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

Soviet Journal of Quantum Electronics

Hyper-Raman scattering and four-wave parametric interaction in two-photon pumping of metal vapors

Yu. P. Malakyan

Published Jul 31, 1985• 8 citations
Publisher

Abstract

Investigations are made of hyper-Raman scattering and four-photon parametric processes in two-photon excitation of metal vapor. The laws of propagation of infrared and ultraviolet radiation generated in a metal vapor medium by these processes are found for the steady-state interaction. The nonlinear polarization of the medium is obtained in terms of elements of the atomic density matrix allowing for saturation by the pump field and for the influence of collisions. The spectral and tuning characteristics of the converted radiation are studied and a comparison is made with experimental data. A dip observed in the infrared radiation spectrum for hyper-Raman scattering and its broadening are explained. A detailed discussion is given of the role of collisions that substantially narrow the tuning range of the infrared radiation in hyper-Raman scattering.

DOI
10.1070/qe1985v015n07abeh007278

Related papers

Theory of transient hyper-Raman scattering in gases

Yu. P. Malakyan

A theory is developed for transient hyper-Raman scattering and four-wave parametric processes in a gaseous medium subjected to an ultrashort pump pulse field. Investigations are made of the intensity and spectrum of the infrared and ultraviolet radiation generated in a medium as a result of these processes, bearing in mind the transient properties of the pump (phase modulation, pulse profile). It is shown that the initial nonlinearity of the pump field and the parametric processes result in new effects not observed in transient stimulated Raman scattering. For a large two-photon detuning, the hyper-Raman forward scattering is suppressed because of destructive interference with stimulated parametric generation of ultraviolet radiation. The gain of the infrared and ultraviolet radiation depends on the pump pulse profile. Under exact two-photon resonance conditions in the absence of any phase modulation of the pump, infrared and ultraviolet pulses are coherently split into various subpulses and a time-dependent Autler–Townes doublet is observed in their spectrum.

Soviet Journal of Quantum Electronics•Sep 30, 1989•2 citations

Nonlinear processes in two-photon pumped atomic vapors

A. Martínez García

A formalism suited for the study of two-photon resonant processes in atomic vapors is developed. Applications to the study of hyper-Raman scattering, four-photon parametric conversion and second-harmonic generation were carried out. Hyper-Raman scattering and four-photon parametric conversion were analyzed at steady state in the small-gain and saturation regimes. For the small-gain region, the results of perturbation theory are reproduced. The behavior of Stokes and idler fields in the saturation regime is shown to be in agreement with experimental results. Several characteristics of the line shapes experimentally observed are also qualitatively explained. A time-frequency analysis of the transients of the Stokes gain provides a method of studying the evolution of Stark shifts and dynamical Stark splittings, as well as constituting a valuable tool to distinguish between Raman-type and population-type lines.

•Sep 1, 1984•3 citations

Nonlinear optical processes near the sodium 4Dtwo-photon resonance

Richard Wunderlich, W. R. Garrett, Roger C. Hart +2 more

The nonlinear response of sodium vapor with a laser tuned near the 4D two-photon resonance is investigated over a large range of sodium concentrations and pump intensities with emphasis on the influence of coherent cancellation effects on the induced polarizations and the primary mechanism for the generation of the new frequencies. Over a wide range of circumstances, the response of the medium is dominated by parametric four-wave mixing as compared to amplified spontaneous emission or stimulated electronic hyper-Raman scattering. Secondary four-wave-mixing fields are generated by stimulated Raman scattering of one parametric four-wave-mixing field and a coupling of these fields with the driving laser field. A sharp onset of saturation of the parametric four-wave-mixing signals with sodium number density and a transition from a quadratic to a linear power dependence is observed. Both effects are explained in terms of the two-photon cancellation effect.

Physical Review A•Jun 1, 1990•63 citations

Parametric conversion under two-photon resonance conditions in the presence of limiting processes

Vv Krasnikov, Maxim S. Pshenichnikov, Vladimir S Solomatin

An investigation was made of the influence of two-photon absorption and inverse Raman scattering on the characteristics of parametric mixing under two-photon resonance conditions. Broadening of the spectral profile and saturation of the conversion efficiency were observed when the intensities of the interacting waves were increased. Good agreement was obtained between experimental and theoretical dependences calculated allowing for two-photon absorption and inverse Raman scattering.

Soviet Journal of Quantum Electronics•Sep 30, 1986•0 citations

Effect of the pump absorption on generation of infrared stimulated electronic Raman scattering in alkali-metal vapors

A. I. Agafonov, G. G. Grigoryan, Nikolay V Znamenskiy +5 more

The main properties of infrared stimulated electronic Raman scattering (SERS) at the 6 2 S 1/2 -7 2 S 1/2, 3/2 transitions in cesium atoms are studied theoretically and experimentally as functions of the atomic concentration, which was varied from 10 11 to 10 16 cm −3 . It is found that the efficiency of generation of Stokes radiation strongly depends on one-photon absorption of the pump radiation tuned near frequencies of the 6 2 S 1/2 -7 2 P 1/2, 3/2 transitions. By using the equation for the density matrix, which describes the evolution of a three-level system, the theory of resonance excitation of IR radiation upon one-photon absorption at an adjacent transition is developed. The theory describes well the main features of IR SERS in alkali-metal vapors.

Journal of Experimental and Theoretical Physics•Apr 1, 2002•0 citations

Semiclassical theory of two-photon induced Raman scattering

W. H. Louisell, Pierre Meystre

Stimulated two-photon induced Raman scattering (hyper-Raman scattering) in an amplifier consisting of four-level atoms is analyzed semiclassically, via the coupled density matrix and Maxwell equations. We consider conditions typically encountered in the optical regime and in vapors. We show that even in the linear regime, it is characterized by a significant depletion of the atomic ground-state population, thus invalidating perturbative analyses based, for instance, on the nonlinear susceptibility tensor. Two major regimes of operation are found, one in which the population is completely consumed by the interaction ("linear regime"), and one in which the pump laser is depleted ("nonlinear regime"). Both regimes are, however, characterized by small photon conversion efficiencies. The tuning range is also briefly discussed.

Physical Review A•Mar 1, 1981•2 citations
Investigations are made of hyper-Raman scattering and four-photon parametric processes in two-photon excitation of metal vapor. The laws of propagation of infrared and ultraviolet radiation generated in a metal vapor medium by these processes are found for the steady-state interaction. The nonlinear polarization of the medium is obtained in terms of elements of the atomic density matrix allowing for saturation by the pump field and for the influence of collisions. The spectral and tuning characteristics of the converted radiation are studied and a comparison is made with experimental data. A dip observed in the infrared radiation spectrum for hyper-Raman scattering and its broadening are explained. A detailed discussion is given of the role of collisions that substantially narrow the tuning range of the infrared radiation in hyper-Raman scattering.
A theory is developed for transient hyper-Raman scattering and four-wave parametric processes in a gaseous medium subjected to an ultrashort pump pulse field. Investigations are made of the intensity and spectrum of the infrared and ultraviolet radiation generated in a medium as a result of these processes, bearing in mind the transient properties of the pump (phase modulation, pulse profile). It is shown that the initial nonlinearity of the pump field and the parametric processes result in new effects not observed in transient stimulated Raman scattering. For a large two-photon detuning, the hyper-Raman forward scattering is suppressed because of destructive interference with stimulated parametric generation of ultraviolet radiation. The gain of the infrared and ultraviolet radiation depends on the pump pulse profile. Under exact two-photon resonance conditions in the absence of any phase modulation of the pump, infrared and ultraviolet pulses are coherently split into various subpulses and a time-dependent Autler–Townes doublet is observed in their spectrum.
A formalism suited for the study of two-photon resonant processes in atomic vapors is developed. Applications to the study of hyper-Raman scattering, four-photon parametric conversion and second-harmonic generation were carried out. Hyper-Raman scattering and four-photon parametric conversion were analyzed at steady state in the small-gain and saturation regimes. For the small-gain region, the results of perturbation theory are reproduced. The behavior of Stokes and idler fields in the saturation regime is shown to be in agreement with experimental results. Several characteristics of the line shapes experimentally observed are also qualitatively explained. A time-frequency analysis of the transients of the Stokes gain provides a method of studying the evolution of Stark shifts and dynamical Stark splittings, as well as constituting a valuable tool to distinguish between Raman-type and population-type lines.
The nonlinear response of sodium vapor with a laser tuned near the 4D two-photon resonance is investigated over a large range of sodium concentrations and pump intensities with emphasis on the influence of coherent cancellation effects on the induced polarizations and the primary mechanism for the generation of the new frequencies. Over a wide range of circumstances, the response of the medium is dominated by parametric four-wave mixing as compared to amplified spontaneous emission or stimulated electronic hyper-Raman scattering. Secondary four-wave-mixing fields are generated by stimulated Raman scattering of one parametric four-wave-mixing field and a coupling of these fields with the driving laser field. A sharp onset of saturation of the parametric four-wave-mixing signals with sodium number density and a transition from a quadratic to a linear power dependence is observed. Both effects are explained in terms of the two-photon cancellation effect.
The main properties of infrared stimulated electronic Raman scattering (SERS) at the 6 2 S 1/2 -7 2 S 1/2, 3/2 transitions in cesium atoms are studied theoretically and experimentally as functions of the atomic concentration, which was varied from 10 11 to 10 16 cm −3 . It is found that the efficiency of generation of Stokes radiation strongly depends on one-photon absorption of the pump radiation tuned near frequencies of the 6 2 S 1/2 -7 2 P 1/2, 3/2 transitions. By using the equation for the density matrix, which describes the evolution of a three-level system, the theory of resonance excitation of IR radiation upon one-photon absorption at an adjacent transition is developed. The theory describes well the main features of IR SERS in alkali-metal vapors.
Stimulated two-photon induced Raman scattering (hyper-Raman scattering) in an amplifier consisting of four-level atoms is analyzed semiclassically, via the coupled density matrix and Maxwell equations. We consider conditions typically encountered in the optical regime and in vapors. We show that even in the linear regime, it is characterized by a significant depletion of the atomic ground-state population, thus invalidating perturbative analyses based, for instance, on the nonlinear susceptibility tensor. Two major regimes of operation are found, one in which the population is completely consumed by the interaction ("linear regime"), and one in which the pump laser is depleted ("nonlinear regime"). Both regimes are, however, characterized by small photon conversion efficiencies. The tuning range is also briefly discussed.