Showing papers by "Gerard Mourou published in 2016"

Roadmap on ultrafast optics

Abstract: The year 2015 marked the 25th anniversary of modern ultrafast optics, since the demonstration of the first Kerr lens modelocked Ti:sapphire laser in 1990 (Spence et al 1990 Conf. on Lasers and Electro-Optics, CLEO, pp 619–20) heralded an explosion of scientific and engineering innovation. The impact of this disruptive technology extended well beyond the previous discipline boundaries of lasers, reaching into biology labs, manufacturing facilities, and even consumer healthcare and electronics. In recognition of such a milestone, this roadmap on Ultrafast Optics draws together articles from some of the key opinion leaders in the field to provide a freeze-frame of the state-of-the-art, while also attempting to forecast the technical and scientific paradigms which will define the field over the next 25 years. While no roadmap can be fully comprehensive, the thirteen articles here reflect the most exciting technical opportunities presented at the current time in Ultrafast Optics. Several articles examine the future landscape for ultrafast light sources, from practical solid-state/fiber lasers and Raman microresonators to exotic attosecond extreme ultraviolet and possibly even zeptosecond x-ray pulses. Others address the control and measurement challenges, requiring radical approaches to harness nonlinear effects such as filamentation and parametric generation, coupled with the question of how to most accurately characterise the field of ultrafast pulses simultaneously in space and time. Applications of ultrafast sources in materials processing, spectroscopy and time-resolved chemistry are also discussed, highlighting the improvements in performance possible by using lasers of higher peak power and repetition rate, or by exploiting the phase stability of emerging new frequency comb sources.

Proton acceleration by single-cycle laser pulses offers a novel monoenergetic and stable operating regime

Abstract: Prompted by the possibility to produce high energy, single-cycle laser pulses with tens of Petawatt (PW) power, we have investigated laser-matter interactions in the few optical cycle and ultra relativistic intensity regimes. A particularly interesting instability-free regime for ion production was revealed leading to the efficient coherent generation of short (femtosecond; 10−15s) monoenergetic ion bunches with a peak energy greater than GeV. Of paramount importance, the interaction is absent of the Rayleigh Taylor Instabilities and hole boring that plague techniques such as target normal sheath acceleration and radiation pressure acceleration.

Particle-in-cell simulation of x-ray wakefield acceleration and betatron radiation in nanotubes

Abstract: Though wakefield acceleration in crystal channels has been previously proposed, x-ray wakefield acceleration has only recently become a realistic possibility since the invention of the single-cycled optical laser compression technique. We investigate the acceleration due to a wakefield induced by a coherent, ultrashort x-ray pulse guided by a nanoscale channel inside a solid material. By two-dimensional particle-in-cell computer simulations, we show that an acceleration gradient of $\mathrm{TeV}/\mathrm{cm}$ is attainable. This is about 3 orders of magnitude stronger than that of the conventional plasma-based wakefield accelerations, which implies the possibility of an extremely compact scheme to attain ultrahigh energies. In addition to particle acceleration, this scheme can also induce the emission of high energy photons at $\ensuremath{\sim}O(10--100)\text{ }\text{ }\mathrm{MeV}$. Our simulations confirm such high energy photon emissions, which is in contrast with that induced by the optical laser driven wakefield scheme. In addition to this, the significantly improved emittance of the energetic electrons has been discussed.

High energy femtosecond pulse compression

Abstract: An original method for retrieving the Kerr nonlinear index was proposed and implemented for TF12 heavy flint glass. Then, a defocusing lens made of this highly nonlinear glass was used to generate an almost constant spectral broadening across a Gaussian beam profile. The lens was designed with spherical curvatures chosen in order to match the laser beam profile, such that the product of the thickness with intensity is constant. This solid-state optics in combination with chirped mirrors was used to decrease the pulse duration at the output of a terawatt-class femtosecond laser. We demonstrated compression of a 33 fs pulse to 16 fs with 170 mJ energy.

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.

Picosecond-petawatt laser-block ignition for avalanche fusion of boron by ultrahigh acceleration and ultrahigh magnetic fields

Abstract: Fusion energy from reacting hydrogen (protons) with the boron isotope 11 (HB11) resulting in three stable helium nuclei, is without problem of nuclear radiation in contrast to DT fusion. But the HB11 reaction driven by nanosecond laser pulses with thermal compression and ignition by lasers is extremely difficult. This changed radically when irradiation with picosecond laser pulses produces a non-thermal plasma block ignition with ultrahigh acceleration. This uses the nonlinear (ponderomotive) force to surprizingly resulting in same thresholds as DT fusion even under pessimistic assumption of binary reactions. After evaluation of reactions trapped cylindrically by kilotesla magnetic fields and using the measured highly increased HB11 fusion gains for the proof of an avalanche of the three alphas in secondary reactions, possibilities for an absolutely clean energy source at comptitive costs were concluded.

Ultra-High Gradient Channeling Acceleration in Nanostructures: Design/Progress of Proof-of-Concept (POC) Experiments

Abstract: This paper describes simulation analyses on beam and laser (X-ray)-driven accelerations in effective nanotube models obtained from Vsim and EPOCH codes. Experimental setups to detect wakefields are also outlined with accelerator facilities at Fermilab and NIU. In the FAST facility, the electron beamline was successfully commissioned at 50 MeV and it is being upgraded toward higher energies for electron accelerator R&D. The 50 MeV injector beamline of the facility is used for X-ray crystal-channeling radiation with a diamond target. It has been proposed to utilize the same diamond crystal for a channeling acceleration POC test. Another POC experiment is also designed for the NIU accelerator lab with time-resolved electron diffraction. Recently, a stable generation of single-cycle laser pulses with tens of Petawatt power based on thin film compression (TFC) technique has been investigated for target normal sheath acceleration (TNSA) and radiation pressure acceleration (RPA). The experimental plan with a nanometer foil is discussed with an available test facility such as Extreme Light Infrastructure - Nuclear Physics (ELI-NP).

X-ray Wakefield Acceleration and Betatron Radiation in Nanotubes

Abstract: We investigate X-ray laser pulse induced wakefield acceleration in a nanotube inside a solid material via 2D particle-in-cell simulations. Meanwhile, QED betatron radiation, improved emittance of the energitc electrons has been discussed.

Compression of High Energy Pulses to the Sub-attosecond Regime: Route to Exawatt Laser Subatomic Physics

Abstract: Laser amplification to extreme peak power offers a new paradigm unifying the atomic and subatomic worlds, to include Nuclear physics, High Energy Physics, Astrophysics and Cosmology. We will review present and future steps that could culminate to exawatt pulses with sub-attosecond duration making possible TeV/cm accelerators.

X-Rays Driven by Single-Cycle, Petawatt Lasers: A Path to Exawatt Pulses

Abstract: The post-compression of high-energy Petawatt (PW) scale laser pulses offers the promise of maximizing the peak intensity deliverable by a given laser system for the amplified energy produced within the pulses. One recent proposal made by Mourou et al. relied upon the flat-top property of modern high-energy laser systems to suggest a solution utilizing self-phase modulation within a thin plastic film material to generate the bandwidth necessary to recompress to a shorter pulse duration through compensation with negative dispersion mirrors. The so-called thin film compressor (TFC) promised to offer an efficient and affordable method to boost the peak pulse achievable with existing facilities. Recent measurements including experiments done at the CETAL PW laser based at the National Institute for Lasers, Plasma, and Radiation Physics (INFLPR) in Magurele, Romania demonstrate the feasibility of the TFC configuration on a small-scale and encourage continued pursuit at increasing laser levels. The applications of such high energy, ultrashort pulses are already being considered in regard to particle acceleration and X-ray generation.