971 : COHERENT OPTICS (S. Lowenthal advisor, at Institut d'Optique)
    • Fourier transform spectroscopy by holography
  • 1974-1985 : NON CLASSICAL PROPERTIES OF LIGHT AS TESTS OF THE FOUNDATIONS OF QUANTUM MECHANICS (with P. Grangier, J. Dalibard, at Institut d'Optique)
    • Tests of Bell’s inequalities with pairs of entangled photons
    • Production of heralded single photons and test of the wave particle duality with single photons
  • 1985-1992 : LASER COOLING OF ATOMS (with C. Cohen-Tannoudji at ENS Paris and College de France)
    • Blue molasses (with J. Dalibard, C. Salomon)
    • Atom channeling in a standing wave (with J. Dalibard, C. Salomon)
    • Laser cooling below the one photon recoil by Velocity Selective Coherent Population Trapping (with E. Arimondo)
  • 1992- : ATOM OPTICS and ULTRA-COLD ATOMS (with C. Westbrook, P. Bouyer, L. Sanchez-Palencia, at Institut d'Optique)
    • Atomic mirrors: role of roughness; van der Waals-Casimir force
    • Atom lasers: ABCD matrices, M2 parameter, guided atom laser
    • Quantum atom optics (Hanbury Brown and Twiss effect, correlated atom pairs) with metastable helium (first observation of Bose Einstein Condensation of metastable helium)
    • Quantum transport and Anderson localization of matter waves in disordered optical potentials


About 200 articles in international journals: more than 20 papers cited more than 100 times, (ISI web of science data).

The three papers on Bell’s inequality tests

  • The three papers on Bell’s inequality tests have been selected as the “Physical Review Milestone Letters” of the year 1981:
    1. Aspect A., Grangier P., Roger G., Phys. Rev. Lett., 47 (1981) p.460:
      "Experimental tests of realistic local theories via Bell's theorem"
    2. Aspect A., Grangier P., Roger G., Phys. Rev. Lett., 49 (1982) p.91:
      "Experimental realization of Einstein-Podolsky-Rosen gedankenexperiment; a new violation of Bell's inequalities"
    3. Aspect A., Dalibard J., Roger G., Phys. Rev. Lett., 49 (1982) p.1804:
      "Experimental test of bell's inequalities using time-varying analyzers"
  • The main idea of the third experiment above had been proposed in:
    • A. Aspect, "Proposed Experiment To Test Separable Hidden-Variable Theories," Physics Letters A 54 (2), 117-118 (1975).
    • A. Aspect, "Proposed Experiment To Test Nonseparability Of Quantum-Mechanics," Physical Review D 14 (8), 1944-1951 (1976).

The paper on laser cooling below the one photon recoil

  • The paper on laser cooling below the one photon recoil has been selected as one of the “Physical Review Milestone Letters” of 1988:
    • Aspect A., Arimondo E., Kaiser R., Vansteenkiste N., Cohen-Tannoudji C., phys. Rev. Lett., 61 (1988) p.826: "Laser cooling below the one-photon recoil energy by velocity-selective coherent population trapping"

The paper on production and characterization of heralded single photons

  • The paper on production and characterization of heralded single photons, and test of wave particle duality, belongs to “the most cited papers” of EuroPhysics Letters:​​​​​​​
    • Grangier P., Roger G., Aspect A., Europhys. Lett., 1 (1986) p.173-179:  "Experimental evidence for a photon anticorrelation effect on a beam splitter: a new light on single-photon interferences"

Selection of papers in the last decade

  • W. Guerin, J. F. Riou, J. P. Gaebler, V. Josse, P. Bouyer, and A. Aspect, Guided quasicontinuous atom laser, Physical Review Letters 97 (2006)
  • D. Clement, A. F. Varon, M. Hugbart, J. A. Retter, P. Bouyer, L. Sanchez-Palencia, D. M. Gangardt, G. V. Shlyapnikov, and A. Aspect, Suppression of transport of an interacting elongated Bose-Einstein condensate in a random potential, Physical Review Letters 95 (2005)
  • M. Schellekens, R. Hoppeler, A. Perrin, J. V. Gomes, D. Boiron, A. Aspect, and C. I. Westbrook, Hanbury Brown Twiss effect for ultracold quantum gases, Science 310 (2005) 648.
  • T. Jeltes, J. M. McNamara, W. Hogervorst, W. Vassen, V. Krachmalnicoff, M. Schellekens, A. Perrin, H. Chang, D. Boiron, A. Aspect, and C. I. Westbrook, Comparison of the Hanbury Brown-Twiss effect for bosons and fermions, Nature 445 (2007) 402.
  • Perrin, H. Chang, V. Krachmalnicoff, M. Schellekens, D. Boiron, A. Aspect, and C. I. Westbrook, Observation of atom pairs in spontaneous four-wave mixing of two colliding Bose-Einstein condensates, Physical Review Letters 99 (2007)
  • V. Jacques, E. Wu, F. Grosshans, F. Treussart, P. Grangier, A. Aspect, and J. F. Roch, Experimental realization of Wheeler's delayed-choice gedanken experiment, Science 315 (2007) 966.
  • J. Billy, V. Josse, Z. C. Zuo, A. Bernard, B. Hambrecht, P. Lugan, D. Clement, L. Sanchez-Palencia, P. Bouyer, and A. Aspect, Direct observation of Anderson localization of matter waves in a controlled disorder, Nature 453 (2008) 891.
  • J. C. Jaskula, M. Bonneau, G. B. Partridge, V. Krachmalnicoff, P. Deuar, K. V. Kheruntsyan, A. Aspect, D. Boiron, and C. I. Westbrook, Sub-poissonian number differences in four-wave mixing of matter waves, Physical Review Letters 105 (2010) 190402.
  • F. Jendrzejewski, A. Bernard, K. Muller, P. Cheinet, V. Josse, M. Piraud, L. Pezze, L. Sanchez-Palencia, A. Aspect, and P. Bouyer, Three-dimensional localization of ultracold atoms in an optical disordered potential, Nature Physics 8 (2012) 398.
  • F. Jendrzejewski, K. Muller, J. Richard, A. Date, T. Plisson, P. Bouyer, A. Aspect, and V. Josse, Coherent Backscattering of Ultracold Atoms, Physical Review Letters 109 (19) (2012).
  • R. Lopes1, A. Imanaliev1, A. Aspect1, M. Cheneau1, D. Boiron1 & C. I. Westbrook1, Atomic Hong–Ou–Mandel experiment, Nature (2015)


  • G. Grynberg, A. Aspect, C. Fabre, “An Introduction to Quantum Optics: From the Semi-classical Approach to Quantized Light” (revised with help of F.Bretenaker and A. Browaeys), 2010, Cambridge University Press.
  • F. Bardou, J.-P. Bouchaud, A. Aspect and C. Cohen-Tannoudji, « Lévy Statistics and Laser Cooling: How Rare Events Bring Atoms to Rest », Cambridge University Press (2002).
  • Aspect, author of the chapter “Bell’s theorem: the naïve view of an experimentalist”, in “Quantum [un]speakables, from Bell to Quantum information”, R.A. Bertlmann and A. Zeilinger edit. (Springer 2002). Available at
  • Aspect, “John Bell and the second quantum revolution”: introduction to the second edition of “Speakable and Unspeakable in Quantum Mechanics”, J.S. Bell, Cambridge University Press (2004).
  • Aspect, co-author of “Demain la Physique”, (ed. O. Jacob 2004; revised 2009), and in particular of the chapter: « Une nouvelle révolution quantique ».
  • Aspect and P. Grangier, « De l’article d’Einstein Podolsky et Rosen à l’information quantique » in « Einstein aujourd’hui », CNRS EDITIONS-EDP Sciences (2005).

CD Audio

Einstein et les révolutions quantiques, De Vive Voix/Académie des Sciences:

Distinguished Membership or Fellowship

  • 1995 /2002 : Académie des Sciences (France) corresponding member / member
  • 2000 : Académie des Technologies (France) member
  • 2008 : National Academy of Sciences (USA) Foreign Associate
  • 2009 : Austrian Academy of Sciences corresponding member abroad
  • 2015 : Académie Royale des Sciences, des Lettres, et des Beaux-Arts de Belgique: associé étranger
  • 2015 : Royal Society (London): Foreign Member
  • 2002 : Optical Society of America Fellow
  • 2005 : American Physical Society Fellow
  • 2010 : European Optical Society Fellow
  • 2017 : City University of Hong Kong, Institute for Advanced Study, Senior Fellow


Distinguished Lectureship

  • 1992 : Loebb lecturer, Harvard University, USA
  • 2000 : Carnegie centennial professor, University of Strathclyde, Scotland
  • 2002 : Klosk lecturer, New York University, USA
  • 2006 : Norman Hascoe distinguished lecturer, UConn, USA
  • 2006 : Yale University distinguished lecturer in quantum information physics
  • 2006 : Wenner-Gren distinguished lecturer, Sweden
  • 2009 : Lecturer at the “Troisième cycle de la physique en Suisse romande”
  • 2009 : Asher Peres memorial lecturer, Technion, Israel
  • 2009 : University of Toronto distinguished lecturer
  • 2010 : Elliott W. Montroll lecturer, U of Rochester
  • 2010 : Schrödinger lecturer, Imperial College, London
  • 2010 : Wright lecturer, Geneva
  • 2011 : Session chair and contributor to the centennial Solvay Conference in Physics on "The Theory of The Quantum World"
  • 2012 : Lecturer of the "XX Jornadas de Optica Cuàntica y Fudamentos de Mecànica Cuàntica", University of Bilbao
  • 2012 : Invited professor at the Joint Quantum Institute of University of Maryland and National Institute of Standard and Technology
  • 2012 : Rochester lecturer, University of Durham
  • 2014 : Hans Jensen lecture, University of Heidelberg
  • 2015 : Max von Laue Kolloquium of the Physikalische Gesellshaft zu Berlin

Honorary Degrees

  • 2006 : Honorary doctor of the Ecole Polytechnique and University of Montreal
  • 2008 : Honorary doctor of the Australian National University, Canberra
  • 2008 : Honorary doctor of the Herriot-Watt University, Edimburgh
  • 2010 : Honorary doctor of the University of Glasgow
  • 2011 : Honorary doctor of Technion (Haifa)
  • 2014 : Honorary doctor of the University of Waterloo, Canada


  • 2005 : Chevalier de la Légion d'Honneur
  • 2011 : Officier de l'Ordre National du Mérite
  • 2011 : Commandeur des palmes académiques (teaching decoration)
  • 2014 : Officier de la Légion d'Honneur