Multiphoton processes in an intense laser field: Harmonic generation and total ionization rates for atomic hydrogen

Journal Article · Fri Sep 15 04:00:00 EDT 1989 · Physical Review (Section) A: General Physics; (USA)

DOI:https://doi.org/10.1103/PhysRevA.40.3061· OSTI ID:5555495

Potvliege, R M; Shakeshaft, R ^[1]

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1. Department of Physics, University of Southern California, Los Angeles, California 90089-0484 (US)

We report results of large-scale nonperturbative (Floquet) calculations of rates for harmonic generation and total ionization of H(1{ital s}) by fields whose intensity ranges from about 10{sup 12} to 3{times}10{sup 13} W/cm{sup 2} and whose wavelength ranges from 265 to 1064 nm. At long wavelengths and moderate to high intensities, perturbation theory yields estimates of total ionization rates that are orders of magnitude too large, and estimates of harmonic-generation rates that exhibit a qualitatively incorrect behavior with respect to order. We have studied the influence of resonances on the ionization rates, and we illustrate the resonance enhancement of the ionization yield for a realistic pulse. Finally, we address several formal aspects of Floquet theory, including the convergence of the induced dipole moment, gauge invariance, and the normalization of the wave function.

• OSTI ID: 5555495
• Journal Information: Physical Review (Section) A: General Physics; (USA), Journal Name: Physical Review (Section) A: General Physics; (USA) Vol. 40:6; ISSN PLRAA; ISSN 0556-2791
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ATOMS
AUGMENTATION
CROSS SECTIONS
ELECTROMAGNETIC RADIATION
ELEMENTS
FLOQUET FUNCTION
FREQUENCY MIXING
FUNCTIONS
HARMONIC GENERATION
HYDROGEN
IONIZATION
LASER RADIATION
MULTI-PHOTON PROCESSES
NONMETALS
PHOTOIONIZATION
RADIATIONS
RESONANCE