Atomic hydrogen irradiated by a strong laser field: Sturmian basis calculations of rates for high-order multiphoton ionization, Raman scattering, and harmonic generation

Journal Article · Sun Apr 01 00:00:00 EST 1990 · Journal of the Optical Society of America, Part B: Optical Physics; (USA)

DOI:https://doi.org/10.1364/JOSAB.7.000433· OSTI ID:6965776

Doerr, M; Potvliege, R M; Shakeshaft, R ^[1]

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

We briefly review some technical aspects of our Sturmian basis calculations of rates for high-order multiphoton processes occurring in atomic hydrogen initially in its ground state. The processes under study include ionization, Raman scattering, and harmonic generation. We present results that illustrate the efficacy of the method and that also highlight some of the interesting physics of multiphoton processes. In particular, we show nonperturbative rates for harmonic generation by 1064-nm light and for ionization by light of wavelengths 532, 608, 616, and 1064 nm, with laser intensities in the range 10{sup 12}--10{sup 14} W/cm{sup 2}. We discuss in some detail the role of intermediate resonances in ionization processes. Some of these resonances strongly enhance the rates; others do not. The influential resonances can be characterized by the orbital angular quantum number of the corresponding intermediate states. At long wavelengths and moderate intensities, perturbation theory grossly overestimates the ionization rates. Consequently, at long wavelengths the peak intensity that atoms can experience in short pulses before undergoing ionization is far higher than would be anticipated on the basis of perturbation theory.

• OSTI ID: 6965776
• Journal Information: Journal of the Optical Society of America, Part B: Optical Physics; (USA), Vol. 7:4; ISSN 0740-3224
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
HYDROGEN
MULTI-PHOTON PROCESSES
QUANTUM ELECTRONICS
ATOMS
ELECTROMAGNETIC FIELDS
HARMONIC GENERATION
LASER RADIATION
NEAR INFRARED RADIATION
PHOTOIONIZATION
POWER RANGE 01-10 TW
PULSES
RAMAN EFFECT
RYDBERG STATES
VISIBLE RADIATION
ELECTROMAGNETIC RADIATION
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FREQUENCY MIXING
INFRARED RADIATION
IONIZATION
NONMETALS
POWER
RADIATIONS
640302* - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory