Dynamics of enhanced and suppressed high-order harmonic generation of He atom by intense frequency-comb laser fields

<font _mstmutation="1">We present an ab initio nonperturbative investigation of enhanced and suppressed high-order harmonic generation (HHG) of He atom driven by the intense frequency-comb laser fields. The HHG is calculated by solving three-dimensional time-dependent Schrödinger equation by means of the time-dependent generalized pseudospectral method. The results show that each harmonic from the first harmonic all the way to the cutoff has a nested comb structure, and the frequency comb structures show immense enhancement and suppression by tuning the number of short laser pulses. The underlying physical mechanism of enhancing and suppressing HHG is illustrated by the interference effect of the HHG spectra originating from each short laser pulse.</font>