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M. Kando,
A. S. Pirozhkov,
Y. Fukuda,
T. Zh. Esirkepov,
I. Daito,
K. Kawase,
J. L. Ma,
L. M. Chen,
Y. Hayashi,
M. Mori, [......],
J. K. Koga,
K. Belyaev,
F. F. Kamenets,
A. Sugiyama,
T. Kawachi,
H. Daido,
T. Kimura,
Y. Kato,
T. Tajima,
S. V. Bulanov
[show abstract]
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ABSTRACT: We present the results of experiments on the generation of both high and
low frequency electromagnetic radiation from the nonlinear interaction
of intense laser beams with underdense plasmas. High frequency radiation
is generated as a result of the reflection of a near-infrared laser beam by breaking plasma waves.
In the proof-of-principle experiment, a 2TW, 76fs Ti:sapphire laser pulse was focused
to generate wake waves, and a ~0.1TW laser pulse was focused to collide with the
electron density modulations. Frequencies of the reflected light were 56–110 times higher than
that of the initial laser. The estimated number of photons per solid angle was 3×107
photons/sr. Low frequency radiation is emitted by the plasma as well.
We found that the polarization of the radiation was similar to that of the driver laser.
These properties are in accordance with the generation mechanism
by relativistic solitons.
The European Physical Journal D 04/2012; 55(2):465-474. · 1.48 Impact Factor
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A S Pirozhkov,
M Kando,
T Zh Esirkepov,
P Gallegos,
H Ahmed, E N Ragozin,
A Ya Faenov,
T A Pikuz,
T Kawachi,
A Sagisaka, [......],
K Kondo,
T Kimura,
T Tajima,
H Daido,
P Rajeev,
P McKenna,
M Borghesi,
D Neely,
Y Kato,
S V Bulanov
[show abstract]
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ABSTRACT: We demonstrate a new high-order harmonic generation mechanism reaching the "water window" spectral region in experiments with multiterawatt femtosecond lasers irradiating gas jets. A few hundred harmonic orders are resolved, giving μJ/sr pulses. Harmonics are collectively emitted by an oscillating electron spike formed at the joint of the boundaries of a cavity and bow wave created by a relativistically self-focusing laser in underdense plasma. The spike sharpness and stability are explained by catastrophe theory. The mechanism is corroborated by particle-in-cell simulations.
Physical Review Letters 03/2012; 108(13):135004. · 7.37 Impact Factor
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M Kando,
A S Pirozhkov,
K Kawase,
T Zh Esirkepov,
Y Fukuda,
H Kiriyama,
H Okada,
I Daito,
T Kameshima,
Y Hayashi, [......],
H Daido,
A Ya Faenov,
T Pikuz,
J Ma,
L-M Chen, E N Ragozin,
T Kawachi,
Y Kato,
T Tajima,
S V Bulanov
[show abstract]
[hide abstract]
ABSTRACT: Laser light reflection by a relativistically moving electron density modulation (flying mirror) in a wake wave generated in a plasma by a high intensity laser pulse is investigated experimentally. A counterpropagating laser pulse is reflected and upshifted in frequency with a multiplication factor of 37-66, corresponding to the extreme ultraviolet wavelength. The demonstrated flying mirror reflectivity (from 3 x 10(-6) to 2 x 10(-5), and from 1.3 x 10(-4) to 0.6 x 10(-3), for the photon number and pulse energy, respectively) is close to the theoretical estimate for the parameters of the experiment.
Physical Review Letters 12/2009; 103(23):235003. · 7.37 Impact Factor
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[show abstract]
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ABSTRACT: The interaction of a gas jet (He, Ne, Xe) with the incident laser plasma from a solid target [B, (CH2)n, (CF4)n] removed by ≈1 cm is investigated. Line spectra arising from the charge exchange of multiply charged plasma ions with rare-gas atoms are recorded in the multiply charged ions–gas interaction region. The ratios between the partial cross sections of the charge exchange with the production of these ions in excited states are determined from the relative intensities of the Balmer series transitions in BV and CVI ions. These results are compared with theoretical data.
Quantum Electronics 01/2008; 37(11):1060. · 0.83 Impact Factor
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[show abstract]
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ABSTRACT: The interaction of a noble gas jet (Xe, Kr, He) with a laser plasma at a distance of ∼1 cm from a solid target (Mg, (CH2)n, LiF, or CF4) was studied for the first time. The line spectra that were excited in the course of charge exchange of multicharged ions
with noble gas atoms in the interaction region were recorded. A clean (debris-free) soft X-ray source excited by laser pulses
focused into a xenon jet was designed and investigated.
Plasma Physics Reports 01/2004; 30(2):149-153. · 0.65 Impact Factor
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[show abstract]
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ABSTRACT: We report on the numerical investigation of the reflection of extremely short (femto-and attosecond) x-ray pulses by multilayer structures (MSs). Periodic and aperiodic MSs are considered. We formulate the conditions whereby the reflection does not significantly change the pulse shape and length. The optimization of broadband aperiodic MSs from the viewpoint of the reflection of few-cycle pulses and the possibility of chirped-pulse compression are considered. It is shown that the power reflection coefficient can be appreciably higher than unity. Aperiodic MSs have been calculated which are capable of reflecting pulses comprising only three wave periods.
Journal of Optics A Pure and Applied Optics 05/2002; 4(4):433. · 1.92 Impact Factor
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[show abstract]
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ABSTRACT: The reflection of femto-and attosecond soft and hard X-ray pulses from multilayer structures (MSs) was investigated. The conditions
are formulated under which the pulse shape and duration barely change upon reflection. The MSs are optimized for the reflection
of extremely short pulses, and the possibility of compressing chirped pulses is considered. It is shown that the power reflection
coefficient can be appreciably larger than unity. The aperiodic MSs capable of effectively reflecting pulses containing no
more than three wave periods are calculated.
JETP Letters 07/2001; 74(3):149-153. · 1.35 Impact Factor
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[show abstract]
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ABSTRACT: We discuss the potentialities of aperiodic multilayer structures for the reflection of XUV radiation, including attooptical applications. Pilot samples of aperiodic normal-incidence broadband focusing multilayer mirrors are employed in a stigmatic transmission grating spectrograph with an operating range of 12.5–30 nm.This spectrograph was used to study (i) the XUV spectra arising from the charge exchange of laser-produced plasma ions with rare-gas (Xe, Kr, He) jet atoms, (ii) a debris-free Xe-jet plasma XUV source driven by Nd-laser pulses.
Radiation Physics and Chemistry. 75(11):1819-1823.
