Attosecond-pulse-controlled high-order harmonic generation in ultrashort laser fields

Abstract

By solving the three-dimensional time-dependent Schr\"odinger equation, we study how to control the high-order harmonic generation (HHG) in a hydrogenlike neon, which is exposed to an extreme-ultraviolet (xuv) attosecond laser pulse followed by an infrared (ir) femtosecond pulse. The xuv pulse prepares the atom as a superposition of the ground state, the excited states, and the continuum. These three types of states provide different contributions to the high-order harmonics generated by the following ir pulse. In particular, the contributions from the excited states and the continuum extend the cutoff frequency of the harmonic spectrum. Moreover, the effect of the carrier-envelope phase of the ir pulse on the HHG has been studied. The structure of the laser-dressed atom can be imaged using this two-color scheme.