- 著者
- Wang Xiaowei Chini Michael Cheng Yan Wu Yi Tong Xiao-Min Chang Zenghu
- 出版者
- The American Physical Society
- 雑誌
- Physical review A (ISSN:10502947)
- 巻号頁・発行日
- vol.87, no.6, pp.063413, 2013-06
- 被引用文献数
- 49 7
The dynamics of an atom in a strong infrared laser field (1013 W/cm2) result in substantial changes to the field-free electronic energy levels, which can be probed on time scales shorter than the laser cycle using isolated attosecond pulses. Here, we measure the transient absorption of an isolated attosecond pulse by laser-dressed bound states of neon near the first ionization threshold. The observed subcycle changes in the absorption spectrum result from both laser-induced ac Stark shifts and from quantum interferences between different multiphoton excitation pathways. We further demonstrate the ability to experimentally turn off the quantum interference mechanism by eliminating one of the interfering pathways.
1 0 0 0 OA Anomalous alignment dependence of the third-order harmonic of H2+ ions in intense laser fields
- 著者
- Jin Ying-Jun Tong Xiao-Min Toshima Nobuyuki
- 出版者
- The American Physical Society
- 雑誌
- Physical review A (ISSN:10502947)
- 巻号頁・発行日
- vol.86, no.5, pp.053418, 2012-11
- 被引用文献数
- 6 1
We studied the high-harmonic generation of H2+ ions in an intense laser field by solving the time-dependent Schrödinger equation in prolate spheroidal coordinates. By analyzing the power spectra of the harmonics with the electric field polarized along the molecular axis, we found that the yield of the third-order harmonic drops by several orders of magnitude at a specified aligned angle between the laser polarization direction and the molecular axis. The laser polarization angle of the minimum depends on the internuclear distance and it disappears both in the separated- and united-atom limits. This infers that the minimum is associated with the molecular symmetry. By decomposing individual contributions of the σ and π states, we identified that the minimum is attributed to the cancellation of the induced dipole moments of the σ and π states, like a dynamical Cooper minimum, but the position of the minimum can be tuned by the laser intensity for a given internuclear distance.