We investigate the target and intensity dependence of plateau in high-order above threshold ionization(HATI) by simulating the two-dimensional(2D) momentum distributions and the energy spectra of photoelectrons in...We investigate the target and intensity dependence of plateau in high-order above threshold ionization(HATI) by simulating the two-dimensional(2D) momentum distributions and the energy spectra of photoelectrons in HATI of rare gas atoms through using the quantitative rescattering model. The simulated results are compared with the existing experimental measurements. It is found that the slope of the plateau in the HATI photoelectron energy spectrum highly depends on the structure of elastic scattering differential cross section(DCS) of laser-induced returning electron with its parent ion. The investigations of the long- and short-range potential effects in the DCSs reveal that the short-range potential, which reflects the structure of the target, plays an essential role in generating the HATI photoelectron spectra.展开更多
We systematically investigate the influence of atomic potentials on the above-threshold ionization (ATI) spectra in one-dimensional (1D) cases and compare them with the three-dimensional (3D) case by numerically...We systematically investigate the influence of atomic potentials on the above-threshold ionization (ATI) spectra in one-dimensional (1D) cases and compare them with the three-dimensional (3D) case by numerically solving the time-dependent Schrrdinger equation. It is found that the direct ionization plateau and the rescattering plateau of the ATI spectrum in the 3D case can be well reproduced by the 1D ATI spectra calculated from the supersolid-core potential and the soft-core potential, respectively. By analyzing the factors that affect the yield of the ATI spectrum, we propose a modified-potential with which we can reproduce the overall 3D ATI spectrum. In addition, the influence of the incident laser intensities and frequencies on the ATI spectra calculated from the proposed modified potential is studied.展开更多
The high-resolution three-dimensional photoelectron momentum distributions via above-threshold ionization(ATI)of Xe atoms are measured in an intense near circularly polarized laser field using velocity map imaging and...The high-resolution three-dimensional photoelectron momentum distributions via above-threshold ionization(ATI)of Xe atoms are measured in an intense near circularly polarized laser field using velocity map imaging and tomography reconstruction. Compared to the linearly polarized laser field, the employed near circularly polarized laser field imposes a more strict selection rule for the transition via resonant excitation, and therefore we can selectively enhance the resonant ATI through certain atomic Rydberg states. Our results show the self-reference ionization delay, which is determined from the difference between the measured streaking angles for nonadiabatic ATI via the 4 f and 5 f Rydberg states, is 45.6 as. Our method provides an accessible route to highlight the role of resonant transition between selected states, which will pave the way for fully understanding the ionization dynamics toward manipulating electron motion as well as reaction in an ultrafast time scale.展开更多
The above-threshold ionization of argon in an intense 70-fs,400-nm linearly polarized laser pulse has been investigated by the velocity map imaging techniques,combined with an attosecond-resolution quantum wave packet...The above-threshold ionization of argon in an intense 70-fs,400-nm linearly polarized laser pulse has been investigated by the velocity map imaging techniques,combined with an attosecond-resolution quantum wave packet dynamics method.There is a quantitative agreement in all dominant features between the experiment and the theory.Moreover,a peak-splitting phenomenon in the first energy peak has been observed at high pulse intensity.Further,through the theoretical analysis,an ac Stark splitting with evident resonant and nonresonant ionization pathways has been found to be the physical reason for the experimental observations.展开更多
The field ionization process of the Eu 4f76snp Rydberg states, converging to the first ionization limit, 4f76s 954, is systematically investigated. The spectra of the Eu 4f76snp Rydberg states are populated with three...The field ionization process of the Eu 4f76snp Rydberg states, converging to the first ionization limit, 4f76s 954, is systematically investigated. The spectra of the Eu 4f76snp Rydberg states are populated with three-step laser excitation, and detected by electric field ionization (EFI) method. Two different kinds of the EFI pulses are applied after laser excitation to observe the possible impacts on the EFI process. The exact EFI ionization thresholds for the 4f76snp Rydberg states can be determined by observing the corresponding EFI spectra. In particular, some structures above the EFI threshold are found in the EFI spectra, which may be interpreted as the effect from black body radiation (BBR). Finally, the scaling law of the EFI threshold for the Eu 4f76snp Rydberg states with the effective quantum number is built.展开更多
We simultaneously investigate variations of a low order harmonic and photoelectron emission with an incident laser intensity by solving the time-dependent Schr6dinger equation in a momentum space. It can be found that...We simultaneously investigate variations of a low order harmonic and photoelectron emission with an incident laser intensity by solving the time-dependent Schr6dinger equation in a momentum space. It can be found that, the intensity of low order harmonic and photoelectron are gradually enhanced with the increase of the laser intensity, when the laser frequency is not in resonance with the transition frequency between the laser-induced high excited states and the ground state. If the resonance occurs, the intensity of the lower order harmonic is reduced and the interference can be observed in the lower order photoelectron spectra.展开更多
We theoretically investigate the photoelectron emission from an atom irradiated by an amplitude modulated sinusoidally phase-modulated pulse through solving the time-dependent Schr¨odinger equation in the momentu...We theoretically investigate the photoelectron emission from an atom irradiated by an amplitude modulated sinusoidally phase-modulated pulse through solving the time-dependent Schr¨odinger equation in the momentum space. By controlling the phase amplitude of the pulse in the frequency domain, it can be found that the photoelectron spectra appear as explicit interference phenomena, which originated from the interference between the directly ionized electron and the ionization of the pre-excited atom from different subpulses.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11274219)the STU Scientific Research Foundation for Talentsthe Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry,China
文摘We investigate the target and intensity dependence of plateau in high-order above threshold ionization(HATI) by simulating the two-dimensional(2D) momentum distributions and the energy spectra of photoelectrons in HATI of rare gas atoms through using the quantitative rescattering model. The simulated results are compared with the existing experimental measurements. It is found that the slope of the plateau in the HATI photoelectron energy spectrum highly depends on the structure of elastic scattering differential cross section(DCS) of laser-induced returning electron with its parent ion. The investigations of the long- and short-range potential effects in the DCSs reveal that the short-range potential, which reflects the structure of the target, plays an essential role in generating the HATI photoelectron spectra.
基金Project supported by the National Basic Research Program of China(Grant No.2013CB922200)the National Natural Science Foundation of China(Grant Nos.11274141,11034003,11304116,11274001,and 11247024)the Jilin Provincial Research Foundation for Basic Research,China(Grant No.20140101168JC)
文摘We systematically investigate the influence of atomic potentials on the above-threshold ionization (ATI) spectra in one-dimensional (1D) cases and compare them with the three-dimensional (3D) case by numerically solving the time-dependent Schrrdinger equation. It is found that the direct ionization plateau and the rescattering plateau of the ATI spectrum in the 3D case can be well reproduced by the 1D ATI spectra calculated from the supersolid-core potential and the soft-core potential, respectively. By analyzing the factors that affect the yield of the ATI spectrum, we propose a modified-potential with which we can reproduce the overall 3D ATI spectrum. In addition, the influence of the incident laser intensities and frequencies on the ATI spectra calculated from the proposed modified potential is studied.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11574101,11674116,11774111,and 11934006)the Open Fund of Hubei Provincial Key Laboratory of Optical Information and Pattern Recognition(Grant No.201902)the International Cooperation Program of Hubei Innovation Fund(Grant No.2019AHB052)。
文摘The high-resolution three-dimensional photoelectron momentum distributions via above-threshold ionization(ATI)of Xe atoms are measured in an intense near circularly polarized laser field using velocity map imaging and tomography reconstruction. Compared to the linearly polarized laser field, the employed near circularly polarized laser field imposes a more strict selection rule for the transition via resonant excitation, and therefore we can selectively enhance the resonant ATI through certain atomic Rydberg states. Our results show the self-reference ionization delay, which is determined from the difference between the measured streaking angles for nonadiabatic ATI via the 4 f and 5 f Rydberg states, is 45.6 as. Our method provides an accessible route to highlight the role of resonant transition between selected states, which will pave the way for fully understanding the ionization dynamics toward manipulating electron motion as well as reaction in an ultrafast time scale.
基金Project supported by the National Natural Science Foundations of China (Grant Nos. 10874096 and 20633070)
文摘The above-threshold ionization of argon in an intense 70-fs,400-nm linearly polarized laser pulse has been investigated by the velocity map imaging techniques,combined with an attosecond-resolution quantum wave packet dynamics method.There is a quantitative agreement in all dominant features between the experiment and the theory.Moreover,a peak-splitting phenomenon in the first energy peak has been observed at high pulse intensity.Further,through the theoretical analysis,an ac Stark splitting with evident resonant and nonresonant ionization pathways has been found to be the physical reason for the experimental observations.
基金supported by the National Natural Science Foundation of China(Grant Nos.11004151 and 11174218)
文摘The field ionization process of the Eu 4f76snp Rydberg states, converging to the first ionization limit, 4f76s 954, is systematically investigated. The spectra of the Eu 4f76snp Rydberg states are populated with three-step laser excitation, and detected by electric field ionization (EFI) method. Two different kinds of the EFI pulses are applied after laser excitation to observe the possible impacts on the EFI process. The exact EFI ionization thresholds for the 4f76snp Rydberg states can be determined by observing the corresponding EFI spectra. In particular, some structures above the EFI threshold are found in the EFI spectra, which may be interpreted as the effect from black body radiation (BBR). Finally, the scaling law of the EFI threshold for the Eu 4f76snp Rydberg states with the effective quantum number is built.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0403300)the National Natural Science Foundation of China(Grant Nos.11774129,11274141,11627807,11604119,and 11534004)the Jilin Provincial Research Foundation for Basic Research,China(Grant No.20170101153JC)
文摘We simultaneously investigate variations of a low order harmonic and photoelectron emission with an incident laser intensity by solving the time-dependent Schr6dinger equation in a momentum space. It can be found that, the intensity of low order harmonic and photoelectron are gradually enhanced with the increase of the laser intensity, when the laser frequency is not in resonance with the transition frequency between the laser-induced high excited states and the ground state. If the resonance occurs, the intensity of the lower order harmonic is reduced and the interference can be observed in the lower order photoelectron spectra.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0403300)the National Natural Science Foundation of China(Grants Nos.11774129,11274141,11627807,11604119,and 11534004)the Jilin Provincial Research Foundation for Basic Research,China(Grant No.20170101153JC)
文摘We theoretically investigate the photoelectron emission from an atom irradiated by an amplitude modulated sinusoidally phase-modulated pulse through solving the time-dependent Schr¨odinger equation in the momentum space. By controlling the phase amplitude of the pulse in the frequency domain, it can be found that the photoelectron spectra appear as explicit interference phenomena, which originated from the interference between the directly ionized electron and the ionization of the pre-excited atom from different subpulses.