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

Physical Review A

Light-induced gain and directional energy flow with counterpropagating light beams in dense media

B. A. Samson, Wojciech Gawlik

Published Dec 1, 1995• 4 citations
Publisher

Abstract

Counterpropagation of two light beams in a resonant medium so dense that the local driving field differs from the external field is considered. It is shown that efficient energy transfer between the two beams occurs if there is some asymmetry between their propagation conditions due to, e.g., their frequency difference or Doppler detuning caused by the motion of the medium. The directional energy flow may predominate over absorption and lead to gain.

DOI
10.1103/physreva.52.r4352

Related papers

Instability and chaos of counterpropagating beams in a nonlinear medium.

Railing Chang

The dynamical behavior of counterpropagating light waves interacting with a nonlinear medium is studied numerically. It is found that the wave and the medium form a system that becomes unstable under certain conditions and exhibits self-oscillation. Because the interacting medium is modeled by an ensemble of two-level systems, we recognize the self-oscillation frequency as the Rabi-frequency of the constituent systems. The physical mechanisms responsible for this self-oscillation are the gain and the distributed feedback of the combined lightwave-medium system. When the environment changes, in particular when the intensity is increased, this system becomes more unstable and we find that the oscillation exhibits more complex behavior, including quasi-periodic motion and chaos. We analyze the output fields by using Fourier spectra, phase portraits, and autocorrelation functions. In the chaotic regime, the Lyapunov exponents and dimensions are also calculated. A physical interpretation of the quasiperiodic motion is given by an exact calculation of the absorption spectrum of our two-level medium. The negative absorption (gain) peaks are found at the frequencies of the quasi-periodic motions, thus implying that the gain of the combined light-medium system is responsible at least in part for the observed complex behavior. In addition, we investigate the stability of the propagating plane wave when a transverse wave is added to the system as a perturbation. Instabilities are analyzed by linearizing the nonlinear equations which model the lightwave-medium system. The results show that the instability is highly-correlated with the four-wave mixing phase conjugation.

•Jan 1, 1991•0 citations

Two-Wave Mixing In Resonant Media

Ragini Saxena, Pao-Chi Yeh

We have studied two-wave mixing in resonant media. Illumination with two beams of the same frequency leads to the formation of a spatially local volume grating with no exchange of energy between the writing beams, each beam merely reducing the absorption experienced by the other beam. Nondegenerate two-wave mixing leads to gain for one beam and additional absorption for the other beam as they propagate through the medium. Starting from first principles, the explicit forms of the two-beam coupling constants are derived using third-order perturbation theory, and their dependence on material and experimental factors is examined.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Aug 8, 1989•0 citations

New Doppler-free resonance in field of counterpropagating waves

Denis V. Brazhnikov, А. В. Тайченачев, Anatolii M Tumaikin +7 more

The resonance of saturated absorption in counterpropagating light fields is experimentally and theoretically studied. We focus on two cases: parallel and linearly polarized waves, driving an open dipole transition and the general case of elliptically polarized waves, driving closed dipole transition. The former reveals a new Doppler-free resonance as a peak within the saturated-absorption dip. The latter case reveals a new polarization effect, causing a shift and asymmetry of the saturated-absorption resonance. The results obtained can be found useful in metrology.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jun 15, 2007•0 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

New features of Doppler-free saturated-absorption resonance in field of counterpropagating waves

Denis V. Brazhnikov, А. В. Тайченачев, Anatolii M Tumaikin +7 more

The resonance of saturated absorption in counterpropagating light fields is experimentally and theoretically studied. We focus on two cases: parallel and linearly polarized waves, driving an open dipole transition and the general case of elliptically polarized waves, driving closed dipole transition. The former reveals a new Doppler-free resonance as a peak within the saturated-absorption dip. The latter case reveals a new polarization effect, causing a shift and asymmetry of the saturated-absorption resonance. The results obtained can be found useful in metrology.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jun 18, 2007•0 citations

New Doppler-free resonance in counterpropagating light waves

Sergei A. Zibrov, Leonid A. Sidorenkov, Peter A. Siushev +6 more

The resonance of saturated absorption in counterpropagating light fields is experimentally and theoretically studied. We focus on a case of parallel and linearly polarized waves, driving an open dipole transition in rubidium vapor. A new Doppler-free resonance within the saturated-absorption dip is revealed. The phenomenon can be gained only in absorption of strong wave in presence of weak one. The effect can not be explained basing on the previously known reasons. The results obtained can be found useful in metrology for the frequency and time standards.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Jul 17, 2008•0 citations
Counterpropagation of two light beams in a resonant medium so dense that the local driving field differs from the external field is considered. It is shown that efficient energy transfer between the two beams occurs if there is some asymmetry between their propagation conditions due to, e.g., their frequency difference or Doppler detuning caused by the motion of the medium. The directional energy flow may predominate over absorption and lead to gain.
The dynamical behavior of counterpropagating light waves interacting with a nonlinear medium is studied numerically. It is found that the wave and the medium form a system that becomes unstable under certain conditions and exhibits self-oscillation. Because the interacting medium is modeled by an ensemble of two-level systems, we recognize the self-oscillation frequency as the Rabi-frequency of the constituent systems. The physical mechanisms responsible for this self-oscillation are the gain and the distributed feedback of the combined lightwave-medium system. When the environment changes, in particular when the intensity is increased, this system becomes more unstable and we find that the oscillation exhibits more complex behavior, including quasi-periodic motion and chaos. We analyze the output fields by using Fourier spectra, phase portraits, and autocorrelation functions. In the chaotic regime, the Lyapunov exponents and dimensions are also calculated. A physical interpretation of the quasiperiodic motion is given by an exact calculation of the absorption spectrum of our two-level medium. The negative absorption (gain) peaks are found at the frequencies of the quasi-periodic motions, thus implying that the gain of the combined light-medium system is responsible at least in part for the observed complex behavior. In addition, we investigate the stability of the propagating plane wave when a transverse wave is added to the system as a perturbation. Instabilities are analyzed by linearizing the nonlinear equations which model the lightwave-medium system. The results show that the instability is highly-correlated with the four-wave mixing phase conjugation.
We have studied two-wave mixing in resonant media. Illumination with two beams of the same frequency leads to the formation of a spatially local volume grating with no exchange of energy between the writing beams, each beam merely reducing the absorption experienced by the other beam. Nondegenerate two-wave mixing leads to gain for one beam and additional absorption for the other beam as they propagate through the medium. Starting from first principles, the explicit forms of the two-beam coupling constants are derived using third-order perturbation theory, and their dependence on material and experimental factors is examined.
The resonance of saturated absorption in counterpropagating light fields is experimentally and theoretically studied. We focus on two cases: parallel and linearly polarized waves, driving an open dipole transition and the general case of elliptically polarized waves, driving closed dipole transition. The former reveals a new Doppler-free resonance as a peak within the saturated-absorption dip. The latter case reveals a new polarization effect, causing a shift and asymmetry of the saturated-absorption resonance. The results obtained can be found useful in metrology.
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].
The resonance of saturated absorption in counterpropagating light fields is experimentally and theoretically studied. We focus on two cases: parallel and linearly polarized waves, driving an open dipole transition and the general case of elliptically polarized waves, driving closed dipole transition. The former reveals a new Doppler-free resonance as a peak within the saturated-absorption dip. The latter case reveals a new polarization effect, causing a shift and asymmetry of the saturated-absorption resonance. The results obtained can be found useful in metrology.
The resonance of saturated absorption in counterpropagating light fields is experimentally and theoretically studied. We focus on a case of parallel and linearly polarized waves, driving an open dipole transition in rubidium vapor. A new Doppler-free resonance within the saturated-absorption dip is revealed. The phenomenon can be gained only in absorption of strong wave in presence of weak one. The effect can not be explained basing on the previously known reasons. The results obtained can be found useful in metrology for the frequency and time standards.