Ionic Angular Distributions Induced by Strong-Field Ionization of Tri-Atomic Molecules* *Supported by the National Natural Science Foundation of China (Grant Nos. 11534004, 11874179, and 11704149), and the Natural Science Foundation of Jilin Province (Grant Nos. 20180101289JC and 20190103045JH).

Abstract

Angular distributions of fragment ions from ionization of several tri-atomic molecules (CO 2, OCS, N 2 O and NO 2 ) by strong 800-nm laser fields are investigated via a time-of-flight mass spectrometer. Anisotropic angular distributions of fragment ions, especially those of atomic ions, are observed for all of the molecules studied. These anisotropic angular distributions are mainly due to the geometric alignment of molecules in the strong field ionization. Distinct different patterns in ionic angular distributions for different molecules are observed. It is indicated that both molecular geometric structure and ionization channels have effects on the angular distributions of strong field ionization/fragmentation.