Abstract-Angle-resolved molecular structures joint measurements of terahertz wave generation and high-harmonic generation from aligned nitrogen molecules

Yindong Huang, Chao Meng, Xiaowei Wang, Zhihui Lü, Dongwen Zhang, Wenbo Chen, Jing Zhao, Jianmin Yuan, and Zengxiu Zhao
http://journals.aps.org/prl/accepted/8b07bY7fR571e35ca57638920f6d60e26b623e2e8

We report the synchronized measurements of terahertz wave generation and high harmonic generation from aligned nitrogen molecules in dual-color laser fields. Both yields are found alignment-dependent showing the importance of molecular structures in the generation processes. By calibrating the angular ionization rates with the THz yields, we present a new way to retrieve the angular differential photoionization cross section (PICS) from the harmonic signals, which avoids specific model calculations or separate measurements of the alignment-dependent ionization rates. The measured PICS is found consistent with theoretical predications, although some discrepancies exist. This all-optical method provides a new alternative to investigate molecular structures.