Femtosecond Resolving Photodissociation Dynamics of the SO<sub>2</sub> Molecule
Kang Lin, Xiaoqing Hu, Shengzhe Pan, Fei Chen, Qinying Ji, Wenbin Zhang, Hanxiao Li, Junjie Qiang, Fenghao Sun, Xiaochun Gong, Hui Li, Peifen Lu, Jianguo Wang, Yong Wu, Jian Wu
Abstract
We experimentally investigate the ultrafast photodissociation dynamics of the SO2 molecule induced by intense ultrashort laser pulses in a pump–probe scheme. Different three-body fragmentation pathways are discriminated using the time-dependent kinetic energy release spectrum with femtosecond time resolution. A nontrivial three-body fragmentation pathway, denoted as the bonding pathway, is unraveled, in which an intermediate fast rotating O2 molecule is formed before complete fragmentation. The ultrafast chemical bond rearrangement after electron release is tracked in real time. The bonding pathway generally exists in the three-body fragmentation processes induced by strong laser fields of different wavelengths, which is observed in infrared, ultraviolet, and mixed two-color cases. Our findings are significant for understanding the photon-induced ultrafast processes of the SO2 molecule in atmospheric chemistry.