Méthodologie des interactions laser-atomes : application à l'ionisation simple quasi-résonante de l'hélium à trois photons
(2009)
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- Authors
- Supervisors
- Piraux, Bernard
- Abstract
- (en) In this work, we are interested in methods for solving the time-dependent Schrödinger equation describing an atom interacting with a laser field. The various methods introduced in this thesis are based on the use of non-hermitian hamiltonians and a spectral method. To identify the validity domain of these methods, we have applied them to the Pöschl-Teller atomic model and to the hydrogen and helium atoms. First, we have shown that it is possible to compute the energy distribution of the emitted electrons during the ionization of an atom when the Hamiltonian has been complex rotated. The advantage of the complex rotation is a significant reduction of the basis dimension for the spectral method. Next, we have generalized the Fatunla explicit method for the propagation of the Schrödinger equation solution in time in order to avoid the stiffness character of the system of differential equations to be solved. Finally, we have used the Floquet method to study laser induced structures which are represented by poles in the complex energy plan. We have shown that at low intensities, positions of these poles can be computed by means of the complex rotated Friedrichs-Fano model. We end our thesis by a preliminary study of three-photon single ionization of helium.
- Affiliations
Citations
Nyengeri, H. (2009). Méthodologie des interactions laser-atomes : application à l’ionisation simple quasi-résonante de l’hélium à trois photons. https://hdl.handle.net/2078.5/131079