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

Bulletin of the Russian Academy of Sciences Physics

Photon echo in superradiant media

Ashat M. Basharov, N. V. Znamenskiı̆

Published Jul 1, 2010• 0 citations
Publisher

Abstract

It was shown that if an additional emission of a superradiance pulse by a medium occurs after an initial exciting pulse, two-pulse photon echoes are formed at a different frequencies and at a new time as compared to an ordinary medium. Conditions for the spatial synchronism of these photon echo were found.
DOI
10.3103/s1062873810070026

Related papers

Superradiant Damping Effects in Photon-Echo Theory

Antonio M. Ponte Goncalves, Andree A. Tallet, R. Lefèbvre

A theoretical model for superradiant damping effect in inhomogeneously broadened media and its application to photon-echo problems are discussed. Only optically thin systems are considered, and all nonradiative relaxation mechanisms are neglected. Numerical calculations are performed for a very wide square inhomogeneous line shape and square applied pulses. It is shown that excitation of the system becomes increasingly difficult as the superradiant lifetime ${\ensuremath{\tau}}_{s}$ becomes comparable with ${T}_{2}^{*}$. The energy reradiated after the end of the exciting pulse is considerable for ${\ensuremath{\tau}}_{s}\ensuremath{\approx}{T}_{2}^{*}$ and for some applied pulse areas. Two-pulse sequences produce multiple echoes as the microscopic polarizations spontaneously rephase. The first-echo amplitude maximum is found to occur for first-applied-pulse areas increasingly above $\frac{1}{2}\ensuremath{\pi}$ as ${\ensuremath{\tau}}_{s}$ decreases. For a given first-pulse area, the echo intensities increase initially as ${\ensuremath{\tau}}_{s}$ decreases (negligible damping) and finally decrease and vanish (important damping). The ratio of the second- to first-echo amplitudes is found to be proportional to $\frac{{T}_{2}^{*}}{{\ensuremath{\tau}}_{s}}$ for small superradiance levels and to decrease when ${\ensuremath{\tau}}_{s}$ approaches ${T}_{2}^{*}$. An approximate estimate of this ratio is derived for the region of linearity in $\frac{{T}_{2}^{*}}{{\ensuremath{\tau}}_{s}}$.

Physical Review A•May 1, 1970•13 citations

Self-induced three-level echo

Ashat M. Basharov

A new type of three-level photon echo has been predicted and analytically described. In contrast to the conventional three-level echo, whose formation involves three resonant ultrashort excitation pulses spaced in time, two of which are resonant to different optically allowed and adjacent transitions with different frequencies, the echo predicted arises under the conditions of formation of the conventional two-pulse echo and requires only two pump pulses of the same frequency. A theory is developed for the conditions of experiments on generation of a superradiance pulse at the 3 P 0-3 H 6 transition in impurity praseodymium ions in the LaF3 matrix upon ultrashort coherent excitation of the adjacent optically allowed 3 H 4-3 P 0 transition in praseodymium. It is shown that the superradiance pulse after its deexcitation does not polarize the medium at the 3 P 0-3 H 6 generation transition and completely eliminates polarization at the 3 H 4-3 P 0 excitation transition. However, simultaneously, the superradiance pulse transfers the optical coherence from the excitation transition to the optically forbidden 3 H 6-3 H 4 transition. Thus, the phase memory about the effect of the excitation superradiance pulse is retained in the medium within a time interval that is shorter than the irreversible relaxation time of the optically forbidden transition.

Optics and Spectroscopy•Sep 1, 2006•7 citations

Photon Echoes in Inverted Media

Mansoureh Azam Azadeh, William Randall Babbitt

We present the results of simulations of two pulse and three pulse photon echoes both in absorbing and inverted media. It is found that under proper conditions the efficiency of the photon echo process may substantially be improved in an inverted medium.

Molecular crystals and liquid crystals science technology. Section A, Molecular crystals and liquid crystals/Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals•Dec 1, 1996•6 citations

Multifrequency photon echo generated by extremely short pulses

A. Yu. Parkhomenko, Sergey Vladimirovich Sazonov

A photon echo in a multilevel quantum medium excited by two extremely short pulses with durations of less than one period of oscillation of the light is investigated theoretically. It is shown thatQ echo signals (Q is the number of allowed transitions) can form at each frequency of the allowed transitions, and the number of echo responses for all the allowed transitions equalsQ 2. Of these,Q(Q−1) signals are separated in both time and space. The otherQ echo signals of all the allowed frequencies all arise at the time 2τ 21 (τ 21 is the time interval between application of the first and second pulses to the medium) and are collinear with one another.

Journal of Experimental and Theoretical Physics Letters•Jun 1, 1998•21 citations

Superradiance of two-component media

A V Andreev, P V Polevoy

The superradiance (SR) phenomenon is considered for the case of a medium consisting of two resonant components. It is shown that the dynamics of emission in this case differs essentially from that for a monocomponent medium. The use of a two-component medium results in a substantial weakness in the requirements for duration of the pumping pulse. The peak pulse intensity of superradiance for the case of a two-component medium can exceed that for each of the components separately. By varying the active medium length and concentration of components we can control the spatiotemporal dynamics of emission. This enables us to transform the broadened pumping pulse of a lower intensity into the ultrashort high intensity pulse of SR.

Quantum Optics Journal of the European Optical Society Part B•Apr 1, 1994•8 citations

Multiple photon echo in optically dense media

Olga M. Fedotova, Oleg Kh Khasanov, T. V. Smirnova +1 more

Multiple photon echo generation process in extended crystals is investigated taking into account both the contribution of irreversible relaxation during whole excitation time and propagation effects caused by the resonant medium influence on the exciting pulse sequence and echo-responses.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Sep 26, 1997•1 citation
A theoretical model for superradiant damping effect in inhomogeneously broadened media and its application to photon-echo problems are discussed. Only optically thin systems are considered, and all nonradiative relaxation mechanisms are neglected. Numerical calculations are performed for a very wide square inhomogeneous line shape and square applied pulses. It is shown that excitation of the system becomes increasingly difficult as the superradiant lifetime ${\ensuremath{\tau}}_{s}$ becomes comparable with T2∗{T}_{2}^{*}T2∗​. The energy reradiated after the end of the exciting pulse is considerable for ${\ensuremath{\tau}}_{s}\ensuremath{\approx}{T}_{2}^{*}$ and for some applied pulse areas. Two-pulse sequences produce multiple echoes as the microscopic polarizations spontaneously rephase. The first-echo amplitude maximum is found to occur for first-applied-pulse areas increasingly above $\frac{1}{2}\ensuremath{\pi}$ as ${\ensuremath{\tau}}_{s}$ decreases. For a given first-pulse area, the echo intensities increase initially as ${\ensuremath{\tau}}_{s}$ decreases (negligible damping) and finally decrease and vanish (important damping). The ratio of the second- to first-echo amplitudes is found to be proportional to $\frac{{T}_{2}^{*}}{{\ensuremath{\tau}}_{s}}$ for small superradiance levels and to decrease when ${\ensuremath{\tau}}_{s}$ approaches T2∗{T}_{2}^{*}T2∗​. An approximate estimate of this ratio is derived for the region of linearity in $\frac{{T}_{2}^{*}}{{\ensuremath{\tau}}_{s}}$.
A new type of three-level photon echo has been predicted and analytically described. In contrast to the conventional three-level echo, whose formation involves three resonant ultrashort excitation pulses spaced in time, two of which are resonant to different optically allowed and adjacent transitions with different frequencies, the echo predicted arises under the conditions of formation of the conventional two-pulse echo and requires only two pump pulses of the same frequency. A theory is developed for the conditions of experiments on generation of a superradiance pulse at the 3 P 0-3 H 6 transition in impurity praseodymium ions in the LaF3 matrix upon ultrashort coherent excitation of the adjacent optically allowed 3 H 4-3 P 0 transition in praseodymium. It is shown that the superradiance pulse after its deexcitation does not polarize the medium at the 3 P 0-3 H 6 generation transition and completely eliminates polarization at the 3 H 4-3 P 0 excitation transition. However, simultaneously, the superradiance pulse transfers the optical coherence from the excitation transition to the optically forbidden 3 H 6-3 H 4 transition. Thus, the phase memory about the effect of the excitation superradiance pulse is retained in the medium within a time interval that is shorter than the irreversible relaxation time of the optically forbidden transition.
A photon echo in a multilevel quantum medium excited by two extremely short pulses with durations of less than one period of oscillation of the light is investigated theoretically. It is shown thatQ echo signals (Q is the number of allowed transitions) can form at each frequency of the allowed transitions, and the number of echo responses for all the allowed transitions equalsQ 2. Of these,Q(Q−1) signals are separated in both time and space. The otherQ echo signals of all the allowed frequencies all arise at the time 2τ 21 (τ 21 is the time interval between application of the first and second pulses to the medium) and are collinear with one another.
The superradiance (SR) phenomenon is considered for the case of a medium consisting of two resonant components. It is shown that the dynamics of emission in this case differs essentially from that for a monocomponent medium. The use of a two-component medium results in a substantial weakness in the requirements for duration of the pumping pulse. The peak pulse intensity of superradiance for the case of a two-component medium can exceed that for each of the components separately. By varying the active medium length and concentration of components we can control the spatiotemporal dynamics of emission. This enables us to transform the broadened pumping pulse of a lower intensity into the ultrashort high intensity pulse of SR.