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 polarisation of collisionally redistributed fluorescence resulting from line wing excitation

E L Lewis, Jim Salter, Martin A. Harris

Published Mar 14, 1981• 19 citations
Publisher

Abstract

The fractional polarisation of radiation redistributed from the red wing to line centre is calculated on the basis of a molecular model for the colliding pair of atoms at the time of excitation and found to be in good agreement with the observation.
DOI
10.1088/0022-3700/14/5/003

Related papers

The polarisation of collisionally redistributed atomic fluorescence

E L Lewis, Martin A. Harris, W. J. Alford +2 more

The polarisation of atomic line fluorescence resulting from the excitation of a collisional complex is calculated on the basis of a simple molecular picture for the pair of colliding atoms. The red-wing region is treated in detail as arising from excitation of both Pi and Sigma molecular states at different internuclear distances, and the blue wing is identified as predominantly due to the Sigma state. A calculation for the strontium 4607 AA line gives good qualitative agreement with the experiment.

Journal of Physics B Atomic and Molecular Physics•Feb 28, 1983•54 citations

Far wing depolarisation of collision-induced fluorescence

Wolfgang Behmenburg, V. Kroop

Redistribution and depolarisation of light scattered by atoms undergoing collisions outside the impact region of the line profile has been studied experimentally and theoretically. In a cell experiment intensity and linear degree of polarisation of the fluorescence components 32S1/2 to or from 32P1/2,3/2 of Na atoms induced by collisions with Ar buffer gas atoms were measured as functions of the laser frequency omega L. The decrease of polarisation of the D2 component observed when omega L is shifted away from the D2 toward D1 resonance disagrees with calculations on the basis of the factorisation approximation of the theory of redistribution. Using Baylis (1975) potentials for the Na/Ar system, the effect is interpreted in terms of adiabatic coupling of the 32P3/2 electronic angular momentum to the collision axis during 'strong' collisions, giving rise to a greater than average depolarisation.

Journal of Physics B Atomic and Molecular Physics•Feb 14, 1981•14 citations

Depolarisation in Na-Ar optical collisions

Wolfgang Behmenburg, V. Kroop, Frank Rebentrost

The depolarisation of the redistributed Na D1and D2line fluorescence caused by Na-Ar collisions after far-wing excitation was investigated. In the limit of zero Ar density the J=1/2orientation and J=3/2alignment reflect the distribution among Zeeman sublevels of Na 32PJproduced after absorption of a photon into one or several excited Na-Ar molecular states at small internuclear separation, followed by a mixing between these states during dissociation. Measurements of these quantities as functions of the detuning up to Delta omegaJ=50 cm-1in the red wings are compared with quantum-mechanical coupled-channel (CC) calculations using realistic molecular potentials and thermal averaging, and with predictions from the factorisation approximation (FA) of the theory of redistribution. Fair agreement with CC calculations and FA predictions was obtained within the impact region, proving the validity of the factorisation assumption there. Outside this region the overall depolarisation is primarily due to reorientation of the Na 3P electronic angular momentum and is reproduced qualitatively by the CC calculations but not by the FA theory. Additional depolarisation connected with the fine-structure coupling was observed.

Journal of Physics B Atomic and Molecular Physics•Jul 14, 1985•19 citations

Polarisation-monitored collisional redistribution experiment in Hg(3P1-1S0)-Kr

D Segal, Keith R. Burnett

The authors have measured the polarisation of collisionally redistributed light as a function of detuning from line centre for the Hg 3 P 1 - 1 S 0 transition in the presence of Kr. These are the first such results for a J=0 to 1 system for which the interatomic potentials are well documented. They present a polarisation profile for the red wing between 5 and 40 cm -1 and polarisation measurements for two individual detunings in the blue wing. The data have been corrected for various mechanisms which affect the polarisation but which do not depend on the original scattering event. The application of some of these corrections has been discussed elsewhere for the CW case. Since they report the first pulsed collisional redistribution experiments involving depolarisation measurements they discuss the differences between the pulsed and CW cases in detail.

Journal of Physics B Atomic Molecular and Optical Physics•Jan 28, 1989•10 citations

The Effect of Collisions on the Polarization of Resonance Fluorescence

V. N. Rebane

Optics and Spectroscopy•Feb 1, 1968•0 citations

Correlation effects in collisional depolarisation and redistribution of radiation

Gerard Nienhuis

The author derives an expression for the spectrum of the radiation scattered by an atom that suffers binary collisions in the weak-field limit. The frequency of the incident radiation is in near-resonance with a multiplet transition. The authors accounts for strong atom-perturber correlations that are induced when the incident or the detected frequency is in the far wing of an absorption line. For an isolated transition between two degenerate atomic levels the model picture of quasistatic absorption followed by adiabatic reorientation of the excited state predicts a redistributed fluorescence line with a polarisation that is determined by geometrical factors.

Journal of Physics B Atomic and Molecular Physics•Jan 14, 1983•25 citations
The polarisation of atomic line fluorescence resulting from the excitation of a collisional complex is calculated on the basis of a simple molecular picture for the pair of colliding atoms. The red-wing region is treated in detail as arising from excitation of both Pi and Sigma molecular states at different internuclear distances, and the blue wing is identified as predominantly due to the Sigma state. A calculation for the strontium 4607 AA line gives good qualitative agreement with the experiment.
Redistribution and depolarisation of light scattered by atoms undergoing collisions outside the impact region of the line profile has been studied experimentally and theoretically. In a cell experiment intensity and linear degree of polarisation of the fluorescence components 32S1/2 to or from 32P1/2,3/2 of Na atoms induced by collisions with Ar buffer gas atoms were measured as functions of the laser frequency omega L. The decrease of polarisation of the D2 component observed when omega L is shifted away from the D2 toward D1 resonance disagrees with calculations on the basis of the factorisation approximation of the theory of redistribution. Using Baylis (1975) potentials for the Na/Ar system, the effect is interpreted in terms of adiabatic coupling of the 32P3/2 electronic angular momentum to the collision axis during 'strong' collisions, giving rise to a greater than average depolarisation.
The depolarisation of the redistributed Na D1and D2line fluorescence caused by Na-Ar collisions after far-wing excitation was investigated. In the limit of zero Ar density the J=1/2orientation and J=3/2alignment reflect the distribution among Zeeman sublevels of Na 32PJproduced after absorption of a photon into one or several excited Na-Ar molecular states at small internuclear separation, followed by a mixing between these states during dissociation. Measurements of these quantities as functions of the detuning up to Delta omegaJ=50 cm-1in the red wings are compared with quantum-mechanical coupled-channel (CC) calculations using realistic molecular potentials and thermal averaging, and with predictions from the factorisation approximation (FA) of the theory of redistribution. Fair agreement with CC calculations and FA predictions was obtained within the impact region, proving the validity of the factorisation assumption there. Outside this region the overall depolarisation is primarily due to reorientation of the Na 3P electronic angular momentum and is reproduced qualitatively by the CC calculations but not by the FA theory. Additional depolarisation connected with the fine-structure coupling was observed.
The authors have measured the polarisation of collisionally redistributed light as a function of detuning from line centre for the Hg 3 P 1 - 1 S 0 transition in the presence of Kr. These are the first such results for a J=0 to 1 system for which the interatomic potentials are well documented. They present a polarisation profile for the red wing between 5 and 40 cm -1 and polarisation measurements for two individual detunings in the blue wing. The data have been corrected for various mechanisms which affect the polarisation but which do not depend on the original scattering event. The application of some of these corrections has been discussed elsewhere for the CW case. Since they report the first pulsed collisional redistribution experiments involving depolarisation measurements they discuss the differences between the pulsed and CW cases in detail.
The author derives an expression for the spectrum of the radiation scattered by an atom that suffers binary collisions in the weak-field limit. The frequency of the incident radiation is in near-resonance with a multiplet transition. The authors accounts for strong atom-perturber correlations that are induced when the incident or the detected frequency is in the far wing of an absorption line. For an isolated transition between two degenerate atomic levels the model picture of quasistatic absorption followed by adiabatic reorientation of the excited state predicts a redistributed fluorescence line with a polarisation that is determined by geometrical factors.