Conference "Ultrafast Optical Phenomena (Ultra fast Light-2023)" October 2-4, 2023, Lebedev Institute of Physics, Russian Academy of Sciences
Spectroscopy and physics of atoms and molecules

Two-photon excitation of nitrogen oxide at photofragmentation of nitrobenzene

A. V. Puchikin^a, Yu. N. Panchenko^ab, M. V. Andreev^b, I. N. Konovalov^a, V. E. Prokop'ev<sup>b

a</sup> Institute of High Current Electronics, Siberian Branch of the Russian Academy of Sciences, 634055 Tomsk, Russia
^b Tomsk State University, 634050 Tomsk, Russia

Abstract: The results of a study of the temporal and spectral characteristics of the fluorescence of nitric oxide NO A$^2\Sigma$ obtained under dual-frequency laser action with nitrobenzene C$_6$H$_5$NO$_2$ are presented. The physical mechanism for the appearance of fluorescence from the electronic level of NO A$^2\Sigma$, $v'$(0), caused by two-photon excitation of the electronic transition NO A$^2\Sigma$–X$^2\Pi$, $v'v''$(0,1) by laser radiation (472 nm) of femtosecond duration, is shown. In this case, vibrationally excited NO X$^2\Pi$, $v''$(1) molecules appear as photofragments of nitrobenzene after interaction with laser radiation of a KrF-laser (248.3 nm) of nanosecond duration. It is noted that registration of the fluorescent signal for this experimental setup is observed at a femtosecond pulse intensity of $\sim$300 GW/cm$^2$.

Keywords: photofragmentation, two-photon absorption, nitro compound, fluorescence.

Received: 11.12.2023
Revised: 09.01.2024
Accepted: 16.01.2024

DOI: 10.61011/OS.2024.01.57542.6-24

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