%A Zhong Hui-Ying (钟慧英), Guo Jing (郭静), Zhang Hong-Dan (张宏丹), Du Hui (杜慧), Liu Xue-Shen (刘学深) %T Quantum path control and isolated attosecond pulse generation in the combination of near-infrared and terahertz pulses %0 Journal Article %D 2015 %J Chin. Phys. B %R 10.1088/1674-1056/24/7/073202 %P 73202-073202 %V 24 %N 7 %U {https://cpb.iphy.ac.cn/CN/abstract/article_117636.shtml} %8 2015-07-05 %X

We present an efficient and realizable scheme for the generation of an ultrashort single attosecond (as) pulse from H atom with a 800-nm fundamental laser field combined with a terahertz (THz) field. The high-order harmonic generation (HHG) can be obtained by solving the time-dependent Schrödinger equation accurately and efficiently with time-dependent generalized pseudo-spectral (TDGPS) method. The result shows that the plateau of high-order harmonics is extended and the broadband spectra can be produced by the combined laser pulse, which can be explained by the corresponding ionization probability. The time–frequency analysis and semi-classical three-step model are also presented to further investigate this mechanism. Besides, by the superposition of the harmonics near the cutoff region, an isolated 133-as pulse can be obtained.