Attosecond Pulse Enhancement by Using Orthogonal Two-Color Field Combined With a Linear Infrared Pulse

Attosecond pulse generation from high-order harmonic spectrum has been theoretically investigated using the two-color orthogonal field combined with a linear infrared pulse. It shows that by properly adding a linear infrared pulse to the orthogonal field in x- or y-direction, not only the harmonic cutoffs and the harmonic yields are enhanced, but also the modulations on the harmonic spectra are decreased, resulting in two intense supercontinua with the bandwidths of 240 and 130 eV, respectively. Finally, the proper superposition of harmonics, two isolated pulses with durations of 43 and 50 as can be obtained, which are 1.5 and 2 orders of magnitude improvement in comparison with the original two-color orthogonal field case.