Alignment dependence of photoelectron momentum distributions for diatomic molecule N2 in strong elliptical laser fields

Abstract

Abstract The ionization dynamics of aligned N2 molecules are studied in strong elliptical laser fields experimentally and theoretically. The alignment-dependent photoelectron momentum distribution of N2 is measured for highlighting the molecular structure contribution by comparing to that of Ar measured synchronously. Our results show that the ionization of N2 depends strongly on the alignment of molecules, relative to the main axis of the polarization ellipse of the laser. In particular, the most-probable electron-emission angle which is often used in attosecond measurement changes remarkably when changing the relative angle between the molecular axis and the major axis of laser fields. The alignment-dependent rotation angles have been well reproduced by our theoretical calculations. We show that the interplay between molecular structure and the laser fields plays an important role in the rotation angles based on the strong-field approximation analysis and this interaction also influences remarkably on the photoelectron angle distribution of aligned N2.