Enhancing High Harmonic Generation in a Short-Pulse Two-Color Laser Field by Controlling the Atomic-Electron Subcycle Detachment and Acceleration Dynamics

We present a study of the possibility to significantly enhance efficiency high-order harmonic generation (HHG) using few-cycle optical waveforms obtained by superposing two laser pulses different color delayed optimally relative each other. Special attention is paid dynamics depopulation atomic states, which, on one hand, promotes electrons continuum take part in high-energy photon emission, but, other depletes nonlinear medium. The use proposed here gives extra flexibility control both bound-state and electron acceleration continuum. demonstrate that approach allows increase frequency conversion into sub-keV or few-keV energy ranges up an order magnitude. High HHG optimal conditions explained peculiarities photoelectron dynamics, which are characterized this case combination high-probability ejection responsible for highest-order production its subsequent strong accompanied relatively low probability depletion during time interval between ionization recollision.