Bio

Bio


Konstantinos Lagoudakis studied in Athens, Greece where he received a Bachelor of Science in Physics with specialization on Solid State Physics at the National Kapodestrian University. He went on with his studies at Imperial College of Science and Technology in London, United Kingdom where he received a Master of Science in Optics and Photonics. He then moved to the Ecole Polytechnique Fédérale de Lausanne in Switzerland where he completed a PhD on fundamental properties of exciton-polariton condensates. His ground-breaking experimental demonstrations of integer and fractional vortices in polariton condensates earned him the prestigious Swiss Physical Society award in 2010 and the EPFL doctorate award in 2012. Since 2012 he has been a postdoctoral research fellow at the Ginzton Lab of Stanford University where he has developed a magnetic spectroscopy experiment for the investigation and coherent manipulation of charged quantum dots in nanoresonators towards the creation of efficient spin photon interfaces.

Honors & Awards


  • EPFL Doctorate Award 2012, Ecole Polytechnique Fédéral de Lausanne (April 2012)
  • General Physics Award, Swiss Physical Society (May 2010)

Professional Education


  • Docteur ès Sciences (PhD), École Polytechnique Fédérale de Lausanne, Photonics (2010)
  • Master of Science (MSc), Imperial College London, Optics and Photonics (2006)
  • Bachelor of Science (BSc), National Kapodistrian University of Athens, Physics (2005)

Stanford Advisors


Publications

All Publications


  • Ultrafast Polariton-Phonon Dynamics of Strongly Coupled Quantum Dot-Nanocavity Systems PHYSICAL REVIEW X Mueller, K., Fischer, K. A., Rundquist, A., Dory, C., Lagoudakis, K. G., Sarmiento, T., Kelaita, Y. A., Borish, V., Vuckovic, J. 2015; 5 (3)
  • Coherent Generation of Nonclassical Light on Chip via Detuned Photon Blockade PHYSICAL REVIEW LETTERS Mueller, K., Rundquist, A., Fischer, K. A., Sarmiento, T., Lagoudakis, K. G., Kelaita, Y. A., Sanchez Munoz, C., del Valle, E., Laussy, F. P., Vuckovic, J. 2015; 114 (23)
  • Inverse design and demonstration of a compact and broadband on-chip wavelength demultiplexer NATURE PHOTONICS Piggott, A. Y., Lu, J., Lagoudakis, K. G., Petykiewicz, J., Babinec, T. M., Vuckovic, J. 2015; 9 (6): 374-?
  • Visible Photoluminescence from Cubic (3C) Silicon Carbide Microdisks Coupled to High Quality Whispering Gallery Modes ACS PHOTONICS Radulaski, M., Babinec, T. M., Mueller, K., Lagoudakis, K. G., Zhang, J. L., Buckley, S., Kelaita, Y. A., Alassaad, K., Ferro, G., Vuckovic, J. 2015; 2 (1): 14-19

    View details for DOI 10.1021/ph500384p

    View details for Web of Science ID 000348339400004

  • Inverse design and implementation of a wavelength demultiplexing grating coupler SCIENTIFIC REPORTS Piggott, A. Y., Lu, J., Babinec, T. M., Lagoudakis, K. G., Petykiewicz, J., Vuckovic, J. 2014; 4

    Abstract

    Nanophotonics has emerged as a powerful tool for manipulating light on chips. Almost all of today's devices, however, have been designed using slow and ineffective brute-force search methods, leading in many cases to limited device performance. In this article, we provide a complete demonstration of our recently proposed inverse design technique, wherein the user specifies design constraints in the form of target fields rather than a dielectric constant profile, and in particular we use this method to demonstrate a new demultiplexing grating. The novel grating, which has not been developed using conventional techniques, accepts a vertical-incident Gaussian beam from a free-space and separates O-band (1300 nm) and C-band (1550 nm) light into separate waveguides. This inverse design concept is simple and extendable to a broad class of highly compact devices including frequency filters, mode converters, and spatial mode multiplexers.

    View details for DOI 10.1038/srep07210

    View details for Web of Science ID 000346252000002

    View details for PubMedID 25428549

  • Photo-oxidative tuning of individual and coupled GaAs photonic crystal cavities OPTICS EXPRESS Piggott, A. Y., Lagoudakis, K. G., Sarmiento, T., Bajcsy, M., Shambat, G., Vuckovic, J. 2014; 22 (12): 15017-15023
  • Second-Harmonic Generation in GaAs Photonic Crystal Cavities in (111)B and (001) Crystal Orientations ACS PHOTONICS Buckley, S., Radulaski, M., Petykiewicz, J., Lagoudakis, K. G., Kang, J., Brongersma, M., Biermann, K., Vuckovic, J. 2014; 1 (6): 516-523

    View details for DOI 10.1021/ph500054u

    View details for Web of Science ID 000337720300007

  • Hole-spin pumping and repumping in a p-type ?-doped InAs quantum dot PHYSICAL REVIEW B Lagoudakis, K. G., Fischer, K. A., Sarmiento, T., Mueller, K., Vu?kovi?, J. 2014; 90: 121402(R)
  • Nonclassical higher-order photon correlations with a quantum dot strongly coupled to a photonic-crystal nanocavity PHYSICAL REVIEW A Rundquist, A., Bajcsy, M., Majumdar, A., Sarmiento, T., Fischer, K., Lagoudakis, K. G., Buckley, S., Piggott, A. ., Vu?kovi?, J. 2014; 8: 023846
  • Deterministically charged quantum dots in photonic crystal nanoresonators for efficient spin-photon interfaces NEW JOURNAL OF PHYSICS Lagoudakis, K. G., Fischer, K., Sarmiento, T., Majumdar, A., Rundquist, A., Lu, J., Bajcsy, M., Vuckovic, J. 2013; 15
  • Spontaneous self-ordered states of vortex-antivortex pairs in a polariton condensate PHYSICAL REVIEW B Manni, F., Liew, T. C., Lagoudakis, K. G., Ouellet-Plamondon, C., Andre, R., Savona, V., Deveaud, B. 2013; 88 (20)
  • Proposed Coupling of an Electron Spin in a Semiconductor Quantum Dot to a Nanosize Optical Cavity PHYSICAL REVIEW LETTERS Majumdar, A., Kaer, P., Bajcsy, M., Kim, E. D., Lagoudakis, K. G., Rundquist, A., Vuckovic, J. 2013; 111 (2)
  • Dissociation dynamics of singly charged vortices into half-quantum vortex pairs NATURE COMMUNICATIONS Manni, F., Lagoudakis, K. G., Liew, T. C., Andre, R., Savona, V., Deveaud, B. 2012; 3

    Abstract

    The quest for identification and understanding of fractional vorticity is a major subject of research in the quantum fluids domain, ranging from superconductors, superfluid Helium-3 to cold atoms. In a two-dimensional Bose degenerate gas with a spin degree of freedom, the fundamental topological excitations are fractional vortical entities, called half-quantum vortices. Convincing evidence for the existence of half-quantum vortices was recently provided in spinor polariton condensates. The half-quantum vortices can be regarded as the fundamental structural components of singly charged vortices but, so far, no experimental evidence of this relation has been provided. Here we report on the direct and time-resolved observation of the dynamical process of the dissociation of a singly charged vortex into its primary components, a pair of half-quantum vortices. The physical origin of the observed phenomenology is found in a spatially inhomogeneous static potential that couples the two spin components of the condensate.

    View details for DOI 10.1038/ncomms2310

    View details for Web of Science ID 000316356700076

    View details for PubMedID 23250439

  • Penrose-Onsager Criterion Validation in a One-Dimensional Polariton Condensate PHYSICAL REVIEW LETTERS Manni, F., Lagoudakis, K. G., Andre, R., Wouters, M., Deveaud, B. 2012; 109 (15)

    Abstract

    We perform quantum tomography on one-dimensional polariton condensates, spontaneously occurring in linear disorder valleys in a CdTe planar microcavity sample. By the use of optical interferometric techniques, we determine the first-order coherence function and the amplitude and phase of the order parameter of the condensate, providing a full reconstruction of the single particle density matrix for the polariton system. The experimental data are used as input to theoretically test the consistency of the Penrose-Onsager criterion for Bose-Einstein condensation in the framework of nonequilibrium polariton condensates. The results confirm the pertinence and validity of the criterion for a nonequilibrium condensed gas.

    View details for DOI 10.1103/PhysRevLett.109.150409

    View details for Web of Science ID 000309658300003

    View details for PubMedID 23102285

  • Spontaneous Symmetry Breaking in a Polariton and Photon Laser PHYSICAL REVIEW LETTERS Ohadi, H., Kammann, E., Liew, T. C., Lagoudakis, K. G., Kavokin, A. V., Lagoudakis, P. G. 2012; 109 (1)

    Abstract

    We report on the simultaneous observation of spontaneous symmetry breaking and long-range spatial coherence both in the strong- and the weak-coupling regime in a semiconductor microcavity. Under pulsed excitation, the formation of a stochastic order parameter is observed in polariton and photon lasing regimes. Single-shot measurements of the Stokes vector of the emission exhibit the buildup of stochastic polarization. Below threshold, the polarization noise does not exceed 10%, while above threshold we observe a total polarization of up to 50% after each excitation pulse, while the polarization averaged over the ensemble of pulses remains nearly zero. In both polariton and photon lasing regimes, the stochastic polarization buildup is accompanied by the buildup of spatial coherence. We find that the Landau criterion of spontaneous symmetry breaking and Penrose-Onsager criterion of long-range order for Bose-Einstein condensation are met in both polariton and photon lasing regimes.

    View details for DOI 10.1103/PhysRevLett.109.016404

    View details for Web of Science ID 000305938100008

    View details for PubMedID 23031120

  • Coexisiting Polariton Condensates and Their Temporal Coherence in Semiconductor Microcavities Exciton Polaritons in Microcavities: New Frontiers Krizhanovskii, D. N., Whittaker, D. M., Skolnick, M. S., Lagoudakis, K. G., Wouters, M. Springer. 2012: 147-172
  • Vortices in Spontaneous Bose-Einstein Condensates of Exciton-Polaritons Exciton Polaritons in Microcavities: New Frontiers Deveaud-Pledran, B., Lagoudakis, K. G. Springer. 2012: 67-84
  • Spontaneous Pattern Formation in a Polariton Condensate PHYSICAL REVIEW LETTERS Manni, F., Lagoudakis, K. G., Liew, T. C., Andre, R., Deveaud-Pledran, B. 2011; 107 (10)

    Abstract

    Exciton-polariton condensation can be regarded as a self-organization phenomenon, where phase ordering is established among particles in the system. In such condensed systems, further ordering can occur in the particle density distribution, under particular experimental conditions. In this work we report on spontaneous pattern formation in a polariton condensate under nonresonant optical pumping. The slightly elliptical ring-shaped excitation laser that we employ forces condensation to occur into a single-energy state with periodic boundary conditions, giving rise to a multilobe standing-wave patterned state.

    View details for DOI 10.1103/PhysRevLett.107.106401

    View details for Web of Science ID 000294474700006

    View details for PubMedID 21981515

  • Spin-to-orbital angular momentum conversion in semiconductor microcavities PHYSICAL REVIEW B Manni, F., Lagoudakis, K. G., Paraiso, T. K., Cerna, R., Leger, Y., Liew, T. C., Shelykh, I. A., Kavokin, A. V., Morier-Genoud, F., Deveaud-Pledran, B. 2011; 83 (24)
  • Polariton Condensation in a One-Dimensional Disordered Potential PHYSICAL REVIEW LETTERS Manni, F., Lagoudakis, K. G., Pietka, B., Fontanesi, L., Wouters, M., Savona, V., Andre, R., Deveaud-Pledran, B. 2011; 106 (17)

    Abstract

    We study the coherence and density modulation of a nonequilibrium exciton-polariton condensate in a one-dimensional valley with disorder. By means of interferometric measurements we evidence a modulation of the first-order coherence function and we relate it to a disorder-induced modulation of the condensate density, that increases as the pump power is increased. The nonmonotonic spatial coherence function is found to be the result of the strong nonequilibrium character of the one-dimensional system, in the presence of disorder.

    View details for DOI 10.1103/PhysRevLett.106.176401

    View details for Web of Science ID 000290100300015

    View details for PubMedID 21635053

  • Probing the Dynamics of Spontaneous Quantum Vortices in Polariton Superfluids PHYSICAL REVIEW LETTERS Lagoudakis, K. G., Manni, F., Pietka, B., Wouters, M., Liew, T. C., Savona, V., Kavokin, A. V., Andre, R., Deveaud-Pledran, B. 2011; 106 (11)

    Abstract

    The experimental investigation of spontaneously created vortices is of utmost importance for the understanding of quantum phase transitions towards a superfluid phase, especially for two-dimensional systems that are expected to be governed by the Berezinski-Kosterlitz-Thouless physics. By means of time-resolved near-field interferometry we track the path of such vortices, created at random locations in an exciton-polariton condensate under pulsed nonresonant excitation, to their final pinning positions imposed by the stationary disorder. We formulate a theoretical model that successfully reproduces the experimental observations.

    View details for DOI 10.1103/PhysRevLett.106.115301

    View details for Web of Science ID 000288450800012

    View details for PubMedID 21469871

  • Coherent Oscillations in an Exciton-Polariton Josephson Junction PHYSICAL REVIEW LETTERS Lagoudakis, K. G., Pietka, B., Wouters, M., Andre, R., Deveaud-Pledran, B. 2010; 105 (12)

    Abstract

    We report on the observation of spontaneous coherent oscillations in a microcavity polariton bosonic Josephson junction. Condensation of exciton polaritons here takes place under incoherent excitation in a double potential well naturally formed in the disorder. Coherent oscillations set on at an excitation power well above the condensation threshold. The time resolved population and phase dynamics reveal the analogy with the ac Josephson effect. A theoretical two-mode model describes the observed effects, explaining how the different realizations of the pulsed experiment can be in phase.

    View details for DOI 10.1103/PhysRevLett.105.120403

    View details for Web of Science ID 000281870100001

    View details for PubMedID 20867617

  • Selective photoexcitation of confined exciton-polariton vortices PHYSICAL REVIEW B Nardin, G., Lagoudakis, K. G., Pietka, B., Morier-Genoud, F., Leger, Y., Deveaud-Pledran, B. 2010; 82 (7)
  • Exciton-polariton Bose-Einstein condensation: advances and issues INTERNATIONAL JOURNAL OF NANOTECHNOLOGY Richard, M., Kasprzak, J., Baas, A., Kundermann, S., Lagoudakis, K. G., Wouters, M., Carusotto, I., Andre, R., Deveaud-Pledran, B., Dang, L. S. 2010; 7 (4-8): 668-685
  • Dynamics of Long-Range Ordering in an Exciton-Polariton Condensate PHYSICAL REVIEW LETTERS NARDIN, G., Lagoudakis, K. G., Wouters, M., RICHARD, M., Baas, A., Andre, R., Dang, L. S., Pietka, B., Deveaud-Pledran, B. 2009; 103 (25)

    Abstract

    We report on time-resolved measurements of the first order spatial coherence in an exciton-polariton Bose-Einstein condensate. Long-range spatial coherence is found to set in right at the onset of stimulated scattering, on a picosecond time scale. The coherence reaches its maximum value after the population and decays slowly, staying up to a few hundred picoseconds. This behavior can be qualitatively reproduced, using a stochastic classical field model describing interaction between the polariton condensate and the exciton reservoir within a disordered potential.

    View details for DOI 10.1103/PhysRevLett.103.256402

    View details for Web of Science ID 000272958300027

    View details for PubMedID 20366268

  • Observation of Half-Quantum Vortices in an Exciton-Polariton Condensate SCIENCE Lagoudakis, K. G., Ostatnicky, T., Kavokin, A. V., Rubo, Y. G., Andre, R., Deveaud-Pledran, B. 2009; 326 (5955): 974-976

    Abstract

    Singly quantized vortices have already been observed in many systems, including the superfluid helium, Bose-Einstein condensates of dilute atomic gases, and condensates of exciton-polaritons in the solid state. Two-dimensional superfluids carrying spin are expected to demonstrate a different type of elementary excitations referred to as half-quantum vortices, characterized by a pi rotation of the phase and a pi rotation of the polarization vector when circumventing the vortex core. We detect half-quantum vortices in an exciton-polariton condensate by means of polarization-resolved interferometry, real-space spectroscopy, and phase imaging. Half-quantum vortices coexist with single-quantum vortices in our sample.

    View details for DOI 10.1126/science.1177980

    View details for Web of Science ID 000271712300034

    View details for PubMedID 19965506

  • Coexisting nonequilibrium condensates with long-range spatial coherence in semiconductor microcavities PHYSICAL REVIEW B Krizhanovskii, D. N., Lagoudakis, K. G., Wouters, M., Pietka, B., Bradley, R. A., Guda, K., Whittaker, D. M., Skolnick, M. S., Deveaud-Pledran, B., RICHARD, M., Andre, R., Dang, L. S. 2009; 80 (4)
  • Bose-Einstein condensation of polaritons in microcavities Quantum Coherence in Solid State Systems Deveaud-Plédran, B., Baas, A., Lagoudakis, K. G., Wouters, M., Kundermann, S., Pietka, B., Sarchi, D., Savona, V., Richard, M., André, R., Dang, L. S., Kasprzak, J., Carusotto, I. IOS Press. 2009: 375-406
  • Quantized vortices in an exciton-polariton condensate NATURE PHYSICS Lagoudakis, K. G., Wouters, M., RICHARD, M., Baas, A., Carusotto, I., Andre, R., Dang, L. E., Deveaud-Pledran, B. 2008; 4 (9): 706-710

    View details for DOI 10.1038/nphys1051

    View details for Web of Science ID 000259686400014

  • Synchronized and desynchronized phases of exciton-polariton condensates in the presence of disorder PHYSICAL REVIEW LETTERS Baas, A., Lagoudakis, K. G., RICHARD, M., Andre, R., Dang, L. S., Deveaud-Pledran, B. 2008; 100 (17)

    Abstract

    Condensation of exciton polaritons in semiconductor microcavities takes place despite in-plane disorder. Below the critical density, the inhomogeneity of the disorder limits the spatial extension of the ground state. Above the critical density, in the presence of weak disorder, this limitation is spontaneously overcome by the nonlinear interaction, resulting in an extended synchronized phase. In the case of strong disorder, several non-phase-locked condensates can be evidenced. The transition from a synchronized phase to a desynchronized phase is addressed by sampling the cavity disorder.

    View details for DOI 10.1103/PhysRevLett.100.170401

    View details for Web of Science ID 000255524300002

    View details for PubMedID 18518258

  • Superconducting nanowire photon-number-resolving detector at telecommunication wavelengths NATURE PHOTONICS Divochiy, A., Marsili, F., Bitauld, D., Gaggero, A., Leoni, R., Mattioli, F., Korneev, A., Seleznev, V., Kaurova, N., Minaeva, O., Gol'tsman, G., Lagoudakis, K. G., Benkhaoul, M., Levy, F., Fiore, A. 2008; 2 (5): 302-306

Footer Links:

Stanford Medicine Resources: