Nonlinear time-dependent density-functional-theory study of ionization and harmonic generation in CO{sub 2} by ultrashort intense laser pulses: Orientational effects

Journal Article · Mon Feb 15 00:00:00 EST 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.023411· OSTI ID:21408264

Fowe, Emmanuel Penka; Bandrauk, Andre D ^[1]

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1. Laboratoire de Chimie Theorique, Faculte des sciences and Universite de Sherbrooke, Quebec, J1K 2R1 (Canada)

Time-dependent density-functional-theory (TDDFT) methods are used to calculate the orientational dependence of ionization and molecular high-order harmonic generation (MHOHG) in the CO{sub 2} molecule as a function of laser intensity I{sub 0{>=}}10{sup 14} W/cm{sup 2} for few-cycle 800 nm laser pulses. A time-series analysis is used to confirm the recollision model in MHOHG for different density potentials. It is found that at intensities I{sub 0}>3.5x10{sup 14} W/cm{sup 2}, lower highest occupied molecular orbitals (HOMO's) contribute significantly to ionization and to the MHOHG process. This is due to the symmetry of these orbitals. Even though such lower orbitals have higher ionization potentials (IP), ionization and MHOHG processes occur when orbital densities are maximum with laser polarization direction.

• OSTI ID: 21408264
• Journal Information: Physical Review. A, Vol. 81, Issue 2; Other Information: DOI: 10.1103/PhysRevA.81.023411; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
CARBON DIOXIDE
DENSITY
DENSITY FUNCTIONAL METHOD
FUNCTIONS
HARMONIC GENERATION
IONIZATION
IONIZATION POTENTIAL
LASERS
MOLECULES
NONLINEAR PROBLEMS
POLARIZATION
POTENTIALS
PULSES
SYMMETRY
TIME DEPENDENCE
TIME-SERIES ANALYSIS
CALCULATION METHODS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
FREQUENCY MIXING
MATHEMATICS
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
STATISTICS
VARIATIONAL METHODS