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

Physics of Wave Processes and Radio Systems

Quasi-degenerate four-wave radiation converter on thermal nonlinearity in a scheme with feedback

А А Акимов, Salavat A. Guzairov, Valery V. Ivakhnik

Published Jul 2, 2026• 0 citations
Publisher

Abstract

Background. Increasing the efficiency of both degenerate four-wave converters and quasi-degenerate four-wave converters is an important task in multi-wave interactions optics. A method for increasing the efficiency of a quasi-degenerate four-wave converter by imposing feedback on the signal or object waves using a ring resonator is considered. Aim. The amplitude and spatial characteristics of a quasi-degenerate four-wave converter on thermal nonlinearity in a scheme with feedback are analyzed. Methods. To analyze the amplitude reflection coefficient and the half-width of the angles band of the object wave of a quasi-degenerate four-wave radiation converter on thermal nonlinearity in the presence of feedback on the signal or object waves, a numerical method was used based on multiple passage of the signal and object waves of the nonlinear layer in a ring resonator. Results. An increase in the amplitude reflection coefficient and the half-width of the band of angles of the object wave is shown in the presence of feedback on the object or signal waves. Conclusion. The optimal operating mode of the quasi-degenerate four-wave converter is determined taking into account the presence of feedback, in which an increase in the amplitude reflection coefficient is observed.

DOI
10.18469/1810-3189.2026.29.2.50-58

Related papers

Four-wave mixing on thermal and resonant nonlinearities with feedback for object and signal waves

Александр Александрович Акимов, Valery V. Ivakhnik, Kseniya G. Kazakova

Background. The need to create highly efficient four-wave radiation converters in order to use them in adaptive optics systems, for real-time processing of complex spatio-temporal fields, in interferometry, quantum cryptography, etc. requires along with the use of traditional methods to increase the efficiency of such converters by increasing the interaction length, radiation power density, effective value of the nonlinear susceptibility of the development of new methods. One of these methods is a method based on the imposition of feedback on one or more interacting waves. Aim. The influence of feedback on the amplitude reflection coefficient of the degenerate four-wave radiation converter on thermal and resonant nonlinearities has been considered. Methods. The amplitude reflection coefficient of a degenerate four-wave radiation converter on thermal and resonant nonlinearities in the presence of feedback for both object and signal waves has been analyzed by a numerical method based on the multiple passage of the signal and object waves of the nonlinear layer in the ring resonator. Results. It was shown, that the difference in the reflection coefficients in the presence and absence of feedback for both object and signal waves increase monotonically with a growth in the pumping waves intensity and does not depend on the parameter characterizing the relationship between thermal and resonant nonlinearities at the approximation of a small reflection coefficient. Conclusion. The range of values of the absorption coefficient in which the imposition of feedback for both object and signal waves leads to an increase in the efficiency of the four-wave radiation converter has been established.

Physics of Wave Processes and Radio Systems•Jul 1, 2023•1 citation

Four-wave mixing on thermal nonlinearity with feedback for signal or object waves

Александр Александрович Акимов, Salavat A. Guzairov, Valery V. Ivakhnik

The coincidence of the amplitude reflection coefficients, half-widths of the spatial frequencies bands of a four-wave radiation converter on thermal nonlinearity with feedback for signal or object waves has been shown at equal pump waves intensity. The dependence of the amplitude reflection coefficient, spatial selectivity of the four-wave radiation converter on thermal nonlinearity on the pump waves intensity has been analyzed. An increase in the half-width of the spatial frequency band is observed with an increase in the pump waves intensity at the compensation for the phase shift arising as a result of the propagation of the pump waves in the medium. There is a threshold value of the pump waves intensity, above which the value of the amplitude reflection coefficient of the four-wave converter with feedback for signal or object waves, is less than in the absence of feedback.

Physics of Wave Processes and Radio Systems•Sep 29, 2022•2 citations

Four-wave mixing on thermal nonlinearity in a scheme with positive feedback

Aleksandr Akimov, Salavat A. Guzairov, Valery V. Ivakhnik

The influence of feedback for both signal and object waves on the amplitude reflection coefficient of a four-wave radiation converter on thermal nonlinearity has been considered. The dependences of the reflection coefficient of a four-wave converter on the parameters of a ring-type resonator, which provides the feedback, and the pump intensity have been obtained and analyzed. It was shown that the use of a ring-type resonator allows one to increase the reflection coefficient of a four-wave radiation converter on thermal nonlinearity by several times.

Computer Optics•Jan 1, 2018•5 citations

Spatial and time characteristics of a four-wave radiation converter in a parabolic waveguide with resonant nonlinearity

E.V. Vorobeva, Valery V. Ivakhnik, D.R. Kapizov

Spatial and temporal characteristics of a degenerate four-wave converter in a multimode waveguide with resonant nonlinearity in a scheme with counter-pumping waves are analyzed using the time response function and the point spread function. For single-mode pump waves with equal mode numbers, the dependences of the time response width on the waveguide length, the intensity of the first pump waves, and the mode number in the mode expansion of the object wave amplitude are obtained for the four-wave converter. The greatest contribution to the object wave amplitude is shown to be from the waveguide mode whose number coincides with the mode number of single-mode pump waves. For the stationary model, taking into account the spatial structure of the Gaussian pump wave leads to a monotonous decrease with a decrease in the pump beam width, followed by a constant value of the PSF module width. With single-mode pump waves with equal mode numbers, An increase in the mode number of the pump waves leads to a redistribution of energy concentrated in the side maxima of the point signal image and improvement in the quality of the wavefront reversal for a model with single-mode pump waves with equal mode numbers.

Computer Optics•Feb 1, 2023•3 citations

Phase conjugation under four-wave mixing on resonant and thermal nonlinearities at relatively high reflection coefficients

A. A. Akimov, Valery V. Ivakhnik, В. И. Никонов

The dependences of the reflection (transmission) coefficients and the half-width of the spatial frequency band on the pump-wave intensity are obtained for an object (signal) wave in degenerate and quasi-degenerate four-wave mixers on resonant and thermal nonlinearities. The effect of the difference of the pump-wave frequencies on the phase-conjugation quality is studied at relatively high reflection coefficients.

Optics and Spectroscopy•Sep 1, 2013•4 citations

Efficiency of ring systems for phase self-conjugation of radiation by four-wave interaction in media with thermal nonlinearity

Igor' M Bel'dyugin, Mark V. Zolotarev, A. A. Stepanov +1 more

A theoretical analysis is made of the efficiency of typical ring systems of phase-conjugating mirrors utilizing a degenerate four-wave interaction in media with a thermal nonlinearity. The analysis is made for steady-state conditions taking into account wave saturation effects in an amplifier situated in a positive feedback circuit. It is shown that the reflection coefficient in these systems is extremely sensitive to the level of the phase-conjugate signal (as the ratio of the signal intensity to the saturation intensity of the amplifier active medium is increased, the reflection coefficient of the ring phase-conjugating mirror decreases sharply). It is also found that at a high level of the nonlinearity and for an appreciable gain per pass, these systems exhibit multistability (i.e., several different steady states exist).

Soviet Journal of Quantum Electronics•Apr 30, 1989•2 citations
Background. Increasing the efficiency of both degenerate four-wave converters and quasi-degenerate four-wave converters is an important task in multi-wave interactions optics. A method for increasing the efficiency of a quasi-degenerate four-wave converter by imposing feedback on the signal or object waves using a ring resonator is considered. Aim. The amplitude and spatial characteristics of a quasi-degenerate four-wave converter on thermal nonlinearity in a scheme with feedback are analyzed. Methods. To analyze the amplitude reflection coefficient and the half-width of the angles band of the object wave of a quasi-degenerate four-wave radiation converter on thermal nonlinearity in the presence of feedback on the signal or object waves, a numerical method was used based on multiple passage of the signal and object waves of the nonlinear layer in a ring resonator. Results. An increase in the amplitude reflection coefficient and the half-width of the band of angles of the object wave is shown in the presence of feedback on the object or signal waves. Conclusion. The optimal operating mode of the quasi-degenerate four-wave converter is determined taking into account the presence of feedback, in which an increase in the amplitude reflection coefficient is observed.
Background. The need to create highly efficient four-wave radiation converters in order to use them in adaptive optics systems, for real-time processing of complex spatio-temporal fields, in interferometry, quantum cryptography, etc. requires along with the use of traditional methods to increase the efficiency of such converters by increasing the interaction length, radiation power density, effective value of the nonlinear susceptibility of the development of new methods. One of these methods is a method based on the imposition of feedback on one or more interacting waves. Aim. The influence of feedback on the amplitude reflection coefficient of the degenerate four-wave radiation converter on thermal and resonant nonlinearities has been considered. Methods. The amplitude reflection coefficient of a degenerate four-wave radiation converter on thermal and resonant nonlinearities in the presence of feedback for both object and signal waves has been analyzed by a numerical method based on the multiple passage of the signal and object waves of the nonlinear layer in the ring resonator. Results. It was shown, that the difference in the reflection coefficients in the presence and absence of feedback for both object and signal waves increase monotonically with a growth in the pumping waves intensity and does not depend on the parameter characterizing the relationship between thermal and resonant nonlinearities at the approximation of a small reflection coefficient. Conclusion. The range of values of the absorption coefficient in which the imposition of feedback for both object and signal waves leads to an increase in the efficiency of the four-wave radiation converter has been established.
The coincidence of the amplitude reflection coefficients, half-widths of the spatial frequencies bands of a four-wave radiation converter on thermal nonlinearity with feedback for signal or object waves has been shown at equal pump waves intensity. The dependence of the amplitude reflection coefficient, spatial selectivity of the four-wave radiation converter on thermal nonlinearity on the pump waves intensity has been analyzed. An increase in the half-width of the spatial frequency band is observed with an increase in the pump waves intensity at the compensation for the phase shift arising as a result of the propagation of the pump waves in the medium. There is a threshold value of the pump waves intensity, above which the value of the amplitude reflection coefficient of the four-wave converter with feedback for signal or object waves, is less than in the absence of feedback.
The influence of feedback for both signal and object waves on the amplitude reflection coefficient of a four-wave radiation converter on thermal nonlinearity has been considered. The dependences of the reflection coefficient of a four-wave converter on the parameters of a ring-type resonator, which provides the feedback, and the pump intensity have been obtained and analyzed. It was shown that the use of a ring-type resonator allows one to increase the reflection coefficient of a four-wave radiation converter on thermal nonlinearity by several times.
Spatial and temporal characteristics of a degenerate four-wave converter in a multimode waveguide with resonant nonlinearity in a scheme with counter-pumping waves are analyzed using the time response function and the point spread function. For single-mode pump waves with equal mode numbers, the dependences of the time response width on the waveguide length, the intensity of the first pump waves, and the mode number in the mode expansion of the object wave amplitude are obtained for the four-wave converter. The greatest contribution to the object wave amplitude is shown to be from the waveguide mode whose number coincides with the mode number of single-mode pump waves. For the stationary model, taking into account the spatial structure of the Gaussian pump wave leads to a monotonous decrease with a decrease in the pump beam width, followed by a constant value of the PSF module width. With single-mode pump waves with equal mode numbers, An increase in the mode number of the pump waves leads to a redistribution of energy concentrated in the side maxima of the point signal image and improvement in the quality of the wavefront reversal for a model with single-mode pump waves with equal mode numbers.
A theoretical analysis is made of the efficiency of typical ring systems of phase-conjugating mirrors utilizing a degenerate four-wave interaction in media with a thermal nonlinearity. The analysis is made for steady-state conditions taking into account wave saturation effects in an amplifier situated in a positive feedback circuit. It is shown that the reflection coefficient in these systems is extremely sensitive to the level of the phase-conjugate signal (as the ratio of the signal intensity to the saturation intensity of the amplifier active medium is increased, the reflection coefficient of the ring phase-conjugating mirror decreases sharply). It is also found that at a high level of the nonlinearity and for an appreciable gain per pass, these systems exhibit multistability (i.e., several different steady states exist).