Atomic stabilization in ultrastrong laser fields

Journal Article · Mon Jul 01 00:00:00 EDT 1991 · Physical Review, A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.44.721· OSTI ID:5467437

Piraux, B ^[1]; Huens, E ^[2]; Knight, P ^[3]

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1. The Blackett Laboratory, Imperial College, London SW72BZ, United Kingdom (GB)
2. Institut de Physique Corpusculaire, Universite Catholique de Louvain, B1348, Louvain-la-Neuve, Belgium (BE)
3. The Blackett Laboratory, Imperial College, London SW72BZ (United Kingdom)

One- and two-photon ionization of atomic hydrogen by an ultrashort hyperbolic secant laser pulse is analyzed in detail by means of the essential-states method. We consider two frequency regimes. For photon energies close to the ionization potential, we show that the excitation of atomic hydrogen, initially in its ground state, leads, at low and moderate laser intensities, to an {ital np}-state population distribution that, for ultrashort pulses, is strongly shifted down to low-lying Rydberg states. At very high intensities in this frequency regime, we show that the time evolution of the Rydberg-state population follows adiabatically the pulse shape and does not lead to population trapping in the Rydberg states. This contrasts with the results obtained in the low-frequency regime. We demonstrate that, when hydrogen is excited from the 2{ital s} state, a substantial inhibition of ionization occurs at high field intensities. The stabilization is caused by the creation of a spatially extended wave packet that results from the Raman mixing of intermediate Rydberg states.

• OSTI ID: 5467437
• Journal Information: Physical Review, A; (United States), Vol. 44:1; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
HYDROGEN
PHOTOIONIZATION
CONFIGURATION MIXING
LASER RADIATION
PHOTON-ATOM COLLISIONS
PULSED IRRADIATION
RYDBERG STATES
STABILIZATION
ATOM COLLISIONS
COLLISIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LEVELS
EXCITED STATES
INTERACTIONS
IONIZATION
IRRADIATION
NONMETALS
PHOTON COLLISIONS
RADIATIONS
640302* - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory