Neutral Rydberg-state excitation of atoms and diatomic molecules in strong laser fields

摘要

Using pulsed-field ionization technique combining with time-of-flight mass spectrometer, we have observed neutral Rydberg-state excitation of Ar atom and NO molecule when irradiated by a 90-fs 800-nm laser with intensity range of 1.5×10~(14) ~ 3.0×10~(15) Wcm~(-2). The dependence of the Rydberg-state excitation on the polarization and intensity of the laser field has been investigated. The results show that Rydberg-state excitation is suppressed by the circular polarized laser and the yield of Rydberg-state exhibits a plateau structure as the laser intensity is increased.