Abstract: A generator of short optical pulses includes: a generator of optical pulses with a wavelength equal to ?/2 and a spectral width less than ?/3; a generator of optical pulses of a duration less than 10 picoseconds at a wavelength ?/3; a device for recombining the pulses from the generators; a parametric amplification device receiving the output of the recombination device as input; a filter extracting, from the output of the amplification device, a band centered about a wavelength ?; a second harmonic generator receiving the output of the filter and generating a band centered over a wavelength ?/2; and a programmable device making it possible to temporally adjust the pulses corresponding to the bands, in order to allow for the generation of a pulse with a wavelength equal to ?/3 and of a duration less than the period of the optical cycle.

Abstract: A system for generating short optical pulses having a very high temporal contrast at a wavelength ?, includes: a generator of optical pulses B1 outputting pulses at a wavelength substantially equal to ?; a generator of optical pulses P, B2 outputting pulses at a wavelength substantially equal to 2*?3; a device R for recombining the pulses from the generators; a parametric amplifier A receiving the output of the recombination device R as an input; a filter F2 extracting, from the output of the parametric amplification device A, a band centered about a wavelength equal to 2*?; a second harmonic generator NL receiving the output of the filter F2, at the input; a filter F3 centered about a wavelength equal to ?, extracting the second harmonic wavelengths of the pulses produced by the second harmonic generator NL.

Abstract: A method and a system for scanning a time delay between a first ultrafast optical pulse of duration shorter than 10 ps and a second ultrafast optical pulse of duration shorter than 10 ps, wherein the second ultrafast pulse is submitted to an acousto-optic Bragg diffraction by an acoustic pulse in the bulk of an acousto-optic material and the delay scanning is produced by time variation of the acoustic pulse in the material.

Abstract: A device for the temporal shaping of the amplitude and phase of ultrashort pulses, includes: —a birefringent waveguide 1 of main axis ? consisting of a nematic liquid crystal 2 located between a photoconductive material 3 and a substrate 4, —two transparent electrodes, one of which 5 is located between the nematic liquid crystal 2 and the substrate 4, and the other 6 such that the photoconductive material 3 is located between the other electrode 6 and the nematic liquid crystal 2, and —projection optics 7 for projecting a programmable optical mask 8 onto the photoconductive material 3.

Abstract: Generator of short optical pulses includes: a generator of optical pulses with a wavelength equal to ?/2 and a spectral width less than ?/3; a generator of optical pulses of a duration less than 10 picoseconds at a wavelength ?/3; a device for recombining the pulses from the generators; a parametric amplification device receiving the output of the recombination device as input; a filter extracting, from the output of the amplification device, a band centred about a wavelength ?; a second harmonic generator receiving the output of the filter and generating a band centred over a wavelength ?/2; a programmable device making it possible to temporally adjust the pulses corresponding to the bands, in order to allow for the generation of a pulse with a wavelength equal to ?/3 and of a duration less than the period of the optical cycle.

Abstract: The invention relates to a device for compensating the temporary scattering applied to the generation of ultra-short light pulses, said device including two identical and parallel optical diffraction gratings RA, RB and two identical prisms PA, PB that are placed inside the above-mentioned optical diffraction gratings RA, RB, given that the above-mentioned optical diffraction gratings RA, RB are volume phase gratings that function, during transmission, on the principle of Bragg diffraction. The outer surfaces FeA, FeB of the above-mentioned prisms PA, PB are parallel to the above-mentioned optical diffraction gratings RA, RB, and the inner surfaces FiA, FiB of the above-mentioned prisms PA, PB are parallel therebetween.

Abstract: A method and a system for scanning a time delay between a first ultrafast optical pulse of duration shorter than 10 ps and a second ultrafast optical pulse of duration shorter than 10 ps, wherein the second ultrafast pulse is submitted to an acousto-optic Bragg diffraction by an acoustic pulse in the bulk of an acousto-optic material and the delay scanning is produced by time variation of the acoustic pulse in the material.

Abstract: A device for compensating time dispersions applied to the generation of ultra-short pulses, includes: two transparent optical diffraction gratings (RA, RB), which are identical and parallel to each other, operating on the principle of the Bragg diffraction, and two identical prisms (PA, PB), placed head to tail, in the space separating the optical diffraction gratings (RA, RB), knowing that the outer faces (FeA, FeB) of the prisms are parallel to each other and form a non-zero angle (?) with the faces of the optical diffraction gratings.

Abstract: The method and device for measuring the spectral phase or combined spectral and spatial phases of ultra short light pulses, consisting of a decomposition of the light pulse to be measured in two identical replicas called signal pulse and primary reference pulse, respectively, of different polarization or direction and the phase characteristics of which are essentially identical to the original pulse, a temporal filtering of the primary reference pulse by a nonlinear interaction generating a secondary reference pulse of average frequency essentially identical and of spectral width greater than the spectral width of the primary reference pulse, and a spectral interferometry measurement by recombination of this secondary reference pulse and the signal pulse with a given temporal offset.

Abstract: A method and a device for acousto-optic filtering with large optic and acoustic interaction length; includes the use of a birefringent acousto-optic crystal whereof the sound wave propagation speed is as low as possible, this acousto-optical crystal including, on one of its faces, a piezoelectric transducer intended to generate a transverse sound wave whereof the energy propagates collinearly to the energy of an incident light wave, all along the path of the incident light wave, in the aforementioned birefringent acousto-optic crystal, knowing that the transverse sound wave and the incident light wave travel a path including multiple reflections on one or the other of the reflective faces of the birefringent acousto-optic crystal perpendicular to the axes of symmetry shared by the acoustic slownesses curve and the curves of the ordinary and extraordinary optical indices of the acousto-optic crystal.

Abstract: The subject matter of the invention is a method of high-resolution acousto-optic programmable filtering in the infrared region of an incident optical wave. To that end it proposes the use of a birefringent acousto-optic crystal whereof the propagation speed of acoustic waves is slow, such as compounds of mercury, which acousto-optic crystal comprises, on one of its faces, a piezoelectric transducer designed to generate a transverse acoustic wave with wave vector whereof the energy propagates according to the same axis but in the opposite direction to the energy of the incident optical wave, knowing that the optical wave resulting from the acousto-optic interaction between the incident optical wave and the acoustic wave with wave vector is diffracted perpendicularly or almost perpendicularly to the direction of the incident optical wave.

Abstract: Device for adaptation of a programmable generator of ultra short wide spectral band light pulses, to long narrow spectral band light pulses comprising a laser source (1) of ultra-short wide spectral band pulses, a device (2) for dispersion of ultra-short pulses output from said laser source (1), a first non-linear optical mixer (4) to mix long modulated pulses output from said dispersion device (2) with long quasi-monochromatic signals output from a pure frequency pump laser (3), a generator (5) of wide spectral band light pulses placed on a first channel (V1), a second non-linear optical mixer (6) to mix the channel output from said generator (5) and a second channel (V2) emerging from said first non-linear optical mixer (4).

Abstract: The method and device for measuring the spectral phase or combined spectral and spatial phases of ultra short light pulses, consisting of performing: a decomposition of the light pulse to be measured in two identical replies called signal pulse and primary reference pulse, respectively, of different polarization or direction and the phase characteristics of which are essentially identical to the original pulse, a temporal filtering of the primary reference pulse by a nonlinear interaction generating a secondary reference pulse of average frequency essentially identical and of spectral width greater than the spectral width of the primary reference pulse, a spectral interferometry measurement by recombination of this secondary reference pulse and the signal pulse with a given temporal offset.

Abstract: The subject matter of the invention is a method of high-resolution acousto-optic programmable filtering in the infrared region of an incident optical wave. To that end it proposes the use of a birefringent acousto-optic crystal whereof the propagation speed of acoustic waves is slow, such as compounds of mercury, which acousto-optic crystal comprises, on one of its faces, a piezoelectric transducer designed to generate a transverse acoustic wave with wave vector whereof the energy propagates according to the same axis but in the opposite direction to the energy of the incident optical wave, knowing that the optical wave resulting from the acousto-optic interaction between the incident optical wave and the acoustic wave with wave vector is diffracted perpendicularly or almost perpendicularly to the direction of the incident optical wave.

Abstract: The invention relates to a method and device for controlling the amplitude of the wavelength spectrum of ultra-short light pulses emitted by multipass laser amplifiers. According to the invention, a programmable acousto-optic device (8) is introduced into a laser cavity of a multipass amplifier (10), in order to modify slightly the amplitude of the spectrum of the light pulse with each passage, owing to a collinear or quasi-collinear interaction between the light pulse and a sound beam, the result from the filtering being used on the non-diffracted direct light beam from the acousto-optic interaction.

Abstract: Device for dispersion of light pulses of an optical beam constituted by two dispersive prisms with the same vertex angle, mounted head to tail, the optical input surface of the first prism being parallel to the optical output surface of the second prism, the distance separating the optical input surface of the first prism and the optical output surface of the second prism being adjustable, given that the material constituting at least one of the first and second prisms is an acousto-optic material allowing for acousto-optic interaction between the optical beam and an acoustic beam, the acoustic wave of the acoustic beam generating, in at least one of the first and second prisms, an integrated deflective Bragg cell.

Abstract: A method for measuring ultrashort light pulse which comprises a first step of linear optical filtering of the signal for which it is desired to measure the amplitude of the pulses by means of an acoustic interaction between the optical signal and a colinear or quasi-colinear acoustic beam, a second step of either mixing in a non-linear response electro-optical element of optical beams diffracted by the acoustic beam, followed by one detector for detecting the light intensity derived from the mixer, or effecting one integration detection of the square of the optical intensity diffracted by the acoustic beam.

Abstract: Device for dispersion of light pulses of an optical beam (Fi) constituted by two dispersive prisms (P1, P2), with the same vertex angle (?), mounted head to tail, the optical input surface of the first prism (P1) being parallel to the optical output surface of the second prism (P2), the distance (L) separating said optical input surface of the first prism (P1) and said optical output surface of the second prism (P2) being adjustable, given that the material constituting at least one of said first and second prisms (P1, P2) is an acousto-optic material allowing for acousto-optic interaction between said optical beam and an acoustic beam, the acoustic wave of said acoustic beam generating, in at least one of said first and second prisms (P1, P2), an integrated deflective Bragg cell.

Abstract: The invention relates to a method and device for controlling the amplitude of the wavelength spectrum of ultra-short light pulses emitted by multipass laser amplifiers. According to the invention, a programmable acousto-optic device (8) is introduced into a laser cavity of a multipass amplifier (10), in order to modify slightly the amplitude of the spectrum of the light pulse with each passage, owing to a collinear or quasi-collinear interaction between the light pulse and a sound beam, the result from the filtering being used on the non-diffracted direct light beam from the acousto-optic interaction.

Abstract: A sweep generator circuit generates a primary pulsed voltage and a secondary voltage which are applied to the deflection plates of a streak camera. A primary pulsed voltage generator includes at least one light operated switch for producing deflection of an electron beam in one direction. A secondary voltage generator means generates the secondary voltage which causes deflection of the electron beam in an opposite direction. Variations in the incident light intensity create substantially identical fluctuations in the deflection of the electron beam produced by the primary pulsed voltage and the secondary voltage. Additionally, any variations with respect to time in the deflection of the electron beam produced by the secondary voltage are small in comparison with variations in the deflection of the electron beam produced by the primary pulsed voltage. The sweep generator circuit has an operating point that is stable with respect to variations in the light intensity.