Key points are not available for this paper at this time.
It is shown that destructive interference between two coherent excitation pathways from different optical harmonics, a fundamental and a third harmonic, inhibits resonance-enhanced multiphoton ionization. Once the role of the third harmonic is realized, the interference follows naturally from simple considerations of Fermi's "golden rule" and Maxwell's equations.
Jackson et al. (1982) studied this question.