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

Four-photon ionisation in Cs I near the 6f resonance

Michele Crance

Published Jun 14, 1978• 33 citations
Publisher

Abstract

Presents the first application to a physical case of the effective-operators method introduced by Armstrong, Beers and Feneuille (1975) to interpret resonant multiphoton ionisation. In particular, the four-photon ionisation of Cs I near the 6f resonance is considered. Atomic quantities needed for the evaluation of effective operators are obtained by using a non-relativistic central-potential model. Theoretical results are compared with experimental data recently obtained by Morellec, Normand and Petite (1976). Taking into account the uncertainty of the measurements, the main experimental features and, in particular, the shapes of the resonance curves are reproduced well by the calculation described here.

DOI
10.1088/0022-3700/11/11/010

Related papers

Interpretation of short-pulse resonant ionisation in Cs I

Michele Crance

By using the effective-operators method, an interpretation of the four-photon 6f-resonant ionisation of Cs I is presented for picosecond pulsed excitation. Theoretical calculations are compared with recently published experimental results. The predictions of several authors when applied to this particular case are discussed.

Journal of Physics B Atomic and Molecular Physics•Nov 28, 1979•3 citations

Effective order of non-linearity in resonant multiphoton ionisation

Michele Crance

The effective order of non-linearity in multiphoton ionisation is defined by k=( delta lg N)/( delta lg I) where N is the number of ions created by the electromagnetic field with intensity I. Strong variations of k are observed in the vicinity of a resonance. Using a simple model for resonant multiphoton ionisation the author derives an expression for k. He takes into account the spatial distribution when excitation is produced by a Gaussian beam. Both long- and short-pulse excitation are investigated. Theoretical results are applied to the interpretation of four-photon ionisation of Cs I near the 6f resonance. The theoretical results are in good agreement with the experimental data on the effective order of non-linearity.

Journal of Physics B Atomic and Molecular Physics•Jan 14, 1980•11 citations

Use of the Green's function formalism in resonant two-photon ionisation of alkali-metal atoms. II. Two-photon ionisation of Cs near the 7P1/2-7P3/2resonances

M. Jaouen, G Laplanche, A. Rachman

For pt.I see ibid., vol. 17, p.4643 (1984). The authors apply the theoretical results obtained in a previous paper in order to study the two-photon resonant ionisation of atomic caesium in the neighbourhood of the fine-structure doublet 7P 1/2 -7P 3/2 when the incident light is right-hand circularly polarised. This formalism allows one to consider these two resonant states on an equal footing and it includes the effects of the infinite summations involved in higher-order perturbation theory. The numerical results show that the two-photon resonant ionisation of caesium takes place through an anticrossing of levels, at least in the intensity range studied. The temporal behaviour of the probability exhibits two distinct temporal regimes: linear for long interaction times and cubic for the shorter ones. The intermediate regime is characterised by quantum beats. At high intensity values, it is found that the induced light shift of the resonances is time dependent. It is also shown that the contribution of the higher-order effects may explain the slight departures between the theoretical and experimental results in the off-resonant two-photon ionisation of atomic caesium.

Journal of Physics B Atomic and Molecular Physics•Dec 14, 1984•4 citations

Critical discussion of an absolute measurement of multiphoton ionisation cross sections in caesium

M Aymar, Michele Crance

Four-photon ionisation of caesium requires strong electromagnetic fields and the usual interpretation in terms of generalised cross sections has to be questioned. A theoretical calculation in the experimental conditions of a recent measurement provides a new interpretation of the results of Morellec and Normand (1979): the effect of light shifts masks the effect of saturation and leads one to overestimate the multiphoton ionisation cross section. The expected overestimation is only 25 per cent for the quoted experiment, but could be larger in some other physical cases.

Journal of Physics B Atomic and Molecular Physics•Nov 28, 1979•19 citations

Experimental multiphoton ionization of cesium atoms through the 9D 3/2 resonant level

G. Brincourt

In this letter we report the results of an experiment concerning the multiphoton ionization of cesium atoms through the 9D3/2 resonant level, using a ruby laser. The experimental dispersion curve of the resonance obtained is compared to the theoretical shape of the resonant multiphoton ionization profile for cesium deduced from the calculations of B. L. Beers and L. Armstrong [1].

Journal de Physique Lettres•Jan 1, 1977•3 citations

Rate Theory for the Four-Photon Ionization of Cs near the 6F Resonance

Burke Ritchie

A previously presented narrow-bandwidth theory is used to interpret recent data on the four-photon ionization of Cs near the $6F$ resonance. The theory is based on treating the amplitude of the radiation field as a constant relative to its rapid phase oscillations. The ionization rate adiabatically follows a pulsed amplitude leading to maximum ionization for times at which the pulse develops sufficient intensity to shift the $6S\ensuremath{\rightarrow}6F$ transition into resonance.

Physical Review Letters•Nov 5, 1979•5 citations
Presents the first application to a physical case of the effective-operators method introduced by Armstrong, Beers and Feneuille (1975) to interpret resonant multiphoton ionisation. In particular, the four-photon ionisation of Cs I near the 6f resonance is considered. Atomic quantities needed for the evaluation of effective operators are obtained by using a non-relativistic central-potential model. Theoretical results are compared with experimental data recently obtained by Morellec, Normand and Petite (1976). Taking into account the uncertainty of the measurements, the main experimental features and, in particular, the shapes of the resonance curves are reproduced well by the calculation described here.
The effective order of non-linearity in multiphoton ionisation is defined by k=( delta lg N)/( delta lg I) where N is the number of ions created by the electromagnetic field with intensity I. Strong variations of k are observed in the vicinity of a resonance. Using a simple model for resonant multiphoton ionisation the author derives an expression for k. He takes into account the spatial distribution when excitation is produced by a Gaussian beam. Both long- and short-pulse excitation are investigated. Theoretical results are applied to the interpretation of four-photon ionisation of Cs I near the 6f resonance. The theoretical results are in good agreement with the experimental data on the effective order of non-linearity.
For pt.I see ibid., vol. 17, p.4643 (1984). The authors apply the theoretical results obtained in a previous paper in order to study the two-photon resonant ionisation of atomic caesium in the neighbourhood of the fine-structure doublet 7P 1/2 -7P 3/2 when the incident light is right-hand circularly polarised. This formalism allows one to consider these two resonant states on an equal footing and it includes the effects of the infinite summations involved in higher-order perturbation theory. The numerical results show that the two-photon resonant ionisation of caesium takes place through an anticrossing of levels, at least in the intensity range studied. The temporal behaviour of the probability exhibits two distinct temporal regimes: linear for long interaction times and cubic for the shorter ones. The intermediate regime is characterised by quantum beats. At high intensity values, it is found that the induced light shift of the resonances is time dependent. It is also shown that the contribution of the higher-order effects may explain the slight departures between the theoretical and experimental results in the off-resonant two-photon ionisation of atomic caesium.
Four-photon ionisation of caesium requires strong electromagnetic fields and the usual interpretation in terms of generalised cross sections has to be questioned. A theoretical calculation in the experimental conditions of a recent measurement provides a new interpretation of the results of Morellec and Normand (1979): the effect of light shifts masks the effect of saturation and leads one to overestimate the multiphoton ionisation cross section. The expected overestimation is only 25 per cent for the quoted experiment, but could be larger in some other physical cases.
A previously presented narrow-bandwidth theory is used to interpret recent data on the four-photon ionization of Cs near the 6F6F6F resonance. The theory is based on treating the amplitude of the radiation field as a constant relative to its rapid phase oscillations. The ionization rate adiabatically follows a pulsed amplitude leading to maximum ionization for times at which the pulse develops sufficient intensity to shift the $6S\ensuremath{\rightarrow}6F$ transition into resonance.