Centre National De La Recherche Scientifique

Ecole Superieure De Physique Et De Chimie Industrielles De La Ville De Paris

Université Paris 7—Denis Diderot

Societe Nationale Des Chemins De Fer Francais

Fotia

Claude Boccara

Mathias Fink

Alexandre Aubry

William Lambert

Victor Barolle

Amaury Badon

Laura Cobus

Arnaud Dubois

Jean-Fran&ccedil;ois Le Gargasson

Pierre Lena

Thierry Guenard

Annick Boccara Née Houssin

Patrice Thouvenot

The present invention relates to a method for the non-invasive optical characterization of a heterogeneous medium, comprising: a step of illuminating, by means of a series of incident light waves, a given field of view of the heterogeneous medium, positioned in a focal plane of a microscope objective (); a step of determining a first distortion matrix (D, D) in an observation basis defined between a conjugate plane of the focal plane (FP) and an observation plane, said first distortion matrix corresponding, in a correction basis defined between a conjugate plane of the focal plane and an aberration correction plane, to the term-by-term matrix product of a first reflection matrix (R) of the field of view, determined in the correction basis, with the phase conjugate matrix of a reference reflection matrix, defined for a model medium, in said correction basis; and a step of determining, from the first distortion matrix, at least one mapping of a physical parameter of the heterogeneous medium.

Method and systems for the non-invasive optical characterization of a heterogeneous medium

In a first aspect, the present description relates to a system for non-invasively characterizing a heterogeneous medium using ultrasound, comprising at least one first array () of transducers configured to generate a series of incident ultrasound waves in a region of said heterogeneous medium and record the ultrasound waves which are backscattered by said region as a function of time, as well as a computing unit () which is coupled to said at least one first array of transducers and configured to: record an experimental reflection matrix defined between an emission basis at the input and the basis of the transducers at the output; determine, from said experimental reflection matrix, at least one first wideband reflection matrix defined in a focused base at the input and output; determine a first distortion matrix defined between said focused basis and an observation basis, said first distortion matrix resulting, directly or after a change of basis, from the term-by-term matrix product of said first wideband reflection matrix defined between said focused basis and an aberration correction basis, with the phase-conjugated matrix of a reference reflection matrix defined for a model medium, between the same bases; determine, from said first distortion matrix, at least one mapping of a physical parameter of said heterogeneous medium.

Methods and systems for non-invasively characterizing a heterogeneous medium using ultrasound

A method and a device for interferential microscopic imaging of an object which comprises sending a light beam in each of the arms of a two-wave interferometer, one of the arms comprising the object to be analyzed. The phase is subjected to a sinusoidal modulation to a frequency f. The signal modulation results from mechanical oscillation of an assembly of elements of the interferometer. The interference signal (S) is integrated during the phase variation via a multichannel sensor. A computer enables to record the integrated interference signal obtained during each period fraction 1/n and to calculate, subsequently, the image of the object. The invention is potentially useful for characterizing thin layers, for controlling components in microelectronics, for reading data stored in volume (3D) and objects unstable in time; in biology and in vivo studies.

Method and device for high-speed interferential microscopic imaging of an object

The invention concerns a device for observing a body, in particular a viewer, comprising means for illuminating ( ) the body ( ), means for sampling ( ) light coming from an illuminated site ( ) of the body and compensating means ( ) for measuring a deformation of the wave front of a beam coming from a point of the body ( ) and for applying to the light sampled by the sampling means ( ) a correction calculated on the basis of said measured deformation. The invention is characterised in that the sampling means and the compensating means are arranged such that, for each point of the body used for calculating the correction, the sampling means sample the light on a selected zone of the body near enough to said calculation point for the deformation of the wave front of the light coming from any point of that zone should be the same as that coming from the point of calculation more or less within a wavelength fraction, and the device includes means ( ) for automatically changing the point of the body ( ) used for the calculation of correction and for changing synchronously the associated sampling zone, such that the device scans the observed body by way of a series of such successive zones for each of which the deformation of the wave front derived from any point in the zone is identical, more or less within a wavelength fraction, to the deformation of the wave front derived from the associated point of calculation.

High resolution device for observing a body

Growing community of inventors

Paris, France

Claude Boccara