Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Journal of Experimental and Theoretical Physics

Local field effects and stimulated multimode scattering of resonance radiation in a two-level medium

M. G. Gladush, A. A. Panteleev, V. Roerich

Published Aug 1, 2006• 3 citations
Publisher

Abstract

Scattering of resonance radiation in a dense two-level medium is considered with allowance for the local field effects. The system is studied in the framework of the mean-field approximation for a modified hierarchy of the Bogoliubov-Born-Green-Kirkwood-Yvon equations for reduced density matrices of an ensemble of atoms and modes of a quantized electromagnetic field. The local field correction is consistently derived from the initial Hamiltonian of the system. The problem of scattering of a short rectangular pulse from a quasi-point sample is considered numerically and theoretically. The possibility of a multimode spectrum of scattered radiation with frequencies multiple of the Rabi frequency and with other intermediate frequencies is demonstrated. The relative intensities of spectral lines are determined.

DOI
10.1134/s1063776106080048

Related papers

Transient scattering of resonance radiation in a two-level system

A. A. Panteleev, V. Roerich, A. N. Starostin

A new method is developed for the description of transfer and scattering of a time-dependent laser pulse, which is based on a hierarchy of Bogoliubov-Born-Green-Kirkwood-Yvone (BBGKY) equations for reduced density matrices. The systems of equations are obtained for the atomic and photon density matrices and the correlation operator in the second-order Born approximation. The system of equations describes stimulated and spontaneous scattering of laser radiation in an optically thin medium, where reabsorption of spontaneous radiation can be neglected. The method proposed in the paper yields for the first time the correct expressions for nonstationary resonance fluorescence spectra, which do not give the negative values for fluorescence intensity. The expressions obtained for the resonance emission spectra coincide in limiting cases with those obtained within the framework of the quantum regression theorem.

Journal of Experimental and Theoretical Physics•Feb 1, 2003•5 citations

Two-wave stimulated Raman scattering in the field of intense radiation resonant to the Raman transition

Victor P. Kochanov, Yu. V. Bogdanova

The influence of a strong field resonant to the Raman transition on the behavior of the Stokes harmonic in saturated two-wave stimulated Raman scattering is theoretically considered based on the description of a gas of three-level atoms by medium density matrix equations. The vibrational mode of energy redistribution between laser and scattered radiation, threshold with respect to the resonant field intensity, is predicted. The action of optical fields on the absorption and amplification of the resonant field in a Raman medium is described.

Journal of Experimental and Theoretical Physics•Feb 1, 2003•4 citations

Rabi oscillations in the scattering-state representation

Ahmet Elçi, David A. Depatie

This paper presents an analysis of the Rabi oscillations of two-level atoms in the scattering-state representation. A collision complex obtained from a pair of identical two-level atoms is coupled to a field mode and it is found that there can be three distinct Rabi frequencies. These reduce to a single Rabi frequency for a photon distribution that is sharply peaked around an average number n\ifmmode\bar\else\textasciimacron\fi{}\ensuremath{\gg}1. One then finds that, in addition to the three frequency components in the off-diagonal element of the atomic density matrix, there are two components that are symmetrically displaced around the mode frequency at intervals of twice the Rabi frequency. They represent the collisionally induced cooperative motion of the atoms. When various observable quantities are averaged over the orientation of the complex, one obtains results that apply to many-atom systems in the binary collision approximation. Collisional effects do not enter the above results as lifetimes due to the fact that scattering states have precisely defined energies and correspond to entire particle histories. The collision potential opens up new radiative coupling channels, which collectively represent spectral line broadening. The collision potential and the radiative coupling combine to produce static and quasistatic dipole moments for the complex. At the threshold for atomic population inversion, the density matrix for the complex, as well as for an atom, becomes a constant multiple of the identity matrix, demonstrating that the threshold of stimulated emission is also a critical point for collisional effects, within the approximations of this paper.

Physical Review A•Aug 1, 1990•0 citations

Scattering of light by an intense saturating pulse in a resonance medium

V. I. Rupasov

A linear response of a resonant medium to a weak electromagnetic field is studied in the case when a medium is a gas of three-level atoms subjected to a strong saturating pulse. A noncoherent intense pulse and a coherent 2π pulse (of the kind encountered in the theory of self-induced transparency) are considered. The expressions obtained are used to study the problem of the spectrum of the reflection of light by a pulse moving in a medium. An analysis is made of the possibility of using the Doppler effect, which occurs when light is reflected by a moving pulse, in an investigation of the characteristics of pulse propagation, determination of its parameters, and study of the nonlinear characteristics of the medium itself. Possibilities of experimental observation of the predicted effects are discussed, particularly the possibility of conversion of an electromagnetic radiation spectrum.

Soviet Journal of Quantum Electronics•Nov 30, 1982•2 citations

Resonance line polarization and the Hanle effect in optically thick media. I - Formulation for the two-level atom

Egidio Landi Degl’Innocenti, V. Bommier, Sylvie Sahal-Bréchot

A general formalism is presented to describe resonance line polarization for a two-level atom in an optically thick, three-dimensional medium embedded in an arbitrary varying magnetic field and irradiated by an arbitrary radiation field. The magnetic field is supposed sufficiently small to induce a Zeeman splitting much smaller than the typical line width. By neglecting atomic polarization in the lower level and stimulated emission, an integral equation is derived for the multipole moments of the density matrix of the upper level. This equation shows how the multipole moments at any assigned point of the medium are coupled to the multipole moments relative at a different point as a consequence of the propagation of polarized radiation between the two points. The equation also accounts for the effect of the magnetic field, described by a kernel locally connecting multipole moments of the same rank, and for the role of inelastic and elastic (or depolarizing) collisions. After having given its formal derivation for the general case, the integral equation is particularized to the one-dimensional and two-dimensional cases. For the one-dimensional case of a plane parallel atmosphere, neglecting both the magnetic field and depolarizing collisions, the equation here derived reduces to a previous one given by Rees (1978).

•Aug 1, 1990•11 citations

Two-photon magneto-optical effects in atomic gases in resonant laser and strong magnetic fields

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.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 4, 2000•0 citations
Scattering of resonance radiation in a dense two-level medium is considered with allowance for the local field effects. The system is studied in the framework of the mean-field approximation for a modified hierarchy of the Bogoliubov-Born-Green-Kirkwood-Yvon equations for reduced density matrices of an ensemble of atoms and modes of a quantized electromagnetic field. The local field correction is consistently derived from the initial Hamiltonian of the system. The problem of scattering of a short rectangular pulse from a quasi-point sample is considered numerically and theoretically. The possibility of a multimode spectrum of scattered radiation with frequencies multiple of the Rabi frequency and with other intermediate frequencies is demonstrated. The relative intensities of spectral lines are determined.
A new method is developed for the description of transfer and scattering of a time-dependent laser pulse, which is based on a hierarchy of Bogoliubov-Born-Green-Kirkwood-Yvone (BBGKY) equations for reduced density matrices. The systems of equations are obtained for the atomic and photon density matrices and the correlation operator in the second-order Born approximation. The system of equations describes stimulated and spontaneous scattering of laser radiation in an optically thin medium, where reabsorption of spontaneous radiation can be neglected. The method proposed in the paper yields for the first time the correct expressions for nonstationary resonance fluorescence spectra, which do not give the negative values for fluorescence intensity. The expressions obtained for the resonance emission spectra coincide in limiting cases with those obtained within the framework of the quantum regression theorem.
The influence of a strong field resonant to the Raman transition on the behavior of the Stokes harmonic in saturated two-wave stimulated Raman scattering is theoretically considered based on the description of a gas of three-level atoms by medium density matrix equations. The vibrational mode of energy redistribution between laser and scattered radiation, threshold with respect to the resonant field intensity, is predicted. The action of optical fields on the absorption and amplification of the resonant field in a Raman medium is described.
This paper presents an analysis of the Rabi oscillations of two-level atoms in the scattering-state representation. A collision complex obtained from a pair of identical two-level atoms is coupled to a field mode and it is found that there can be three distinct Rabi frequencies. These reduce to a single Rabi frequency for a photon distribution that is sharply peaked around an average number n\ifmmode\bar\else\textasciimacron\fi{}\ensuremath{\gg}1. One then finds that, in addition to the three frequency components in the off-diagonal element of the atomic density matrix, there are two components that are symmetrically displaced around the mode frequency at intervals of twice the Rabi frequency. They represent the collisionally induced cooperative motion of the atoms. When various observable quantities are averaged over the orientation of the complex, one obtains results that apply to many-atom systems in the binary collision approximation. Collisional effects do not enter the above results as lifetimes due to the fact that scattering states have precisely defined energies and correspond to entire particle histories. The collision potential opens up new radiative coupling channels, which collectively represent spectral line broadening. The collision potential and the radiative coupling combine to produce static and quasistatic dipole moments for the complex. At the threshold for atomic population inversion, the density matrix for the complex, as well as for an atom, becomes a constant multiple of the identity matrix, demonstrating that the threshold of stimulated emission is also a critical point for collisional effects, within the approximations of this paper.
A linear response of a resonant medium to a weak electromagnetic field is studied in the case when a medium is a gas of three-level atoms subjected to a strong saturating pulse. A noncoherent intense pulse and a coherent 2π pulse (of the kind encountered in the theory of self-induced transparency) are considered. The expressions obtained are used to study the problem of the spectrum of the reflection of light by a pulse moving in a medium. An analysis is made of the possibility of using the Doppler effect, which occurs when light is reflected by a moving pulse, in an investigation of the characteristics of pulse propagation, determination of its parameters, and study of the nonlinear characteristics of the medium itself. Possibilities of experimental observation of the predicted effects are discussed, particularly the possibility of conversion of an electromagnetic radiation spectrum.
A general formalism is presented to describe resonance line polarization for a two-level atom in an optically thick, three-dimensional medium embedded in an arbitrary varying magnetic field and irradiated by an arbitrary radiation field. The magnetic field is supposed sufficiently small to induce a Zeeman splitting much smaller than the typical line width. By neglecting atomic polarization in the lower level and stimulated emission, an integral equation is derived for the multipole moments of the density matrix of the upper level. This equation shows how the multipole moments at any assigned point of the medium are coupled to the multipole moments relative at a different point as a consequence of the propagation of polarized radiation between the two points. The equation also accounts for the effect of the magnetic field, described by a kernel locally connecting multipole moments of the same rank, and for the role of inelastic and elastic (or depolarizing) collisions. After having given its formal derivation for the general case, the integral equation is particularized to the one-dimensional and two-dimensional cases. For the one-dimensional case of a plane parallel atmosphere, neglecting both the magnetic field and depolarizing collisions, the equation here derived reduces to a previous one given by Rees (1978).
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.