Model for describing resonance-enhanced strong-field ionization with shaped ultrafast laser pulses

Abstract

We present a simple model for calculating strong field atomic and molecular ionization dominated by Freeman resonances. Our model combines multiphoton coupling between bound states, including dynamic Stark shifts, with coupling to a discretized continuum. The simplicity of the model allows us to interpret pulse shape dependent strong field ionization yields and to demonstrate the relevance of strong field atomic/molecular phase matching to ionization as well as bound state population transfer. Comparison with experimental measurements demonstrates that the calculations capture the essence of the pulse shape dependent ionization yields.