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

Quantum Electronics

Refractive distortions of partially coherent beams in inhomogeneously absorbing (amplifying) media

Vadim V. Dudorov, В. В. Колосов, O. A. Kolosova

Published Sep 30, 2001• 0 citations
Publisher

Abstract

Based on the equation for the second-order coherence function, the propagation of partially coherent radiation is studied under the combined action of diffraction and refraction caused by the inhomogeneous distribution of the real and imaginary parts of the perturbation of the permittivity of a medium in the case of inhomogeneous absorption (amplification). The limits of application of the method of geometrical optics for inhomogeneously absorbing (amplifying) media are studied, as well as of the methods that neglect refraction caused by the inhomogeneous distribution of the imaginary part of the permittivity of the medium.

DOI
10.1070/qe2001v031n09abeh002045

Related papers

Propagation of spatially inhomogeneous radiation in nonlinear resonant media

Igor' M Bel'dyugin, Michail G. Galushkin, E M Zemskov

A theoretical study is made of the influence of diffraction by self-induced amplitude gratings on propagation of spatially inhomogeneous radiation in nonlinear resonant media. Dependences of the gain and absorption, and also of the distortion of the spatial spectrum on the parameters of the medium and radiation are determined. It is shown that interfering radiation is amplified and absorbed under saturation conditions less strongly than is spatially homogeneous radiation.

Soviet Journal of Quantum Electronics•Oct 31, 1983•5 citations

Coherent states and light propagation in inhomogeneous media

Sergei G. Krivoshlykov, I N Sisakyan

Methods of integrals of motion, coherent states, dynamical symmetry group, and density matrix formalism are used to describe the propagation of light in weakly inhomogeneous media, in particular, in a two-dimensional medium having a quadratic transverse distribution of the refractive index and an arbitrarily inhomogeneous longitudinal distribution. Expressions are obtained for the trajectories and widths of the modes and rays. The coefficients of coupling between the modes and rays due to the longitudinal inhomogeneity of the medium and distortion of the axis are discussed. It is shown that, for certain laws of longitudinal inhomogeneity, matching occurs when no energy redistribution takes place between the modes and mismatch is found when all the energy is coupled out of the medium. On the basis of these effects, methods of matched joining of two different graded-index optical waveguides and of coupling light out of a graded-index waveguide are proposed. It is shown that each initial mode of the medium is strongly coupled to three final modes. These results may be used in fiber-optic communication lines.

Soviet Journal of Quantum Electronics•Mar 31, 1980•12 citations

Electromagnetic Waves in Amplifying Media

Vladimir Mitin, Dmitry I. Sementsov

The analysis of the phenomenon of refraction of electromagnetic waves at the interface between two media suggests that their velocity when passing from one medium to another changes. This chapter describes the basic principles of amplification and discusses the main features of wave propagation in amplifying media. Amplification occurs due to the induced coherent emission by excited atoms under the influence of the field of the electromagnetic wave. The chapter illustrates the attenuation of waves in an absorbing medium by using the Bouguer’s law. Bouguer’s law holds for a wide range of electromagnetic radiation—from radio waves to X-rays and gamma rays. The chapter discusses the main features of the different types of lasers such as solid-state lasers, gas lasers, dye lasers, and semiconductor lasers. It also includes some exercise problems related to the propagation of electromagnetic waves in amplifying media.

CRC Press eBooks•Nov 18, 2016•0 citations

Investigation of the amplification of ultrashort light pulses in three-level resonant systems

Leonid A Bol'shov, Nickolai N. Elkin, T. K. Kirichenko +2 more

An analysis is made of simultaneous propagation of pulses of different frequencies in many-level resonantly amplifying and absorbing media. Analytic expressions are obtained for the envelopes of fields in the case of propagation of two-frequency radiation in a three-level medium with a common lower level. Self-similar equations are obtained for the radiation propagating in an amplifying medium; in certain special cases, these equations are identical with those considered earlier.

Soviet Journal of Quantum Electronics•Jul 31, 1982•5 citations

Wave-mixing and Phase Conjugation in Laser Active Media

Kazuo Kuroda

Nonlinear optics normally involves the change in the susceptibility of a material due to the presence of optical radiation. In many cases, the light-matter interaction produces a change in the refractive index of the medium, as occurs in photorefractive media, as well as in Kerr-like media, Brillouin-active media and absorbing media with thermallyinduced refractive index changes. Such nonlinear refractive index variation corresponds to a change in the real part of the optical susceptibility %. In resonant materials, the optical radiation induces stimulated emission (or absorption) causing transfer of population between different energy states of the medium. This can lead to saturation of the amplification (or absorption) corresponding to changes in the imaginary part of the susceptibility x= i2odk where the amplitude gain coefficient a(I) is a saturable function of the intensity /, and k is the magnitude of the wavevector of the optical radiation. The interference of two (or more) coherent beams I(x) in the laser amplifier can cause a modulation of the population inversion N(x). This modulation of the inversion is commonly known as spatial hole burning in lasers and leads to formation of a gain-grating a(x) = 1/2GN(X) where G is the stimulated emission cross-section. The gain grating can act as a very efficient diffractive optical element exhibiting high diffraction efficiency that may be even greater than unity [16] and also very high phase conjugate reflectivity using four-wave mixing (FWM) geometries [5-7].

CRC Press eBooks•Mar 14, 2002•0 citations

Mechanisms of diffraction of light by optically induced gratings in absorbing media

Pavel A Apanasevich, Anatolii A Afanas'ev, А. И. Урбанович

A theoretical analysis is made of the transformation of light waves by optically induced amplitude-phase gratings of different order in a saturable absorbing medium. Allowance is made for gratings appearing; due to the absorption saturation and inhomogeneous heating of the medium. It is shown that, under certain conditions, the higher-order gratings may play a considerable role in the diffraction process. The contributions made by multistage and direct mechanisms to the n-th order diffraction are calculated. Estimates are obtained of the conditions which must be satisfied by the intensity and duration of radiation pulses, as well as by the optical properties and thickness of the absorbing medium, for these contributions to be comparable.

Soviet Journal of Quantum Electronics•Nov 30, 1975•2 citations
Based on the equation for the second-order coherence function, the propagation of partially coherent radiation is studied under the combined action of diffraction and refraction caused by the inhomogeneous distribution of the real and imaginary parts of the perturbation of the permittivity of a medium in the case of inhomogeneous absorption (amplification). The limits of application of the method of geometrical optics for inhomogeneously absorbing (amplifying) media are studied, as well as of the methods that neglect refraction caused by the inhomogeneous distribution of the imaginary part of the permittivity of the medium.
Methods of integrals of motion, coherent states, dynamical symmetry group, and density matrix formalism are used to describe the propagation of light in weakly inhomogeneous media, in particular, in a two-dimensional medium having a quadratic transverse distribution of the refractive index and an arbitrarily inhomogeneous longitudinal distribution. Expressions are obtained for the trajectories and widths of the modes and rays. The coefficients of coupling between the modes and rays due to the longitudinal inhomogeneity of the medium and distortion of the axis are discussed. It is shown that, for certain laws of longitudinal inhomogeneity, matching occurs when no energy redistribution takes place between the modes and mismatch is found when all the energy is coupled out of the medium. On the basis of these effects, methods of matched joining of two different graded-index optical waveguides and of coupling light out of a graded-index waveguide are proposed. It is shown that each initial mode of the medium is strongly coupled to three final modes. These results may be used in fiber-optic communication lines.
The analysis of the phenomenon of refraction of electromagnetic waves at the interface between two media suggests that their velocity when passing from one medium to another changes. This chapter describes the basic principles of amplification and discusses the main features of wave propagation in amplifying media. Amplification occurs due to the induced coherent emission by excited atoms under the influence of the field of the electromagnetic wave. The chapter illustrates the attenuation of waves in an absorbing medium by using the Bouguer’s law. Bouguer’s law holds for a wide range of electromagnetic radiation—from radio waves to X-rays and gamma rays. The chapter discusses the main features of the different types of lasers such as solid-state lasers, gas lasers, dye lasers, and semiconductor lasers. It also includes some exercise problems related to the propagation of electromagnetic waves in amplifying media.
Nonlinear optics normally involves the change in the susceptibility of a material due to the presence of optical radiation. In many cases, the light-matter interaction produces a change in the refractive index of the medium, as occurs in photorefractive media, as well as in Kerr-like media, Brillouin-active media and absorbing media with thermallyinduced refractive index changes. Such nonlinear refractive index variation corresponds to a change in the real part of the optical susceptibility %. In resonant materials, the optical radiation induces stimulated emission (or absorption) causing transfer of population between different energy states of the medium. This can lead to saturation of the amplification (or absorption) corresponding to changes in the imaginary part of the susceptibility x= i2odk where the amplitude gain coefficient a(I) is a saturable function of the intensity /, and k is the magnitude of the wavevector of the optical radiation. The interference of two (or more) coherent beams I(x) in the laser amplifier can cause a modulation of the population inversion N(x). This modulation of the inversion is commonly known as spatial hole burning in lasers and leads to formation of a gain-grating a(x) = 1/2GN(X) where G is the stimulated emission cross-section. The gain grating can act as a very efficient diffractive optical element exhibiting high diffraction efficiency that may be even greater than unity [16] and also very high phase conjugate reflectivity using four-wave mixing (FWM) geometries [5-7].
A theoretical analysis is made of the transformation of light waves by optically induced amplitude-phase gratings of different order in a saturable absorbing medium. Allowance is made for gratings appearing; due to the absorption saturation and inhomogeneous heating of the medium. It is shown that, under certain conditions, the higher-order gratings may play a considerable role in the diffraction process. The contributions made by multistage and direct mechanisms to the n-th order diffraction are calculated. Estimates are obtained of the conditions which must be satisfied by the intensity and duration of radiation pulses, as well as by the optical properties and thickness of the absorbing medium, for these contributions to be comparable.