High-Intensity Harmonic Generation with Energy Tunability Produced by Robust Two-Color Linearly Polarized Laser Fields

By using the numerical solution of time-dependent Schrödinger equation, we theoretically explored high-order harmonic generation process under interaction high-intensity two-color ultrashort driving laser pulses with atoms. The symmetry electric field pulse will be broken. producing was controlled at subcycle level by an IR and its second harmonic, which has unique characteristic that two sequential half-cycles become distinct, rather than merely opposite in sign. Compared case atom fundamental pulse, efficiency showed increase 1?2 orders magnitude specific order this combined action. Through theoretical analysis “three-step model”, it demonstrated enhancement intensity is due to fast ionization electrons moment short time from recombination ionized electrons. In addition, effects peak amplitude ratio, full width half maximum, phase delay pulses, probability on were also investigated.