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

Relaxation time of phase-conjugate reflection via four-wave mixing of radiation in the active medium of a CO2laser

Valeri I. Kovalev

Published Sep 30, 1994• 1 citation
Publisher

Abstract

The experimental relaxation time of degenerate four-wave mixing based on the nonlinearity of saturation of the active media of TEA CO 2 lasers (~0.3 μs) is shown to be an order of magnitude less than the time calculated on the basis of the existing theories. A new mechanism is proposed to account for the relaxation of such mixing in the active media of TEA CO 2 lasers. This mechanism postulates erasure of gratings, formed in the course of the fourwave mixing, of the population inversion of the active levels of a laser due to a high rate of filling of the upper level by resonant energy transfer from nitrogen molecules.

DOI
10.1070/qe1994v024n09abeh000254

Related papers

Reflection efficiency and response relaxation time in degenerate four-wave mixing in the active media of TEA CO2lasers

Valeri I. Kovalev, M. B. Suvorov

An experimental investigation was made of the reflection by a nonlinearity from gain saturation in the active medium of a TEA CO 2 laser under degenerate four-wave mixing conditions. A new mechanism of relaxation of the response to such a nonlinearity was identified and processes with submicrosecond and subnanosecond relaxation times were found in CO 2 . The saturation intensities for these processes and the conditions for achieving high reflection intensities as a result of such a mixing were determined.

Quantum Electronics•Jan 31, 1996•2 citations

Nonlinear optical properties of the active medium in intracavity phase conjugation of the radiation of a pulsed electron-beam-controlled discharge CO2laser. II. Theoretical analysis

Michail G. Galushkin, А. А. Ионин, А. А. Котков +1 more

Numerical simulation is used as the basis of an analysis of nonlinear optical properties of the active medium in intracavity four-wave mixing of the radiation of a pulsed electron-beam-controlled discharge CO 2 laser on saturated-gain and refractive-index diffraction gratings. The reflection coefficient of the phase-conjugated signal is determined for various cavity Q -factors, specific input energies, and pressures of the laser-active mixture. A comparison is made of the theoretical and experimental results. It is found that the rate of formation of amplitude gratings is governed primarily by the initial population inversion and by the intensities of the interacting waves. It is shown that transient phase gratings make the dominant contribution to the phase-conjugate reflection coefficient at high pressures of the mixture.

Quantum Electronics•Oct 31, 1998•0 citations

Degenerate four-wave mixing and phase conjugation of pulsed 10-μm laser radiation on transient gratings inside an inverted CO 2 medium

L. A. Afanas’ev, Michail G. Galushkin, А. А. Ионин +3 more

Degenerate four-wave mixing (DFWM) and phase conjugation (PC) of pulsed carbon-dioxide laser radiation on transient gratings inside its own laser medium have been studied both experimentally and theoretically. The operational mode of the e-beam controlled discharge carbon-dioxide laser has been chosen in such a way (CO2:N2:He equals 1:2:4, p equals 0.28 atm, tin equals 30 microseconds) that the laser pulse length ((tau) out approximately equals 10 - 20 microseconds) is comparable with an effective relaxation time of the upper laser level ((tau) rel approximately 15 - 30 microseconds). The time-history of the carbon-dioxide laser and PC signal pulses, and PC reflectivity have been thoroughly investigated for different cavity Q factors and specific electrical energy inputs. It has been shown, that the formation of the PC signal under the intracavity DFWM on gain (amplitude) and thermal (phase) gratings is characterized by a complicated time history that reflects the main relaxation processes taking place inside the inverted medium. A feature of the transient PC process inside the laser active medium is the dependence of the effective relaxation time of the upper laser level on the intensity of pumping waves. PC reflectivity has been obtained by numerical calculations. A comparison of the theoretical and experimental data confirms the contribution of two different mechanisms of grating formation under DFWM inside the active medium of the carbon-dioxide laser.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•May 20, 1996•0 citations

Degenerate four-wave mixing and phase conjugation of pulsed CO2 laser radiation on transient gratings inside its own inverted medium

L. A. Afanas’ev, А. А. Ионин, А. А. Котков +3 more

Degenerate four-wave mixing (DFWM) and phase conjugation (PC) of pulsed CO2 laser radiation on transient gratings inside its own laser medium have been studied both experimentally and theoretically. The operational mode of the e-beam controlled discharge CO2 laser has been chosen in such a way (CO2:N2:He equals 1:2:4, p equals 0.28 atm, tin equals 30 microsecond(s) ) that the laser pulse length ((tau) out approximately 10 - 20 microsecond(s) ) is comparable with an effective relaxation time of the upper laser level ((tau) rel approximately 15 - 30 microsecond(s) ). The time-history of the CO2 laser and PC signal pulses, and PC reflectivity have been thoroughly investigated for different cavity Q factors and specific electrical energy inputs. It has been shown, that the formation of the PC signal under the intracavity DFWM on gain (amplitude) and thermal (phase) gratings is characterized by a complicated time history that reflects the main relaxation processes taking place inside the inverted medium. A feature of the transient PC process inside the laser active medium is the dependence of the effective relaxation time of the upper laser level on the intensity of pumping waves. PC reflectivity has been obtained by numerical calculations. A comparison of the theoretical and experimental data confirms the contribution of two different mechanisms of grating formation under DFWM inside the active medium of the CO2 laser.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Mar 29, 1996•0 citations

Degenerate four-wave mixing and phase conjugation of pulsed CO 2 laser radiation on transient gratings inside its own inverted medium

L. A. Afanas’ev, А. А. Ионин, А. А. Котков +3 more

Degenerate four-wave mixing (DFWM) and phase conjugation (PC) of pulsed carbon-dioxide laser radiation on transient gratings inside its own laser medium have been studied both experimentally and theoretically. The operational mode of the e-beam controlled discharge carbon-dioxide laser has been chosen in such a way (CO2:N2:He equals 1:2:4, p equals 0.28 atm, tin equals 30 microseconds) that the laser pulse length (tauout approximately 10 - 20 microseconds) is comparable with an effective relaxation time of the upper laser level (taurel approximately 15 - 30 microseconds). The time-history of the carbon-dioxide laser and pc signal pulses, and pc reflectivity have been thoroughly investigated for different cavity Q factors and specific electrical energy inputs. It has been shown, that the formation of the PC signal under the intracavity DFWM on gain (amplitude) and thermal (phase) gratings is characterized by a complicated time history that reflects the main relaxation processes taking place inside the inverted medium. A feature of the transient pc process inside the laser active medium is the dependence of the effective relaxation time of the upper laser level on the intensity of pumping waves. Pc reflectivity has been obtained by numerical calculations. A comparison of the theoretical and experimental data confirms the contribution of two different mechanisms of grating formation under DFWM inside the active medium of the carbon-dioxide laser.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Aug 26, 1996•0 citations

Active Medium of CO2 Laser Under Degenerate Four-Wave Mixing

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

Degenerate four-wave mixing (DFWM) and phase conjugation (PC) of pulsed CO2 laser radiation inside its own laser medium were studied experimentally. The operational mode of the e-beam controlled discharge CO2 laser has been chosen in such a way (CO2:N2:He gas mixture, p=0.1 -0.56 atm, tin=30 μs) that the laser pulse length (τout~10 - 20 μs) is comparable with the relaxation time of the upper laser level (τrel~l5 - 30 μs). The interaction length of DFWM was about 100 cm.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jan 1, 1996•0 citations
The experimental relaxation time of degenerate four-wave mixing based on the nonlinearity of saturation of the active media of TEA CO 2 lasers (~0.3 μs) is shown to be an order of magnitude less than the time calculated on the basis of the existing theories. A new mechanism is proposed to account for the relaxation of such mixing in the active media of TEA CO 2 lasers. This mechanism postulates erasure of gratings, formed in the course of the fourwave mixing, of the population inversion of the active levels of a laser due to a high rate of filling of the upper level by resonant energy transfer from nitrogen molecules.
An experimental investigation was made of the reflection by a nonlinearity from gain saturation in the active medium of a TEA CO 2 laser under degenerate four-wave mixing conditions. A new mechanism of relaxation of the response to such a nonlinearity was identified and processes with submicrosecond and subnanosecond relaxation times were found in CO 2 . The saturation intensities for these processes and the conditions for achieving high reflection intensities as a result of such a mixing were determined.
Numerical simulation is used as the basis of an analysis of nonlinear optical properties of the active medium in intracavity four-wave mixing of the radiation of a pulsed electron-beam-controlled discharge CO 2 laser on saturated-gain and refractive-index diffraction gratings. The reflection coefficient of the phase-conjugated signal is determined for various cavity Q -factors, specific input energies, and pressures of the laser-active mixture. A comparison is made of the theoretical and experimental results. It is found that the rate of formation of amplitude gratings is governed primarily by the initial population inversion and by the intensities of the interacting waves. It is shown that transient phase gratings make the dominant contribution to the phase-conjugate reflection coefficient at high pressures of the mixture.
Degenerate four-wave mixing (DFWM) and phase conjugation (PC) of pulsed carbon-dioxide laser radiation on transient gratings inside its own laser medium have been studied both experimentally and theoretically. The operational mode of the e-beam controlled discharge carbon-dioxide laser has been chosen in such a way (CO2:N2:He equals 1:2:4, p equals 0.28 atm, tin equals 30 microseconds) that the laser pulse length ((tau) out approximately equals 10 - 20 microseconds) is comparable with an effective relaxation time of the upper laser level ((tau) rel approximately 15 - 30 microseconds). The time-history of the carbon-dioxide laser and PC signal pulses, and PC reflectivity have been thoroughly investigated for different cavity Q factors and specific electrical energy inputs. It has been shown, that the formation of the PC signal under the intracavity DFWM on gain (amplitude) and thermal (phase) gratings is characterized by a complicated time history that reflects the main relaxation processes taking place inside the inverted medium. A feature of the transient PC process inside the laser active medium is the dependence of the effective relaxation time of the upper laser level on the intensity of pumping waves. PC reflectivity has been obtained by numerical calculations. A comparison of the theoretical and experimental data confirms the contribution of two different mechanisms of grating formation under DFWM inside the active medium of the carbon-dioxide laser.
Degenerate four-wave mixing (DFWM) and phase conjugation (PC) of pulsed CO2 laser radiation on transient gratings inside its own laser medium have been studied both experimentally and theoretically. The operational mode of the e-beam controlled discharge CO2 laser has been chosen in such a way (CO2:N2:He equals 1:2:4, p equals 0.28 atm, tin equals 30 microsecond(s) ) that the laser pulse length ((tau) out approximately 10 - 20 microsecond(s) ) is comparable with an effective relaxation time of the upper laser level ((tau) rel approximately 15 - 30 microsecond(s) ). The time-history of the CO2 laser and PC signal pulses, and PC reflectivity have been thoroughly investigated for different cavity Q factors and specific electrical energy inputs. It has been shown, that the formation of the PC signal under the intracavity DFWM on gain (amplitude) and thermal (phase) gratings is characterized by a complicated time history that reflects the main relaxation processes taking place inside the inverted medium. A feature of the transient PC process inside the laser active medium is the dependence of the effective relaxation time of the upper laser level on the intensity of pumping waves. PC reflectivity has been obtained by numerical calculations. A comparison of the theoretical and experimental data confirms the contribution of two different mechanisms of grating formation under DFWM inside the active medium of the CO2 laser.
Degenerate four-wave mixing (DFWM) and phase conjugation (PC) of pulsed carbon-dioxide laser radiation on transient gratings inside its own laser medium have been studied both experimentally and theoretically. The operational mode of the e-beam controlled discharge carbon-dioxide laser has been chosen in such a way (CO2:N2:He equals 1:2:4, p equals 0.28 atm, tin equals 30 microseconds) that the laser pulse length (tauout approximately 10 - 20 microseconds) is comparable with an effective relaxation time of the upper laser level (taurel approximately 15 - 30 microseconds). The time-history of the carbon-dioxide laser and pc signal pulses, and pc reflectivity have been thoroughly investigated for different cavity Q factors and specific electrical energy inputs. It has been shown, that the formation of the PC signal under the intracavity DFWM on gain (amplitude) and thermal (phase) gratings is characterized by a complicated time history that reflects the main relaxation processes taking place inside the inverted medium. A feature of the transient pc process inside the laser active medium is the dependence of the effective relaxation time of the upper laser level on the intensity of pumping waves. Pc reflectivity has been obtained by numerical calculations. A comparison of the theoretical and experimental data confirms the contribution of two different mechanisms of grating formation under DFWM inside the active medium of the carbon-dioxide laser.