High-order harmonics and attosecond pulse generation with coherent wake emission are theoretically investigated for the effect of pulse duration and carrier envelope phase(CEP)of few-cycle laser pulse.We find that sho...High-order harmonics and attosecond pulse generation with coherent wake emission are theoretically investigated for the effect of pulse duration and carrier envelope phase(CEP)of few-cycle laser pulse.We find that short pulse duration will cause the negative chirp for the high harmonics.When the laser pulse is shortened to a few cycles,the influence of the laser CEP on the chirp of the harmonics will also become more prominent.展开更多
We theoretically investigate the delay-dependent attosecond transient absorption spectra in the helium atom dressed by an infrared laser pulse in the wavelength range of 800–2400 nm. By numerically solving the three-...We theoretically investigate the delay-dependent attosecond transient absorption spectra in the helium atom dressed by an infrared laser pulse in the wavelength range of 800–2400 nm. By numerically solving the three-dimensional time-dependent Schrdinger equation, we find that the absorption spectrogram exhibits a multiple-fringe structure for using the mid-infrared dressing pulse. The quantitative calculation of the transition matrix between different Floquet states provides direct evidence on the origin of the multiple-fringe structure.Our result shows that the wavelength of the dressing pulse is an important parameter and the unique feature of attosecond transient absorption spectroscopy can be induced in the mid-infrared regime.展开更多
High-order harmonic generation originated from zigzag graphene nanoribbons(ZGNRs) induced by intense laser pulses is investigated theoretically. During the interaction between the intense mid-infrared laser and the ZG...High-order harmonic generation originated from zigzag graphene nanoribbons(ZGNRs) induced by intense laser pulses is investigated theoretically. During the interaction between the intense mid-infrared laser and the ZGNR,we find that localized edge states mainly contribute to the generation of the low-order harmonics, while cutoff harmonics result from the other confined states. Our result shows that the edge-state effect of ZGNR with narrow width can enhance the conversion efficiency of low-order harmonics, rather than the higher-order harmonics extended to the cutoff region.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.91950203,11874374,and 61690223)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB16).
文摘High-order harmonics and attosecond pulse generation with coherent wake emission are theoretically investigated for the effect of pulse duration and carrier envelope phase(CEP)of few-cycle laser pulse.We find that short pulse duration will cause the negative chirp for the high harmonics.When the laser pulse is shortened to a few cycles,the influence of the laser CEP on the chirp of the harmonics will also become more prominent.
基金The authors would like to thank Huang, Z., and Ding, Y. from SLAC and Feng, C., Deng, H., Lan, T., Shen, L., Wang, X. and Liu, B. from SINAP for helpful discussions. The authors are grateful for the support of Major State Basic Research Development Program of China （No. 2011CB808300）, and Natural Science Foundation of China （No. 11075199）.
基金supported by the National Natural Science Foundation of China(Nos.61690223,11774363,11561121002,61521093,11127901,11227902,and 11574332)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB16)the Youth Innovation Promotion Association CAS
文摘We theoretically investigate the delay-dependent attosecond transient absorption spectra in the helium atom dressed by an infrared laser pulse in the wavelength range of 800–2400 nm. By numerically solving the three-dimensional time-dependent Schrdinger equation, we find that the absorption spectrogram exhibits a multiple-fringe structure for using the mid-infrared dressing pulse. The quantitative calculation of the transition matrix between different Floquet states provides direct evidence on the origin of the multiple-fringe structure.Our result shows that the wavelength of the dressing pulse is an important parameter and the unique feature of attosecond transient absorption spectroscopy can be induced in the mid-infrared regime.
基金supported by the National Natural Science Foundation of China (Nos. 91950203,11874374,11574332,61690223,and 11774363)the Strategic Priority Research Program of the Chinese Academy of Sciences(No. XDB16)the Chinese Academy Sciences (CAS)Youth Innovation Promotion Association
文摘High-order harmonic generation originated from zigzag graphene nanoribbons(ZGNRs) induced by intense laser pulses is investigated theoretically. During the interaction between the intense mid-infrared laser and the ZGNR,we find that localized edge states mainly contribute to the generation of the low-order harmonics, while cutoff harmonics result from the other confined states. Our result shows that the edge-state effect of ZGNR with narrow width can enhance the conversion efficiency of low-order harmonics, rather than the higher-order harmonics extended to the cutoff region.
