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12 pages, 1058 KiB

Open AccessArticle

X-ray Chirped Pulse Amplification: towards GW Soft X-ray Lasers

by Philippe Zeitoun, Eduardo Oliva, Thi Thu Thuy Le, David Ros, Stéphane Sebban, Lu Li, Pedro Velarde and Marta Fajardo

Appl. Sci. 2013, 3(3), 581-592; https://doi.org/10.3390/app3030581 - 12 Jul 2013

Cited by 4 | Viewed by 11708

Abstract

Extensive modeling of the seeding of plasma-based soft X-ray lasers is reported in this article. Seminal experiments on amplification in plasmas created from solids have been studied in detail and explained. Using a transient collisional excitation scheme, we show that a 18 µJ, [...] Read more.

Extensive modeling of the seeding of plasma-based soft X-ray lasers is reported in this article. Seminal experiments on amplification in plasmas created from solids have been studied in detail and explained. Using a transient collisional excitation scheme, we show that a 18 µJ, 80 fs fully coherent pulse is achievable by using plasmas pumped by a compact 10 Hz laser. We demonstrate that direct seeding of plasmas created by nanosecond lasers is not efficient. Therefore, we propose and fully study the transposition to soft X-rays of the Chirped Pulse Amplification (CPA) technique. Soft X-ray pulses with energy of 6 mJ and 200 fs duration are reachable by seeding plasmas pumped by compact 100 J, sub-ns, 1 shot/min lasers. These soft X-ray lasers would reach GW power, corresponding to an increase of 100 times as compared to the highest peak power achievable nowadays in the soft X-ray region (30 eV–1 keV). X-ray CPA is opening new horizon for soft x-ray ultra-intense sources. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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22 pages, 6455 KiB

Open AccessArticle

Laser-Plasma Acceleration with FLAME and ILIL Ultraintense Lasers

by Leonida Antonio Gizzi, Carlo Benedetti, Carlo Alberto Cecchetti, Giampiero Di Pirro, Andrea Gamucci, Giancarlo Gatti, Antonio Giulietti, Danilo Giulietti, Petra Koester, Luca Labate, Tadzio Levatoy, Naveen Pathak and Francesco Piastra

Appl. Sci. 2013, 3(3), 559-580; https://doi.org/10.3390/app3030559 - 5 Jul 2013

Cited by 21 | Viewed by 9787

Abstract

We report on the development of radiation and electron sources based on laser-plasma acceleration for biomedical and nuclear applications, using both the table top TW laser at ILIL and the 220 TW FLAME laser system at LNF. We use the ILIL laser to [...] Read more.

We report on the development of radiation and electron sources based on laser-plasma acceleration for biomedical and nuclear applications, using both the table top TW laser at ILIL and the 220 TW FLAME laser system at LNF. We use the ILIL laser to produce wakefield electrons in a self-focusing dominated regime in a mm scale gas-jet to generate large, uniform beams of MeV electrons for electron radiography and radiobiology applications. This acceleration regime is described in detail and key parameters are given to establish reproducible and reliable operation of this source. We use the FLAME laser to drive laser-plasma acceleration in a cm-scale gas target to obtain stable production of >100 MeV range electrons to drive a Thomson scattering ɣ-ray source for nuclear applications. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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11 pages, 1535 KiB

Open AccessArticle

Front-End Light Source for aWaveform-Controlled High-Contrast Few-Cycle Laser System for High-Repetition Rate Relativistic Optics

by Aurélien Ricci, Aurélie Jullien, Jean-Philippe Rousseau and Rodrigo Lopez-Martens

Appl. Sci. 2013, 3(1), 314-324; https://doi.org/10.3390/app3010314 - 18 Mar 2013

Cited by 14 | Viewed by 6612

Abstract

We present the current development of an injector for a high-contrast, ultrashort laser system devoted to relativistic laser-plasma interaction in the few-cycle regime. The front-end is based on CEP-stabilized Ti:Sa CPA followed by XPW filter designed at the mJ level for temporal cleaning [...] Read more.

We present the current development of an injector for a high-contrast, ultrashort laser system devoted to relativistic laser-plasma interaction in the few-cycle regime. The front-end is based on CEP-stabilized Ti:Sa CPA followed by XPW filter designed at the mJ level for temporal cleaning and shortening. Accurate characterization highlights the fidelity of the proposed injector. Measured CEP drift is 170 mrad rms. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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11 pages, 326 KiB

Open AccessArticle

Numerical Simulation of High-Energy, Ytterbium-Doped Amplifier Tunability

by Celso P. João, João Wemans and Gonçalo Figueira

Appl. Sci. 2013, 3(1), 288-298; https://doi.org/10.3390/app3010288 - 13 Mar 2013

Cited by 5 | Viewed by 8374

Abstract

The study of wavelength tunability for the gain media Yb:CaF₂ and Yb:YAG in a regenerative amplifier configuration, was performed by using a simulation code previously benchmarked with real data. The results demonstrate that both materials have potential for amplifying pulses up to [...] Read more.

The study of wavelength tunability for the gain media Yb:CaF₂ and Yb:YAG in a regenerative amplifier configuration, was performed by using a simulation code previously benchmarked with real data. The results demonstrate that both materials have potential for amplifying pulses up to the milijoule level for wavelengths around 1048–1049 nm. In light of this, we propose and evaluate their performance as gain media in the pre-amplifier of a hybrid chain operating at 1053 nm. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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10 pages, 792 KiB

Open AccessArticle

Laser Induced Multiphoton Effects in Nano-Graphene Molecules

by Mingqiang Gu, Guoping Zhang and Xiaoshan Wu

Appl. Sci. 2013, 3(1), 278-287; https://doi.org/10.3390/app3010278 - 13 Mar 2013

Cited by 3 | Viewed by 6205

Abstract

We perform first-principles calculations to study the high-order harmonic generation induced in graphene nanostructures by the laser field. Three distinct signals are noticed: the integer higher-order harmonic generation (HHG), the shifted fractional order peaks from the integer order harmonics, and the intrinsic emissions. [...] Read more.

We perform first-principles calculations to study the high-order harmonic generation induced in graphene nanostructures by the laser field. Three distinct signals are noticed: the integer higher-order harmonic generation (HHG), the shifted fractional order peaks from the integer order harmonics, and the intrinsic emissions. Due to the small gap between HOMO and LUMO of graphene molecule, the HHG can be generated for the infrared laser pulse with the photon energy ranging from 20 meV to 1 eV. The intrinsic emission corresponds to the electron excitation between eigenstates. Using a laser pulse with a photon energy of 0.042 eV and amplitude of 0.2 V/A° , HHGs up to 19th order are identified. Unsaturated graphene molecule is an excellent media for HHG. Moreover, the HHG signals are very sensitive to the hydrogen passivation. Our results also indicate that HHG can be a promising method for detecting the product in the fabrication of graphene molecules. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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25 pages, 1351 KiB

Open AccessArticle

Photoelectron Angular Distribution and Phase in Two-Photon Single Ionization of H and He by a Femtosecond and Attosecond Extreme-Ultraviolet Pulse

by Kenichi L. Ishikawa and Kiyoshi Ueda

Appl. Sci. 2013, 3(1), 189-213; https://doi.org/10.3390/app3010189 - 5 Mar 2013

Cited by 30 | Viewed by 9633

Abstract

We theoretically study the photoelectron angular distribution (PAD) from the two-photon single ionization of H and He by femtosecond and attosecond extreme-ultraviolet pulses, based on the time-dependent perturbation theory and simulations with the full time-dependent Schrodinger equation. The PAD is formed by the [...] Read more.

We theoretically study the photoelectron angular distribution (PAD) from the two-photon single ionization of H and He by femtosecond and attosecond extreme-ultraviolet pulses, based on the time-dependent perturbation theory and simulations with the full time-dependent Schrodinger equation. The PAD is formed by the interference of the s and d continuum wave packets, and, thus, contains the information on the relative phase and amplitude ratio between them. We find that, when a spectrally broadened femtosecond pulse is resonant with an excited level, the PAD substantially changes with pulse width, since the competition between resonant and nonresonant ionization paths, leading to distinct from the scattering phase shift difference, changes with it. In contrast, when the Rydberg manifold is excited, and for the case of above-threshold two-photon ionization, and the PAD do not depend much on pulse width, except for the attosecond region. Thus, the Rydberg manifold and the continuum behave similarly in this respect. For a high-harmonic pulse composed of multiple harmonic orders, while the value is different from that for a single-component pulse, the PAD still rapidly varies with pulse width. The present results illustrate a new way to tailor the continuum wave packet. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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21 pages, 1374 KiB

Open AccessArticle

Linear Electro Optic Effect for High Repetition Rate Carrier Envelope Phase Control of Ultra Short Laser Pulses

by Olivier Gobert, Daniele Rovera, Gabriel Mennerat and Michel Comte

Appl. Sci. 2013, 3(1), 168-188; https://doi.org/10.3390/app3010168 - 26 Feb 2013

Cited by 2 | Viewed by 9735

Abstract

This paper is devoted to analyzing the principle and applications of the linear electro-optic (EO) effect for the control of the carrier-envelope-phase (CEP). We introduce and detail here an original method, which relies on the use of an EO dispersive prism pair in [...] Read more.

This paper is devoted to analyzing the principle and applications of the linear electro-optic (EO) effect for the control of the carrier-envelope-phase (CEP). We introduce and detail here an original method, which relies on the use of an EO dispersive prism pair in a compressor-like configuration. We show that, by choosing an adequate geometry, it is possible to shift the CEP without changing the group delay (isochronous carrier-envelope-phase shifter) or change the induced group delay without varying the CEP. According to our calculations, when applying an electric field around 400 V/cm to the rubidium titanyle phosphate (RTP) prisms in a double pass configuration (2 × 40 mm total length), one obtains a CEP shift of π rad at 800 nm without inducing a group delay. In contrast, this CEP shift is obtained for an electric field around 1.4 kV/cm in a RTP rectangular slab of the same total length and, in this case, the group delay is of the order of a few fs. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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15 pages, 1100 KiB

Open AccessArticle

Pulse Compression of Ultrashort UV Pulses by Self-Phase Modulation in Bulk Material

by Nils Krebs, Igor Pugliesi and Eberhard Riedle

Appl. Sci. 2013, 3(1), 153-167; https://doi.org/10.3390/app3010153 - 8 Feb 2013

Cited by 27 | Viewed by 11425

Abstract

The bandwidth of ultrafast pulses in the UV is limited by the finite acceptance bandwidth of the nonlinear crystals used for their generation. For fundamental laser pulses it is well established that spectral broadening can be used to overcome intrinsic bandwidth limits. We [...] Read more.

The bandwidth of ultrafast pulses in the UV is limited by the finite acceptance bandwidth of the nonlinear crystals used for their generation. For fundamental laser pulses it is well established that spectral broadening can be used to overcome intrinsic bandwidth limits. We show that self-phase modulation of UV pulses in bulk materials leads to large spectral broadening and allows for a significant reduction of the pulse duration. We find that for pulse energies in the range of a few μJ, a thin crystal is favorable due to the strong dispersion in the UV and the limitations set by self-focusing. In contrast to spectral broadening in gaseous media, the self-focus has to lie outside the crystal to avoid beam break up. We focus UV pulses into a 1 mm thick CaF₂ crystal. For moderately short input pulses, a shortening factor up to 2.4 is achieved: the 120 fs long third harmonic output of a Ti:sapphire amplifier is compressed down to 50 fs FWHM. For a central wavelength of 315 nm, we generate pulses as short as 14.9 fs after compression with an UV pulse shaper. In both cases the resulting beam shape is close to Gaussian and fully usable for spectroscopic experiments. We use the pulses in a collinear 2D-UV experiment and clearly resolve vibronic off-diagonal peaks of the S₂ ¹B_2u vibronic progression of pyrene. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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14 pages, 1392 KiB

Open AccessArticle

Adaptive Generation and Diagnostics of Linear Few-Cycle Light Bullets

by Martin Bock and Ruediger Grunwald

Appl. Sci. 2013, 3(1), 139-152; https://doi.org/10.3390/app3010139 - 8 Feb 2013

Cited by 8 | Viewed by 9303

Abstract

Recently we introduced the class of highly localized wavepackets (HLWs) as a generalization of optical Bessel-like needle beams. Here we report on the progress in this field. In contrast to pulsed Bessel beams and Airy beams, ultrashort-pulsed HLWs propagate with high stability in [...] Read more.

Recently we introduced the class of highly localized wavepackets (HLWs) as a generalization of optical Bessel-like needle beams. Here we report on the progress in this field. In contrast to pulsed Bessel beams and Airy beams, ultrashort-pulsed HLWs propagate with high stability in both spatial and temporal domain, are nearly paraxial (supercollimated), have fringe-less spatial profiles and thus represent the best possible approximation to linear “light bullets”. Like Bessel beams and Airy beams, HLWs show self-reconstructing behavior. Adaptive HLWs can be shaped by ultraflat three-dimensional phase profiles (generalized axicons) which are programmed via calibrated grayscale maps of liquid-crystal-on-silicon spatial light modulators (LCoS-SLMs). Light bullets of even higher complexity can either be freely formed from quasi-continuous phase maps or discretely composed from addressable arrays of identical nondiffracting beams. The characterization of few-cycle light bullets requires spatially resolved measuring techniques. In our experiments, wavefront, pulse and phase were detected with a Shack-Hartmann wavefront sensor, 2D-autocorrelation and spectral phase interferometry for direct electric-field reconstruction (SPIDER). The combination of the unique propagation properties of light bullets with the flexibility of adaptive optics opens new prospects for applications of structured light like optical tweezers, microscopy, data transfer and storage, laser fusion, plasmon control or nonlinear spectroscopy. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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17 pages, 1951 KiB

Open AccessArticle

Generation of Phase-Stable Sub-Cycle Mid-Infrared Pulses from Filamentation in Nitrogen

by Takao Fuji and Yutaka Nomura

Appl. Sci. 2013, 3(1), 122-138; https://doi.org/10.3390/app3010122 - 6 Feb 2013

Cited by 52 | Viewed by 8885

Abstract

Sub-single-cycle pulses in the mid-infrared (MIR) region were generated through a laser-induced filament. The fundamental (ω₁) and second harmonic (ω₂) output of a 30-fs Ti:sapphire amplifier were focused into nitrogen gas and produce phase-stable broadband MIR pulses (ω₀ [...] Read more.

Sub-single-cycle pulses in the mid-infrared (MIR) region were generated through a laser-induced filament. The fundamental (ω₁) and second harmonic (ω₂) output of a 30-fs Ti:sapphire amplifier were focused into nitrogen gas and produce phase-stable broadband MIR pulses (ω₀) by using a four-wave mixing process (ω₁ + ω₁ - ω₂→ ω₀) through filamentation. The spectrum spread from 400 cm^-1 to 5500 cm^-1, which completely covered the MIR region. The low frequency components were detected by using an electro-optic sampling technique with a gaseous medium. The efficiency of the MIR pulse generation was very sensitive to the delay between the fundamental and second harmonic pulses. It was revealed that the delay dependence of the efficiency came from the interference between two opposite parametric processes, ω₁ + ω₁ - ω₂ → ω₀ and ω₂ - ω₁ - ω₁ → ω₀. The pulse duration was measured as 6.9 fs with cross-correlation frequency-resolved optical gating by using four-wave mixing in nitrogen. The carrier-envelope phase of the MIR pulse was passively stabilized. The instability was estimated as 154 mrad rms in 2.5 h. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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13 pages, 568 KiB

Open AccessArticle

Double Relativistic Electron Accelerating Mirror

by Alexander Andreev, Konstantin Platonov and Saltanat Sadykova

Appl. Sci. 2013, 3(1), 94-106; https://doi.org/10.3390/app3010094 - 4 Feb 2013

Cited by 5 | Viewed by 6099

Abstract

In the present paper, the possibility of generation of thin dense relativistic electron layers is shown using the analytical and numerical modeling of laser pulse interaction with ultra-thin layers. It was shown that the maximum electron energy can be gained by optimal tuning [...] Read more.

In the present paper, the possibility of generation of thin dense relativistic electron layers is shown using the analytical and numerical modeling of laser pulse interaction with ultra-thin layers. It was shown that the maximum electron energy can be gained by optimal tuning between the target width, intensity and laser pulse duration. The optimal parameters were obtained from a self-consistent system of Maxwell equations and the equation of motion of electron layer. For thin relativistic electron layers, the gaining of maximum electron energies requires a second additional overdense plasma layer, thus cutting the laser radiation off the plasma screen at the instant of gaining the maximum energy (DREAM-schema). Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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13 pages, 277 KiB

Open AccessArticle

Single-Grating Monochromators for Extreme-Ultraviolet Ultrashort Pulses

by Luca Poletto and Fabio Frassetto

Appl. Sci. 2013, 3(1), 1-13; https://doi.org/10.3390/app3010001 - 27 Dec 2012

Cited by 12 | Viewed by 8130

Abstract

A single-grating monochromator can be used for the spectral selection of ultrashort pulses without altering in a significant way the pulse duration, provided that the number of illuminated grooves is equal to the resolution. Two configurations are compared: the classical-diffraction mount (CDM) and [...] Read more.

A single-grating monochromator can be used for the spectral selection of ultrashort pulses without altering in a significant way the pulse duration, provided that the number of illuminated grooves is equal to the resolution. Two configurations are compared: the classical-diffraction mount (CDM) and the off-plane mount (OPM). The advantages and drawbacks of both configurations are presented. The two geometries can be joined in a new and innovative design of a monochromator with two interchangeable diffracting stages both used at grazing incidence, one with the gratings in the CDM and the other in the OPM. The use of two stages gives great flexibility: the OPM stage is used for sub-50 fs time response and low spectral resolution and the CDM stage for 100-200 fs time response and high spectral resolution. The design overcomes the limits of the two single configurations, giving on the same instrument either ultrafast response with low spectral resolution or slower response with higher resolution. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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15 pages, 1113 KiB

Open AccessArticle

Broadband Spectral Amplitude Control in High-Order Harmonic Generation

by Carles Serrat

Appl. Sci. 2012, 2(4), 816-830; https://doi.org/10.3390/app2040816 - 19 Dec 2012

Cited by 10 | Viewed by 6601

Abstract

A technique for broadband spectral amplitude control of light pulses produced in high-order harmonic generation (HHG) is presented. It has been shown elsewhere that broadband spectral phase control in HHG is achievable using a computerized feedback loop scheme by coherently adding a filtered [...] Read more.

A technique for broadband spectral amplitude control of light pulses produced in high-order harmonic generation (HHG) is presented. It has been shown elsewhere that broadband spectral phase control in HHG is achievable using a computerized feedback loop scheme by coherently adding a filtered region of the HHG emission to the intense IR driving pulse with optimal attenuation and time delay parameters. In the present study, further computational evidence of the capabilities of this control scheme is provided by considering the spectral amplitude in a broadband region of the HHG spectrum as the control target for the production of isolated attosecond pulses. Different spectral widths and central photon energies are examined, such as a spectral width of 30 eV centered at 36 eV, well in the plateau, and a width of 20 eV centered at 60 eV in the cutoff region. An iterative procedure of the method is implemented and optimal isolated single cycle pulses at a central photon energy of 36 eV are obtained. This control scheme is a fundamental tool that can be implemented for amplitude and phase shaping of any suitable spectral region in HHG. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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Review

Jump to: Research

30 pages, 1051 KiB

Open AccessReview

What We Can Learn about Ultrashort Pulses by Linear Optical Methods

by Adam Borzsonyi, Attila P. Kovacs and Karoly Osvay

Appl. Sci. 2013, 3(2), 515-544; https://doi.org/10.3390/app3020515 - 26 Apr 2013

Cited by 34 | Viewed by 13708

Abstract

Spatiotemporal compression of ultrashort pulses is one of the key issues of chirped pulse amplification (CPA), the most common method to achieve high intensity laser beams. Successful shaping of the temporal envelope and recombination of the spectral components of the broadband [...] Read more.

Spatiotemporal compression of ultrashort pulses is one of the key issues of chirped pulse amplification (CPA), the most common method to achieve high intensity laser beams. Successful shaping of the temporal envelope and recombination of the spectral components of the broadband pulses need careful alignment of the stretcher-compressor stages. Pulse parameters are required to be measured at the target as well. Several diagnostic techniques have been developed so far for the characterization of ultrashort pulses. Some of these methods utilize nonlinear optical processes, while others based on purely linear optics, in most cases, combined with spectrally resolving device. The goal of this work is to provide a review on the capabilities and limitations of the latter category of the ultrafast diagnostical methods. We feel that the importance of these powerful, easy-to-align, high-precision techniques needs to be emphasized, since their use could gradually improve the efficiency of different CPA systems. We give a general description on the background of spectrally resolved linear interferometry and demonstrate various schematic experimental layouts for the detection of material dispersion, angular dispersion and carrier-envelope phase drift. Precision estimations and discussion of potential applications are also provided. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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41 pages, 1710 KiB

Open AccessReview

Cutting-Edge High-Power Ultrafast Thin Disk Oscillators

by Clara J. Saraceno, Cinia Schriber, Florian Emaury, Oliver H. Heckl, Cyrill R. E. Baer, Martin Hoffmann, Kolja Beil, Christian Kränkel, Matthias Golling, Thomas Südmeyer and Ursula Keller

Appl. Sci. 2013, 3(2), 355-395; https://doi.org/10.3390/app3020355 - 2 Apr 2013

Cited by 33 | Viewed by 11043

Abstract

A growing number of applications in science and industry are currently pushing the development of ultrafast laser technologies that enable high average powers. SESAM modelocked thin disk lasers (TDLs) currently achieve higher pulse energies and average powers than any other ultrafast oscillator technology, [...] Read more.

A growing number of applications in science and industry are currently pushing the development of ultrafast laser technologies that enable high average powers. SESAM modelocked thin disk lasers (TDLs) currently achieve higher pulse energies and average powers than any other ultrafast oscillator technology, making them excellent candidates in this goal. Recently, 275 W of average power with a pulse duration of 583 fs were demonstrated, which represents the highest average power so far demonstrated from an ultrafast oscillator. In terms of pulse energy, TDLs reach more than 40 μJ pulses directly from the oscillator. In addition, another major milestone was recently achieved, with the demonstration of a TDL with nearly bandwidth-limited 96-fs long pulses. The progress achieved in terms of pulse duration of such sources enabled the first measurement of the carrier-envelope offset frequency of a modelocked TDL, which is the first key step towards full stabilization of such a source. We will present the key elements that enabled these latest results, as well as an outlook towards the next scaling steps in average power, pulse energy and pulse duration of such sources. These cutting-edge sources will enable exciting new applications, and open the door to further extending the current performance milestones. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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15 pages, 2150 KiB

Open AccessReview

Recent Developments in Experimental Techniques for Measuring Two Pulses Simultaneously

by Tsz Chun Wong and Rick Trebino

Appl. Sci. 2013, 3(1), 299-313; https://doi.org/10.3390/app3010299 - 18 Mar 2013

Cited by 6 | Viewed by 7529

Abstract

As many high-intensity ultrafast-optical measurements involve more than one pulse—typically one to excite a medium under study and another to probe it—a technique for measuring two pulses simultaneously is highly desirable. In two decades, two-pulse measurement techniques have advanced from ambiguity-laden to a [...] Read more.

As many high-intensity ultrafast-optical measurements involve more than one pulse—typically one to excite a medium under study and another to probe it—a technique for measuring two pulses simultaneously is highly desirable. In two decades, two-pulse measurement techniques have advanced from ambiguity-laden to a recently developed technique that can measure a pulse pair with arbitrary central wavelengths, complexities and bandwidths. Here, we review recent efforts to simultaneously measure two ultrashort laser pulses using a single device. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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11 pages, 1334 KiB

Open AccessReview

Spectral Shifts of Nonadiabatic High-Order Harmonic Generation

by Xue-Bin Bian and André D. Bandrauk

Appl. Sci. 2013, 3(1), 267-277; https://doi.org/10.3390/app3010267 - 13 Mar 2013

Cited by 17 | Viewed by 8728

Abstract

High-order harmonic generation (HHG) is a nonlinear nonperturbative process in ultrashort intense laser-matter interaction. It is the main source of coherent attosecond (1 as = 10⁻¹⁸ s) laser pulses to investigate ultrafast electron dynamics. HHG has become an important table-top source covering [...] Read more.

High-order harmonic generation (HHG) is a nonlinear nonperturbative process in ultrashort intense laser-matter interaction. It is the main source of coherent attosecond (1 as = 10⁻¹⁸ s) laser pulses to investigate ultrafast electron dynamics. HHG has become an important table-top source covering a spectral range from infrared to extreme ultraviolet (XUV). One way to extend the cutoff energy of HHG is to increase the intensity of the laser pulses. A consequence of HHG in such intense short laser fields is the characteristic nonadiabatic red and blue shifts of the spectrum, which are reviewed in the present work. An example of this nonperturbative light-matter interaction is presented for the one-electron nonsymmetric molecular ion HeH²⁺, as molecular systems allow for the study of the laser-molecule orientation dependence of such new effects including a four-step model of MHOHG (Molecular High-order Harmonic Generation). Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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16 pages, 801 KiB

Open AccessReview

Attosecond Hard X-ray Free Electron Laser

by Sandeep Kumar, Heung-Sik Kang and Dong-Eon Kim

Appl. Sci. 2013, 3(1), 251-266; https://doi.org/10.3390/app3010251 - 12 Mar 2013

Cited by 7 | Viewed by 8222

Abstract

In this paper, several schemes of soft X-ray and hard X-ray free electron lasers (XFEL) and their progress are reviewed. Self-amplified spontaneous emission (SASE) schemes, the high gain harmonic generation (HGHG) scheme and various enhancement schemes through seeding and beam manipulations are discussed, [...] Read more.

In this paper, several schemes of soft X-ray and hard X-ray free electron lasers (XFEL) and their progress are reviewed. Self-amplified spontaneous emission (SASE) schemes, the high gain harmonic generation (HGHG) scheme and various enhancement schemes through seeding and beam manipulations are discussed, especially in view of the generation of attosecond X-ray pulses. Our recent work on the generation of attosecond hard X-ray pulses is also discussed. In our study, the enhanced SASE scheme is utilized, using electron beam parameters of an XFEL under construction at Pohang Accelerator Laboratory (PAL). Laser, chicane and electron beam parameters are optimized to generate an isolated attosecond hard X-ray pulse at 0.1 nm (12.4 keV). The simulations show that the manipulation of electron energy beam profile may lead to the generation of an isolated attosecond hard X-ray of 150 attosecond pulse at 0.1 nm. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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37 pages, 2757 KiB

Open AccessReview

Ultra-Intense, High Spatio-Temporal Quality Petawatt-Class Laser System and Applications

by Hiromitsu Kiriyama, Takuya Shimomura, Michiaki Mori, Yoshiki Nakai, Manabu Tanoue, Shuji Kondo, Shuhei Kanazawa, Alexander S. Pirozhkov, Timur Z. Esirkepov, Yukio Hayashi, Koichi Ogura, Hideyuki Kotaki, Masayuki Suzuki, Izuru Daito, Hajime Okada, Atsushi Kosuge, Yuji Fukuda, Mamiko Nishiuchi, Masaki Kando, Sergei V. Bulanov, Keisuke Nagashima, Mitsuru Yamagiwa, Kiminori Kondo, Akira Sugiyama, Paul R. Bolton, Shinichi Matsuoka and Hirofumi Kan Show full author list Hide full author list

Appl. Sci. 2013, 3(1), 214-250; https://doi.org/10.3390/app3010214 - 7 Mar 2013

Cited by 15 | Viewed by 10495

Abstract

This paper reviews techniques for improving the temporal contrast and spatial beam quality in an ultra-intense laser system that is based on chirped-pulse amplification (CPA). We describe the design, performance, and characterization of our laser system, which has the potential for achieving a [...] Read more.

This paper reviews techniques for improving the temporal contrast and spatial beam quality in an ultra-intense laser system that is based on chirped-pulse amplification (CPA). We describe the design, performance, and characterization of our laser system, which has the potential for achieving a peak power of 600 TW. We also describe applications of the laser system in the relativistically dominant regime of laser-matter interactions and discuss a compact, high efficiency diode-pumped laser system. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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24 pages, 1937 KiB

Open AccessReview

Direct Electron Acceleration with Radially Polarized Laser Beams

by Charles Varin, Stéphane Payeur, Vincent Marceau, Sylvain Fourmaux, Alexandre April, Bruno Schmidt, Pierre-Louis Fortin, Nicolas Thiré, Thomas Brabec, François Légaré, Jean-Claude Kieffer and Michel Piché

Appl. Sci. 2013, 3(1), 70-93; https://doi.org/10.3390/app3010070 - 30 Jan 2013

Cited by 80 | Viewed by 11168

Abstract

In the past years, there has been a growing interest in innovative applications of radially polarized laser beams. Among them, the particular field of laser-driven electron acceleration has received much attention. Recent developments in high-power infrared laser sources at the INRS Advanced Laser [...] Read more.

In the past years, there has been a growing interest in innovative applications of radially polarized laser beams. Among them, the particular field of laser-driven electron acceleration has received much attention. Recent developments in high-power infrared laser sources at the INRS Advanced Laser Light Source (Varennes, Qc, Canada) allowed the experimental observation of a quasi-monoenergetic 23-keV electron beam produced by a radially polarized laser pulse tightly focused into a low density gas. Theoretical analyses suggest that the production of collimated attosecond electron pulses is within reach of the actual technology. Such an ultrashort electron pulse source would be a unique tool for fundamental and applied research. In this paper, we propose an overview of this emerging topic and expose some of the challenges to meet in the future. Full article

(This article belongs to the Special Issue Ultraintense Ultrashort Pulse Lasers)

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