Articles récents

Summer 2007 article selection

27 Octobre 2007 , Rédigé par JW Publié dans #Nanophotonics pick

As member of the OMNT “materials and components for optics” committee, I regularly give a selection and a brief description of articles, that I found particularly relevant to the field. Here is my latest selection :


"Generation of optical Schrödinger cats from photon number states"; Alexei Ourjoumtsev, Hyunseok Jeong, Rosa Tualle-Brouri et Philippe Grangier, Nature 448, 784-786 (2007). 

Schrodinger’s cat is a Gedankenexperiment in quantum physics, in which an atomic decay triggers the death of the cat. Because quantum physics allow atoms to remain in superpositions of states, the classical cat would then be simultaneously dead and alive. By analogy, a ‘cat’ state of freely propagating light can be defined as a quantum superposition of well separated quasiclassical states—it is a classical light wave that simultaneously possesses two opposite phases. Such states play an important role in fundamental tests of quantum theory and in many quantum information processing tasks, including quantum computation, quantum teleportation and precision measurements. Recently, optical Schrodinger ‘kittens’ were prepared; however, they are too small for most of the aforementioned applications and increasing their size is experimentally challenging. Here we demonstrate, theoretically and experimentally, a protocol that allows the generation of arbitrarily large squeezed Schrodinger cat states, using homodyne detection and photon number states as resources. We implemented this protocol with light pulses containing two photons, producing a squeezed Schro¨dinger cat state with a negative Wigner function. This state clearly exhibits several quantum phase-space interference fringes between the ‘dead’ and ‘alive’ components, and is large enough to become useful for quantum information processing and experimental tests of quantum theory.

"Label-free single molecule detection with optical microcavities"; A. A. Armani, R. P. Kulkarni, S.E. Fraser, R. C. Flagan et K. J. Vahala, Science 317, 783-787 (2007). 

Current single-molecule detection techniques require labeling the target molecule. We report a highly specific and sensitive optical sensor based on an ultrahigh quality (Q) factor (Q > 1e8) whispering-gallery microcavity. The silica surface is functionalized to bind the target molecule; binding is detected by a resonant wavelength shift. Single-molecule detection is confirmed by observation of single-molecule binding events that shift the resonant frequency, as well as by the statistics for these shifts over many binding events. These shifts result from a thermo-optic mechanism. Additionally, label-free, single-molecule detection of interleukin-2 was demonstrated in serum. These experiments demonstrate a dynamic range of 1e12 in concentration, establishing the microcavity as a sensitive and versatile detector.

"Electromigrated nanoscale gaps for surface enhanced Raman spectroscopy"; D.R. Ward, N.K. Grady, C.S. Levin, N.J. Halas, Y. Wu, P. Nordlander et D. Nathelson, Nano Letters 7, 1396-1400 (2007).

Single-molecule detection with chemical specificity is a powerful and much desired tool for biology, chemistry, physics, and sensing technologies. Surface-enhanced spectroscopies enable single-molecule studies, yet reliable substrates of adequate sensitivity are in short supply. We present a simple, scaleable substrate for surface-enhanced Raman spectroscopy (SERS) incorporating nanometer-scale electromigrated gaps between extended electrodes. Molecules in the nanogap active regions exhibit hallmarks of very high Raman sensitivity, including blinking and spectral diffusion. Electrodynamic simulations show plasmonic focusing, giving electromagnetic enhancements approaching those needed for singlemolecule SERS.

Workshop : Plasmonics in biology and medicine

22 Octobre 2007 , Rédigé par JW Publié dans #Nanophotonics pick

I’ll attend (and give a talk) at the next workshop on plasmonics in biology and medicine, to be held on  Friday December 14th 2007 at ESPCI, 10 rue vauquelin 75005, Paris

Visit the website :

Registration is free !!!

Because of their unique optical properties, the use of plasmons is getting more and more important for biological and medical research. These applications include the use of surface plasmon resonance (SPR) to measure bioaffinity reactions, tailoring fluorescence properties and the use of metal colloids as new light-scattering probes fro imaging or phototherapy. 

The goal of this workshop is to provide an interdisciplinary forum for state-of-the-art methods and instrumentation related the new research area of plasmonics and related nanosystems and their applications in biology and medicine. A poster session will complete the lectures and allows everyone to exchange their ideas on plasmonic.

Latest funded project : ANR ANTARES

17 Septembre 2007 , Rédigé par JW Publié dans #Recent research work

The 3-years ANTARES project aims at fabricating and characterizing nanostructured substrates for surface enhanced Raman scattering (SERS) and fluorescence emission. The controlled arrangement of the colloidal structure and the use of single crystal colloids will enable to adapt the optical specifications in terms of spectral response and electromagnetic enhancement.

Learn more at

Summer time

7 Septembre 2007 , Rédigé par JW Publié dans #Fancy lab

OK, nothing really new on this blog for quite a while… Ah, summer time, “perfect-time-to-get-research-done”, and so few new findings by the end of it. At least, I perfected my knowledge about the carrying babies stuff, and increased by left forearm muscles with this cute 6kg princess :o)

PhD in France…

14 Juillet 2007 , Rédigé par JW Publié dans #Recent research work

I often get applications from students wishing to start a PhD in France. Therefore, I think it’s necessary to clarify the eligibility conditions for a PhD funding grant from the French ministry of research (the standard grant in France, but there exist many other possibilities through specific programs AMN/AMX, DGA, CIFRE, ONERA…).

Below is a translation of the eligibility conditions found on the research ministry website :


The student who wishes to profit from a research grant must make the request of it for the academic year which immediately follows the date on which he obtained a master’s degree. This condition does not apply to the titular candidates of Aggregation. Exemptions are possible if, between the year of obtaining the DEA or the master research and the year of candidature, student has:
- carried out its national service, whatever the duration of this one, or accompanied its spouse who carried out his national service abroad
- prepared, during one year, and presented Aggregation or the CAPES,
- carried out the practical training course of Aggregation or the CAPES,
- been in disease or maternity leave during more than four months consecutive,
- carried out a training course abroad within the one year limit.
- finished their boarding school of speciality for the pharmacy and house physicians, having profited from a year-research to prepare a master’s degree or a DEA.

Actually, I just got a candidate rejected because of this [odd] condition. I'm very disappointed/upset since I thought my country would be more open-minded that this, and that exemptions could still be possible... As far as I understand it, since there are only few grants per lab each year, competition is tough, and any non-scientific argument to reject somebody is highly welcome !

Country of obtaining master's degree: The candidate for a PhD grant must have obtained his diploma of thorough studies or his master research in France or an equivalent diploma in a country signatory of the agreement on the European Space of the higher education (in addition to by the Member States of the European Union, this agreement was signed by Albania, Andorra, Armenia, Azerbaïdjan, Bosnia-Herzegovinia, Croatia, federation of Russia, Georgia, Iceland, Liechtenstein, Macedonia, Moldavia, Norway, Serbia-Montenegro, Switzerland, Turkey, Ukraine, Vatican). 

Age: Less than 25 years at the civil end of the year of the inscription in first year of thesis. Exemptions, granted by the chief of establishment, are possible for the old students of less than 30 years to January 1 of the year of candidature, on presentation of a request express and justified of the person in charge for the doctoral school.