Author: Chen Liangyuan 2014-09-17
Imaging the structure of atoms and molecules and the ultrafast electron dynamics with ultrahigh temporal and spatial resolution is one of important goals in the ultrafast physics and attosecond science. Strong-field photoelectron holography, as a newly developed imaging method, has attracted more and more attentions due to its high temporal and spatial resolution. Up to now, the researches on the strong-field photoelectron holography mainly focus on the infrared wavelength regime. However, in this case the direct electron wave packets released from different times can interfere with each other, which blurs the holographic pattern in the photoelectron momentum spectrum. Thus, it is difficult to extract the structural information of targets.
Ultrafast laser research group led by professor Lu Peixiang affiliated to Wuhan National Lab for Optoelectronics has devoted their researches on the interactions of strong laser with atoms and molecules for a long time. In recent works, they studied molecular photoelectron holography by an attosecond XUV pulse in the assistance of a strong infrared laser pulse. Comparing with the single infrared pulse scenario, in this study the electron wave packets are mainly released by the attosecond pulse and thus the direct electron wave packets can not interfere with each other. So a clear holographic pattern is observed in the photoelectron momentum spectrum. Furthermore, this holographic pattern depends strongly on the molecular orbitals and internuclear distance. This result will provide guidelines for further researches on the molecular imaging by photoelectron holography.
This work was supported by the 973 Program of China under Grant No. 2011CB808103, and the National Natural Science Foundation of China under Grant No. 11234004 and No. 61275126. This work is published on Opt. Express 22, 20421-20431 (2014)。