利用强场近似(Strong field approximation,SFA)方法研究氢负离子(H^-)在强激光场中双光子电离的能量谱,所得到的电离谱随角度的变化规律与实验结果符合得很好.进一步的研究表明,H^-离子在强激光场中双光子电离的能量谱与有质动力能有关...利用强场近似(Strong field approximation,SFA)方法研究氢负离子(H^-)在强激光场中双光子电离的能量谱,所得到的电离谱随角度的变化规律与实验结果符合得很好.进一步的研究表明,H^-离子在强激光场中双光子电离的能量谱与有质动力能有关.激光场强度越大,光电子的有质动力能也越大,能量谱向左移动越明显.我们的结果表明,使用强场近似是一种研究负离子在强激光场中电离过程的有效方法.展开更多
We derive a general ionization rate formula for the system of diatomic molecules in the velocity gauge. A more concise expression of the photoionization rate in the tunnel region is obtained for the first time. Compar...We derive a general ionization rate formula for the system of diatomic molecules in the velocity gauge. A more concise expression of the photoionization rate in the tunnel region is obtained for the first time. Comparisons are made among the different versions of strong-field approximation. The numerical study shows that the ionization rate in the velocity gauge is underestimated by a few orders compared with that in the length gauge. Our simple formula of ionization rate may provide an insight into the ionization mechanism for the system of diatomic molecules.展开更多
This paper proposes a modified strong field approximation model for evaluating nondipole effects on the ionization of an atom in an intense laser field. The photoelectron longitudinal momentum distributions （PLMD） o...This paper proposes a modified strong field approximation model for evaluating nondipole effects on the ionization of an atom in an intense laser field. The photoelectron longitudinal momentum distributions （PLMD） of a hydrogen-like atom exposed to a mid-infrared laser field is calculated. The theoretical results indicate an obvious asymmetry in the PLMD, and an offset of the PLMD peak appears in the opposite direction of the beam propagation due to nondipole effects. The peak offsets of the PLMD increased with the laser intensity, imposed by the initial state of the hydrogen-like atom.展开更多
In this review,we will focus on recent progress on the investigations of nondipole effects in few-electron atoms and molecules interacting with light fields.We first briefly survey several popular theoretical methods ...In this review,we will focus on recent progress on the investigations of nondipole effects in few-electron atoms and molecules interacting with light fields.We first briefly survey several popular theoretical methods and relevant concepts in strong field and attosecond physics beyond the dipole approximation.Physical phenomena stemming from the breakdown of the dipole approximation are then discussed in various topics,including the radiation pressure and photon-momentum transfer,the atomic stabilization,the dynamic interference,and the high-order harmonic generation.Whenever available,the corresponding experimental observations of these nondipole effects are also introduced respectively in each topics.展开更多
We derive a simple ionization rate formula for the ground state of a hydrogen atom in the velocity gauge under the conditions：ω〈〈1 a.u.（a.u.is short for atomic unit） and γ〈〈1（ω is the laser frequency and y ...We derive a simple ionization rate formula for the ground state of a hydrogen atom in the velocity gauge under the conditions：ω〈〈1 a.u.（a.u.is short for atomic unit） and γ〈〈1（ω is the laser frequency and y is the Keldysh parameter）.Comparisons are made among the different versions of the Keldysh-Faisal-Reiss（KFR） theory.The numerical study shows that with considering the quasi-classical（WKB） Coulomb correction in the final state of the ionized electron,the photoionization rate is enhanced compared with without considering the Coulomb correction,and the Reiss theory with the WKB Coulomb correction gives the correct result in the tunneling regime.Our concise formula of the ionization rate may provide an insight into the ionization mechanism for the ground state of a hydrogen atom.展开更多
文摘利用强场近似(Strong field approximation,SFA)方法研究氢负离子(H^-)在强激光场中双光子电离的能量谱,所得到的电离谱随角度的变化规律与实验结果符合得很好.进一步的研究表明,H^-离子在强激光场中双光子电离的能量谱与有质动力能有关.激光场强度越大,光电子的有质动力能也越大,能量谱向左移动越明显.我们的结果表明,使用强场近似是一种研究负离子在强激光场中电离过程的有效方法.
基金supported by the National Natural Science Foundation of China(Grant No.11274149)the Natural Science Foundation of Liaoning Province,China(Grant No.20121032)
文摘We derive a general ionization rate formula for the system of diatomic molecules in the velocity gauge. A more concise expression of the photoionization rate in the tunnel region is obtained for the first time. Comparisons are made among the different versions of strong-field approximation. The numerical study shows that the ionization rate in the velocity gauge is underestimated by a few orders compared with that in the length gauge. Our simple formula of ionization rate may provide an insight into the ionization mechanism for the system of diatomic molecules.
基金Project supported by the National Natural Science Foundation of China(Grant No.11274149)the Program of Shenyang Key Laboratory of Optoelectronic Materials and Technology,China(Grant No.F12-254-1-00)
文摘This paper proposes a modified strong field approximation model for evaluating nondipole effects on the ionization of an atom in an intense laser field. The photoelectron longitudinal momentum distributions （PLMD） of a hydrogen-like atom exposed to a mid-infrared laser field is calculated. The theoretical results indicate an obvious asymmetry in the PLMD, and an offset of the PLMD peak appears in the opposite direction of the beam propagation due to nondipole effects. The peak offsets of the PLMD increased with the laser intensity, imposed by the initial state of the hydrogen-like atom.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11961131008,11725416,and 11574010)the National Key Research and Development Program of China(Grant No.2018YFA0306302)
文摘In this review,we will focus on recent progress on the investigations of nondipole effects in few-electron atoms and molecules interacting with light fields.We first briefly survey several popular theoretical methods and relevant concepts in strong field and attosecond physics beyond the dipole approximation.Physical phenomena stemming from the breakdown of the dipole approximation are then discussed in various topics,including the radiation pressure and photon-momentum transfer,the atomic stabilization,the dynamic interference,and the high-order harmonic generation.Whenever available,the corresponding experimental observations of these nondipole effects are also introduced respectively in each topics.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11274149 and 11304185)the Program of Shenyang Key Laboratory of Optoelectronic Materials and Technology,China(Grant No.F12-254-1-00)
文摘We derive a simple ionization rate formula for the ground state of a hydrogen atom in the velocity gauge under the conditions：ω〈〈1 a.u.（a.u.is short for atomic unit） and γ〈〈1（ω is the laser frequency and y is the Keldysh parameter）.Comparisons are made among the different versions of the Keldysh-Faisal-Reiss（KFR） theory.The numerical study shows that with considering the quasi-classical（WKB） Coulomb correction in the final state of the ionized electron,the photoionization rate is enhanced compared with without considering the Coulomb correction,and the Reiss theory with the WKB Coulomb correction gives the correct result in the tunneling regime.Our concise formula of the ionization rate may provide an insight into the ionization mechanism for the ground state of a hydrogen atom.
