Showing papers by "Gerard Mourou published in 2010"
TL;DR: It is shown that even a single e- e+ pair created by a superstrong laser field in vacuum would cause development of an avalanchelike QED cascade which rapidly depletes the incoming laser pulse.
Abstract: It is shown that even a single e-e+ pair created by a superstrong laser field in vacuum would cause development of an avalanchelike QED cascade which rapidly depletes the incoming laser pulse. This confirms Bohr's old conjecture that the electric field of the critical QED strength ES=m2c3/e could never be created. © 2010 The American Physical Society.
275 citations
TL;DR: The system of integro-differential kinetic equations for electrons, positrons and γ photons is derived and solved numerically and the range of laser pulse intensities of J≥5×10(22) W/cm2 combined with electron beam energies of tens of GeV is discussed.
Abstract: QED effects are known to occur in a strong laser pulse interaction with a counterpropagating electron beam, among these effects being electron-positron pair creation. We discuss the range of laser pulse intensities of J>5×1022W/cm2 combined with electron beam energies of tens of GeV. In this regime multiple pairs may be generated from a single beam electron, some of the newborn particles being capable of further pair production. Radiation backreaction prevents avalanche development and limits pair creation. The system of integro-differential kinetic equations for electrons, positrons and ? photons is derived and solved numerically. © 2010 The American Physical Society.
122 citations
TL;DR: The radiation force experienced by an electron is for the first time derived from theQED principles and its applicability range is extended toward the QED-strong fields.
Abstract: The emission from an electron in the field of a relativistically strong laser pulse is analyzed. At pulse intensities of J2× 1022W/ cm2 the emission from counterpropagating electrons is modified by the effects of quantum electrodynamics (QED), as long as the electron energy is sufficiently high: E1GeV. The radiation force experienced by an electron is for the first time derived from the QED principles and its applicability range is extended toward the QED-strong fields. © 2010 The American Physical Society.
97 citations
TL;DR: In this paper, the results of non-contact measurements of papyrus texts, including images of hidden papyri, were presented and inks for modern papyrus specimens were prepared using the historical binder, Arabic gum, and two common pigments used to write ancient texts, carbon black and red ochre.
Abstract: Terahertz time domain spectroscopic imaging (THz-TDSI) is a non-ionizing, non-contact and non-destructive measurement technique that has been recently utilized to study cultural heritage artifacts. We will present this technique and the results of non-contact measurements of papyrus texts, including images of hidden papyri. Inks for modern papyrus specimens were prepared using the historical binder, Arabic gum, and two common pigments used to write ancient texts, carbon black and red ochre. The samples were scanned in reflection at normal incidence with a pulse with a spectral range between 0.1 and 1.5 THz. Temporal analysis of the signals provides the depths of the layers, and their frequency spectra give information about the inks.
64 citations
53 citations
TL;DR: In this paper, the energy spectrum of hot electrons emitted from the interaction of a relativistically intense laser with an Al plasma is measured at a repetition rate of 0.5 kHz by accumulating ∼103 highly reproducible laser shots.
Abstract: The energy spectrum of hot electrons emitted from the interaction of a relativistically intense laser with an Al plasma is measured at a repetition rate of 0.5 kHz by accumulating ∼103 highly reproducible laser shots. In the 1017–2×1018 W/cm2 range, the temperature of electrons escaping the plasma along the specular direction scales as (Iλ2)0.64±0.05 for p-polarized pulses incident at 45°. This scaling is in good agreement with three-dimensional particle-in-cell simulations and a simple model that estimates the hot-electron temperature by considering the balance between the deposited laser intensity and the energy carried away by those electrons.
33 citations
TL;DR: This is the first demonstration of high-harmonic generation with a very short focal length paraboloid and kilohertz laser system and the harmonics have a low divergence compared to the driving beam and conversion efficiencies comparable to gas harmonics.
Abstract: Harmonics up to the 18th order are generated from solid targets by focusing 2 mJ, 50 fs pulses at 800 nm to a spot size of 1:7 µm (FWHM). To our knowledge, this is the first demonstration of high-harmonic generation with a very short focal length paraboloid (f /1.4) and kilohertz laser system. The harmonics have a low divergence ( 10-7 per harmonic) comparable to gas harmonics. No contrast enhancement techniques are employed, and the system is capable of operating at 500 Hz. © 2010 Optical Society of America.
10 citations
28 Oct 2010
TL;DR: In this paper, the authors used terahertz to analyze different models of Egyptian papyrus and demonstrated the possibility to image multilayer papyrus distant by 500 μm.
Abstract: THz Time Domain Spectroscopy can be use to image optically opaque objects or detect different materials. It is a non-destructive, non-ionizing and non-contact measurement technique. We propose to use terahertz to analyze different models of Egyptian papyrus. By using the ink parameters we demonstrate the possibility to image multilayer papyrus distant by 500 μm.
9 citations
16 May 2010
TL;DR: In this article, an easy-scalable pulse recompression method based on spectral broadening due to self phase modulation in bulk medium is presented, which demonstrates a possibility of compression of high-energy pulses above 1J from 30 to 14 fs.
Abstract: We present easy-scalable pulse recompression method based on spectral broadening due to self phase modulation in bulk medium. Our experiment demonstrates a possibility of compression of high-energy pulses above 1J from 30 to 14 fs.
8 citations
01 Dec 2010
TL;DR: The Extreme Light Infrastructure (ELI) as discussed by the authors is dedicated to the fundamental study of laser-matter interaction in the ultra-relativistic regime and provides the link between high-field science and ultrafast science.
Abstract: The Extreme Light Infrastructure (ELI) [1] will be the first research infrastructure dedicated to the fundamental study of laser-matter interaction in the ultra-relativistic regime. It provides the link between high-field science and ultrafast science. It further offers a few gigantic steps towards connecting optics, high-energy physics, nuclear physics, medicine and nuclear engineering, only to name a few.
TL;DR: Theoretical investigation of second harmonic generation (SHG) of super intense femtosecond radiation demonstrated that temporal Intensity Contrast Ratio (ICR) of output radiation of petawatt level laser complexes can be significantly increased.
Abstract: Theoretical investigation of second harmonic generation (SHG) of super intense femtosecond radiation demonstrated that temporal Intensity Contrast Ratio (ICR) of output radiation of petawatt level laser complexes can be significantly increased. The cubic polarization effects in the process give possibility of additional pulse compression. We present experimental results of SHG of radiation with average intensity 2TW/cm 2 in 0.6mm KDP crystal. Theoretical model of linear regime of plane wave instability in mediums with quadratic and cubic nonlinearity is developed and thoroughly discussed. Analysis of small-scale self-focusing suppression methodic is presented. The influence of surface dust to spatial noises generation in SHG process is pointed out.
03 May 2010
TL;DR: In this paper, the interaction of super-strong laser fields with an electron and with plasma electrons is analyzed and an efficient conversion of incident radiation to γ-ray emission is predicted by numerical simulations for intensities of ∼1022 W/cm2.
Abstract: We analyze the interactions of super‐strong laser fields with an electron and with plasma electrons. An efficient conversion of incident radiation to γ‐ray emission is predicted by numerical simulations for intensities of ∼1022 W/cm2, recently achieved in experiments. At larger intensities the emission from counter‐propagating electrons is modified by the effects of Quantum ElectroDynamics (QED), as long as the electron energy is sufficiently high: e≥1 GeV. The radiation force experienced by an electron is for the first time derived from QED principles and its applicability range is extended towards QED‐strong fields.
01 Aug 2010
TL;DR: In this article, the authors proposed a new scheme for fast ignition of precompressed DT fusion targets by using two laser pulses with intensities exceeding 1022 W/cm2.
Abstract: An analytical model and numerical simulations demonstrate that pulses with intensities exceeding 1022 W/cm2 may penetrate deeply into the plasma and accelerate efficiently ions in the forward direction. We propose a new scheme for fast ignition of precompressed DT fusion targets by using two laser pulses. The first pulse (or a sequence of several pulses) creates a channel with diameter ~ 30μm through the plasma corona up to the fuel density ~ 1 g/cm3. The second pulse with a higher intensity accelerates the deuterium and tritium ions at the head of this channel. The overall ignition energy is ~ 100 kJ.
03 May 2010
TL;DR: The ELI (Extreme Light Infrastructure) project as mentioned in this paper aims to time-resolve the structure of matter from solid to vacuum, based on fundamentally new approaches, with the goal of time-resolution.
Abstract: Based on fundamentally new approaches, ELI’s (Extreme Light Infrastructure) scientific program is ambitious, far‐reaching, compelling, with the goal to time‐resolve the structure of matter from solid to vacuum. We give an overview of the guiding principles underpinning ELI, like the concept of the power‐pulse‐duration conjecture, relativistic laser‐matter interaction and the new ultrarelativistic regime: gateways to the generation of synchronized bursts of high energy particles and radiations in the attosecond and zeptosecond range.
16 May 2010
TL;DR: ELI has been put on the European Roadmap for Research infrastructures by the European Strategy Forum on Research Infrastructure (ESFRI) as mentioned in this paper, and the photonuclear facility will explore nuclei with hard x-ray and gamma-ray photons produced by high intensity interaction with matter.
Abstract: ELI has been put on the European Roadmap for Research infrastructures by the European Strategy Forum on Research Infrastructures (ESFRI). It will be the first Paneuropean Infrastructure utilizing an ultra-intense laser with a peak-power of 200 PW for interaction experiments with electric field strength well above the PV/m (1015 V/m ). With the high focused intensity (above 4 × 1024W/cm2) it will be possible to enter the ultra-relativistic regime when protons are accelerated to nearly the speed of light at a distance in the order of the wavelength of the driving extreme light. Fundamental physics phenomena can be investigated for the first time including nonlinear vacuum interaction and pair generation. ELI intermediate beam lines with peak-powers in the few PW range but higher repetition rates (10 Hz) will enable scientific and societal including medical applications based on laser particle acceleration (proton therapy) and x-ray generation. The photonuclear facility will explore nuclei with hard x-ray and gamma-ray photons produced by high intensity interaction with matter. The Attosecond science laser driver with its high repetition rate (1 kHz) and high average power (>1 kW, 5–10fs) opens the way to ultrafast investigations in different scientific and technological areas with time resolutions in the Attosecond and may by even faster (zeptosecond) time domains using very brilliant VUV-light and x-rays generated by harmonics from gases or solids.
16 May 2010
TL;DR: In this paper, up to the 15th order harmonics are produced from solid targets using 3 mJ, 30 fs pulses focused to a spot size of 17 µm and 3×1018 W/cm2 combined conversion efficiency to the highest harmonics is > 10−5
Abstract: Harmonics up to the 15th order are produced from solid targets using 3 mJ, 30 fs pulses focused to a spot size of 17 µm and 3×1018 W/cm2 Combined conversion efficiency to the highest harmonics is > 10−5