Smirnova Olga, Patchkovskii Sergei, Spanner Michael
Steacie Institute for Molecular Science, National Research Council of Canada, Ottawa, Ontario, K1A 0R6 Canada.
Phys Rev Lett. 2007 Mar 23;98(12):123001. doi: 10.1103/PhysRevLett.98.123001. Epub 2007 Mar 20.
We demonstrate that the recolliding electron wave packet, fundamental to many strong field phenomena, can be directly imaged with sub-A spatial and attosecond temporal resolution using attosecond extreme ultraviolet (XUV) pulses. When the recolliding electron revisits the parent ion, it can absorb an XUV photon yielding high energy electron and thereby providing a measurement of the electron energy at the moment of recollision. The full temporal evolution of the recollision wave packet can be reconstructed by measuring the photoelectron spectra for different time delays between the driving laser and the attosecond XUV probe. The strength of the photoelectron signal can be used to characterize the spatial distribution of the electron density in the longitudinal direction. Elliptical polarization can be used to characterize the electron probability in transversal direction.
我们证明，对于许多强场现象至关重要的再碰撞电子波包，可以使用阿秒极紫外（XUV）脉冲以亚埃空间分辨率和阿秒时间分辨率直接成像。当再碰撞电子重新回到母离子时，它可以吸收一个XUV光子，产生高能电子，从而提供再碰撞时刻电子能量的测量。通过测量驱动激光和阿秒XUV探针之间不同时间延迟下的光电子能谱，可以重建再碰撞波包的完整时间演化。光电子信号的强度可用于表征纵向电子密度的空间分布。椭圆偏振可用于表征横向的电子概率。
