Centre National De La Recherche Scientifique

Université De Limoges

Compagnie Industrielle Des Lasers Cilas

Astrium Sas

Mauna Kea Technologies

Compagnie Industrielle Des Laser Cilas

Airbus Safran Launchers Sas

Jean-marc Blondy

Vincent Tombelaine

Alain Barthelemy

Jean-louis Auguste

Sebastien Fevrier

Pierre-alain Champert

Philippe Leproux

Vincent Couderc

Vincent Kermene

Agnès Desfarges-Berthelemot

Frédéric Louradour

Jean-Eucher Montagne

Dominique Pagnoux

David Sabourdy

Bruno Esmiller

Bertrand Vergne

Brigitte Serreault

Joël Benoist

Claude Froehly

Paul Armand

Francois Lacombe

Bertrand Viellerobe

Jean-Marc Blondy

Sébastien Fevrier

Jérôme Desroches

Julien Brevier

Julien Guillot

Jean-Louis Auguste

Alexandre Loiseau

Patrick Brunel

Pierre-Alain Champert

Paul-Henri Pioger

Sandrine Auroux

Dominique Gontier

Serge Maneuf

Jérémy Saucourt

Bernard Colombeau

Michel Vampouille

Eric Suran

Agnès Desfarges-Berthellemot

Tigran Mansuryan

David Kabeya

Mickael Lelek

Julien Leval

Guillaume Huss

Philippe Paul Leproux

Michaël Lelek

A method and system for adjusting the profile of a laser wavefront formed by at least a laser beam to a desired laser wavefront profile, the laser beam or beams presenting random phases and intensities, comprises a mixing module, configured to generate, from interference phenomena among the laser beam or beams, a laser field, a second intensity measuring module configured to measure the mixed intensities of the laser field portions, a calculation unit configured to calculate one or several phase correction values of the phase of the laser beam or the phases of laser beams, from the intensities of the laser beams, the mixed intensities and one or several predetermined target phases, and a phase adjustment module configured to apply the phase correction value or values obtained from the calculation unit to the laser beam phases.

Method and system for adjusting the profile of a laser wavefront

The invention relates to a device for forming laser pulses comprising: an input for a pulsed laser beam; a spatial phase modulator (), arranged on the trajectory of said pulsed laser beam so as to be illuminated thereby; a control means designed to configure said spatial phase modulator so as to emulate a diffraction grating (') having a diffraction efficiency that varies along one spatial direction (s) identified by the intersection of the modulator surface with the diffraction plane (xz); and spatial filtering means () for a light beam diffracted by said grating; whereby a laser pulse (P) at the device input is converted to a train of elementary output pulses (PS) having temporal intensity and/or phase and/or polarization modulation. The invention further relates to a laser pulse forming process based on the use of such a device.

Device and process for forming laser pulses

According to the invention, a plurality of elementary laser beams (f) are generated, the phases of which are adjusted by an electro-optical feedback loop () implementing the matrix equation of a phase-contrast filtering device ().

Method and system for generating a high laser power

Method and laser oscillator for the generation of a laser beam&#x2014;According to the invention with a view to adjusting, inside said laser oscillator (), the phase of each of the N elementary laser beams (FLE., FLE., FLE.N) generated on the basis of said laser oscillator () in such a way that said elementary laser beams are in phase, the deviation between the phase of an individual elementary laser beam (FLE.) and the phases of the N&#x2212;1 other elementary laser beams (FLE., FLE.N) is converted into a level of luminous intensity by means of at least one optical filtering element to which at least a part of each elementary laser beam is directed.

Method and laser oscillator for the generation of a laser beam

The invention relates to a laser cavity with central extraction by polarisation for coherent coupling of intense intra-cavity beams. The laser cavity () according to the invention comprises an extraction unit () with central extraction, which divides the laser cavity () longitudinally into two functional portions (P, P), namely a first portion (P) including the active components (), which amplifies the laser beams (), and a second portion (P) which performs coherent coupling of the laser beams ().

Laser cavity with central extraction by polarisation for coherent coupling of intense intra-cavity beams

According to the invention, the optical signal (SE) is spatially divided into N elementary optical signals (SE., SE., . . . , SE.N), the spectral ranges thereof being adjacent in pairs and forming, substantially by juxtaposition, the spectral range of the optical signal; these N elementary signals are amplified respectively by means of N elementary amplifiers (.N), the spectral ranges thereof respectively comprising the spectral ranges of said N elementary signals; the N amplified elementary signals (Ss., Ss., . . . , Ss.N) are assembled to form an amplified optical signal (Ss), the spectral range thereof substantially coinciding with a predetermined spectral range, and finally the spectral phases of the N initial elementary signals (Ss., Ss., . . . , Ss.N) are adjusted before amplification on the basis of the spectral phase of said amplified signal (Ss).

Method and device for amplifying an optical signal

The invention relates to a method and to a device for determining at least one piece of polarization information on a measurement point of a target sample, the device comprising:&#x2014;a light source capable of emitting a rectilinearly polarized light beam, the light beam being intended to be reflected by the measurement point;&#x2014;a means for computing polarization information on the measurement point using the beam reflected by the target sample;&#x2014;at least one waveguide for guiding the incident beam towards the target sample and the reflected beam towards the computing means; and&#x2014;a means for rotating the polarization, capable of rotating two orthogonal polarimetric components of the incident beam after passing through the waveguide and two orthogonal polarimetric components of the reflected beam before passing through the waveguide.

Device and method for determining a piece of polarization information and polarimetric imaging device

The invention relates to a method and to a device for determining a piece of polarisation information on a measurement point of a target sample, the device comprising: &#x2014;a light source capable of emitting a rectilinearly polarised light beam in a predefined direction, the light beam being intended to be reflected by the measurement point of the target sample; &#x2014;a unit for computing the piece of polarisation information on the measurement point using the beam reflected by the target sample; -a waveguide for guiding the incident beam towards the target sample and the reflected beam towards the computing means; and &#x2014;a unit for rotating the polarisation, capable of rotating two orthogonal polarimetric components of the incident beam exiting the waveguide and two orthogonal polarimetric components of the reflected beam before passing through the waveguide.

Device and method for determining a piece of polarisation information and polarimetric imaging device

A system for carrying out fibered multiphoton microscopic imagery of a sample () for use in endoscopy or fluorescence microscopy includes: a femtosecond pulsed laser () for generating a multiphoton excitation laser radiation; an image guide () having a number of optical fibers and permitting the sample to be illuminated by a point-by-point scanning in a subsurface plane; pre-compensating elements () for pre-compensating for dispersion effects of the excitation pulses in the image guide (), these elements being situated between the pulsed laser and the image guide (); scanning elements for directing, in succession, the excitation laser beam in a fiber of the image guide, and; in particular, an optical head () for focussing the excitation laser beam exiting the image guide in the sample ().

System and method for carrying out fibre-type multiphoton microscopic imaging of a sample

The invention relates to a device () for generating short pulses, said device being characterized in that it comprises: a polarized pulse laser () having a polarization direction; a bi-refringent optical fiber () having bi-refringence axes, wherein said polarization direction is not co-linear with said bi-refringence axes; an output polarizer () provided at the output of said fiber, said polarizer being capable of selecting a polarization at the output of said fiber; wherein said pulse laser in a longitudinally quasi-single mode laser.

Laser system with picosecond pulse emission

A high power electric pulse generator includes a charge storage device, a high voltage source for charging the charge storage device, a first photoconductor element connected to the reference potential and to the storage device, a second photoconductor element connected to the storage device and to a useful load, a first light source for delivering a pulse of light to the first photoconductor, a second light source for delivering a pulse of light to the second photoconductor and a synchronization device for synchronizing the emission delay between the first light source and the second light source. The first photoconductor and the second photoconductor are passive semiconductor elements with a linear regime forming photosensitive switches, with the first and second photoconductors being doped silicon photoconductors.

High-power electric pulse generator

Laser generator with phase mode-locking

The optical phase modulator device comprises a source of short laser pulses, a material having self-induced variation in refraction index, and an interferometer device interposed between the source of short laser pulses and the material having self-induced variation of refractive index in order to form four fragmented waves for which the average value of the correlation product is zero. The device enables stable optical phase shifts of more than 2.pi. radians to be obtained in beams having a regular geometrical structure, and it is also applicable to high power laser amplification.

Method and device for stable and controllable optical phase modulation

Growing community of inventors

Limoges, France

Alain Barthelemy