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

Suppressed excitation due to the dynamic Stark effect that arises from amplified spontaneous emission

Jon P. Davis, Edward T. Dressler

Published Mar 1, 1992• 4 citations
Publisher

Abstract

We have numerically solved a simplified set of Maxwell-Bloch equations for a two-field, three-level model. Excitation from the ground state to the upper state is a two-photon process with a nonresonant intermediate state. Amplified spontaneous emission can occur from the upper excited state of the model system to the intermediate state. The equations can contain terms corresponding to the dynamic Stark effect resulting from the amplified spontaneous-emission field. Inclusion of these terms significantly reduces the excitation probability when the irradiance of the exciting field is above the threshold for occurrence of amplified spontaneous emission from the upper excited state. These theoretical results qualitatively explain a recent experimental observation of the decreased excitation probability for such a process in gas-phase xenon.

DOI
10.1103/physreva.45.3104

Related papers

Stark shift/broadening by stimulated emission

Edward T. Dressler, Jon P. Davis

Previous experimental work by our group1 has shown that the two-photon excitation of the 6p[1/2,0] state of xenon has a fairly sharp threshold for the onset of amplified spontaneous emission (ASE) from the 6p[1/2,0] state to the excited 6s state. The excitation probability has the expected quadratic dependence on excitation intensity below the ASE threshold but an unexpected linear dependence above threshold. We hypothesize that the reduced excitation probability results from an ac Stark shift/broadening of 6p[1/2,0] state by the ASE field. We have numerically solved the coupled Maxwell-Bloch equations with and without the relevant Stark terms. The ASE threshold predicted by the numerical solutions occurs at an intensity about an order of magnitude higher than the experimental value. Because of uncertainties in some of the experimental parameters this difference is not unreasonable. Solution of the equations without Stark terms gives quadratic excitation dependence above the ASE threshold. Including the Stark terms reduces the dependence to a 1.2 power law. The change to a 1.2 power occurs ~50% above ASE threshold, whereas the experimental change occurs almost right at threshold.

Annual Meeting Optical Society of America•Jan 1, 1991•0 citations

Competition between amplified spontaneous emission and the four-wave-mixing process

Robert W. Boyd, Michelle S. Malcuit, Daniel J. Gauthier +1 more

Competition between amplified spontaneous emission (ASE) and the four-wave-mixing (FWM) process has been observed under conditions of two-photon resonant excitation of the sodium 3d level. The nature of the competition is that the FWM process is able to prevent the occurrence of ASE, even though the gain of the ASE process calculated in the absence of competition effects is much larger than that of FWM. The ASE is suppressed because the fields generated by the FWM process create a new excitation pathway connecting the ground and 3d levels, and under quite general conditions this pathway interferes destructively with that due solely to the applied laser field. These effects are modeled theoretically by solving perturbatively the density-matrix equations of the atomic system, thereby determining the population in the upper level and the nonlinear polarization of the medium. The coupling between the various optical fields due to the nonlinear polarization is described by coupled amplitude equations. The solution to these equations predicts that when the wave-vector mismatch is not too large the fields evolve spatially to reach steady-state values, and that the population excited to the 3d level by the total steady-state optical field is much smaller than that due to the incident laser field alone. We have observed experimentally the suppression of ASE by FWM and have observed that this suppression does not occur when the medium is excited with counterpropagating beams that cannot efficiently excite the FWM process. In addition, we have conducted a series of experiments that shows that the degree of suppression of ASE depends on the intensity and focusing characteristics of the incident laser as expected on the basis of our theoretical model.

Physical Review A•Feb 1, 1987•118 citations

Analysis of dynamical suppression of spontaneous emission

P. R. Berman

It has been shown recently [see, for example, S.-Y. Zhu and M. O. Scully, Phys. Rev. Lett. 76, 388 (1996)] that a dynamical suppression of spontaneous emission can occur in a three-level system when an external field drives transitions between a metastable state and two decaying states. What is unusual in the decay scheme is that the decaying states are coupled directly by the vacuum radiation field. It is shown that the decay dynamics required for total suppression of spontaneous emission necessarily implies that the level scheme is isomorphic to a three-level \ensuremath{\Lambda} system, in which the lower two levels are both metastable and each is coupled to the decaying state. As such, the total suppression of spontaneous emission can be explained in terms of conventional dark states and coherent population trapping.

arXiv:physics/9809005•Physical Review A•Dec 1, 1998•102 citations

Suppression of Amplified Spontaneous Emission by the Four-Wave Mixing Process

Michelle S. Malcuit, Daniel J. Gauthier, Robert W. Boyd

Two-photon-resonant excitation of the sodium $3d$ level can lead to the generation of new frequencies either by amplified spontaneous emission at the $3d\ensuremath{\rightarrow}3p$ transition frequency or by a resonantly enhanced four-wave mixing process. Competition between these two processes has been observed. The four-wave mixing process can suppress amplified spontaneous emission by preventing the excitation of the $3d$ level due to an interference between two different pathways connecting the ground ($3s$) and $3d$ states.

Physical Review Letters•Sep 2, 1985•108 citations

Laser control of decay rates in three-level atoms

Yevgeny V. Radeonychev, Olga A. Kocharovskaya

Summary form only given. In three-level atoms the drastic modification of the decay rates by the driving field may occur in the free space as soon as one dynamic Stark level crosses a neighboring unperturbed atomic energy state. This leads to appearance of spontaneous emission from the former ground state to the lower dynamic Stark level or spontaneous decay from the upper dynamic Stark level to the excited atomic state. For an experimental realization we propose to use a cell with potassium (/sup 39/K) vapor in magnetic field driven on D1-transition by circular polarized radiation of Ti:sapphire or dye laser.

Conference on Lasers and Electro-Optics•Aug 29, 2005•0 citations

Amplification of spontaneous emission and coherence in three-dimensional systems

G. Hazak

The steady-state wave equation, used in the literature for the description of amplified spontaneous emission (ASE) in a refractive medium with inverted atoms, focuses on a narrow frequency band at the atomic line center. In the present work, the effect of this approximation was studied by comparison to an alternative procedure that accounts for the full line shape. The three-dimensional time-dependent Maxwell-Bloch equations for ASE in a refraction guided system were solved as an initial-value problem by using transverse-mode expansion. The steady-state limit was approached only for quantities that are bilinear in the field (autorcorrelation function, complex degree of coherence, and radiation intensity). It was found that, except for a gain narrowing factor, the inclusion of the full line shape (or equivalently the detailed dynamics of atomic polarization) does not change the theoretical prediction for the amplification of mode intensities. However, it drastically changes the prediction for the behavior of cross correlations of mode amplitudes. In the high-gain limit the steady-state wave equation predicts that these cross correlations, normalized to the intensity of the involved modes, are independent of the system length and of the excitation strength of the modes. The solution of the Maxwell-Bloch equations predicts that the normalized cross correlations are exponentially decreasing functions of the system length and of the difference between the excitation strengths of the modes. It is therefore argued that the inclusion of the detailed atomic line shape is essential to the analysis of spatial coherence in ASE systems.

Physical Review A•Oct 1, 1990•2 citations
We have numerically solved a simplified set of Maxwell-Bloch equations for a two-field, three-level model. Excitation from the ground state to the upper state is a two-photon process with a nonresonant intermediate state. Amplified spontaneous emission can occur from the upper excited state of the model system to the intermediate state. The equations can contain terms corresponding to the dynamic Stark effect resulting from the amplified spontaneous-emission field. Inclusion of these terms significantly reduces the excitation probability when the irradiance of the exciting field is above the threshold for occurrence of amplified spontaneous emission from the upper excited state. These theoretical results qualitatively explain a recent experimental observation of the decreased excitation probability for such a process in gas-phase xenon.
Previous experimental work by our group1 has shown that the two-photon excitation of the 6p[1/2,0] state of xenon has a fairly sharp threshold for the onset of amplified spontaneous emission (ASE) from the 6p[1/2,0] state to the excited 6s state. The excitation probability has the expected quadratic dependence on excitation intensity below the ASE threshold but an unexpected linear dependence above threshold. We hypothesize that the reduced excitation probability results from an ac Stark shift/broadening of 6p[1/2,0] state by the ASE field. We have numerically solved the coupled Maxwell-Bloch equations with and without the relevant Stark terms. The ASE threshold predicted by the numerical solutions occurs at an intensity about an order of magnitude higher than the experimental value. Because of uncertainties in some of the experimental parameters this difference is not unreasonable. Solution of the equations without Stark terms gives quadratic excitation dependence above the ASE threshold. Including the Stark terms reduces the dependence to a 1.2 power law. The change to a 1.2 power occurs ~50% above ASE threshold, whereas the experimental change occurs almost right at threshold.
Competition between amplified spontaneous emission (ASE) and the four-wave-mixing (FWM) process has been observed under conditions of two-photon resonant excitation of the sodium 3d level. The nature of the competition is that the FWM process is able to prevent the occurrence of ASE, even though the gain of the ASE process calculated in the absence of competition effects is much larger than that of FWM. The ASE is suppressed because the fields generated by the FWM process create a new excitation pathway connecting the ground and 3d levels, and under quite general conditions this pathway interferes destructively with that due solely to the applied laser field. These effects are modeled theoretically by solving perturbatively the density-matrix equations of the atomic system, thereby determining the population in the upper level and the nonlinear polarization of the medium. The coupling between the various optical fields due to the nonlinear polarization is described by coupled amplitude equations. The solution to these equations predicts that when the wave-vector mismatch is not too large the fields evolve spatially to reach steady-state values, and that the population excited to the 3d level by the total steady-state optical field is much smaller than that due to the incident laser field alone. We have observed experimentally the suppression of ASE by FWM and have observed that this suppression does not occur when the medium is excited with counterpropagating beams that cannot efficiently excite the FWM process. In addition, we have conducted a series of experiments that shows that the degree of suppression of ASE depends on the intensity and focusing characteristics of the incident laser as expected on the basis of our theoretical model.
It has been shown recently [see, for example, S.-Y. Zhu and M. O. Scully, Phys. Rev. Lett. 76, 388 (1996)] that a dynamical suppression of spontaneous emission can occur in a three-level system when an external field drives transitions between a metastable state and two decaying states. What is unusual in the decay scheme is that the decaying states are coupled directly by the vacuum radiation field. It is shown that the decay dynamics required for total suppression of spontaneous emission necessarily implies that the level scheme is isomorphic to a three-level \ensuremath{\Lambda} system, in which the lower two levels are both metastable and each is coupled to the decaying state. As such, the total suppression of spontaneous emission can be explained in terms of conventional dark states and coherent population trapping.
Two-photon-resonant excitation of the sodium 3d3d3d level can lead to the generation of new frequencies either by amplified spontaneous emission at the $3d\ensuremath{\rightarrow}3p$ transition frequency or by a resonantly enhanced four-wave mixing process. Competition between these two processes has been observed. The four-wave mixing process can suppress amplified spontaneous emission by preventing the excitation of the 3d3d3d level due to an interference between two different pathways connecting the ground (3s3s3s) and 3d3d3d states.
Summary form only given. In three-level atoms the drastic modification of the decay rates by the driving field may occur in the free space as soon as one dynamic Stark level crosses a neighboring unperturbed atomic energy state. This leads to appearance of spontaneous emission from the former ground state to the lower dynamic Stark level or spontaneous decay from the upper dynamic Stark level to the excited atomic state. For an experimental realization we propose to use a cell with potassium (/sup 39/K) vapor in magnetic field driven on D1-transition by circular polarized radiation of Ti:sapphire or dye laser.
The steady-state wave equation, used in the literature for the description of amplified spontaneous emission (ASE) in a refractive medium with inverted atoms, focuses on a narrow frequency band at the atomic line center. In the present work, the effect of this approximation was studied by comparison to an alternative procedure that accounts for the full line shape. The three-dimensional time-dependent Maxwell-Bloch equations for ASE in a refraction guided system were solved as an initial-value problem by using transverse-mode expansion. The steady-state limit was approached only for quantities that are bilinear in the field (autorcorrelation function, complex degree of coherence, and radiation intensity). It was found that, except for a gain narrowing factor, the inclusion of the full line shape (or equivalently the detailed dynamics of atomic polarization) does not change the theoretical prediction for the amplification of mode intensities. However, it drastically changes the prediction for the behavior of cross correlations of mode amplitudes. In the high-gain limit the steady-state wave equation predicts that these cross correlations, normalized to the intensity of the involved modes, are independent of the system length and of the excitation strength of the modes. The solution of the Maxwell-Bloch equations predicts that the normalized cross correlations are exponentially decreasing functions of the system length and of the difference between the excitation strengths of the modes. It is therefore argued that the inclusion of the detailed atomic line shape is essential to the analysis of spatial coherence in ASE systems.