Study of processes taking place in the interaction of coherent radiation with multicomponent gaseous media

H.P. Grieneisen

Aleksandr M Leontovich, A. M. Mozharovskiǐ

Vladimir Leonardovich Derbov, Inna L. Plastun

Michail G. Galushkin, Evgenii B Gordon, М. С. Дроздов +1 more

An analysis is made of a nonlinear interaction of laser radiation with a chemically active medium in which a branched-chain reaction takes place. This reaction enhances greatly the contrast of phase gratings formed as a result of photodecomposition. The example of a gaseous mixture of hydrogen disulfide with oxygen is used in a theoretical investigation of a degenerate four-wave interaction in the course of photodissociation of CS2 molecules and subsequent reactions of the dissociation products. The dynamics of reflection is calculated for different CS2 concentrations and radiation intensities, and it is shown that a high efficiency can be achieved in such systems.

B. A. Veklenko

B. A. Veklenko

It is demonstrated that presence of stimulated radiation processes in gaseous media makes it possible to generate rays inversely reflected from interfaces of thermally excited gaseous media and the processes of left-hand refraction of the rays having passed through these media. These processes are caused by availability of coupled photonic states and stimulated radiation in media the properties of which differ from those of stimulated radiation in vacuum. Estimation of these processes is based on exclusion of the procedure of forced breaking of quantum correlators and correct consideration of high-order correlators. Along with Schrödinger’s and Heisenberg’s representations, this article uses also the less-known Γ- representation, which allows us to reduce a multi-particle problem of quantum electrodynamics to a single-particle problem within the an infinite-dimensional space. The equations formed in Г- representation are mathematically simpler and may be studied using the standard Wick’s theorem rather than its approximated thermodynamic variant suggested by T.A. Matsubara. Therefore it is possible to keep all possible solutions of the initial system of equations in mind. Of course, approximation methods are used for explicit solution of these equations. Using Feynman diagrams instead of the Dyson equation for quantum correlators, it is possible to find an equation defining the complete density matrix of a photonic sub-system.