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

Selective reflection of resonance radiation from excited media

B. A. Veklenko, R. B. Gusarov, Yu. B. Sherkunov

Published Feb 1, 1998• 3 citations
Publisher

Abstract

According to quantum electrodynamics, the cross section for resonant scattering of radiation on an aggregate of excited atoms can be written as a sum of positive definite terms. This type of structure is not consistent with the Fresnel formulas for the reflection coefficient of radiation from thermally excited media. The difference shows up on a macroscopic level and indicates that semiclassical radiation theory cannot be used. A study of the correlation between elastic scattering and stimulated emission processes clarifies the reason for the discrepancies. The resulting singularities require summing of Feynman diagrams which appear beginning in the sixth order of perturbation theory. A lower bound estimate for the reflection coefficient from a plane layer is given, including processes which violate the statistics of radiation. The contribution of stimulated emission processes caused by the initially scattered photon are examined specifically. An experiment is proposed which would settle the choice of theories.

DOI
10.1134/1.558455

Related papers

Coherent effects in the incoherent channel of resonant radiation scattering from excited atoms

B. A. Veklenko

Scattering of a resonance electromagnetic field from excited atoms cannot be described by the semiclassical theory of radiation operating with nonquantized electromagnetic fields. Field quantization effects are manifested in this case on the macroscopic level and lead to evolution of statistical properties of radiation in the course of scattering. It is found that a combined process coupling elastic scattering from an atom and induced emission from the same atom, which cannot be studied by the methods of the standard perturbation theory, plays a significant role in this effect. The process of combined scattering in extended media exhibits coherent properties that cannot be described by the standard refractive index.

Journal of Experimental and Theoretical Physics•May 1, 2011•0 citations

Coherent Stimulated Radiation, Coherent Spontaneous Radiation and Coupled Photon Pairs in Non-Uniform Thermally Excited Gaseous Media: The Theory

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.

Light & Engineering•Feb 1, 2022•0 citations

Statistical properties of resonance radiation selectively reflected from a cold semi-infinite medium

B. A. Veklenko, Yu. B. Sherkunov

The problem of the quantum-statistical properties of resonance radiation selectively reflected from unexcited media in the case where the photons are mutually correlated in the incident radiation flux is posed and solved. Allowance for mutual photon correlation precludes, in principle, solving the problem by perturbation methods. A quantum analog of the optical theorem of absorption, which causes an infinite subsequence of Feynman diagrams to vanish, is pointed out. The frequency-angle distribution of the photons in the reflected flux is predicted. The Fresnel formulas are reconstructed for the averaged reflection characteristics. The limits for their applicability in describing the reflection of mutually correlated photons are given. A suppression effect is predicted for the reflection of radiation from a laser source.

Journal of Experimental and Theoretical Physics•Sep 1, 1999•1 citation

Optical resonant processes in thin excited films

B. A. Veklenko, Yu. B. Sherkunov

It is shown that coherent processes of elastic scattering of resonant radiation form a “buffer” electromagnetic field near the boundary of excited media. This part of radiation is not governed by the standard refractive index, but precisely this part of radiation forms the beams reflected and refracted by the excited medium. The presence of the “buffer” field causes the suppression of stimulated emission near the boundary and leads to the appearance of a frequency angular broadening of the beam transmitted through a thin film of excited atoms at an oblique angle.

Optics and Spectroscopy•Sep 1, 2005•0 citations

COHERENT EFFECTS IN OPTICAL AND ATOMIC-MOLECULAR PROCESSES Change of Quantum Statistical Properties of Resonance Radiation during Its Scattering by Excited Systems

B. A. Veklenko

Quantum electrodynamics is a very cumbersome theory, and one tries to avoid it in applied problems. Experience shows that the semiclassical theory of radiation, which operates with a nonquantized elec� tromagnetic field, provides, as a rule, required accu� racy of calculations. The authority of the semiclassical theory of radiation has grown greatly, because it describes adequately the operation of quantum devices such as lasers. In this work we present an example that demon� strates the inadequacy of the semiclassical theory of radiation. It is shown that, upon resonance scattering of an electromagnetic field by excited systems, quanti� zation of the electromagnetic field is necessary and the consequences of this operation manifest themselves at the macroscopic level. Suppose that resonance radiation is scattered by a certain system, the initial state of which is described in the interaction representation by the wave function . The total wave function of the electromagnetic field and scattering system after the scattering is denoted by . Expansion of the function in terms of the basis of the wave functions of the scatterer has the form

•Jan 1, 2011•0 citations

The Hanle effect in forward scattering in excited media

B. A. Veklenko

A new method for calculating the density matrix of a quantized electromagnetic field which interacts with the environment in the presence of kinetic processes in the medium is suggested. This method accurately takes into account photon-photon quantum correlators and possesses certain symmetry properties, which substantially facilitate the summation of the Feynman diagrams that arise in the calculations. Forward scattering of resonance radiation by two-level gas atoms in a magnetic field is considered as an application. Insufficiency of a semiclassical description of this coherent process in excited media with the use of the unique tensor index of refraction is shown to follow from quantum electrodynamics. The introduction of one more function depending on the frequency of irradiation and the concentration of excited atoms is necessary. Experiments that simultaneously determine both this additional function and the standard refractive index of the medium are specified.

Journal of Experimental and Theoretical Physics•Jun 1, 2001•0 citations
According to quantum electrodynamics, the cross section for resonant scattering of radiation on an aggregate of excited atoms can be written as a sum of positive definite terms. This type of structure is not consistent with the Fresnel formulas for the reflection coefficient of radiation from thermally excited media. The difference shows up on a macroscopic level and indicates that semiclassical radiation theory cannot be used. A study of the correlation between elastic scattering and stimulated emission processes clarifies the reason for the discrepancies. The resulting singularities require summing of Feynman diagrams which appear beginning in the sixth order of perturbation theory. A lower bound estimate for the reflection coefficient from a plane layer is given, including processes which violate the statistics of radiation. The contribution of stimulated emission processes caused by the initially scattered photon are examined specifically. An experiment is proposed which would settle the choice of theories.
Scattering of a resonance electromagnetic field from excited atoms cannot be described by the semiclassical theory of radiation operating with nonquantized electromagnetic fields. Field quantization effects are manifested in this case on the macroscopic level and lead to evolution of statistical properties of radiation in the course of scattering. It is found that a combined process coupling elastic scattering from an atom and induced emission from the same atom, which cannot be studied by the methods of the standard perturbation theory, plays a significant role in this effect. The process of combined scattering in extended media exhibits coherent properties that cannot be described by the standard refractive index.
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.
The problem of the quantum-statistical properties of resonance radiation selectively reflected from unexcited media in the case where the photons are mutually correlated in the incident radiation flux is posed and solved. Allowance for mutual photon correlation precludes, in principle, solving the problem by perturbation methods. A quantum analog of the optical theorem of absorption, which causes an infinite subsequence of Feynman diagrams to vanish, is pointed out. The frequency-angle distribution of the photons in the reflected flux is predicted. The Fresnel formulas are reconstructed for the averaged reflection characteristics. The limits for their applicability in describing the reflection of mutually correlated photons are given. A suppression effect is predicted for the reflection of radiation from a laser source.
It is shown that coherent processes of elastic scattering of resonant radiation form a “buffer” electromagnetic field near the boundary of excited media. This part of radiation is not governed by the standard refractive index, but precisely this part of radiation forms the beams reflected and refracted by the excited medium. The presence of the “buffer” field causes the suppression of stimulated emission near the boundary and leads to the appearance of a frequency angular broadening of the beam transmitted through a thin film of excited atoms at an oblique angle.
Quantum electrodynamics is a very cumbersome theory, and one tries to avoid it in applied problems. Experience shows that the semiclassical theory of radiation, which operates with a nonquantized elec� tromagnetic field, provides, as a rule, required accu� racy of calculations. The authority of the semiclassical theory of radiation has grown greatly, because it describes adequately the operation of quantum devices such as lasers. In this work we present an example that demon� strates the inadequacy of the semiclassical theory of radiation. It is shown that, upon resonance scattering of an electromagnetic field by excited systems, quanti� zation of the electromagnetic field is necessary and the consequences of this operation manifest themselves at the macroscopic level. Suppose that resonance radiation is scattered by a certain system, the initial state of which is described in the interaction representation by the wave function . The total wave function of the electromagnetic field and scattering system after the scattering is denoted by . Expansion of the function in terms of the basis of the wave functions of the scatterer has the form
A new method for calculating the density matrix of a quantized electromagnetic field which interacts with the environment in the presence of kinetic processes in the medium is suggested. This method accurately takes into account photon-photon quantum correlators and possesses certain symmetry properties, which substantially facilitate the summation of the Feynman diagrams that arise in the calculations. Forward scattering of resonance radiation by two-level gas atoms in a magnetic field is considered as an application. Insufficiency of a semiclassical description of this coherent process in excited media with the use of the unique tensor index of refraction is shown to follow from quantum electrodynamics. The introduction of one more function depending on the frequency of irradiation and the concentration of excited atoms is necessary. Experiments that simultaneously determine both this additional function and the standard refractive index of the medium are specified.