We present a theory that incorporates the vibrational degrees of freedom in a high-order harmonic generation (HHG) process with ultrashort intense laser pulses. In this model, laser-induced time-dependent transition dipoles for each fixed molecular geometry are added coherently, weighted by the laser-driven time-dependent nuclear wave packet distribution. We show that the nuclear distribution can be strongly modified by the HHG driving laser. The validity of this model is first checked against results from the numerical solution of the time-dependent Schrödinger equation for a simple model system. We show that in combination with the established quantitative rescattering theory this model is able to reproduce the time-resolved pump-probe HHG spectra of N₂O₂ reported by Li et al. [Science 322, 1207 (2008)].
A. Le et al., "Theory of High Harmonic Generation for Probing Time-Resolved Large-Amplitude Molecular Vibrations with Ultrashort Intense Lasers," Physical Review Letters, vol. 109, no. 20, American Physical Society (APS), Nov 2012.
The definitive version is available at https://doi.org/10.1103/PhysRevLett.109.203004
Keywords and Phrases
Dinger Equation; High Harmonic Generation; High Order Harmonic Generation; Intense Laser; Laser Induced; Model System; Molecular Geometries; Nuclear Distribution; Nuclear Wave Packet; Numerical Solution; Pump-Probe; Rescattering; Time-Dependent; Time-Resolved; Transition Dipole; Ultra-Short Intense Laser Pulse; Vibrational Degrees Of Freedom, Harmonic Generation, Laser Theory
International Standard Serial Number (ISSN)
Article - Journal
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