scholarly journals Relativistic plasma aperture for laser intensity enhancement

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
M. Jirka ◽  
O. Klimo ◽  
M. Matys
Keyword(s):  
Laser Intensity ◽  
Relativistic Plasma ◽  
Intensity Enhancement

Intensity enhancement of attosecond XUV pulse by using asymmetric inhomogeneous mid-infrared down-chirped field

2017 ◽  
Vol 31 (26) ◽  
pp. 1750185 ◽  
Author(s):  
Liqiang Feng ◽  
Wenliang Li ◽  
Hang Liu
Keyword(s):  
Laser Intensity ◽  
Temporal Frequency ◽  
Three Dimensional ◽  
Pulse Generation ◽  
Homogeneous Field ◽  
Inhomogeneous Field ◽  
Plasmonic Enhancement ◽  
Positive Direction ◽  
Chirped Pulse ◽  
Intensity Enhancement

Intensity enhancement of the attosecond pulse generation from the high-order harmonic spectra has been theoretically investigated through solving the three-dimensional time-dependent Schrödinger equation. It is found that with the introduction of the down-chirped pulse, the temporal frequency of the down-chirp region is decreased. As a result, the ionized electrons can receive much more energy during its acceleration in this region, showing the extension of the harmonic cutoff. Moreover, due to the multi-harmonic emission events contribute to the higher harmonics, the intensity of the harmonic cutoff from the down-chirped pulse is 1.5 orders of magnitude higher than those from the chirp-free pulse. Further, by properly introducing the asymmetric inhomogeneous effect, the plasmonic enhancement of the laser intensity in the negative direction is larger than that in the positive direction. As a consequence, the ionized electron from the down-chirp region with the negative amplitude can obtain the additional acceleration, thus leading to the further extension of the harmonic cutoff. Especially when the spatial position of the inhomogeneous field is chosen to be the negative value, due to the improved enhancement of the laser intensity, not only the harmonic cutoff is extended but also the harmonic yield is near-stable, showing a 175 eV supercontinuum with the single short quantum path contribution. Finally, by directly superposing the selected harmonics, three attosecond XUV pulses with the full widths at half maximum of 38, 35 and 36 as can be obtained, which are nearly 1.5 orders of magnitude enhancement compared with the chirp-free homogeneous field case.

Problems in the theory of relativistic plasma microwave electronics

1997 ◽  
Vol 167 (10) ◽  
pp. 1025 ◽  
Author(s):  
M. Birau ◽  
M.A. Krasil'nikov ◽  
M.V. Kuzelev ◽  
Anri A. Rukhadze
Keyword(s):  
Relativistic Plasma ◽  
Microwave Electronics ◽  
Plasma Microwave

Effects of the Laser Intensity Profile on Ignition of Hydrogen-Air Mixture

2021 ◽  
Author(s):  
Albina Tropina ◽  
Sagar Pokharel ◽  
Mikhail N. Shneider
Keyword(s):  
Laser Intensity ◽  
Intensity Profile

scholarly journals Bright betatron radiation from direct-laser-accelerated electrons at moderate relativistic laser intensity

2021 ◽  
Vol 6 (4) ◽  
pp. 048401
Author(s):  
O. N. Rosmej ◽  
X. F. Shen ◽  
A. Pukhov ◽  
L. Antonelli ◽  
F. Barbato ◽  
...  
Keyword(s):  
Laser Intensity ◽  
Accelerated Electrons ◽  
Direct Laser

scholarly journals Nonlinear Absorption and Ultrafast Dynamics of Ag Nanoparticle

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 233
Author(s):  
Jijuan Jiang ◽  
Jun Wang ◽  
Tong Wu ◽  
Yachen Gao
Keyword(s):  
Silver Nanoparticles ◽  
Time Constant ◽  
Laser Intensity ◽  
Photon Absorption ◽  
Saturable Absorption ◽  
Phonon Coupling ◽  
Saturated Absorption ◽  
Coupling Process ◽  
Two Photon Absorption ◽  
Two Photon

Resonant nonlinear optical absorption of silver nanoparticles was studied experimentally via open aperture Z-scan using 130 fs, 400 nm laser pulses. Experimental results show that, at low laser intensity, silver nanoparticles can exhibit saturated absorption. While at high laser intensity, it shows reverse saturated absorption. The saturable absorption is explained in terms of ground state plasmon bleaching, while the reverse saturable absorption is believed to be from two-photon absorption. Saturable optical intensity and two-photon absorption coefficient were obtained to be 1.3×1010 W/m2 and 3.3×10−10 m/W, respectively. The energy relaxation process of Ag nanoparticles after laser excitation was studied via pump-probe technique at 400 nm. Experimental results demonstrated that energy relaxation included electron-phonon coupling process with time constant τ1=(713±50) fs, and phonon-phonon coupling process with time constant τ2=(25.2±3) ps, respectively.

Effects of ion and electron drifts on large amplitude solitary waves in a relativistic plasma

1997 ◽  
Vol 4 (12) ◽  
pp. 4232-4235 ◽  
Author(s):  
Rajkumar Roychoudhury ◽  
S. K. Venkatesan ◽  
Chandra Das
Keyword(s):  
Solitary Waves ◽  
Large Amplitude ◽  
Relativistic Plasma

scholarly journals Reflecting petawatt lasers off relativistic plasma mirrors: a realistic path to the Schwinger limit

2021 ◽  
Vol 9 ◽  
Author(s):  
Fabien Quéré ◽  
Henri Vincenti
Keyword(s):  
Light Intensity ◽  
High Power ◽  
Quantum Electrodynamics ◽  
Laser Light ◽  
Optical Breakdown ◽  
Relativistic Plasma ◽  
Laser Beams ◽  
Relativistic Motion ◽  
Quantum Vacuum ◽  
High Power Lasers

Abstract The quantum vacuum plays a central role in physics. Quantum electrodynamics (QED) predicts that the properties of the fermionic quantum vacuum can be probed by extremely large electromagnetic fields. The typical field amplitudes required correspond to the onset of the ‘optical breakdown’ of this vacuum, expected at light intensities >4.7×1029 W/cm2. Approaching this ‘Schwinger limit’ would enable testing of major but still unverified predictions of QED. Yet, the Schwinger limit is seven orders of magnitude above the present record in light intensity achieved by high-power lasers. To close this considerable gap, a promising paradigm consists of reflecting these laser beams off a mirror in relativistic motion, to induce a Doppler effect that compresses the light pulse in time down to the attosecond range and converts it to shorter wavelengths, which can then be focused much more tightly than the initial laser light. However, this faces a major experimental hurdle: how to generate such relativistic mirrors? In this article, we explain how this challenge could nowadays be tackled by using so-called ‘relativistic plasma mirrors’. We argue that approaching the Schwinger limit in the coming years by applying this scheme to the latest generation of petawatt-class lasers is a challenging but realistic objective.

Thermally activated delayed fluorescent photosensitizer for photodynamic therapy of oral squamous cell carcinoma under low laser intensity

2021 ◽  
Author(s):  
Shiqi Hu ◽  
Bin Huang ◽  
Yumei Pu ◽  
Chengwan Xia ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Squamous Cell Carcinoma ◽  
Photodynamic Therapy ◽  
Oral Squamous Cell Carcinoma ◽  
Cell Carcinoma ◽  
Squamous Cell ◽  
Laser Intensity ◽  
Thermally Activated

In this report, a new Thermally activated delayed fluorescent(TADF) molecule [2-(4-triphenylvinyl-phenyl)-anthraquinone (TPE-AQ)] was synthesized. This nanomaterial has satisfactory photostability. In vitro, it was indicated that these TADF nanoparticles (NPs) were...

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