The photoionization by two elliptically polarized, time delayed attosecond pulses is investigated to display a momentum distribution having the helical vortex or ring structuresi The results are obtained by the strong...The photoionization by two elliptically polarized, time delayed attosecond pulses is investigated to display a momentum distribution having the helical vortex or ring structuresi The results are obtained by the strong field approximation method and analyzed by the pulse decomposition. The ellipticities and time delay of the two attosecond pulses are found to determine the rotational symmetry and the number of vortex arms. For observing these vortex patterns, the energy bandwidth and temnoral duration of the attosecond pulses are ideal.展开更多
The carrier envelope phase（CEP） has a direct impact on the physical properties of an isolated attosecond pulse（IAP） and many strong field processes,but it is difficult to measure in reality.Aiming at obtaining mor...The carrier envelope phase（CEP） has a direct impact on the physical properties of an isolated attosecond pulse（IAP） and many strong field processes,but it is difficult to measure in reality.Aiming at obtaining more accurate and complete characterization of CEP,we numerically investigate the annular photoelectron momentum spectra of the hydrogen atom ionized by overlapped fields of an IAP and an infrared（IR） pulse.By defining an overlapping parameter,the momentum patterns are classified and optimized for unambiguously measuring the rotation angle of a momentum pattern versus the CEP value.A series of simulations verify its robustness.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11674243 and 11674242)the Fundamental Research Funds for the Central Universities(No.3122016D029)
文摘The photoionization by two elliptically polarized, time delayed attosecond pulses is investigated to display a momentum distribution having the helical vortex or ring structuresi The results are obtained by the strong field approximation method and analyzed by the pulse decomposition. The ellipticities and time delay of the two attosecond pulses are found to determine the rotational symmetry and the number of vortex arms. For observing these vortex patterns, the energy bandwidth and temnoral duration of the attosecond pulses are ideal.
基金supported by the National Natural Science Foundation of China(Nos.11674243 and 11674242)the Fundamental Research Funds for the Central Universities(No.3122016D029)
文摘The carrier envelope phase（CEP） has a direct impact on the physical properties of an isolated attosecond pulse（IAP） and many strong field processes,but it is difficult to measure in reality.Aiming at obtaining more accurate and complete characterization of CEP,we numerically investigate the annular photoelectron momentum spectra of the hydrogen atom ionized by overlapped fields of an IAP and an infrared（IR） pulse.By defining an overlapping parameter,the momentum patterns are classified and optimized for unambiguously measuring the rotation angle of a momentum pattern versus the CEP value.A series of simulations verify its robustness.
