Gerard Mourou

Bio: Gerard Mourou is an academic researcher from École Polytechnique. The author has contributed to research in topics: Laser & Ultrashort pulse. The author has an hindex of 82, co-authored 653 publications receiving 34147 citations. Previous affiliations of Gerard Mourou include University of Michigan & San Diego State University.

Spatially-uniform temporal recompression of intense femtosecond optical pulses

Abstract: A specially designed telescope with defocusing lens and off-axis parabolic mirror, which is working as a nonlinear element and producing self-phase modulation, was implemented for intense (31 TW/cm2) Fourier Transform Limit femtosecond laser pulses with Gaussian beam profiles The pulse spectrum was broadened quasi- homogeneously over the beam cross-section due to the change in the lens thickness compensating for the reduction of the beam intensity from its center to periphery In experimental demonstrations a set of chirped mirrors allowed for the spectral phase correction to a final pulse compression of 20 fs from 40 fs

Energy scaling of quasi-monoenergetic electron beams from laser wakefields driven by 40-TW ultra-short pulses

Abstract: By focusing 40-TW, 30-fs laser pulses to the peak intensity of 1019 W/cm2 onto a supersonic He gas jet, we generate quasi-monoenergetic electron beams for plasma density in the specific range 1.5×1019 cm-3≤ne≤3.5×1019 cm-3. We show that the energy, charge, divergence and pointing stability of the beam can be controlled by changing ne, and that higher electron energies and more stable beams are produced for lower densities. The observed variations are explained physically by the interplay among pump depletion and dephasing between accelerated electrons and plasma wave. Two-dimensional particle-in-cell simulations support the explanation by showing the evolution of the laser pulse in plasma and the specifics of electron injection and acceleration. An optimized quasi-monoenergetic beam of over 300 MeV and 10 mrad angular divergence is demonstrated at a plasma density of ne≃1.5×1019 cm-3.

Time-resolved kiloelectron-volt spectroscopy of ultrashort plasmas.

Abstract: We describe a technique for spectrally and temporally resolving the kilo-electron-volt emission from ultrashort plasmas produced from solid targets with a tabletop terawatt 400-fs laser. The first time-resolved Al spectra (near 8 A) obtained with a 2-ps time resolution are presented. The results clearly demonstrate that the resonance emission width decreases as the plasma density increases. The ultrafast Kα emission component is also measured in our experimental conditions.

Generation and characterization of the highest laser intensities

Abstract: 2by focusing a 45-TW laser beam with an f0.6 off-axis paraboloid. The aberrations of the paraboloid and the low-energy reference laser beam were measured and corrected, and a focal spot size of 0.8 mm was achieved. It is shown that the peak intensity can be increased to 1.0 3 10 22 Wcm 2 by correction of the wave front of a 45-TW beam relative to the reference beam. The phase and amplitude measurement provides for an efficient full characterization of the focal field. © 2004 Optical Society of America OCIS codes: 010.1080, 140.3590, 320.7090.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Phd by thesis

Abstract: Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

A roadmap for graphene

Abstract: Recent years have witnessed many breakthroughs in research on graphene (the first two-dimensional atomic crystal) as well as a significant advance in the mass production of this material. This one-atom-thick fabric of carbon uniquely combines extreme mechanical strength, exceptionally high electronic and thermal conductivities, impermeability to gases, as well as many other supreme properties, all of which make it highly attractive for numerous applications. Here we review recent progress in graphene research and in the development of production methods, and critically analyse the feasibility of various graphene applications.

Black Hole Explosions

Abstract: QUANTUM gravitational effects are usually ignored in calculations of the formation and evolution of black holes. The justification for this is that the radius of curvature of space-time outside the event horizon is very large compared to the Planck length (Għ/c3)1/2 ≈ 10−33 cm, the length scale on which quantum fluctuations of the metric are expected to be of order unity. This means that the energy density of particles created by the gravitational field is small compared to the space-time curvature. Even though quantum effects may be small locally, they may still, however, add up to produce a significant effect over the lifetime of the Universe ≈ 1017 s which is very long compared to the Planck time ≈ 10−43 s. The purpose of this letter is to show that this indeed may be the case: it seems that any black hole will create and emit particles such as neutrinos or photons at just the rate that one would expect if the black hole was a body with a temperature of (κ/2π) (ħ/2k) ≈ 10−6 (M/M)K where κ is the surface gravity of the black hole1. As a black hole emits this thermal radiation one would expect it to lose mass. This in turn would increase the surface gravity and so increase the rate of emission. The black hole would therefore have a finite life of the order of 1071 (M/M)−3 s. For a black hole of solar mass this is much longer than the age of the Universe. There might, however, be much smaller black holes which were formed by fluctuations in the early Universe2. Any such black hole of mass less than 1015 g would have evaporated by now. Near the end of its life the rate of emission would be very high and about 1030 erg would be released in the last 0.1 s. This is a fairly small explosion by astronomical standards but it is equivalent to about 1 million 1 Mton hydrogen bombs. It is often said that nothing can escape from a black hole. But in 1974, Stephen Hawking realized that, owing to quantum effects, black holes should emit particles with a thermal distribution of energies — as if the black hole had a temperature inversely proportional to its mass. In addition to putting black-hole thermodynamics on a firmer footing, this discovery led Hawking to postulate 'black hole explosions', as primordial black holes end their lives in an accelerating release of energy.

Materials for terahertz science and technology

Abstract: Terahertz spectroscopy systems use far-infrared radiation to extract molecular spectral information in an otherwise inaccessible portion of the electromagnetic spectrum. Materials research is an essential component of modern terahertz systems: novel, higher-power terahertz sources rely heavily on new materials such as quantum cascade structures. At the same time, terahertz spectroscopy and imaging provide a powerful tool for the characterization of a broad range of materials, including semiconductors and biomolecules.