Effect of laser polarization on strong-field ionization and fragmentation of nitrous oxide molecules**Project supported by the National Natural Science Foundation of China (Grant Nos. 11534004, 11874179, and 11704149) and the Natural Science Foundation of Jilin Province, China (Grant No. 20180101289JC).

Abstract

Ionization of molecules in femtosecond laser fields is the most fundamental and important step of various strong-field physical processes. In this study, we experimentally investigate strong field ionization of linear N2O molecules using a time-of-flight mass spectrometer in 800-nm laser fields. Yields of the parent ion and different fragment ions are measured as a function of laser intensity in the range of 2.0×1013 W/cm2 to 3.6×1014 W/cm2. We also investigate the dependence of strong field ionization and dissociation of N2O on laser ellipticity and polarization direction. The significant role of laser induced electron re-collision in the formation of highly charged fragment ions is proved. The physical mechanism of strong field ionization and fragmentation is discussed, based on our experimental results.