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

Journal of Physics B Atomic and Molecular Physics

The modified stimulated photon echo as a new method for measuring population, orientation and alignment relaxation times

Igor V. Yevseyev, Valery M. Yermachenko, Решетов Владимир Александрович

Published Jan 28, 1986• 7 citations
Publisher

Abstract

The modified stimulated photon echo is proposed as a method for the investigation of elastic collisions of excited atoms with non-excited foreign gas atoms, which induce the redistribution of the excited atoms in Zeeman sublevels. Such collisions cause the difference in the population, orientation and alignment relaxation times of a resonant level. It is shown that the proper choice of mutual orientation of the exciting-light polarisation vectors makes it possible to determine the relaxation times for the population, orientation and alignment of a resonant level. It is found that the formulae, derived in the limit of exciting-pulse small areas, are the most attractive for spectroscopic purposes, as in this case the polarisation properties of the modified stimulated photon echo do not depend on the exciting-pulse shapes, nor on their areas. A detailed discussion of the experimental results of Hartmann and collaborators (1979) and of Keller and Le Gouet (1984), mainly concerned with the investigation of the modified stimulated photon echoes in gases, is carried out.

DOI
10.1088/0022-3700/19/2/008

Related papers

Application of modified stimulated photon echo technique for measuring relaxation rates of orientation and alignment in an atomic gas

Хворостов Евгений Борисович, Sergei A. Kochubei, Рубцова Наталия Николаевна

The phenomenon of modified stimulated photon echo is registered on two adjacent quantum transitions of 174Yb atoms. The experiments were performed in a rarefied atomic vapour of ytterbium, strongly diluted by the noble gas xenon. Light pulses of linear polarization with specially selected mutual orientations of the polarization vectors were used to excite the atoms, which made it possible to measure the relaxation rates of the orientation and alignment for a three times degenerated intermediate quantum level of 174Yb atoms. The method of modified stimulated photon echo is compared to the method of conventional stimulated photon echo.

Journal of Modern Optics•Jul 30, 2026•0 citations

Collisional decay rates of population, orientation, and alignment studied by stimulated photon echo technique in molecular gas SF 6

L. S. Vasilenko, Н. Н. Рубцова, Хворостов Евгений Борисович

The method of a stimulated photon echo with specially selected linear polarizations of pumping pulses of a coherent resonant radiation is applied to a research of depolarizing collisions in molecular gas SF6 and its mixtures with buffer gases He and Xe. For the first time in one experiment the rates of a collisional decay of three lowest moments of polarization (population, orientation and alignment) are defined in an ensemble of gas particles. These rates of a relaxation are measured as functions on longitudinal velocities of resonant particles. In the frames of an experimental accuracy any noticeable dependence on velocities of particles was not detected both for orientation and alignment neither in pure resonant gas SF6 nor in mixtures. This result confirms the standard theoretical approach to depolarizing collisions. In pure SF6 decay rates of orientation and alignment have proved lesser than relaxation rate constant due to velocity changing (elastic) collisions. It means, that only the part of elastic collisions participates in destruction of multipole polarization moments of resonant levels. In comparison with our previous work the evidence is obtained that the relaxation of multipole moments seems to be j-dependent one in a medium of molecular gas SF6.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Sep 26, 1997•0 citations

Study of the rates of collisional decay of population, orientation, and alignment by stimulated photon echo in a molecular gas

L. S. Vasilenko, Н. Н. Рубцова, Хворостов Евгений Борисович

A stimulated photon echo technique with specially selected linear polarizations of the coherent resonant driver pulses is used to study depolarizing collisions in the molecular gas SF 6 and in mixtures of it with buffer He and Xe. The collisional decay rates of the population, orientation, and alignment in an ensemble of gas particles are determined for the first time in a single experiment. These relaxation rates are measured as a function of the longitudinal translational velocities of the resonant particles. To within the experimental accuracy, no significant dependence of the collisional decay rates on the translational velocities of the particles was observed. This result confirms the conventional theoretical approach to depolarizing collisions. In pure SF 6 the decay rates for the orientation and alignment were lower than the relaxation constant for collisions involving a change in the longitudinal velocity (elastic collisions) that is known from experimental observations of the ordinary photon echo. This means that only some of the elastic collisions participate in destroying the multipole moments of the levels. Evidence is found that the relaxation of the multipole moments created by polarized radiation in a resonant medium of molecular SF 6 gas depends on j , the total angular momentum of the level.

Journal of Experimental and Theoretical Physics•Mar 1, 1998•4 citations

Measurements of relaxation constants of orientation and alignment by method of stimulated photon echo in molecular gas

L. S. Vasilenko, Н. Н. Рубцова, Хворостов Евгений Борисович

The method of stimulated photon echo with specially chosen linear polarizations of the pumping pulses of coherent resonant radiation is applied for the investigation of collisional decay of orientation and alignment in the molecular gas SF6 and its mixtures with buffers He and Xe. These relaxation rates are measured as a function of longitudinal velocities. Within the experiment accuracy, no remarkable velocity dependence of the depolarizing collisions rates was detected. This result confirms conventional approach of the depolarizing collisions theoretical treatment. In pure SF6 the rates of elastic depolarizing collisions for orientation and alignment proved smaller than the known rate of velocity changing collisions. It means that only part of the elastic collisions participates in destroying of the level multipole moments.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Mar 3, 1997•0 citations

Depolarizing collisions of 174 Yb with rare gas atoms

Н. Н. Рубцова, Igor V. Yevseyev, В. Н. Ищенко +2 more

Polarization stimulated photon echo technique is applied to measure the difference between relaxation rates of alignment and orientation of the level 3P1 (6s6p) of 174Yb. At the transition 1S0 (6s2) - 3P1 (6s6p) 174Yb (of type 0 ↔ 1) a collision induced echo is revealed, which is generated by two pulses of linear and mutually orthogonal polarizations. Photon echo arises exclusively due to collisions between atoms of ytterbium and buffer gases; its power depends non-monotonously on the buffer pressure, and the echo polarizations coincides with the polarization of the first exciting pulse of radiation.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Mar 3, 2008•1 citation

Study of collisional decay rates of population, orientation, and alignment using stimulated photon echo in SF 6 molecular gas

L. S. Vasilenko, Н. Н. Рубцова, Хворостов Евгений Борисович

Stimulated photon echo technique with specially chosen linear polarizations of pumping pulses of exciting radiation is applied to investigation of depolarizing collisions in molecular gas SF6 and its mixtures with buffer gases He and Xe. For the first time, the collisional decay rates of population, orientation and alignment of SF6 levels are determined simultaneously. Translational velocity dependence of orientation and alignment collisional decay rates was under investigation. This velocity dependence proved to be negligible within the frames of experimental accuracy both in pure SF6 and in mixtures, which is in agreement with standard theoretical approach accepted for depolarizing collisions. Decay rates of orientation and alignment in pure SF6 have proved lower than velocity changing (elastic) collisions relaxation rate, which allows to conclude, that only some part of elastic collisions participates in destruction of multipole polarization moments of resonant levels. The evidence is obtained for j-dependence of multipole moments relaxation rates SF6.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Oct 21, 1998•0 citations
The modified stimulated photon echo is proposed as a method for the investigation of elastic collisions of excited atoms with non-excited foreign gas atoms, which induce the redistribution of the excited atoms in Zeeman sublevels. Such collisions cause the difference in the population, orientation and alignment relaxation times of a resonant level. It is shown that the proper choice of mutual orientation of the exciting-light polarisation vectors makes it possible to determine the relaxation times for the population, orientation and alignment of a resonant level. It is found that the formulae, derived in the limit of exciting-pulse small areas, are the most attractive for spectroscopic purposes, as in this case the polarisation properties of the modified stimulated photon echo do not depend on the exciting-pulse shapes, nor on their areas. A detailed discussion of the experimental results of Hartmann and collaborators (1979) and of Keller and Le Gouet (1984), mainly concerned with the investigation of the modified stimulated photon echoes in gases, is carried out.
The phenomenon of modified stimulated photon echo is registered on two adjacent quantum transitions of 174Yb atoms. The experiments were performed in a rarefied atomic vapour of ytterbium, strongly diluted by the noble gas xenon. Light pulses of linear polarization with specially selected mutual orientations of the polarization vectors were used to excite the atoms, which made it possible to measure the relaxation rates of the orientation and alignment for a three times degenerated intermediate quantum level of 174Yb atoms. The method of modified stimulated photon echo is compared to the method of conventional stimulated photon echo.
The method of a stimulated photon echo with specially selected linear polarizations of pumping pulses of a coherent resonant radiation is applied to a research of depolarizing collisions in molecular gas SF6 and its mixtures with buffer gases He and Xe. For the first time in one experiment the rates of a collisional decay of three lowest moments of polarization (population, orientation and alignment) are defined in an ensemble of gas particles. These rates of a relaxation are measured as functions on longitudinal velocities of resonant particles. In the frames of an experimental accuracy any noticeable dependence on velocities of particles was not detected both for orientation and alignment neither in pure resonant gas SF6 nor in mixtures. This result confirms the standard theoretical approach to depolarizing collisions. In pure SF6 decay rates of orientation and alignment have proved lesser than relaxation rate constant due to velocity changing (elastic) collisions. It means, that only the part of elastic collisions participates in destruction of multipole polarization moments of resonant levels. In comparison with our previous work the evidence is obtained that the relaxation of multipole moments seems to be j-dependent one in a medium of molecular gas SF6.
A stimulated photon echo technique with specially selected linear polarizations of the coherent resonant driver pulses is used to study depolarizing collisions in the molecular gas SF 6 and in mixtures of it with buffer He and Xe. The collisional decay rates of the population, orientation, and alignment in an ensemble of gas particles are determined for the first time in a single experiment. These relaxation rates are measured as a function of the longitudinal translational velocities of the resonant particles. To within the experimental accuracy, no significant dependence of the collisional decay rates on the translational velocities of the particles was observed. This result confirms the conventional theoretical approach to depolarizing collisions. In pure SF 6 the decay rates for the orientation and alignment were lower than the relaxation constant for collisions involving a change in the longitudinal velocity (elastic collisions) that is known from experimental observations of the ordinary photon echo. This means that only some of the elastic collisions participate in destroying the multipole moments of the levels. Evidence is found that the relaxation of the multipole moments created by polarized radiation in a resonant medium of molecular SF 6 gas depends on j , the total angular momentum of the level.
The method of stimulated photon echo with specially chosen linear polarizations of the pumping pulses of coherent resonant radiation is applied for the investigation of collisional decay of orientation and alignment in the molecular gas SF6 and its mixtures with buffers He and Xe. These relaxation rates are measured as a function of longitudinal velocities. Within the experiment accuracy, no remarkable velocity dependence of the depolarizing collisions rates was detected. This result confirms conventional approach of the depolarizing collisions theoretical treatment. In pure SF6 the rates of elastic depolarizing collisions for orientation and alignment proved smaller than the known rate of velocity changing collisions. It means that only part of the elastic collisions participates in destroying of the level multipole moments.
Polarization stimulated photon echo technique is applied to measure the difference between relaxation rates of alignment and orientation of the level 3P1 (6s6p) of 174Yb. At the transition 1S0 (6s2) - 3P1 (6s6p) 174Yb (of type 0 ↔ 1) a collision induced echo is revealed, which is generated by two pulses of linear and mutually orthogonal polarizations. Photon echo arises exclusively due to collisions between atoms of ytterbium and buffer gases; its power depends non-monotonously on the buffer pressure, and the echo polarizations coincides with the polarization of the first exciting pulse of radiation.
Stimulated photon echo technique with specially chosen linear polarizations of pumping pulses of exciting radiation is applied to investigation of depolarizing collisions in molecular gas SF6 and its mixtures with buffer gases He and Xe. For the first time, the collisional decay rates of population, orientation and alignment of SF6 levels are determined simultaneously. Translational velocity dependence of orientation and alignment collisional decay rates was under investigation. This velocity dependence proved to be negligible within the frames of experimental accuracy both in pure SF6 and in mixtures, which is in agreement with standard theoretical approach accepted for depolarizing collisions. Decay rates of orientation and alignment in pure SF6 have proved lower than velocity changing (elastic) collisions relaxation rate, which allows to conclude, that only some part of elastic collisions participates in destruction of multipole polarization moments of resonant levels. The evidence is obtained for j-dependence of multipole moments relaxation rates SF6.