Electron Motion Control in HHG Process with Multi-Color Laser Field

The electron motion during the HHG process is sensitive to the waveform of the electric field. With multi-color laser field, a single high-order harmonic among the harmonic comb can be selectively enhanced by using a driving laser field with subcycle waveform control, which is synthesized by the fundamental 800 nm laser pulse and two controlling laser pulses at 400 and 267 nm with perpendicular polarizations. Such phenomena can be mainly attributed to the intra-atomic phase matching realized with the sub-cycle waveform controlled field.