Collisionally induced dephasing and rotational energy transfer in the CO2 Fermi dyad 'red' Q-branch 1285 cm(-1)статья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Аннотация:The present paper is focused on the development of an adequate description of collisionally induced dephasing and rotational energy transfer (RET) in the CO2 Fermi dyad v(1)/2v(2). We have made comparative analysis of two approaches to RET simulation for the 2v(2) Q-branch 1285 cm(-1) based on spectral exchange (SE) and rotational relaxation (RR) ideas. A special fitting procedure based on the minimization of an approximation error has been developed for fitting theoretical impulse responses to the experimental ones measured by picosecond time-domain coherent anti-Stokes Raman spectroscopy (CARS). A series of experiments on frequency-domain CARS were carried out in order to improve measurements of the dephasing time T-2 and to extend the simulation to the whole gas density range using a uniform set of fitting parameters. Special attention was paid to a detailed analysis of the rotational structure manifestation in the impulse response beating structure. In the case of the 'red' Q-branch, the RR model proved to be more appropriate in comparison with the SE model. It is shown that the rotational structure contribution to the time-domain signal decay and the cumulative spectral width remains essential and comparable with the collisional dephasing contribution up to the highest gas densities.