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.

Electro-electron oscilloscope

Abstract: A system for time-resolving ultra-short electrical waveforms of up to a few hundred gigahertz bandwidth is presented. The system utilizes a fast electro-optic modulator capable of subpicosecond responsivity. A CW (continuous wave) laser is used to probe the change in birefringence resulting in the modulator due to an induced electric field. The rapid change in the transmitted optical signal due to an equally rapid changing electric field (picosecond pulse) is then detected and temporally dispersed using a picosecond resolution streak camera. The modulator operates in a region close to minimum transmission where the average optical power is below the damage threshold for the photocathode of the streak camera and where small electrical signals can significantly modulate the transmitted beam. The system can be used in either sampling mode where the modulation and subsequent detection are repeated and the data accumulated at repetition rates as high as 100 MHz or in single shot mode.

Radiation back-reaction in relativistically strong and QED-strong laser fields

Abstract: The emission from an electron in the field of a relativistically strong laser pulse is analyzed. At the pulse intensities of \ge 10^{22} W/cm^2 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 \ge 1 GeV. The radiation force experienced by an electron is for the first time derived from the QED principles and its applicability range is extended towards the QED-strong fields.

Laser wakefield acceleration based x ray source using 225-TW and 13-fs laser pulses produced by thin film compression.

Abstract: We show that 13-fs laser pulses associated with 225 TW of peak power can be used to produce laser wakefield acceleration (LWFA) and generate synchrotron radiation. To achieve this, 130-TW high-power laser pulses (3.2 J, 24 fs) are efficiently compressed down to 13 fs with the thin film compression (TFC) technique using large chirped mirrors after propagation and spectral broadening through a 1-mm-thick fused silica plate. We show that the compressed 13-fs laser pulse can be properly focused even if it induces a 10% degradation of the Strehl ratio. We demonstrate the usability of such a laser beam. We observe both an increase of the electron energy and of the betatron radiation critical energy when the pulse duration is reduced to 13 fs compared with the 24-fs case.

Laser Technology for Advanced Acceleration: Accelerating Beyond TeV

Abstract: The implementation of the suggestion of thin film compression (TFC) allows the newest class of high power, ultrafast laser pulses (typically 20fs at near-infrared wavelengths) to be compressed to the limit of a single-cycle laser pulse (2fs). Its simplicity and high efficiency, as well as its accessibility to a single-cycle laser pulse, introduce a new regime of laser–plasma interaction that enhances laser acceleration. Single-cycle laser acceleration of ions is a far more efficient and coherent process than the known laser-ion acceleration mechanisms. The TFC-derived single-cycle optical pulse is capable of inducing a single-cycle X-ray laser pulse (with a far shorter pulse length and thus an extremely high intensity) through relativistic compression. The application of such an X-ray pulse leads to the novel regime of laser wakefield acceleration of electrons in the X-ray regime, yielding a prospect of “TeV on a chip.” This possibility of single-cycle X-ray pulses heralds zeptosecond and EW lasers (and zeptoscience). The additional invention of the coherent amplification network (CAN) fiber laser pushes the frontier of high repetition, high efficiency lasers, which are the hallmark of needed applications such as laser-driven LWFA colliders and other, societal applications. CAN addresses the crucial aspect of intense lasers that have traditionally lacked the above properties.

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.