scholarly journals Combined modulation of incident laser light by multiple surface scratches and their effects on the laser damage properties of KH2PO4 crystal

2020 ◽  
Vol 28 (6) ◽  
pp. 8764 ◽  
Author(s):  
Jian Cheng ◽  
Jinghe Wang ◽  
Enhong Peng ◽  
Hao Yang ◽  
Hao Chen ◽  
...  
Keyword(s):  
Laser Light ◽  
Laser Damage ◽  
Incident Laser

scholarly journals Dynamics of ultrafast heated radiative plasmas driven by petawatt laser light

2021 ◽  
Author(s):  
Kaoru Sugimoto ◽  
Natsumi Iwata ◽  
Atsushi Sunahara ◽  
Takayoshi Sano ◽  
Yasuhiko Sentoku
Keyword(s):  
Energy Density ◽  
Laser Light ◽  
Laser Intensity ◽  
High Energy ◽  
High Energy Density ◽  
Silver Foil ◽  
Cooling Process ◽  
Incident Laser ◽  
X Ray ◽  
Cooling Effects

Abstract A relativistic petawatt laser light can heat heavy metals over keV temperature isochorically and ionize them almost fully. Copious hard X-rays are emitted from the high-Z hot plasma which acts as X-ray sources, while they work as a cooling process of the plasma. The cooling process can affect on the creation of high energy density plasma via the interaction, however, the details are unknown. The X-ray spectrum depends on the plasma temperature, so that it is worthwhile to investigate the radiation cooling effects. We here study the isochoric heating of a solid silver foil irradiated by relativistic laser lights with a help of particle-in-cell simulations including Coulomb collisions, ionizations, and radiation processes. We have conducted a parameter survey varying laser intensity, 1018-20 W/cm2, to check the cooling effects while keeping the incident laser energy constant. The silver plasma heated mainly by the resistive heating dissipates its energy by keV X-ray emissions in a picosecond time scale. The radiation power from the silver foil is found to be comparable to the incident laser power when the laser intensity is less than 1019 W/cm2 under the constant energy situation. The evolution of the plasma energy density inside the target is then suppressed, due to which a highly compressed collisional shock is formed at the target surface and propagates into the plasma. The radiation spectra of the keV silver plasma are also demonstrated.

scholarly journals Brilliance of X rays and gamma rays produced by Compton backscattering of laser light from high-energy electrons

1998 ◽  
Vol 16 (1) ◽  
pp. 115-127 ◽  
Author(s):  
R. W. John
Keyword(s):  
Photon Energy ◽  
Laser Light ◽  
High Energy ◽  
Scattered Photon ◽  
Spectral Brightness ◽  
X Rays ◽  
Incident Laser ◽  
Laser Photon ◽  
Defining Relation ◽  
Compton Backscattering

In the Compton backscattering of laser light from a high-energy electron beam, the scattered photons are, as is well known, much harder than the incident photons. In connection with the inverse Compton effect, the spectral brightness, the brilliance of the backscattered radiation is theoretically investigated. For the brilliance B [photons/(sec × mm2 × sr × 0.1% bandwidth)] of the scattered radiation a defining relation is given. Then, the intensity I0 and the wavelength λ 0 of the incident laser light are assumed such that the intensity parameter η is sufficiently smaller than 1, so that with regard to the scattering process, multiphoton effects need not be considered, and the backscattered photon energy hν and the differential cross section dσ/dω approximately do not depend on η. In this case, the brilliance B linearly scales with I0. Furthermore, it is assumed that the primary electron and the incident laser photon are counterpropagating along a straight line, the head-on incidence of the laser photon. On these assumptions, for the brilliance B of the backscattered radiation, B depending on the back-scattered photon energy hν, an explicit formula is derived; from it, by approximations, a shorter formula for B is obtained.

scholarly journals Three-wave parametric instabilities in long-scale-length, somewhat planar, laser-produced plasmas

1992 ◽  
Vol 10 (4) ◽  
pp. 599-616 ◽  
Author(s):  
R. P. Drake
Keyword(s):  
Laser Light ◽  
Light Wave ◽  
Scaling Behavior ◽  
Large Role ◽  
Incident Laser ◽  
Plasma Parameters ◽  
Planar Laser ◽  
Transverse Scale ◽  
Parametric Instabilities ◽  
Scale Length

Three-wave parametric instabilities, in which an incident, laser-light wave resonantly decays into two decay waves, have long been recognized to potentially play a large role in the physics of laser-produced plasmas. Many effects have been predicted, but only gradually and with difficulty have experiments developed the ability to observe some of them. One obstacle has been that the behavior of the instabilities often depends upon the scale length and planarity of the plasma. My collaborators and I have worked for several years to overcome this specific obstacle and when necessary now work routinely with plasmas that are thousands of laser wavelengths in the axial and transverse scale lengths of the plasma parameters. This has allowed us to report the first observations of some instabilities and study the scaling behavior of several instabilities as well.

Self-Focusing of Laser Light and Stimulated Scattering Processes in Transparent and Absorbing Liquids: 1. Self-Focusing

1970 ◽  
Vol 25 (12) ◽  
pp. 1868-1879 ◽  
Author(s):  
M. Maier ◽  
O. Rahn ◽  
G. Wendl
Keyword(s):  
Laser Power ◽  
Laser Light ◽  
Beam Diameter ◽  
Incident Laser ◽  
Stimulated Scattering ◽  
Light Pulses ◽  
Incident Laser Power ◽  
Self Focusing ◽  
Stimulated Brillouin ◽  
Good Agreement

Abstract The spatial and temporal development of self-focusing of light pulses is investigated. The beam diameter in CS2 and molten para-di-chlorobenzene decreases with increasing incident laser power to small values in good agreement with theory. The strong influence of beam divergence, non-linearity of refractive index, and absorption on self-focusing action is found to agree well with numerical calculations. It is shown that both backward stimulated Brillouin and Raman scattering terminate the self-focusing process.

Photorefractive Optical Limiters

1994 ◽  
Vol 374 ◽  
Author(s):  
Gregory J. Salamo ◽  
Galen C. Duree ◽  
Matthew Morin ◽  
Edward J. Sharp ◽  
Gary L. Wood ◽  
...  
Keyword(s):  
Electric Fields ◽  
Optical Density ◽  
Pulse Width ◽  
Optical Pulse ◽  
Laser Light ◽  
Photorefractive Crystal ◽  
Incident Laser ◽  
Optical Limiters ◽  
Optical Limiter

AbstractWe consider the application of photorefractive beam fanning as an optical limiter. Results indicate that by focusing the incident laser light into the photorefractive crystal and by applying electric fields that limiting is possible at the 10μJ range with an optical density or O. D. of 3. These results are independent of the incident optical pulse width.

scholarly journals Numerical modelling of the cluster targets for their optimization in femtosecond-laser-cluster-driven experiments

2017 ◽  
Vol 35 (3) ◽  
pp. 397-408 ◽  
Author(s):  
A.S. Boldarev ◽  
A.Y. Faenov ◽  
Y. Fukuda ◽  
S. Jinno ◽  
T.A. Pikuz ◽  
...  
Keyword(s):  
Numerical Model ◽  
Femtosecond Laser ◽  
Numerical Modelling ◽  
Laser Light ◽  
Spatial Configuration ◽  
Laser Pulses ◽  
Intense Laser ◽  
Incident Laser ◽  
Intense Laser Pulses ◽  
Nozzle Flows

AbstractThe interaction of femtosecond ultra-intense laser pulses with clusters increases absorption of the incident laser light compared with the interaction with solid targets and leads to enhanced generation of different quantum beams with unique parameters. Future investigations of such interaction urgently need detailed modeling and optimization of cluster parameters, for instance, in order to obtain the clusters with desired size, or some specific spatial configuration of the target etc. A numerical model of gas-cluster targets production by the nozzle flows of gases and binary mixtures is presented. Some previous results of the model utilization are summarized, and some new results are given. Techniques of experimental verification of the numerical results are discussed.

Crystalline Structure Determination of Anisotropic Dimethyl Terephthalate Crystallites by Micro-Raman Spectroscopy

2000 ◽  
Vol 15 (6) ◽  
pp. 1397-1403 ◽  
Author(s):  
R. Rodrĺguez ◽  
S. Pacheco ◽  
S. Vargas ◽  
S. Jiménez ◽  
V. M. Castaño
Keyword(s):  
Molecular Orientation ◽  
Symmetry Axis ◽  
Laser Light ◽  
Incident Laser ◽  
Crystal Axis ◽  
Micro Raman Spectroscopy ◽  
Dimethyl Terephthalate ◽  
Novel Approach ◽  
Tilting Angle

A novel approach to determine the molecular orientation of dimethyl terephthalate molecules with respect to the direction of the crystal axis is reported. This determination was achieved by changing the crystal orientation with respect to the incident laser light of a micro-Raman spectrometer. Raman spectra were obtained at different incidence angles of the laser beam with respect to the crystal symmetry axis. The intensities of some specific bands were analyzed as a function of the tilting angle. With this information the molecular orientation with respect to the crystal axis was determined making use of a simple mechanical model.

scholarly journals Conversion of laser light into soft X rays with 3-ns and 30-ps laser pulses

1991 ◽  
Vol 9 (2) ◽  
pp. 551-562 ◽  
Author(s):  
K. Eidmann ◽  
W. Schwanda
Keyword(s):  
Laser Light ◽  
Laser Energy ◽  
Short Pulse ◽  
Laser Pulses ◽  
X Rays ◽  
Incident Laser ◽  
X Ray ◽  
Transmission Grating ◽  
Incident Laser Energy ◽  
Temporal And Spatial

The X-ray emission from planar targets made of aluminum, copper, or gold irradiated by a frequency-doubled Nd laser (530-nm wavelength and 1012–1014-W/cm2 laser intensity) was measured at two pulse durations: 3 ns and 30 ps. We absolutely measured the X-ray emission with spectral, temporal, and spatial resolution in the wavelength range 3 Å < λ < 250 Å by using filtered bolometers, a transmission grating spectrometer, X-ray diodes, and an X-ray streak camera as diagnostics. In addition, the absorption of laser light was measured. For the short, 30-ps laser pulse the conversion of incident laser energy into X rays was considerably less than that with the long, 3-ns pulse. This is caused by less absorption of laser light and, in addition, by less conversion of absorbed laser energy into X rays in the case of the short pulse. The results are compared with numerical simulations performed with the MULTI hydrocode.

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