Attosecond pulse generation from aligned molecules—dynamics and propagation in H₂⁺

Abstract

The dynamics and propagation effects in attosecond (asec) pulse generation from high-order harmonic generation (HHG) of aligned one- dimensional (1D) H + molecules are investigated from numerical solutions of fully coupled Maxwell and time-dependent Schrodinger equations (Maxwell- TDSEs), in the highly nonlinear nonperturbative regime of laser-molecule interaction. Density, laser-phase and propagation length effects are studied on the total electric field and nonlinear polarization from the Maxwell-TDSE for intense few cycle (800 nm) laser pulses interacting with a 1D H + gas. We show how single and double asec pulses can be generated and propagated as a function of the phase of individual harmonics created by ultrashort intense laser pulses in aligned H + molecules. We find furthermore extension of maximum HHG plateaux with increasing gas pressure.