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

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Reflectivity of gain gratings induced by CO laser multifrequency radiation in flow-active medium

А. В. Бердышев, A K Kurnosov, Anatoly P. Napartovich

Published Apr 11, 1996• 0 citations
Publisher

Abstract

The spectra of reflectivity and transmissivity of gain gratings induced by cw CO laser radiation in a flow active medium were calculated. Strong variations in the reflectivity spectrum for the different sets of relative phases of the interference fields were disclosed.
DOI
10.1117/12.238054

Related papers

Formation of amplitude gratings in the medium of a CO laser subject to the field of its own multifrequency radiation

А. В. Бердышев, A K Kurnosov, Anatoly P. Napartovich

It is shown that, under conditions typical of the active medium of a continuous-flow CO laser, large-scale gain gratings play the main role in a phase-conjugation system based on degenerate four-wave mixing. The multifrequency nature of the emission spectrum of a CO laser increases the depth of modulation of the amplitude gratings as a result of two principal mechanisms: the dependence of the rate of relaxation of the function describing the distribution of molecules between vibrational levels on the number of such levels, when this function is disturbed; and the mutual influence of the emission and amplification processes involving adjacent vibrational transitions.

Quantum Electronics•Jan 31, 1994•4 citations

Mechanism for phase conjugation of the beam from a flowing-gas CO laser

А. В. Бердышев, A K Kurnosov, Anatolii P. Napartovich

A mechanism for the interaction of light with a nonlinear medium which leads to an efficient phase conjugation of the beam from a flowing-gas CO laser has been studied. The interaction occurs in four-wave mixing with a feedback loop. The interaction of the light with the active gain medium results from the formation of large-scale amplitude gratings in the medium. These gratings are created by copropagating pump waves.

Quantum Electronics•Jun 30, 1993•1 citation

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

Transmission and reflection spectra of a Raman induced grating in atomic media

Vasily G. Arkhipkin, S. A. Myslivets

The spectral properties of an electromagnetically induced grating that is based on the spatial modulation of the Raman gain in the field of a standing pump wave in a three-level homogeneous medium have been discussed. It has been shown that, by varying the intensity or the frequency of the pump field, one can control the transmission and reflection spectra, while the transmission and reflection coefficients of the probe (Raman) wave can simultaneously be greater than unity. The influence of the nonideality of the standing wave on the spectral characteristics of the grating has been studied.

Optics and Spectroscopy•Nov 1, 2015•0 citations

Phase conjugation of radiation in an inverted medium of an electron-beam-controlled CO laser

А. В. Бердышев, A M Borodin, В. А. Гурашвили +6 more

An experimental investigation was made of the feasibility of phase conjugation by four-wave mixing in the active medium of an electron-beam-controlled CO laser when generating a backscattered wave in a loop system. The energy of a backscattered pulse was 0.3 J, representing nearly 10% of the pump energy at the entry to the amplifier. Theoretical calculations were made of the reflection coefficients of weak waves incident on gain gratings. This was done for all the transitions as a function of the angle of incidence. The strongest reflection was observed for the radiation propagating opposite to the pump waves.

Quantum Electronics•Jan 31, 1996•0 citations

Temporal and Spectral Characteristics of Phase Conjugation Signal under 4-Wave Mixing in Active Medium of CO Laser

L. A. Afanas’ev, А. А. Ионин, Yu. M. Klimachëv +3 more

The phase conjugation (PC) reflectivity of the laser radiation inside its own laser medium reflects the non-linear properties of the medium. To study the properties of carbon monoxide (CO) laser medium the temporal and spectral characteristics of PC reflectivity of pulsed e-beam controlled discharge cryogenically cooled CO laser radiation under degenerate four-wave mixing (DFWM) inside its own laser medium were studied experimentally. The interaction length of DFWM was about 100 cm. The pulse length of the CO laser beam was 50 - 500 µs, the gas density was up to 0.5 Amagat, the gas temperature was about 120 K.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jan 1, 1996•0 citations
It is shown that, under conditions typical of the active medium of a continuous-flow CO laser, large-scale gain gratings play the main role in a phase-conjugation system based on degenerate four-wave mixing. The multifrequency nature of the emission spectrum of a CO laser increases the depth of modulation of the amplitude gratings as a result of two principal mechanisms: the dependence of the rate of relaxation of the function describing the distribution of molecules between vibrational levels on the number of such levels, when this function is disturbed; and the mutual influence of the emission and amplification processes involving adjacent vibrational transitions.
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 spectral properties of an electromagnetically induced grating that is based on the spatial modulation of the Raman gain in the field of a standing pump wave in a three-level homogeneous medium have been discussed. It has been shown that, by varying the intensity or the frequency of the pump field, one can control the transmission and reflection spectra, while the transmission and reflection coefficients of the probe (Raman) wave can simultaneously be greater than unity. The influence of the nonideality of the standing wave on the spectral characteristics of the grating has been studied.
An experimental investigation was made of the feasibility of phase conjugation by four-wave mixing in the active medium of an electron-beam-controlled CO laser when generating a backscattered wave in a loop system. The energy of a backscattered pulse was 0.3 J, representing nearly 10% of the pump energy at the entry to the amplifier. Theoretical calculations were made of the reflection coefficients of weak waves incident on gain gratings. This was done for all the transitions as a function of the angle of incidence. The strongest reflection was observed for the radiation propagating opposite to the pump waves.
The phase conjugation (PC) reflectivity of the laser radiation inside its own laser medium reflects the non-linear properties of the medium. To study the properties of carbon monoxide (CO) laser medium the temporal and spectral characteristics of PC reflectivity of pulsed e-beam controlled discharge cryogenically cooled CO laser radiation under degenerate four-wave mixing (DFWM) inside its own laser medium were studied experimentally. The interaction length of DFWM was about 100 cm. The pulse length of the CO laser beam was 50 - 500 µs, the gas density was up to 0.5 Amagat, the gas temperature was about 120 K.