Coherent excitation of equidistant multilevel systems in a resonant monochromatic field

M. K. Ermolaev, V. M. Chetverikov

G. K. Paramonov, В. А. Савва

В. А. Савва, V. I. Zelenkov, A. S. Mazurenko

A method based on the use of integral transform and orthogonal polynomials is presented to obtain the analytic solutions of the equations for coherent dynamics of multilevel quantum systems as simple molecular models describing molecule-radiation interactions in the high-power laser field and many other processes. As an example the Jacobi polynomials have been used and exact analytic solution has been obtained for dynamics of the family of multilevel Jacobi systems with both equidistant and nonequidistant energy levels, with various dependencies of dipole transition moments on energy, with both resonant and non-resonant laser excitation. Some special cases of the solution for definite systems from the family are given.

T. Ya. Karagodova, Alexander I. Karagodov, Andrey A. Eliseev

The theory of interaction of intense bichromatic field of laser radiation with multilevel atomic system in the external magnetic field is considered. The magnitudes of interaction are much larger than the width of atomic levels. The vector-potential of radiation field consisting of two monochromatic components with the frequencies resonant to adjacent transitions is taken in electric dipole approximation. The eigenvalues and eigenstates of the Hamiltonian, including spin-orbit interaction and interactions with laser radiation and external magnetic fields, are found without perturbation theory using resonant approximation. When the effects of resonantly excited radiation are considered the Hamiltonian of interaction with the weak field of scattered radiation is included also. Its eigenfunctions are found with the help of perturbation theory. We consider tow types of effects: polarization effects and effects of resonantly excited radiation. As the atomic system is multilevel we use the numerical methods. The influence of the magnetic field on coherent population trapping effect for multilevel systems is considered. Some of our theoretical results coincide with known experimental ones.

Alexander A. Makarov

Dmitrii I. Gruev

A study is made of the resonant interaction of monochromatic radiation with many-level weakly nonequidistant systems and also of the interaction of ultrashort radiation pulses with systems of the same kind when the carrier frequency of the pulses is near a resonance frequency. In both cases, equations are obtained that describe the interaction of the radiation with the many-level systems. Analytic solutions of the problem are obtained for a three-level equidistant system under certain additional assumptions. A way of reducing the problem to a set of homogeneous algebraic equations is indicated for the case of monochromatic radiation.