Tuesday, August 25, 2015
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
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.