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

Anomalous Hanle effect signals in sensitised fluorescence

W. D. Evans, W Gough

Published Jul 28, 1979• 2 citations
Publisher

Abstract

Hanle effect signals in mercury-cadmium sensitised fluorescence have been observed which are different from those found in direct cadmium fluorescence. Many of the anomalies are explained by multiple scattering of radiation. Anomalies in the shapes of the signals in a previously reported experiment on 'light beats' in mercury-cadmium sensitised fluorescence are also explained.

DOI
10.1088/0022-3700/12/14/011

Related papers

Observation of modulation of mercury-cadmium sensitized fluorescence under the influence of a rotating magnetic field

R S Baker, W Gough

Modulation has been observed in mercury-cadmium sensitized fluorescence under the simultaneous application of a static and a rotating magnetic field. The dependence of the depth of modulation at various frequencies on the static field has been investigated. There are discrepancies between theory and experiment which indicate an anisotropy in the observation of the various collisions. An attempt is made to explain the discrepancies for one particular case on a simple model of the collision, but this attempt is unsuccessful.

Journal of Physics B Atomic and Molecular Physics•Mar 11, 1975•4 citations

The Hanle effect and the theory of resonance fluorescence experiments

Alan Corney

This chapter provides an account of atomic resonance fluorescence and its depolarization by external magnetic fields, also known as the Hanle effect. Experiments in mercury vapour and their theoretical description are explained both by classical and quantum mechanical density matrix methods. Radiative lifetimes of alkali atoms and Group IIB atoms are reported. Optical and radio-frequency coherence, and experiments using pulsed and intensity modulated radiation are discussed.

Oxford University Press eBooks•Oct 5, 2006•0 citations

The polarization of sensitized fluorescence

W Gough

By means of the selection rule Σ m J = constant along the axis of a collision between two atoms, it is shown that sensitized fluorescence should in some cases be partially polarized. The degree of polarization of the fluorescence of cadmium vapour sensitized by the presence of mercury vapour is calculated for certain states of polarization of the incident radiation. In the case studied experimentally the degree of polarization varies over a range of 2-5%. The theoretical value is 3/11, which is reduced in practice by various depolarizing effects. The possibility of transfer coherence between eigenstates from mercury to cadmium during a collision is considered.

Proceedings of the Physical Society•Jan 1, 1967•29 citations

Secondary Radiation and Polarization of Resonance Radiation in Cadmium

Walter A. MacNair

Secondary radiation in cadmium vapor containing mercury as an impurity.---Attention is called to the points of difference between the conditions under which the two types of optically excited spectra of mercury vapor appear, namely resonance radiation and fluorescence. In the present experiments it is noted that when a bulb containing cadmium with a slight impurity of mercury is illuminated by light of 2288A wave-length the secondary radiation contains the mercury line 2536.7A in addition to the cadmium lines 2288A and 3261A provided the metal is distilling. As soon as the vapor is stagnant, however, only the cadmium 2288A line appears. The suggestion is made that the phenomenon is due to the presence in the distilling vapor of unstable HgCd molecules. In such a molecule the Cd atom may absorb the 2288A radiation and subsequently in the breakdown of the molecule may excite the Hg atom by a collision of the second kind.Polarization of the cadmium resonance, radiation in zero magnetic field.---The polarization of the cadmium resonance radiation (3261A) in zero magnetic field under certain conditions was found to be 35 percent. In order to explain this value by the kinetic theory, one must assign effective radii to the colliding atoms which are thirty times the radii effective in ordinary collisions.

Physical Review•May 1, 1927•5 citations

Narrowing of Level-Crossing Signals by Radiative Transfer in Diffuse Reflection. II. Experiments on the 6P13 Level of Mercury

B. Dodsworth, J. C. Gay, A. Omont

We present experimental verification of a certain number of theoretical predictions given in the preceding paper. The narrowing of the different Hanle-effect signals by multiple diffusion is clearly weaker if observed using the light scattered in the backward direction than if observed using the laterally scattered light. This narrowing can become very small if the vapor is illuminated with light whose frequency is in the wings of the Doppler absorption width of the vapor. The values of the ratios of the widths and intensities of the different Hanle-effect signals that were measured are in good agreement with the values predicted by theory.

Physical Review A•Jun 1, 1971•8 citations

Peculiar Signal in the Hanle Effect Experiments on the 6p01 Level of Xenon

Takanori Suzuki

The Hanle effect was studied on the xenon 6 p 01 level by using a xenon laser at 3.99 µm (5 d 00 -6 p 01 ) and fluorescences of 979.9 nm (6 p 01 -6 s 12 ) and 1083.8 nm (6 p 01 -6 s 12 ) transitions. In addition to the intensity variation due to the Hanle signal and Doppler profile, a peculiar signal was observed which had a width of about twenty times the Hanle width of the 6 p 01 level. This signal is found to be independent of the coherence among the Zeeman sublevels of the 6 p 01 level.

Journal of the Physical Society of Japan•Jan 1, 1978•0 citations
Hanle effect signals in mercury-cadmium sensitised fluorescence have been observed which are different from those found in direct cadmium fluorescence. Many of the anomalies are explained by multiple scattering of radiation. Anomalies in the shapes of the signals in a previously reported experiment on 'light beats' in mercury-cadmium sensitised fluorescence are also explained.
Modulation has been observed in mercury-cadmium sensitized fluorescence under the simultaneous application of a static and a rotating magnetic field. The dependence of the depth of modulation at various frequencies on the static field has been investigated. There are discrepancies between theory and experiment which indicate an anisotropy in the observation of the various collisions. An attempt is made to explain the discrepancies for one particular case on a simple model of the collision, but this attempt is unsuccessful.
By means of the selection rule Σ m J = constant along the axis of a collision between two atoms, it is shown that sensitized fluorescence should in some cases be partially polarized. The degree of polarization of the fluorescence of cadmium vapour sensitized by the presence of mercury vapour is calculated for certain states of polarization of the incident radiation. In the case studied experimentally the degree of polarization varies over a range of 2-5%. The theoretical value is 3/11, which is reduced in practice by various depolarizing effects. The possibility of transfer coherence between eigenstates from mercury to cadmium during a collision is considered.
Secondary radiation in cadmium vapor containing mercury as an impurity.---Attention is called to the points of difference between the conditions under which the two types of optically excited spectra of mercury vapor appear, namely resonance radiation and fluorescence. In the present experiments it is noted that when a bulb containing cadmium with a slight impurity of mercury is illuminated by light of 2288A wave-length the secondary radiation contains the mercury line 2536.7A in addition to the cadmium lines 2288A and 3261A provided the metal is distilling. As soon as the vapor is stagnant, however, only the cadmium 2288A line appears. The suggestion is made that the phenomenon is due to the presence in the distilling vapor of unstable HgCd molecules. In such a molecule the Cd atom may absorb the 2288A radiation and subsequently in the breakdown of the molecule may excite the Hg atom by a collision of the second kind.Polarization of the cadmium resonance, radiation in zero magnetic field.---The polarization of the cadmium resonance radiation (3261A) in zero magnetic field under certain conditions was found to be 35 percent. In order to explain this value by the kinetic theory, one must assign effective radii to the colliding atoms which are thirty times the radii effective in ordinary collisions.
We present experimental verification of a certain number of theoretical predictions given in the preceding paper. The narrowing of the different Hanle-effect signals by multiple diffusion is clearly weaker if observed using the light scattered in the backward direction than if observed using the laterally scattered light. This narrowing can become very small if the vapor is illuminated with light whose frequency is in the wings of the Doppler absorption width of the vapor. The values of the ratios of the widths and intensities of the different Hanle-effect signals that were measured are in good agreement with the values predicted by theory.