Nonlinear photon processes in molecules at high intensities-route to XUV—attosecond pulse generation*

Numerical solutions of the time-dependent Schroedinger equation, TDSE, for a non-Born Oppenheimer HC2 molecule exposed to the combination of a sub-femtosecond (attosecond) XUV pulse and a short (w5 fs) intense (IR1013 W/cm2) 800 nm pulse allow for studying the nonlinear nonperturbative response of electrons and nuclei in molecules exposed to extreme laser conditions. New nonlinear phenomena, such as high order harmonic generation (HOHG), are considerably enhanced. This is a consequence of nonlinear photon processes and offers new routes for ‘attosecond’ pulse generation. Coupling the molecular TDSE to the photon Maxwell equations leads to the synthesis of even shorter attosecond and wavelength pulses, as new ultrashort sources for time-resolved XUV-Raman spectroscopy. q 2004 Elsevier B.V. All rights reserved.