%A Ze-Hui Ma(马泽慧), Cai-Ping Zhang(张彩萍), Jun-Lin Ma(马俊琳), Xiang-Yang Miao(苗向阳)
%T Controlling paths of high-order harmonic generation by orthogonal two-color fields
%0 Journal Article
%D 2020
%J Chin. Phys. B
%R 10.1088/1674-1056/ab7189
%P 43201-043201
%V 29
%N 4
%U {https://cpb.iphy.ac.cn/CN/abstract/article_122373.shtml}
%8 2020-04-05
%X Controlling paths of high-order harmonic generation from H2+ is theoretically investigated by numerically solving the time-dependent Schrödinger equation based on the Born-Oppenheimer approximation in orthogonal two-color fields. Our simulations show that the change of harmonic emission paths is dependent on time-dependent distribution of electrons. Compared with one-dimensional linearly polarized long wavelength laser, multiple returns are suppressed and short paths are dominant in the process of harmonic emission by two-dimensional orthogonal ω/2ω laser fields. Furthermore, not only are multiple returns weaken, but also the harmonic emission varies from twice to once in an optical cycle by orthogonal ω/1.5ω laser fields. Combining the time-frequency distributions and the time-dependent electron wave packets probability density, the mechanism of controlling paths is further explained. As a result, a 68-as isolated attosecond pulse is obtained by superposing a proper range of the harmonics.