Abstract: The process and device for diagnosing the quality of compression of an ultrashort pulse, consist of performing an approximation of the Strehl ratio by: —a first step allowing the measurement of spatio-spectral images of the ultrashort light pulse brief initial (Ii) using one or more parallel imaging spectrometers; —a second step allowing an interaction of said pulse with a nonlinear optical material (DMNL), the aforementioned interaction generating, by a nonlinear optical mechanism of an n order, a secondary pulse (Is) of intensity proportional to the temporal intensity aforementioned ultrashort light pulse (Ii) raised to the power of n; —a third step allowing the measurement of the spatio-spectral image or images of the secondary pulse (Is); —the processing of the images thus obtained will be translated into an expression of the ratio of the maximum intensity obtained by that which could be obtained for the pulse without phase distortion.

Abstract: A pulsed generator of electrically charged particles includes a vacuum chamber; wherein the vacuum chamber is configured to maintain an internal operating pressure between 10-6 mbar and atmospheric pressure; the vacuum chamber is configured to accommodate a photocathode and an anode, the photocathode and the anode being separated by an adjustable distance less than or equal to 30 mm; the vacuum chamber includes a window enabling pulsed light to reach firstly a rear face of the photocathode; the anode is arranged downstream of the photocathode and has an orifice suitable for the passage of electrically charged particles; the generator of electrically charged particles includes a system to apply a difference in potential between the photocathode and the anode, the voltage being configured to accelerate the charged particles.

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: 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 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 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: 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: The invention concerns a device comprising a birefringent elasto-optic medium (1) equipped with a transducer (5) generating in the medium (1) a modulated acoustic wave along a specific direction, and means for coupling in the medium (1) an input optical wave with unknown polarisation, and a programming circuit for (amplitude-phase-frequency) modulation of the acoustic wave. Said device supplies a direct wave and two perpendicular diffracted waves of H, V polarisation each bearing a modulation based on the input optical wave modulation and the acoustic wave modulation.

Abstract: The e method of the invention consists of carrying out: