scholarly journals Effects of oblique incidence and colliding pulses on laser-driven proton acceleration from relativistically transparent ultrathin targets

2020 ◽  
Vol 86 (5) ◽  
Author(s):  
J. Ferri ◽  
E. Siminos ◽  
L. Gremillet ◽  
T. Fülöp
Keyword(s):  
Oblique Incidence ◽  
Laser Pulses ◽  
High Energy ◽  
Femtosecond Laser Pulses ◽  
Reference Case ◽  
Proton Acceleration ◽  
Ion Energy ◽  
High Energies ◽  
Proton Charge ◽  
Induced Transparency

The use of ultrathin solid foils offers optimal conditions for accelerating protons to high energies from laser–matter interactions. When the target is thin enough that relativistic self-induced transparency sets in, all of the target electrons get heated to high energies by the laser, which maximizes the accelerating electric field and therefore the final ion energy. In this work, we first investigate how ion acceleration by ultraintense femtosecond laser pulses in transparent CH $_2$ solid foils is modified when turning from normal to oblique ( $45^\circ$ ) incidence. Due to stronger electron heating, we find that higher proton energies can be obtained at oblique incidence but in thinner optimum targets. We then show that proton acceleration can be further improved by splitting the laser pulse into two half-pulses focused at opposite incidence angles. An increase by ${\sim }30\,\%$ in the maximum proton energy and by a factor of ${\sim }4$ in the high-energy proton charge is reported compared to the reference case of a single normally incident pulse.

scholarly journals Concept of generation of extremely compressed high-energy electron bunches in several interfering intense laser pulses with tilted amplitude fronts

2012 ◽  
Vol 31 (1) ◽  
pp. 23-28 ◽  
Author(s):  
V.V. Korobkin ◽  
M.Yu. Romanovskiy ◽  
V.A. Trofimov ◽  
O.B. Shiryaev
Keyword(s):  
Laser Pulses ◽  
High Energy ◽  
Intense Laser ◽  
High Energy Electron ◽  
Speed Of Light ◽  
Electron Bunches ◽  
Newton Equation ◽  
High Energies ◽  
Neutral Gas ◽  
Intense Laser Pulses

AbstractA new concept of generating tight bunches of electrons accelerated to high energies is proposed. The electrons are born via ionization of a low-density neutral gas by laser radiation, and the concept is based on the electrons acceleration in traps arising within the pattern of interference of several relativistically intense laser pulses with amplitude fronts tilted relative to their phase fronts. The traps move with the speed of light and (1) collect electrons; (2) compress them to extremely high density in all dimensions, forming electron bunches; and (3) accelerate the resulting bunches to energies of at least several GeV per electron. The simulations of bunch formation employ the Newton equation with the corresponding Lorentz force.

Wavelength tunable, high energy femtosecond laser pulses directly generated from large-mode-area photonic crystal fiber

2012 ◽  
Vol 285 (10-11) ◽  
pp. 2715-2718 ◽  
Author(s):  
Chi Zhang ◽  
Yu-ying Zhang ◽  
Ming-lie Hu ◽  
Si-jia Wang ◽  
You-jian Song ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Femtosecond Laser ◽  
Photonic Crystal Fiber ◽  
Laser Pulses ◽  
High Energy ◽  
Femtosecond Laser Pulses ◽  
Large Mode Area ◽  
Crystal Fiber ◽  
Wavelength Tunable ◽  
Mode Area

scholarly journals Femtosecond Laser Pulses Amplification in Crystals

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 347
Author(s):  
Dabu
Keyword(s):  
Femtosecond Laser ◽  
Laser Pulses ◽  
High Energy ◽  
Femtosecond Laser Pulses ◽  
Phase Matching ◽  
Chirped Pulse ◽  
Nonlinear Crystals ◽  
Pulse Amplification ◽  
Chirped Pulse Amplification ◽  
Laser Crystals

This paper describes techniques for high-energy laser pulse amplification in multi-PW femtosecond laser pulses. Femtosecond laser pulses can be generated and amplified in laser media with a broad emission spectral bandwidth, like Ti:sapphire crystals. By chirped pulse amplification (CPA) techniques, hundred-Joule amplified laser pulses can be obtained. Multi-PW peak-power femtosecond pulses are generated after recompression of amplified chirped laser pulses. The characteristics and problems of large bandwidth laser pulses amplification in Ti:sapphire crystals are discussed. An alternative technique, based on optical parametric chirped pulse amplification (OPCPA) in nonlinear crystals, is presented. Phase-matching conditions for broad bandwidth parametric amplification in nonlinear crystals are inferred. Ultra-broad phase matching bandwidth of more than 100 nm, able to support the amplification of sub-10 fs laser pulses, are demonstrated in nonlinear crystals, such as Beta Barium Borate (BBO), Potassium Dideuterium Phosphate (DKDP), and Lithium Triborate (LBO). The advantages and drawbacks of CPA amplification in laser crystals and OPCPA in nonlinear crystals are discussed. A hybrid amplification method, which combines low-medium energy OPCPA in nonlinear crystals with high energy CPA in large aperture laser crystals, is described. This technique is currently used for the development of 10-PW laser systems, with sub-20 fs pulse duration and more than 1012 intensity contrast of output femtosecond pulses.

scholarly journals Petawatt Femtosecond Laser Pulses from Titanium-Doped Sapphire Crystal

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 783
Author(s):  
Hiromitsu Kiriyama ◽  
Alexander S. Pirozhkov ◽  
Mamiko Nishiuchi ◽  
Yuji Fukuda ◽  
Akito Sagisaka ◽  
...  
Keyword(s):  
High Intensity ◽  
Short Pulse ◽  
Beam Quality ◽  
Laser Pulses ◽  
High Energy ◽  
Femtosecond Laser Pulses ◽  
Small Scale ◽  
Sapphire Crystal ◽  
Chirped Pulse Amplification ◽  
Ultra Short Pulse

Ultra-high intensity femtosecond lasers have now become excellent scientific tools for the study of extreme material states in small-scale laboratory settings. The invention of chirped-pulse amplification (CPA) combined with titanium-doped sapphire (Ti:sapphire) crystals have enabled realization of such lasers. The pursuit of ultra-high intensity science and applications is driving worldwide development of new capabilities. A petawatt (PW = 1015 W), femtosecond (fs = 10−15 s), repetitive (0.1 Hz), high beam quality J-KAREN-P (Japan Kansai Advanced Relativistic ENgineering Petawatt) Ti:sapphire CPA laser has been recently constructed and used for accelerating charged particles (ions and electrons) and generating coherent and incoherent ultra-short-pulse, high-energy photon (X-ray) radiation. Ultra-high intensities of 1022 W/cm2 with high temporal contrast of 10−12 and a minimal number of pre-pulses on target has been demonstrated with the J-KAREN-P laser. Here, worldwide ultra-high intensity laser development is summarized, the output performance and spatiotemporal quality improvement of the J-KAREN-P laser are described, and some experimental results are briefly introduced.

scholarly journals Directional transport of fast electrons at the front target surface irradiated by intense femtosecond laser pulses with preformed plasma

2012 ◽  
Vol 30 (1) ◽  
pp. 39-43 ◽  
Author(s):  
X.X. Lin ◽  
Y.T. Li ◽  
B.C. Liu ◽  
F. Liu ◽  
F. Du ◽  
...  
Keyword(s):  
Electron Transport ◽  
Incidence Angle ◽  
Target Surface ◽  
Laser Pulses ◽  
High Energy ◽  
Femtosecond Laser Pulses ◽  
Fast Electrons ◽  
High Energy Electrons ◽  
Preformed Plasma ◽  
Directional Transport

AbstractThe effects of laser incidence angle on lateral fast electron transport at front target surface, when a plasma is preformed, irradiated by intense (>1018 W/cm2) laser pulses, are studied by Kα imaging technique and electron spectrometer. A horizontally asymmetric Kα halo, resulting from directional lateral electron transport and energy deposition, is observed for a large incidence angle (70°). Moreover, a group of MeV high energy electrons is emitted along target surface. It is believed that the deformed preplasma and the asymmetrical distribution of self-generated magnetic field, at large incidence angle, play an important role in the directional lateral electron transport.

scholarly journals Towards optimization of femtosecond laser pulse nanostructuring of targets for high-intensity laser experiments in vacuum

2021 ◽  
Vol 127 (7) ◽  
Author(s):  
A. Andreev ◽  
J. Imgrunt ◽  
V. Braun ◽  
I. Dittmar ◽  
U. Teubner
Keyword(s):  
Laser Pulse ◽  
Femtosecond Laser ◽  
High Intensity ◽  
Extreme Ultraviolet ◽  
Theoretical Models ◽  
Laser Pulses ◽  
High Energy ◽  
Femtosecond Laser Pulses ◽  
Laser Development ◽  
Laser Experiments

AbstractThe interaction of intense femtosecond laser pulses with solid targets is a topic that has attracted a large amount of interest in science and applications. For many of the related experiments a large energy deposition or absorption as well as an efficient coupling to extreme ultraviolet (XUV), X-ray photon generation, and/or high energy particles is important. Here, much progress has been made in laser development and in experimental schemes, etc. However, regarding the improvement of the target itself, namely its geometry and surface, only limited improvements have been reported. The present paper investigates the formation of laser-induced periodic surface structures (LIPSS or ripples) on polished thick copper targets by femtosecond Ti:sapphire laser pulses. In particular, the dependence of the ripple period and ripple height has been investigated for different fluences and as a function of the number of laser shots on the same surface position. The experimental results and the formation of ripple mechanisms on metal surfaces in vacuum by femtosecond laser pulses have been analysed and the parameters of the experimentally observed “gratings” interpreted on base of theoretical models. The results have been specifically related to improve high-intensity femtosecond-laser matter interaction experiments with the goal of an enhanced particle emission (photons and high energy electrons and protons, respectively). In those experiments the presently investigated nanostructures could be generated easily in situ by multiple pre-pulses irradiated prior to a subsequent much more intense main laser pulse.

scholarly journals Chirped-pulse oscillators for the generation of high-energy femtosecond laser pulses

2005 ◽  
Vol 23 (2) ◽  
pp. 113-116 ◽  
Author(s):  
ALEXANDER FUERBACH ◽  
A. FERNANDEZ ◽  
A. APOLONSKI ◽  
T. FUJI ◽  
F. KRAUSZ
Keyword(s):  
Repetition Rate ◽  
Laser Cavity ◽  
Laser Pulses ◽  
High Energy ◽  
Femtosecond Laser Pulses ◽  
Group Delay Dispersion ◽  
Picosecond Pulses ◽  
Chirped Pulse ◽  
Novel Approach ◽  
Extended Cavity

This paper reports on a novel approach for producing high energy femtosecond pulses without external amplification. The so-called chirped-pulse oscillator (CPO) concept is based on an extended-cavity oscillator, operating at small net positive intracavity group delay dispersion (GDD), over a broad spectral range by the use of chirped multilayer mirrors. The resultant chirped picosecond pulses are compressed by a dispersive delay line external to the laser cavity. Utilizing this technique, sub-30 fs pulses with an energy exceeding 200 nJ at a repetition rate of 11 MHz were produced. The demonstrated peak power in excess of 5 MW is the highest ever achieved from a cw-pumped laser and is expected to be scaleable to tens of megawatts by increasing the pump power and/or decreasing the repetition rate. The demonstrated source allows micromachining of any materials under relaxed focusing conditions.

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