Extended Two-Level Theory of the Exponential Index of Multiphoton Processes
Joseph H. Eberly · Physical Review Letters · 1979
A nonperturbative formula is given for the r-photon-resonant, (r+p)-photon ionization rate of an atom and from it is derived an expression for the exponential index.Received 25 August 1978DOI:https://doi.org/10.1103/PhysRevLett.42.1049©1979 American Physical Society