Abstract

Nonlinear susceptibilities have been very successful in handling the vast majority of experimental situations involving nonlinear optical interactions, including the extra resonances.¹ Strong fields, however, where a field is defined as strong if its Rabi frequency is large compared to its detuning and all other rates involved in the relevant transition, are not described properly by perturbative approaches, even when these approaches are used in high order, In two recent theoretical papers,^2,3 we have used the generalized rotating-wave approximation

© 1993 Optical Society of America