Open AccessTime-resolved optical probing of the non-equilibrium supercritical state in molecular media under ns laser-plasma impact
Author(s) -
Evgenii Mareev,
Н. В. Минаев,
Е. О. Епифанов,
I. N. Tsymbalov,
Аlexander P. Sviridov,
Vyacheslav M Gordienko
Publication year - 2021
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.441690
Subject(s) - raman spectroscopy , optics , laser , materials science , nanosecond , supercritical fluid , spectroscopy , dye laser , optoelectronics , chemistry , physics , organic chemistry , quantum mechanics
We proposed a complex method based on a combination of shadow photography and time-resolved Raman spectroscopy to observe the non-stationary laser-induced supercritical state in molecular media. Shadow photography is applied for retrieving pressure values, while Raman spectroscopy with molecular dynamics for temperature estimation. Time resolution of 0.25 ns is achieved by varying the delay between the pump (creating an extreme energy delivery) and the probe laser pulses by the self-made digital delay electronic circuit . The proposed method was employed in liquid carbon dioxide and water. Under nanosecond laser pulse impact, the estimated temperatures and pressures (∼700 K and ∼0.5 GPa) achieved in media are higher than the critical parameters of the samples.