Spectral widths of H[sub 2][sup +] multiphoton dissociation with short intense laser pulses

Journal Article · Tue Feb 01 04:00:00 EST 1994 · Physical Review A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.49.1186· OSTI ID:5259397

Atabek, O ^[1]; Jolicard, G ^[2]

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1. Laboratoire de Photophysique Moleculaire du Centre National de la Recherche Scientifique, Batiment 213, Universite Paris-Sud, 91405 Orsay Cedex (France)
2. Laboratoire de Physique Moleculaire, Faculte des Sciences de Besancon, La Bouloie emRoute de Gray, 25030 Besancon Cedex (France)

Photodissociation spectra of H[sub 2][sup +], obtained using ultrashort (a few femtoseconds), intense (within the range of 10[sup 12] to 10[sup 14] W/cm[sup 2]) laser pulses (with a peak frequency of 3.761 eV), and displaying well-separated proton kinetic-energy peaks corresponding to one-, two-, or three-photon absorptions are analyzed. Within some approximations, the validity range of which is related to the aforementioned assumptions on the laser and spectrum characteristics, a simple analytic formula is deduced. It gives the spectral widths of the observed peaks in terms of the total number of photons which are absorbed and/or emitted during the dissociation process. A quantitative support to some recent dynamical interpretations is provided. The successive absorption of three photons seems basically to be the initial step which, at intermediate intensities, leads to the three-photon peaks. A subsequent emission of one (or two) photons is responsible for the two- (or one-) photon peaks. Bond softening occurs at higher intensities by the lowering of potential-energy barriers. Dissociation proceeds through these barriers by reflection and tunneling. It involves at least three photons to end in a one-photon peak.

• OSTI ID: 5259397
• Journal Information: Physical Review A; (United States), Journal Name: Physical Review A; (United States) Vol. 49:2; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

664200* -- Spectra of Atoms & Molecules & their Interactions with Photons-- (1992-)
74 ATOMIC AND MOLECULAR PHYSICS
BARYONS
CATIONS
CHARGED PARTICLES
ELEMENTARY PARTICLES
ENERGY RESOLUTION
ENERGY SPECTRA
FERMIONS
HADRONS
HYDROGEN IONS
IONS
IRRADIATION
LASERS
LINE WIDTHS
MATHEMATICS
MOLECULAR IONS
MULTI-PHOTON PROCESSES
NUCLEONS
PROTONS
PULSED IRRADIATION
RESOLUTION
SPECTRA
STATISTICS