Abstract: A method and a system, the system, comprising a laser source, a ionization and acceleration unit, a separation unit, and a collecting unit, wherein the laser source comprises a large bandwidth laser delivering successive pulses of fixed central wavelength and bandwidth to a surface of a target positioned inside the ionization and acceleration unit, surface atoms of the target being ionized by the pulses, accelerated from the surface of the target to a kinetic energy in the range between 100 eV and 10 KeV, and focused to the separation unit, the separation unit separating received atoms into different ions species, and the collecting unit separately collecting the different ion species.

Abstract: A system for laser-driven propulsion, system comprising a laser source and a target comprising an accelerating part and a projectile part, the accelerating part comprising a metal layer and a porous layer pressed against the metal layer; wherein the laser source is selected to emit pulse beams directed to the metal layer at a fluence below the plasma ablation threshold of the material of the metal layer.

Abstract: A method and a system for measurement of high laser field intensity, the method comprising tight focusing a non-Gaussian azimuthally polarized laser mode beam to a focusing spot, measuring a spectral line shape of a selected ionization state induced by a longitudinal oscillating magnetic field created by the tight focusing in the focusing spot; and determining the laser intensity from the spectral line shape.

Abstract: A X-ray source, comprising a laser, of a pulse duration of at most 40 fs, instantaneous power of at least about 80 TW, a pulse repetition rate of at least 1 Hz; an optical compressor spectrally shaping the laser beam; focusing optics in the range between f#10 and f#15; and a gas target of electron density after ionization by the laser beam in a range between 1018 cm3 and 1019 cm?3; wherein the focusing optics focuses the laser beam in the gas target, and interaction of the focused laser beam with the gas target generates an X-ray beam, with a focused laser amplitude a0, given by a0=0.855 [IL (1018W/cm2)?L,2 (?m)]1/2, where IL is the on-target laser intensity and ?L is the laser wavelength, of at least 2 and a P/Pc ratio value of at least 20, with P being the beam power and Pc a critical power given by Pc=17 (nc/n) GW where n is the electron density and nc is a critical electron density at which the plasma acts as a mirror reflecting the laser beam.

Abstract: A system for laser-driven propulsion, system comprising a laser source and a target comprising an accelerating part and a projectile part, the accelerating part comprising a metal layer and a porous layer pressed against the metal layer; wherein the laser source is selected to emit pulse beams directed to the metal layer at a fluence below the plasma ablation threshold of the material of the metal layer.

Abstract: A X-ray source, comprising a laser, of a pulse duration of at most 40 fs, instantaneous power of at least about 80TW, a pulse repetition rate of at least 1 Hz; an optical compressor spectrally shaping the laser beam; focusing optics in the range between f#10 and f#15; and a gas target of electron density after ionization by the laser beam in a range between 1018 cm3 and 1019 cm?3; wherein the focusing optics focuses the laser beam in the gas target, and interaction of the focused laser beam with the gas target generates an X-ray beam, with a focused laser amplitude a0, given by a0=0.855 [IL (1018W/cm2)?L,2 (?m)]1/2, where IL is the on-target laser intensity and ?L is the laser wavelength, of at least 2 and a P/Pc ratio value of at least 20, with P being the beam power and Pc a critical power given by Pc=17 (nc/n) GW where n is the electron density and nc is a critical electron density at which the plasma acts as a mirror reflecting the laser beam.

Abstract: A system and a method for laser-driven propulsion, comprising transferring momentum to a projectile through a low-density material at laser fluences below plasma ablation threshold, the method comprising providing a metal layer having a first surface and a second opposite surface; providing a low density layer having a first surface and a second opposite surface; positioning the low density layer with the first surface thereof in direct contact with the second surface of the metal layer; positioning a projectile on the second surface of the low density layer; and heating the metal layer with laser pulses to temperatures below the liquefaction and ionization thresholds of the metal.

Abstract: A method and a system, the system, comprising a laser source, a ionization and acceleration unit, a separation unit, and a collecting unit, wherein the laser source comprises a large bandwidth laser delivering successive pulses of fixed central wavelength and bandwidth to a surface of a target positioned inside the ionization and acceleration unit, surface atoms of the target being ionized by the pulses, accelerated from the surface of the target to a kinetic energy in the range between 100 eV and 10 KeV, and focused to the separation unit, the separation unit separating received atoms into different ions species, and the collecting unit separately collecting the different ion species.

Abstract: A method and a system for measurement of high laser field intensity, the method comprising tight focusing a non-Gaussian azimuthally polarized laser mode beam to a focusing spot, measuring a spectral line shape of a selected ionization state induced by a longitudinal oscillating magnetic field created by the tight focusing in the focusing spot; and determining the laser intensity from the spectral line shape.

Abstract: A method and a system for laser pulse wavefront correction and focusing optimization for laser Wakefield interaction to accelerate electrons to high energy, and more generally for laser matter interaction where both far field and intermediate field optimization are important, allowing a robust wavefront correction and focusing optimization with a high-power laser system at its nominal laser pulse energy and laser pulse duration. The method comprises, after laser beam focusing by focusing optics, coupling an imaging unit to a wavefront sensor, thereby measuring the laser beam wavefront, and adjusting the measured laser beam wavefront to converge to a reference wavefront of the imaging unit using a spatial phase-modifying device.

Abstract: A system and a method for laser-driven propulsion, comprising transferring momentum to a projectile through a low-density material at laser fluences below plasma ablation threshold, the method comprising providing a metal layer having a first surface and a second opposite surface; providing a low density layer having a first surface and a second opposite surface; positioning the low density layer with the first surface thereof in direct contact with the second surface of the metal layer; positioning a projectile on the second surface of the low density layer; and heating the metal layer with laser pulses to temperatures below the liquefaction and ionization thresholds of the metal.

Abstract: In a general aspect, a chirped optical pulse is compressed by operation of diffraction gratings and a dispersive mirror having a smooth reflective surface. In some aspects, a chirped pulse laser system includes a programmable optical dispersive filter (PODF) operable to modify a spectral phase of optical pulses and a pulse compressor that receives an optical pulse based on an output of the PODF. The pulse compressor includes optical elements in a vacuum chamber. The optical elements define an optical path through the pulse compressor, and are arranged to disperse the optical pulse in the optical path. The optical elements include diffraction gratings and a dispersive mirror, which has a smooth reflective surface that defines a portion of the optical path.

Abstract: A method and a system for laser pulse wavefront correction and focusing optimization for laser Wakefield interaction to accelerate electrons to high energy, and more generally for laser matter interaction where both far field and intermediate field optimization are important, allowing a robust wavefront correction and focusing optimization with a high-power laser system at its nominal laser pulse energy and laser pulse duration. The method comprises, after laser beam focusing by focusing optics, coupling an imaging unit to a wavefront sensor, thereby measuring the laser beam wavefront, and adjusting the measured laser beam wavefront to converge to a reference wavefront of the imaging unit using a spatial phase-modifying device.

Abstract: In a general aspect, a chirped optical pulse is compressed by operation of diffraction gratings and a dispersive mirror having a smooth reflective surface. In some aspects, a chirped pulse laser system includes a programmable optical dispersive filter (PODF) operable to modify a spectral phase of optical pulses and a pulse compressor that receives an optical pulse based on an output of the PODF. The pulse compressor includes optical elements in a vacuum chamber. The optical elements define an optical path through the pulse compressor, and are arranged to disperse the optical pulse in the optical path. The optical elements include diffraction gratings and a dispersive mirror, which has a smooth reflective surface that defines a portion of the optical path.

Abstract: A system comprising a laser emitting an ultrashort pulse beam; and a dielectric bulk medium having a refractive index depending on intensity, the bulk medium broadening the laser beam homogeneously versus transversal spatial coordinates, and a method for compressing high energy femtosecond laser pulses, comprising propagating the laser beam inside a dielectric bulk medium having a refractive index depending on the beam intensity, the bulk medium broadening the laser beam homogeneously versus transversal spatial coordinates; and compressing a resulting broadened spectrum.

Abstract: A method comprising using a pulse shaper in the spectral domain to generate multiple-color pulses directly at the output of the laser amplifier. The delay can thus be controlled directly in the spectral domain and there is no need for an optical delay line. The method allows reducing the number of optical components and insures insensitivity to alignment, vibrations and turbulence on long distance propagation and filamentation, particularly in air. The method allows programmable and tunable interaction, since the pulse shaper is able to control the laser spectral amplitude and phase.

Abstract: A system comprising a laser emitting an ultrashort pulse beam; and a dielectric bulk medium having a refractive index depending on intensity, the bulk medium broadening the laser beam homogeneously versus transversal spatial coordinates, and a method for compressing high energy femtosecond laser pulses, comprising propagating the laser beam inside a dielectric bulk medium having a refractive index depending on the beam intensity, the bulk medium broadening the laser beam homogeneously versus transversal spatial coordinates; and compressing a resulting broadened spectrum.

Abstract: A method for generating an ultrashort charged particle beam, comprising creating a high intensity longitudinal E-field by shaping and tightly focusing, in an on-axis geometry, a substantially radially polarized laser beam, and using the high intensity longitudinal E-field for interaction with a medium to accelerate charged particles.

Abstract: A method comprising using a pulse shaper in the spectral domain to generate multiple-color pulses directly at the output of the laser amplifier. The delay can thus be controlled directly in the spectral domain and there is no need for an optical delay line. The method allows reducing the number of optical components and insures insensitivity to alignment, vibrations and turbulence on long distance propagation and filamentation, particularly in air. The method allows programmable and tunable interaction, since the pulse shaper is able to control the laser spectral amplitude and phase.

Abstract: The present invention concerns x-ray sources for mammography. A microfocused x-ray source of small size (30 ?m and smaller) with x-ray spectrum optimized for enhanced mammography is obtained with a method and system according to the invention. The proposed x-ray source is based on the use of plasmas created by the energy distribution of suprathermal electrons that are produced during the interaction of the laser beam with a solid target. These hot electrons penetrate the surface layer of cold plasma and interact with the solid core of the target. The method and system according to the present invention allows optimizing the x-ray source size, its spectral distribution, and the conversion efficiency in the 17.3-28.5 keV range (adapted to the breast thickness).