Strong-field ionization and AC-Stark shifted Rydberg states in OCS

We present theoretical results for intensity-dependent above-threshold ionization (ATI) spectra from oriented OCS molecules probed by intense femtosecond laser pulses with wavelengths of 800 and 400 nm. The calculations were performed using the time-dependent Schroodinger equation within the single-active-electron approximation and including multielectron polarization effects. The results are in qualitative agreement with experimental data [Yu et al., J. Phys. B: At. Mol. Opt. Phys. 50, 235602 (2017)]. In particular, characteristic features in the ATI spectra which correspond to resonant multiphoton ionization via highly-excited Rydberg states are captured by the theory.