NEWS
December 2015 Liwang Liu joins the team as a postdoctoral researcher.
April 2015 Actualités scientifiques du CNRS (INSIS) : Un nouveau type d’échographie pour imager les propriétés mécaniques des cellules.
October 2013 Thomas Dehoux received a CNRS Bronze medal

February 2013 Listening to Cells: Scientists Probe Human Cells With High-Frequency Sound

LASER OPTO-ACOUSTICS

Overview


The production of audible sound with the focusing and modulation of sun light has been demonstrated since the 19th century. The modern application of this idea relies on the development of controllable coherent light sources such as lasers. Higher frequency acoustic waves propagating in solids or liquids, namely ultrasounds, could then be generated and detected at a distance without any contact to the specimen.

Laser opto-acoustics is thus a field where acoustic waves, potentially of extremely high frequencies (up to THz), are both generated and detected with short lasers pulses (fs). The team has been developing researches on the opto-acoustic transduction and on the acousto-optic detection relevant with acoustic propagation in viscoelastic materials or materials with anisotropy. The opto-acoustics of thin layers or fibres has been under the scope of their interest. Recent researches are focused on the dynamic response of single nanoparticles, and on the laser opto-acoustic elastography of single biological cells.

The group has notably demonstrated that the picosecond opto-acoustic technique in a reflectometry configuration is suitable to optically generate and detect hypersonic waves in the volume of a single sub-micronic gold particle and in the surrounding matrix. The very high frequencies involved in the acoustic spectra of nano-particles are extremely promising for imaging micrometric to nanometric structures.

In parallel, the team has demonstrated the suitability of the picosecond opto-acoustic technique for hypersound generation and detection in single biological cells. Exciting abilities for the non-invasive study of a cell and of organelles have been reported. These abilities developed in nano-phononics, based on the diffraction of optically generated acoustic pulses with nm wavelength, contribute to the development of innovative multi-physics imaging processes.

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Nanophononics

Contact: Yannick Guillet


Motivations

A promising way to locally probe the elasticity of micrometric to nanometric structures (e.g. solid state devices, biological media) is to exploit the high frequency acoustic field radiated by a single nanoparticle (NP). For instance, the femtosecond optical excitation of a 100 nm diameter gold nanoparticle generate in water an acoustic field with a 50 nm acoustic wavelength, i.e. far below the best optical resolution. The aim of this project is to design local GHz opto-acoustic transducers.

Nanoparticle mediated generation of GHz longitudinal acoustic waves

The optoacoustic response of a single submicron (430 nm) gold particle embedded in a silica thin film has been experimentally revealed by transient reflectivity measurements with a femtosecond pump-probe setup. The detection mechanism relies on an intrinsic common-path interferometer where the reference beam comes from a fixed interface of the sample. A semianalytical model is developed to calculate the transient reflectivity accounting for optical index changes in both media and for particle and film surface displacements. The displacement of the particle-film interface turns out to be the major contribution to the measured signal.

Related publications :
Y. Guillet et al. Appl. Phys. Lett. 95, 061909 (2009)
Y. Guillet et al. J. Phys.: Conf. Ser. 214, 012046 (2010)

All-optical probing of a single nanoparticle-substrate contact

We investigate the GHz dynamics of the elastic contact between a single metallic nanoparticle and a substrate. We detect the known breathing mode of the nanoparticle but we also unravel the axial oscillation of the nanoparticle through an intrinsic common-path interferometer. We measured the eigenfrequency and the lifetime of this vertical motion, which are related to the contact stiffness and hysteresis, and to the acoustic leakage at the nanoparticle-substrate interface. Measurements have been performed for single particles with radii ranging from 60 to 700 nm.

Related publication :
Y. Guillet et al. Phys. Rev. B. 86, 035456 (2012)

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Picosecond biophononics

Contact: Bertrand Audoin


Motivations

Understanding the mechanical properties of cells and their relation to different physiological conditions is essential to the study of fundamental processes such as proliferation, migration, or differentiation.
The group has pioneered the applications of ultrafast opto-acoustics to probe and image single biological cells. We have demonstrated that the coherent generation of GHz acoustic waves using ultrashort laser pulses, namely picosecond ultrasonics, can efficiently be used to perform single cell ultrasonography. This unconventional cell imaging modality is label free and relies on the organelles mechanical properties as the contrast mechanism.
The technique allows probing the contact between cell and biomaterial with a micron in plane resolution and yields access to the local cell compressibility, remotely. The unequalled capabilities and the foreseen applications suggest tremendous potentialities for single-cell biology.

Single cell ultrasonography

We developped an inverted pulsed opto-acoustic microscope (iPOM) operating in the 10 to 100 GHz range. These frequencies allow mapping quantitatively cell structures as thin as 10 nm and resolving the fibrillar details of cells. Using this non-invasive all-optical system, we produce high-resolution images based on mechanical properties as the contrast mechanisms, and we can observe the stiffness and adhesion of single migrating stem cells.
However, manipulating biological media in physiological conditions is often a technical challenge when using a laser-based setup. We have therefore designed a new opto-acoustic bio-transducer composed of a thin metal film sputtered on a transparent heat sink that allows reducing importantly the laser-induced cellular stresses, and offers a wide variety of optical configurations (see figure 1). In particular, by exploiting the acoustic reflection coefficient at the sample-transducer interface and the photoacoustic interaction inside the transparent sample, we have probed simultaneously the density and compressibility of a single vegetal cell. [2].


Absorption of fs light pulses in a thin metal layer launches longitudinal acoustic pulses with ps dynamics. Coherent phonons propagate through the transducer, are reflected at the metal-cell interface and are optically detected. Scanning laser pulses at the metal interface we image the inhomogeneous reflection of sound by the cell.

Raw acoustic images of the nuclear region and of the lamellipodium of a migrating human mesenchymal stem cell (hMSC) after fixation. The very high acoustic contrast reveals the structure of the nucleus, the actin network and the fine details of the complexity of the adhesion sites at the edge of the lamellipodium. Processing of acoustic signals allows mapping interfacial stiffness and acoustic impedance with same micron resolution. Click on the links to watch nucleus and lamellipodium videoscopy on a ps time frame.


Related publications :
T. Dehoux et al., Sci. Rep. 5, 8650 (2015)

Probing the nano-contact between a cell and a biomaterial

We have demonstrated the ability of the picosecond ultrasonic technique to image non-specific contacts of single animal cells with metallic substrates. Monocytes were cultured on top of an opto-acoustic bio-transducer. Low-energy femtosecond pump laser pulses were focused at the bottom of the Ti film to a micron spot. The subsequent ultrafast thermal expansion launched a longitudinal acoustic pulse in Ti, with a broad spectrum extending up to 100 GHz. We measured the acoustic echoes reflected from the film/cell interface through the transient optical reflectance changes. The time-frequency analysis of the reflected acoustic pulses with a wavelet transform gives access to a map of the acoustic impedance of the cell and of the stiffness of the film-cell interface.


a) schematic view of the sample. (b) White-light image of the monocyte and line scanned across the cell. (c) Measured (black plain line) and theoretical (red dashed line) reflection coefficient vs frequency at three positions in the first cell (8, 14 and 20 µm). These positions are indicated in Fig. (d) with red dots. (d) Acoustic reflection coefficient along the cell contact area at frequencies 30 GHz (black) and 60 GHz (grey).


Related publication :
M. Abi Ghanem et al., J. Biophoton. (2013)

Speed of sound in a cell organelle with the time resolved Brillouin spectroscopy

Absorption of fs laser pulses in the metal launches an acoustic wavefront in the fixed cell. Its propagation along the cell thickness is detected through the Brillouin acousto-optic interaction.[1] The time resolved so-called Brillouin oscillations yield remote measurements of the cell thickness and of the sound velocity and attenuation in the GHz range for vegetal and animal cells.[2]

(a) Experimental configuration for Brillouin scattering detection. (b) Transient optical reflectivity measured for the intranuclear region of a single osteosarcoma cell.
We have probed the stiffness and viscosity of nuclei in single animal cells in the previously unexplored GHz range with a 100 nm axial resolution. The probing of cells at contrasted differentiation stages, ranging from stem cells to mature cells originating from different tissues, demonstrates that the mechanical properties of the nuclear network are common across various cell types.[3] This pointed to an asymptotically increasing influence of a solid meshwork of connected chromatin fibres.
We have developed alternative optical configurations. In particular, the acoustic wave was launched at the bottom of a thin metal film and the reflectivity was measured through the cell. By both exploiting the acoustic reflection coefficient at the sample-transducer interface and the photoacoustic interaction inside the transparent sample, the density and compressibility of the sample can be probed simultaneously.[4]
We probed the mechanical properties of vegetal live cells sub-compartiments. Experiments with onion cells revealed that single-cell wall transverse stiffness in the direction perpendicular to the epidermis layer is close to that of cellulose.[5] This observation demonstrated that cellulose micro-fibrils are the main load-bearing structure in this direction, and suggested strong bonding of micro-fibrils by hemicelluloses. Altogether measurement of the viscosity at such high frequencies suggest that the rheology of the wall is dominated by glass-like dynamics, a behaviour attributed to the influence of the pectin matrix.

(a) Experimental configuration for acoustic reflection coefficient measurements. (b) Transient optical reflectivity measured (plain line) in a thin wall (800 nm) of a vegetal cell. Theoretical calculations are plotted with dotted lines. (c) Longitudinal sound velocity for the cell vacuole (left n = 13) and cell wall (right n = 8).


Related publications :
[1] C. Rossignol et al., Appl. Phys. Lett.93, 123901 (2008)
[2] M. Ducousso et al., Eur. Phys. J. Appl. Phys. 61, 11201 (2013)
[3] O. F. Zouani et al., Soft Matter10, 8737-8743 (2014)
[4] T. Dehoux and B. Audoin, J. Appl. Phys.112, 124702 (2012)
[5] A. Gadalla et al., Planta 239, 1129 (2014)

Relaxation dynamics in single polymer microcapsules

Soft polymer micro-objects are of great interest for their biological cell-mimicking properties their encapsulation capacities, their use as contrast agents for ultrasonic imaging, as well as their use in self-healing materials. All the same, their compressibility, viscosity and shell thickness play an important role in the adhesion involved in specific tissues targeting, in the drug release rate, or in their echogenicity. However, at submicrometer scales, controlling these properties is challenging and requires elaborate characterization methods.

In particular, a large body of work has been devoted to microcapsules due to their potential in the food and pharmaceutical industries. Microcapsules are mostly used at MHz frequencies, and their individual rheological behavior is usually inferred from their collective response by modelling. Correlating the input of these models with the mechanics of single capsules at higher frequencies is therefore of the utmost importance to complete the description of their intricate dynamics in view of improving their design and modelling.

Using an ultrafast optical technique (Fig. x, left) we probe coherent-phonon propagation inside a single microcapsule composed of a nanometric polymer shell made of poly(lactide-co-glycolide) (PLGA) encapsulating a liquid perfluorooctyl bromide (PFOB) core. Longitudinal storage and loss moduli are measured simultaneously in the transparent shell and core at frequencies ~18 and ~4 GHz, respectively, using time-resolved Brillouin spectroscopy (Fig. x, right). A time-frequency analysis allows determination of the thickness of several capsule shells ranging from 620 down to 80 nm. Comparison with lower frequency data shows a weak power-law frequency dependence of phonon attenuation in the PLGA shell, signature of thermally activated processes in glasses.




Related publications :
T. Dehoux et al., Soft Matter 8, 2586 (2012)

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Laser Ultrasonics

Contact: Bertrand Audoin


The team holds a long-term experience in the optical generation of ultrasonic waves in the MHz range. They developed simulation schemes and inversion procedures suited for anisotropic and viscoelastic materials, and either plane stratified or cylinder structures. Latest advances concern mastering of the directivity of longitudinal and shear acoustic modes.

Acoustic beam steering with the light refraction

The symmetry of a thermoelastic source resulting from laser absorption can be broken when the direction of light propagation in an elastic half-space is inclined relatively to the surface. This leads to an asymmetry of the directivity patterns of both compressional and shear acoustic waves. Physical interpretations of the evolution of the directivity patterns with the increasing light angle of incidence and of the relations between the preferential directions of compressional-and shear-wave emission was proposed. The ability to steer MHz acoustic waves by light refraction was demonstrated with experiments using ns laser pulse duration. The ability to modulate bulk-wave amplitudes and to select the directivity of volume sources, suggest important applications in non-destructive testing and imaging.

(a) Absorbed electromagnetic power density in the volume of an absorbing half-space for light incident on the surface with 0 and 45° incident angle. (b-c) Calculated directivity patterns for compressional waves in Schott NG1glass for a wavelength smaller (b) or equal to (c) the penetration depth. In both cases the angle of incidence is 0 and 45°.


Related publications :
S. Raetz et al., J. Acoust. Soc. Am.130, 3691 (2011)
S. Raetz et al., J. Acoust. Soc. Am.134, 4381 (2013)

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Optical Detetcionion


Broadband (0.3-150 GHz) opto-acoustic imaging with very high spectral resolution (48 MHz)



Related publications :
[1] A. Abbas et al., Opt. Express 22, 7831 (2014)

Compact and passive in-line common-path femtosecond interferometer



Related publications :
[1] J. Chandezon et al., Opt. Express 23, 27011 (2015)

Measuring pm surface displacement at a ps time scale through the hole of a diaphragm

The measurement of acoustic surface displacements can be achieved with optical set-up based on interferometry techniques. Instead we implemented a simple detection scheme where the optical probe beam deformation is detected (BDD). After reflection on the sample surface, the probe beam passes through an iris diaphragm. The local transient curvature of the surface changes the angle of divergence of the reflected probe beam and its radius before the diaphragm. The probe beam power after the diaphragm varies according to this change of radius. We thus detected pm surface displacement at a ps time scale. The technique was used to analyse either bulk, surface or interface waves.

(a) Schematic of the BDD technique. 1- sample, 2- objective, 3- iris diaphragm, 4- focusing lens, 5-photodetector. (b) Optoacoustic signal in a tungsten layer of ~0.25 µm thickness on silicon substrate: measured (dots) and theoretical (line) signals. 1- interferometric signal, 2- reflectivity signal without diaphragm, and 3- reflectivity signal with diaphragm


Related publications :
[1] N. Chigarev et al., Rev. Sci. Instrum. 77, 114901 (2006)
[2] J. Higuet et al., Rev. Sci. Instrum. 82, 114905 (2011)

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GROUP MEMBERS
Bertrand
Audoin
Professor
Group coordinator
bertrand.audoin_AT_u-bordeaux.fr33 (0)5 40 00 69 69
Yannick
Guillet
Assistant
Professor
yannick.guillet_AT_u-bordeaux.fr33 (0)5 40 00 66 12
Alexandre
Jouglard
PhDalexandre.jouglard_AT_u-bordeaux.fr33 (0)5 40 00 87 87
Liwang
Liu
Postdocliwang.liu_AT_u-bordeaux.fr33 (0)5 40 00 89 30
Clément
Rossignol
Assistant
Researcher
clement.rossignol_AT_u-bordeaux.fr33 (0)5 40 00 62 21
Alexis
Viel
PhD alexis.viel_AT_etu.u-bordeaux.fr33 (0)5 40 00 87 87

Former group members

Allaoua AbbasPhD 2010 - 2013
Maroun Abi GhanemPhD 2011 - 2014
Julien ChandezonPhD 2012 - 2015
Nikolay ChigarevPostdoc 2004 - 2007
Thomas DehouxPhD 2004 - 2007 and CNRS researcher 2009-2014
Mathieu DucoussoPhD 2007 - 2010
Atef GadallaPostdoc 2011 - 2012
Julien HiguetPostdoc 2010 - 2011
Claude InserraPostdoc 2008 - 2009
Romain LegrandPostdoc 2014 - 2015
Hinde MeriPhD 2001 - 2004
Salvatore MinissalePostdoc 2012 - 2013
Yongdong PanAssociate assistant professor 2001-2008
Mathieu PertonPhD 2003 - 2006
Damien SégurPhD 2006 - 2009
Samuel RaetzPhD 2009 - 2012
Tony Valier-BrasierPostdoc 2010 - 2011
Feng XuPostdoc 2013 - 2014

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PUBLICATIONS
2015 | 2014 | 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 | 1999 | 1998 | 1997 | 1996

2015


  • Thermal microscopy of single biological cells
    R. Legrand, M. Abi Ghanem, L. Plawinski, M.-C. Durrieu, B. Audoin and T. Dehoux
    Appl. Phys. Lett. 107, 263703 (2015)

  • Effect of refracted light distribution on the photoelastic generation of ZGV Lamb modes in optically low-absorbing plates
    S. Raetz, J. Laurent, T. Dehoux, D. Royer, and C. Prada
    J. Acoust. Soc. Am. 138, 3522-3532 (2015)

  • In-line femtosecond common-path interferometer in reflection mode
    J. Chandezon, J.-M. Rampnoux, S. Dilhaire, B. Audoin, and Y. Guillet
    Opt. Express 23, 27011 (2015)

  • Broadband Spectral Signature of the Ultrafast Transient Optical Response of Gold Nanorods
    X. L. Wang, Y. Guillet, P. R. Selvakannan, H. Remita, and B. Palpant
    J. Phys. Chem. C 119, 7416 (2015)

  • All-optical broadband ultrasonography of single cells
    T. Dehoux, M. Abi Ghanem, O. F. Zouani, J.-M. Rampnoux, Y. Guillet, S. Dilhaire, M.-C. Durrieu and B. Audoin
    Sci. Rep. 5, 8650 (2015)

  • Probing single-cell mechanics with picosecond ultrasonics
    T. Dehoux, M. Abi Ghanem, O. F. Zouani, M. Ducousso, N. Chigarev, C. Rossignol, N. Tsapis, M.-C. Durrieu and B. Audoin
    Ultrasonics 56, 160-171 (2015)

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2014


  • Nanoscale mechanical contacts mapped by ultrashort time-scale electron transport
    M. Tomoda, T. Dehoux, Y. Iwasaki, O. Matsuda, V. Gusev and O. B. Wright
    Sci. Rep. 4, 4790 (2014)

  • Picosecond time resolved opto-acoustic imaging with 48 MHz frequency resolution
    A. Abbas, Y. Guillet, J.-M. Rampnoux, P. Rigail, E. Mottay, B. Audoin and S. Dilhaire
    Opt. Express 22, 7831 (2014)

  • Transverse mechanical properties of cell walls of single living plant cells probed by laser-generated acoustic waves
    A. Gadalla, T. Dehoux and B. Audoin
    Planta 239, 1129 (2014)

  • Universality of the network-dynamics of the cell nucleus at high frequencies
    O. F. Zouani, T. Dehoux, M.-C. Durrieu and B. Audoin
    Soft Matter 10, 8737-8743 (2014)

  • Remote opto-acoustic probing of single-cell adhesion on metallic surfaces
    M. Abi Ghanem, T. Dehoux, O. F. Zouani, A. Gadalla, M.-C. Durrieu and B. Audoin
    J. Biophoton. 7, 453 (2014)

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2013


  • Evaluation of mechanical properties of fixed bone cells with sub-micrometer thickness by picosecond ultrasonics
    M. Ducousso, O. F. Zouani, C. Chanseau, C. Chollet, C. Rossignol, B. Audoin and M.-C. Durrieu
    Eur. Phys. J. Appl. Phys. 61, 11201 (2013)

  • Acoustic beam steering by light refraction: Illustration with directivity patterns of a tilted volume photoacoustic source
    S. Raetz, T. Dehoux, M. Perton and B. Audoin
    J. Acoust. Soc. Am. 134, 4381 (2013)

  • Listening to cells: a non-contact optoacoustic nanoprobe
    T. Dehoux, O. F. Zouani, B. Audoin and M.-C. Durrieu
    Biophys. J. 104, 193A (2013)

  • Laser-generated GHz acoustic waves reveal a universal nuclear stiffness probed during cell differentiation
    O. F. Zouani, T. Dehoux, M.-C. Durrieu and B. Audoin
    Biophys. J. 104, 478A-479A (2013)

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2012


  • Non-invasive optoacoustic probing of the density and stiffness of single biological cells
    T. Dehoux and B. Audoin
    J. Appl. Phys 112, 124702 (2012)

  • All-optical ultrafast spectroscopy of a single nanoparticle-substrate contact
    Y. Guillet, B. Audoin, M. Ferrié and S. Ravaine
    Phys. Rev. B 86, 035456 (2012)

  • Scaled behavior of interface waves at an imperfect solid-solid interface
    T. Valier-Brasier, T. Dehoux and B. Audoin
    J. Appl. Phys. 112, 024904 (2012)

  • Relaxation dynamics in single polymer microcapsules probed with laser-generated GHz acoustic waves
    T. Dehoux, N. Tsapis and B. Audoin
    Soft Matter 8, 2586 (2012)

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2011


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2010


  • Picosecond time scale imaging of mechanical contacts
    T. Dehoux, O. B. Wright and R. Li Voti
    Physics Procedia 3, 351 (2010)

  • Bulk waves excited by a laser line pulse in a two-layered cylinder
    Y. D. Pan, N. Chigarev and B. Audoin
    J. Appl. Phys. 107, 023527 (2010)

  • Intrinsic geometric scattering probed by picosecond optoacoustics in a cylindrical cavity: Application to acoustic and optical characterizations of a single micron carbon fiber
    D. Ségur, Y. Guillet and B. Audoin
    Appl. Phys. Lett. 97, 031901 (2010)

  • Experimental and theoretical study of acoustic waves generated by a laser line pulse in an optically absorptive isotropic cylinder
    D. Ségur, A. L. Shuvalov, B. Audoin and Y. D. Pan
    J. Acoust. Soc. Am. 127, 181-185 (2010)

  • Picosecond acoustics in vegetal cells: Non-invasive in vitro measurements at a sub-cell scale
    B. Audoin, C. Rossignol, N. Chigarev, M. Ducousso, G. Forget, F. Guillemot and M.C. Durrieu
    Ultrasonics 50, 202-207 (2010)

  • One-Pot Radiolytic Synthesis of Gold Nanorods and Their Optical Properties
    W. Abidi, P. R. Selvakannan, Y. Guillet, I. Lampre, P. Beaunier, B. Pansu, B. Palpant and H. Remita
    J. Phys. Chem. C 114, 14794-14803 (2010)

  • Bulk waves excited by a laser line pulse in a bi-layer cylinder
    Y. D. Pan, N. Chigarev and B. Audoin
    J. Phys. Conf. Ser. 214, 012044 (2010)

  • Photo-acoustic response of a single 430 nm gold particle: Semi-analytical model and picosecond ultrasonics measurements
    Y. Guillet, C. Rossignol, B. Audoin, G. Calbris and S. Ravaine
    J. Phys.: Conf. Ser. 214, 012046 (2010)

  • Picosecond acoustics in vegetal cells: non invasive in vitro measurements at a sub-cell scale
    B. Audoin, C. Rossignol, N. Chigarev, M. Ducousso, G. Forget, F. Guillemot and M.-C. Durrieu
    Physics Procedia 3, 323-321 (2010)

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2009


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2008


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2007


  • Three-dimensional elasto-optical interaction for reflectometric detection of diffracted acoustic fields in picosecond ultrasonics
    T. Dehoux, N. Chigarev, C. Rossignol and B. Audoin
    Phys. Rev. B 76, 024311 (2007)

  • Coherent phonons in Si/SiGe superlattices
    Y. Ezzahri, S. Grauby, J. M. Rampnoux, H. Michel, G. Pernot, W. Claeys, S. Dilhaire, C. Rossignol, G. Zeng and A. Shakouri
    Phys. Rev. B 75, 195309 (2007)

  • Theory and illustration of the three-dimensional elasto-optic interaction in picosecond ultrasonics
    T. Dehoux, N. Chigarev, C. Rossignol and B. Audoin
    J. Phys. Conf. Ser. 92, 012020 (2007)

  • Picosecond acoustic diffraction in anisotropic thin film (µm); application to the measurement of stiffness coefficients
    B. Audoin, M. Perton, N. Chigarev and C. Rossignol
    J. Phys. Conf. Ser. 92, 012028 (2007)

  • Surface waves in highly ordered poly-graphite and gold micro-layers studied by picosecond ultrasonic technique
    N. Chigarecv, T. Dehoux, C. Rossignol, B. Audoin, and V. Levin
    J. Phys. Conf. Ser. 92, 012029 (2007)

  • Thermal diffusivity of a metallic thin layer using the time-domain thermo reflectance technique
    J. L. Battaglia, A. Kusiak, C. Rossignol and N. Chigarev
    J. Phys. Conf. Ser. 92, 012083 (2007)

  • Calculation of the dispersion curves of a functionally graded hollow cylinder
    Y. Zhao, Y. D. Pan, C. Rossignol and B. Audoin
    J. Phys. Conf. Ser. 92, 012106 (2007)

  • Beam distortion detection technique for picosecond ultrasonics
    N. Chigarev, C. Rossignol and B. Audoin
    J. Phys. Conf. Ser. 92, 012178 (2007)

  • Picosecond acoustic measurement of anisotropic properties of thin films
    M. Perton, C. Rossignol, N. Chigarev and B. Audoin
    AIP Conf. Proc. 894, 1148-1158 (2007)

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2006


  • Two-dimensional diffraction of plasma, thermal, and elastic waves generated by an infrared laser pulse in semiconductors
    B. Audoin, H. Meri and C. Rossignol
    Phys. Rev. B. 74, 214304 (2006)

  • Surface displacement measured by beam distortion detection technique: Application to picosecond ultrasonics
    N. Chigarev, C. Rossignol and B. Audoin
    Rev. Sci. Instrum. 77, 114901 (2006)

  • Effect of laser pulse duration in picosecond ultrasonics
    T. Dehoux, M. Perton, N. Chigarev, C. Rossignol, J.-M. Rampnoux, and B. Audoin
    J. Appl. Phys. 100, 064318 (2006)

  • Bulk conical and surface helical acoustic waves in transversely isotropic cylinders; application to the stiffness tensor measurement
    M. Perton, B. Audoin, Y. D. Pan and C. Rossignol
    J. Acoust. Soc. Am. 119, 3752-3759 (2006)

  • Picosecond ultrasonics time resolved spectroscopy using a photonic crystal fiber
    C. Rossignol, J. M. Rampnoux, T. Dehoux, S. Dilhaire, and B. Audoin
    Rev. Sci. Instrum. 77, 033101 (2006)

  • Acoustic waves generated by a laser point pulse in a transversely isotropic cylinder
    Y. D. Pan, M. Perton, B. Audoin, and C. Rossignol
    J. Acoust. Soc. Am. 119, 243-250 (2006)

  • The transient response of a transversely isotropic cylinder under a laser point source impact
    Y. D. Pan, M. Perton, C. Rossignol, and B. Audoin
    Ultrasonics 44, E823-E827 (2006)

  • Acoustic waves generated by a laser line pulse in a hollow cylinder
    Y. D. Pan, L. Li, C. Rossignol, B. Audoin and N. Chigarev
    Ultrasonics 44, E843-E847 (2006)

  • Numerical analysis of bulk conical waves in anisotropic cylinders; application to stiffness tensor measurement
    M. Perton, B. Audoin, Y. D. Pan and C. Rossignol
    Ultrasonics 44, E859-E862 (2006)

  • On the use of laser-ultrasonics technique to excite selectively cylinder acoustic resonances
    B. Audoin, Y. D. Pan, C. Rossignol and N. Chigarev
    Ultrasonics 44, E1195-E1198 (2006)

  • Identification of laser-generated ultrasounds in the response of the cylinder over time and space
    Y. D. Pan, C. Rossignol, B. Audoin an dN. Chigarev
    Ultrasonics 44, E1249-E1253 (2006)

  • Picosecond ultrasonics time resolved spectroscopy using a photonic crystal fiber
    C. Rossignol, J. M. Rampnoux, T. Dehoux, S. Dilhaire, and B. Audoin
    Ultrasonics 44, E1283-E1287 (2006)

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2005


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2004


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2003


  • Acoustic waves generated by a laser line pulse in a transversely isotropic cylinder
    Y. D. Pan, C. Rossignol and B. Audoin
    Appl. Phys. Lett. 82, 4379-4381 (2003)

  • Laser generation of acoustic waves in an anisotropic medium; parametric analysis for application to material characterization
    C. Rossignol, H. Meri and B. Audoin
    Rev. Sci. Instrum. 74, 470 (2003)

  • Application of picosecond ultrasonics to non-destructive analysis in VLSI circuits
    G. Andriamonje, V. Pouget, Y. Ousten, D. Lewis, Y. Danto, J. M. Rampnoux, Y. Ezzahri, S. Dilhaire, S. Grauby, W. Claeys, C. Rossignol and B. Audoin
    Microelectron. Reliab. 43, 1803-1807 (2003)

  • Generation and detection of ultrasonic waves in micrometric and sub-micrometric films using picosecond laser pulses
    C. Rossignol, R. Libgot, B. Audoin, J.-M. Rampnoux and S. Dilhaire
    2003 IEEE Ultrasonics Symposium, 286-293 (2003)

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2002


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2001


  • Ultrasonic measurement of elastic constants of anisotropic materials with laser source and laser receiver focused on the same interface
    F. Reverdy and B. Audoin
    J. Appl. Phys. 90, 4829-4835 (2001)

  • Elastic constants determination of anisotropic materials from phase velocities of acoustic waves generated and detected by lasers
    F. Reverdy and B. Audoin
    J. Acoust. Soc. Am. 109, 1965-1972 (2001)

  • Extension to cuspidal edges of wave surfaces of anisotropic solids: Treatment of near cusp behavior
    O. Poncelet, M. Deschamps, A. G. Every and B. Audoin
    AIP Conf. Proc. 557, 51-58 (2001)

  • Characterization of temperature-induced stiffness changes in a C-PMR15 composite material by means of laser generated and detected ultrasound
    S. Guilbaud and B. Audoin
    Compos. Sci. Technol. 61, 433-438 (2001)

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2000


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1999


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1998


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1997


  • Measurement by LASER-Generated Ultrasound of Four Stiffness Coefficients of an Anisotropic Material at Elevated Temperatures
    B. Audoin and C. Bescond
    J. Nondestr. Eval. 16, 91-100 (1997)

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1996


  • Measurement of stiffness coefficients of anisotropic materials from pointlike generation and detection of acoustic waves
    B. Audoin, C. Bescond and M. Deschamps
    J. Appl. Phys. 80, 3760-3771 (1996)

  • Bulk and surface waves in anisotropic solids generated with pulsed laser beam: Comparison between theory and experiment
    C. Bescond, M. Deschamps and B. Audoin
    Prog. Nat. Sci. 6, S374-S377 (1996)

  • Ultrasonic displacement field generated by a laser pulse line source in a homogeneous semi-infinitive medium
    M. Qian, Y. Pan, C. Bescond, M. Deschamps, and B. Audoin
    Prog. Nat. Sci. 6, S378-S381 (1996)

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