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

Optical transient signal induced by strong fluctuating pulses

Vladimir Finkelstein, P. R. Berman

Published Sep 1, 1990• 10 citations
Publisher

Abstract

The coherent transient signal emitted when a sample of two-level atoms is irradiated by a sequence of two fluctuating pulses is discussed. The pulses have bandwidth ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}^{\mathrm{\ensuremath{-}}1}$. They are correlated with one another, and have a relative delay time ${\mathit{t}}_{12}$. It is shown that for strong excitation pulses the transient signal, as a function of ${\mathit{t}}_{12}$, can exhibit a peak of width of order ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}$. This peak is found to disappear when the Doppler width of the atomic ensemble becomes sufficiently large, in qualitative agreement with existing experimental data.

DOI
10.1103/physreva.42.3145

Related papers

Optical coherent transients induced by time-delayed fluctuating pulses

Vladimir Finkelstein, P. R. Berman

A theory is developed to describe the optical transient signals that arise when a sample of two-level atoms is irradiated by a sequence of two or three broad-bandwidth pulses is presented. The first two pulses have a relative delay time of order of the correlation time of the pulse fluctuations. These pulses whose temporal width is much greater than the delay time are fully correlated with one another and can be strong enough to saturate the two-level atomic transition. In the case of three-pulse transients the third pulse is weak non-correlated with the first two and is delayed in time so that it does not overlap them. Taking into account the effects ofinhomogeneous and homogeneous broadening we calculate the intensity of the transient signals as a function of delay time. The signals are found to depend dramatically on the intensities of the excitation pulses. It is shown that for strong excitation pulses a direct dependence of the signal on the cross-correlation time of the pulses r occurs that does not exist when the pulses are weak. In particular for saturating pulses the signals exhibit a peak of width of order r . In the case of the two-pulse transient the peak is found to disappear when the Doppler width of the atomic ensemble becomes sufficiently large. This peak can have a very narrow dip near its maximum whose width is much

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Mar 1, 1991•2 citations

Optical coherent transients induced by time-delayed fluctuating pulses: Three-pulse transients

Vladimir Finkelstein, P. R. Berman

A theoretical analysis of the optical coherent transients that arise when a sample of two-level atoms is irradiated by a sequence of three broad-bandwidth pulses is presented. The first two pulses have a relative delay time of order of the correlation time of the pulse fluctuations and are sent into an atomic vapor from different directions. These pulses, whose temporal width is much greater than the delay time, can be correlated with one another and can be strong enough to saturate the two-level atomic transition. The third pulse is weak, noncorrelated with the first two, and is delayed in time so that it does not overlap them. We present a detailed examination of the transient signal that is produced when the third pulse is scattered by the spatial gratings in the population difference of atoms created by the first two pulses. Taking into account the effects of inhomogeneous and homogeneous broadening, we calculate the intensity of the transient signal, emitted in different directions, as a function of delay time. The signal is found to depend dramatically on the intensities of the excitation pulses. It is shown that, for strong excitation pulses, there is a direct dependence of the signal on the cross-correlation time of pulses ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}^{12}$ that does not exist when the pulses are weak. In particular, the strongest signals exhibit a peak of width of order ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}^{12}$. This peak can have a very narrow dip near its maximum whose width is much smaller than ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}^{12}$, if the pulses are fully correlated. We develop a representation of the time evolution of the Bloch vector of a two-level atom, driven by time-delayed pulses, that enables us to explain our results. In this representation, the two time-delayed pulses are replaced by two fully overlapping pulses having some effective amplitudes and atomic field detunings.

Physical Review A•Jun 1, 1990•11 citations

Atomic response to optical fluctuating fields: Temporal resolution on a scale less than pulse correlation time

Vladimir Finkelstein

Excitation of a three-level atom irradiated by a sequence of two fluctuating pulses is discussed. The pulses have bandwidth ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}^{\mathrm{\ensuremath{-}}1}$, relative delay time ${\mathit{t}}_{12}$, and can be correlated with one another. It is shown that, for strong excitation pulses, the level populations and atomic coherence as functions of ${\mathit{t}}_{12}$ can vary on a time scale much smaller than ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}$. This effect may lead to a means for obtaining high temporal and spatial resolution.

Physical Review A•May 1, 1991•8 citations

Optical coherent transients induced by time-delayed correlated broad-bandwidth pulses in the strong-field regime

P. Tchénio, Anne Débarre, J. Keller +1 more

A diagrammatic technique is developed to account for the saturation effects which occur when optical coherent transients are generated by broad-bandwidth light pulses. The paper is focused on the calculation of the two-atom, single-time dipole correlation function which originates the signal. In addition to the single-excitation-field situation, we examine the coherent transient generation by overlapping time-delayed correlated pulses. Our approach requires that one of the two correlated pulses be weak. The calculation of the delay dependence of the signal intensity is thoroughly worked out in the case of two-pulse and three-pulse transients in an angled-beam configuration.

Physical Review A•Feb 1, 1989•16 citations

Population grating induced by time-delayed, correlated, broadband light pulses in the strong-field regime

P. Tchénio, Anne Débarre, J. Keller +1 more

Formation of coherent transients by incoherent light pulses has stimulated renewed interest in time-resolved coherent spectroscopy. Standard theories conveniently account for the weak-field regime experiments, but they fail to interpret the power effects that occur during resonant excitation of a sample by time-delayed, correlated, broadband laser pulses. We report on a new approach to this problem. We have been able to determine the expectation value of the population grating induced by two time-delayed, correlated, broadband light pulses under the limitation that one of the fields is weak. We have developed a diagrammatic technique that seems promising for the calculation of actual coherent-transient signals in the strong-field regime.

Journal of the Optical Society of America B•Jun 1, 1988•11 citations

Non-Markovian Strong-Field Excitation of Optical Coherent Transients

P. Tchénio, Anne Débarre, J. Keller +1 more

A transient, time-delayed, four-wave mixing experiment is performed in strontium vapor under stochastic excitation conditions. The first two broad-bandwidth laser pulses are correlated and their delay is adjustable. Thus they combine into a non-Markovian excitation process with adjustable memory time. One of the correlated pulses is allowed to be strong. In contrast with previous investigations, it is shown both theoretically and experimentally that under strong-field conditions the atoms are not able to keep the excitation memory over time intervals longer than the inverse laser bandwidth.

Physical Review Letters•Jan 23, 1989•29 citations
The coherent transient signal emitted when a sample of two-level atoms is irradiated by a sequence of two fluctuating pulses is discussed. The pulses have bandwidth \ensuremathτc\ensuremath−1{\mathrm{\ensuremath{\tau}}}_{\mathit{c}}^{\mathrm{\ensuremath{-}}1}\ensuremathτc\ensuremath−1​. They are correlated with one another, and have a relative delay time t12{\mathit{t}}_{12}t12​. It is shown that for strong excitation pulses the transient signal, as a function of t12{\mathit{t}}_{12}t12​, can exhibit a peak of width of order \ensuremathτc{\mathrm{\ensuremath{\tau}}}_{\mathit{c}}\ensuremathτc​. This peak is found to disappear when the Doppler width of the atomic ensemble becomes sufficiently large, in qualitative agreement with existing experimental data.
A theory is developed to describe the optical transient signals that arise when a sample of two-level atoms is irradiated by a sequence of two or three broad-bandwidth pulses is presented. The first two pulses have a relative delay time of order of the correlation time of the pulse fluctuations. These pulses whose temporal width is much greater than the delay time are fully correlated with one another and can be strong enough to saturate the two-level atomic transition. In the case of three-pulse transients the third pulse is weak non-correlated with the first two and is delayed in time so that it does not overlap them. Taking into account the effects ofinhomogeneous and homogeneous broadening we calculate the intensity of the transient signals as a function of delay time. The signals are found to depend dramatically on the intensities of the excitation pulses. It is shown that for strong excitation pulses a direct dependence of the signal on the cross-correlation time of the pulses r occurs that does not exist when the pulses are weak. In particular for saturating pulses the signals exhibit a peak of width of order r . In the case of the two-pulse transient the peak is found to disappear when the Doppler width of the atomic ensemble becomes sufficiently large. This peak can have a very narrow dip near its maximum whose width is much
A theoretical analysis of the optical coherent transients that arise when a sample of two-level atoms is irradiated by a sequence of three broad-bandwidth pulses is presented. The first two pulses have a relative delay time of order of the correlation time of the pulse fluctuations and are sent into an atomic vapor from different directions. These pulses, whose temporal width is much greater than the delay time, can be correlated with one another and can be strong enough to saturate the two-level atomic transition. The third pulse is weak, noncorrelated with the first two, and is delayed in time so that it does not overlap them. We present a detailed examination of the transient signal that is produced when the third pulse is scattered by the spatial gratings in the population difference of atoms created by the first two pulses. Taking into account the effects of inhomogeneous and homogeneous broadening, we calculate the intensity of the transient signal, emitted in different directions, as a function of delay time. The signal is found to depend dramatically on the intensities of the excitation pulses. It is shown that, for strong excitation pulses, there is a direct dependence of the signal on the cross-correlation time of pulses ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}^{12}$ that does not exist when the pulses are weak. In particular, the strongest signals exhibit a peak of width of order ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}^{12}$. This peak can have a very narrow dip near its maximum whose width is much smaller than ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}^{12}$, if the pulses are fully correlated. We develop a representation of the time evolution of the Bloch vector of a two-level atom, driven by time-delayed pulses, that enables us to explain our results. In this representation, the two time-delayed pulses are replaced by two fully overlapping pulses having some effective amplitudes and atomic field detunings.
Excitation of a three-level atom irradiated by a sequence of two fluctuating pulses is discussed. The pulses have bandwidth ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}^{\mathrm{\ensuremath{-}}1}$, relative delay time t12{\mathit{t}}_{12}t12​, and can be correlated with one another. It is shown that, for strong excitation pulses, the level populations and atomic coherence as functions of t12{\mathit{t}}_{12}t12​ can vary on a time scale much smaller than ${\mathrm{\ensuremath{\tau}}}_{\mathit{c}}$. This effect may lead to a means for obtaining high temporal and spatial resolution.
A diagrammatic technique is developed to account for the saturation effects which occur when optical coherent transients are generated by broad-bandwidth light pulses. The paper is focused on the calculation of the two-atom, single-time dipole correlation function which originates the signal. In addition to the single-excitation-field situation, we examine the coherent transient generation by overlapping time-delayed correlated pulses. Our approach requires that one of the two correlated pulses be weak. The calculation of the delay dependence of the signal intensity is thoroughly worked out in the case of two-pulse and three-pulse transients in an angled-beam configuration.
Formation of coherent transients by incoherent light pulses has stimulated renewed interest in time-resolved coherent spectroscopy. Standard theories conveniently account for the weak-field regime experiments, but they fail to interpret the power effects that occur during resonant excitation of a sample by time-delayed, correlated, broadband laser pulses. We report on a new approach to this problem. We have been able to determine the expectation value of the population grating induced by two time-delayed, correlated, broadband light pulses under the limitation that one of the fields is weak. We have developed a diagrammatic technique that seems promising for the calculation of actual coherent-transient signals in the strong-field regime.
A transient, time-delayed, four-wave mixing experiment is performed in strontium vapor under stochastic excitation conditions. The first two broad-bandwidth laser pulses are correlated and their delay is adjustable. Thus they combine into a non-Markovian excitation process with adjustable memory time. One of the correlated pulses is allowed to be strong. In contrast with previous investigations, it is shown both theoretically and experimentally that under strong-field conditions the atoms are not able to keep the excitation memory over time intervals longer than the inverse laser bandwidth.