STABILITY CRITERIA FOR NONLINEAR OPTICAL BALANCE

The suppression of resonance enhancement of muitiphoton ionization by coherent nonlinear optical generation1 has been explained by invoking the concept of nonlinear optical balance.2 In nonlinear optical balance, coherent light waves, that may excite a resonant intermediate state of a medium via two or more distinct pathways, are coupled together via the nonlinear polarizability of the medium, and the waves then develop amplitudes and phases that suppress the resonant excitation. Essentially, there is a destructive interference between the distinct excitation pathways.