High-energy laser summators based on the phenomenon of stimulated Raman scattering

1998 ◽  
Author(s):  
Nikolai G. Basov ◽  
A. Z. Grasyuk ◽  
E. M. Zemskov ◽  
V. M. Kazansky ◽  
V. M. Izgorodin ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Stimulated Raman Scattering ◽  
High Energy ◽  
Energy Laser ◽  
High Energy Laser ◽  
Stimulated Raman

scholarly journals Time evolution of stimulated Raman scattering and two-plasmon decay at laser intensities relevant for shock ignition in a hot plasma

2019 ◽  
Vol 7 ◽  
Author(s):  
G. Cristoforetti ◽  
L. Antonelli ◽  
D. Mancelli ◽  
S. Atzeni ◽  
F. Baffigi ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Raman Scattering ◽  
Inertial Confinement Fusion ◽  
Stimulated Raman Scattering ◽  
Critical Density ◽  
Time History ◽  
High Energy ◽  
Experimental Results ◽  
Stimulated Raman ◽  
Shock Ignition

Laser–plasma interaction (LPI) at intensities $10^{15}{-}10^{16}~\text{W}\cdot \text{cm}^{-2}$ is dominated by parametric instabilities which can be responsible for a significant amount of non-collisional absorption and generate large fluxes of high-energy nonthermal electrons. Such a regime is of paramount importance for inertial confinement fusion (ICF) and in particular for the shock ignition scheme. In this paper we report on an experiment carried out at the Prague Asterix Laser System (PALS) facility to investigate the extent and time history of stimulated Raman scattering (SRS) and two-plasmon decay (TPD) instabilities, driven by the interaction of an infrared laser pulse at an intensity ${\sim}1.2\times 10^{16}~\text{W}\cdot \text{cm}^{-2}$ with a ${\sim}100~\unicode[STIX]{x03BC}\text{m}$ scalelength plasma produced from irradiation of a flat plastic target. The laser pulse duration (300 ps) and the high value of plasma temperature ( ${\sim}4~\text{keV}$ ) expected from hydrodynamic simulations make these results interesting for a deeper understanding of LPI in shock ignition conditions. Experimental results show that absolute TPD/SRS, driven at a quarter of the critical density, and convective SRS, driven at lower plasma densities, are well separated in time, with absolute instabilities driven at early times of interaction and convective backward SRS emerging at the laser peak and persisting all over the tail of the pulse. Side-scattering SRS, driven at low plasma densities, is also clearly observed. Experimental results are compared to fully kinetic large-scale, two-dimensional simulations. Particle-in-cell results, beyond reproducing the framework delineated by the experimental measurements, reveal the importance of filamentation instability in ruling the onset of SRS and stimulated Brillouin scattering instabilities and confirm the crucial role of collisionless absorption in the LPI energy balance.

scholarly journals STIMULATED RAMAN SCATTERING IN PLASMAS PRODUCED BY LOW-ENERGY LASER

1998 ◽  
Vol 47 (1) ◽  
pp. 35
Author(s):  
JIANG XIAO-HUA ◽  
LI WEN-HONG ◽  
LIU YONG-GANG ◽  
DENG WU ◽  
DING YONG-KUN ◽  
...  
Keyword(s):  
Raman Scattering ◽  
Stimulated Raman Scattering ◽  
Low Energy ◽  
Energy Laser ◽  
Low Energy Laser ◽  
Stimulated Raman

scholarly journals Study of Impulsive Stimulated Raman Scattering Effects Using the Femtosecond Pump–Probe Z-Scan Technique

2021 ◽  
Vol 11 (24) ◽  
pp. 11667
Author(s):  
Mauro Falconieri ◽  
Serena Gagliardi ◽  
Flaminia Rondino ◽  
Michele Marrocco ◽  
Waruna D. Kulatilaka
Keyword(s):  
Raman Scattering ◽  
Stimulated Raman Scattering ◽  
Pump Probe ◽  
Practical Applications ◽  
Scattering Effects ◽  
Consistent Picture ◽  
Energy Laser ◽  
Probe Spectroscopy ◽  
Impulsive Stimulated Raman Scattering ◽  
Stimulated Raman

Impulsive stimulated Raman scattering (ISRS) is a nonlinear pump–probe spectroscopy technique particularly suitable to study vibrational intermolecular and intramolecular modes in complex systems. For the latter, recent studies of ISRS microscopy with low-energy laser sources have attracted attention for investigation of photosensitive or biological samples. Following this stream of interest, in this paper, we report an investigation on the relationship between femtosecond ISRS data and pump–probe Z-scan measurements, showing that the latter technique is capable of capturing the Kerr nonlinearities induced by the molecular vibrational modes. To this aim, firstly, spectrally filtered and Raman-induced Kerr ISRS signals were simultaneously acquired to determine the sample nonlinear response and to establish the reference data for the Z-scan analysis. Then, by adopting a suitable experimental arrangement to avoid thermo-optical effects, we were able to unambiguously observe the Raman-induced effects in Z-scan measurements, thus obtaining a consistent picture between ISRS and Z-scan for the first time, to the best of our knowledge. Practical applications of the proposed method include calibrated measurements of the contribution of the internal (Raman) and external molecular modes to the nonlinear refractive index.

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