High-harmonic generation with combined infrared and extreme ultraviolet fields

Abstract

High-order harmonic generation (HHG) is a nonlinear optical process usually interpreted as a sequence of ionization of an atom or molecule by a strong laser field and the following recombination under emission of an extreme ultraviolet photon. We investigate HHG for combined infrared and extreme ultraviolet fields acting on a system possessing two essential states, with the excited state being either a bound state or a resonance. We report shifts of the HHG peak positions compared to the HHG spectrum from an infrared field only and a peak splitting depending on the presence of Rabi oscillations.

Keywords:

• high harmonic generation
• Rabi oscillations
• two-level system

Notes

We acknowledge the support from the European Marie Curie Initial Training Network Grant No. CA-ITN-214962-FASTQUAST. We thank the Deutsche Forschungsgemeinschaft for funding the Centre for Quantum Engineering and Space-Time Research (QUEST).