Abstract: 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.

Abstract: 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.

Abstract: The invention relates to a device for forming laser pulses comprising: an input for a pulsed laser beam; a spatial phase modulator (300), 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 (3, 3?) 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 (5) for a light beam diffracted by said grating; whereby a laser pulse (P1) 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.

Abstract: According to the invention, a plurality of elementary laser beams (fi) are generated, the phases of which are adjusted by an electro-optical feedback loop (6, 7i, 8i, 9) implementing the matrix equation of a phase-contrast filtering device (6).

Abstract: According to the invention, a plurality of elementary laser beams (fi) are generated, the phases of which are adjusted by an electro-optical feedback loop (6, 7i, 8i, 9) implementing the matrix equation of a phase-contrast filtering device (6).

Abstract: Method and laser oscillator for the generation of a laser beam—According to the invention with a view to adjusting, inside said laser oscillator (1), the phase of each of the N elementary laser beams (FLE.1, FLE.2, FLE.N) generated on the basis of said laser oscillator (1) in such a way that said elementary laser beams are in phase, the deviation between the phase of an individual elementary laser beam (FLE.1) and the phases of the N?1 other elementary laser beams (FLE.2, 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.

Abstract: The invention relates to a laser cavity with central extraction by polarisation for coherent coupling of intense intra-cavity beams. The laser cavity (1) according to the invention comprises an extraction unit (7) with central extraction, which divides the laser cavity (1) longitudinally into two functional portions (P1, P2), namely a first portion (P1) including the active components (3), which amplifies the laser beams (4), and a second portion (P2) which performs coherent coupling of the laser beams (4).

Abstract: According to the invention, the optical signal (SE) is spatially divided into N elementary optical signals (SE.1, SE.2, . . . , 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 (4.1, 4.2, . . . , 4.N), the spectral ranges thereof respectively comprising the spectral ranges of said N elementary signals; the N amplified elementary signals (Ss.1, Ss.2, . . . , 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.1, Ss.2, . . . , Ss.N) are adjusted before amplification on the basis of the spectral phase of said amplified signal (Ss).

Abstract: 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:—a light source capable of emitting a rectilinearly polarized light beam, the light beam being intended to be reflected by the measurement point;—a means for computing polarization information on the measurement point using the beam reflected by the target sample;—at least one waveguide for guiding the incident beam towards the target sample and the reflected beam towards the computing means; and—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.

Abstract: 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: —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; —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 —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.

Abstract: Method and laser oscillator for the generation of a laser beam—According to the invention with a view to adjusting, inside said laser oscillator (1), the phase of each of the N elementary laser beams (FLE.1, FLE.2, FLE.N) generated on the basis of said laser oscillator (1) in such a way that said elementary laser beams are in phase, the deviation between the phase of an individual elementary laser beam (FLE.1) and the phases of the N?1 other elementary laser beams (FLE.2, 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.

Abstract: According to the invention, the optical signal (SE) is spatially divided into N elementary optical signals (SE.1, SE.2, . . . , 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 (4.1, 4.2, . . . , 4.N), the spectral ranges thereof respectively comprising the spectral ranges of said N elementary signals; the N amplified elementary signals (Ss.1, Ss.2, . . . , 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.1, Ss.2, . . . , Ss.N) are adjusted before amplification on the basis of the spectral phase of said amplified signal (Ss).

Abstract: The invention relates to a laser cavity with central extraction by polarisation for coherent coupling of intense intra-cavity beams. The laser cavity (1) according to the invention comprises an extraction unit (7) with central extraction, which divides the laser cavity (1) longitudinally into two functional portions (P1, P2), namely a first portion (P1) including the active components (3), which amplifies the laser beams (4), and a second portion (P2) which performs coherent coupling of the laser beams (4).

Abstract: The invention relates to a device for forming laser pulses comprising: an input for a pulsed laser beam; a spatial phase modulator (300), 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 (3, 3?) 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 (5) for a light beam diffracted by said grating; whereby a laser pulse (P1) 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.

Abstract: A system for carrying out fibered multiphoton microscopic imagery of a sample (10) for use in endoscopy or fluorescence microscopy includes: a femtosecond pulsed laser (1, 2) for generating a multiphoton excitation laser radiation; an image guide (8) 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 (4) for pre-compensating for dispersion effects of the excitation pulses in the image guide (8), these elements being situated between the pulsed laser and the image guide (8); scanning elements for directing, in succession, the excitation laser beam in a fiber of the image guide, and; in particular, an optical head (9) for focussing the excitation laser beam exiting the image guide in the sample (10).

Abstract: The invention relates to a device (1) for generating short pulses, said device being characterized in that it comprises: a polarized pulse laser (10, 2, 3) having a polarization direction; a bi-refringent optical fiber (6) having bi-refringence axes, wherein said polarization direction is not co-linear with said bi-refringence axes; an output polarizer (9) 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.

Abstract: The invention relates to a method and to a device for determining at least one piece of polarisation information on a measurement point of a target sample, the device comprising: —a light source capable of emitting a rectilinearly polarised light beam, the light beam being intended to be reflected by the measurement point; —a means for computing polarisation information on the measurement point using the beam reflected by the target sample; —at least one waveguide for guiding the incident beam towards the target sample and the reflected beam towards the computing means; and—a means for rotating the polarisation, 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.

Abstract: 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: -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; -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 -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.

Abstract: The disclosure relates to an optical waveguide serving to propagate an original light signal, the optical waveguide including a non-linear waveguide first core that is suitable for generating leaky modes from the original light signal, the waveguide including at least a second core, the first core being included in the second core, the second core being arranged relative to the first core in such a manner as to confine at least the leaky modes generated by the first core from the original light signal outside the first core. By the above-described waveguide, in particular by the non-linearities of the first core of the waveguide, a light continuum can be generated inside the fiber by collinear phase matching. In addition, by Cerenkov effect, other wavelengths are generated by the wavelengths of the continuum by non-collinear phase matching.

Abstract: A device for producing a polychromatic light including an optical pump that delivers a first radiation at a first wavelength; a light guide; and a selective injector that injects the radiation into the guide, the guide being arranged to generate a harmonic corresponding to the selected injector and provide a polychromatic light at an outlet, by non-linear excitation of the first radiation and the harmonic.