Quantum-electrodynamical treatment of second-harmonic generation through phase-conjugate six-wave mixing: Temporal analysis - art. no. 023807

It is shown how the effects of molecular reorientation may be incorporated in a fully quantized quantum-electrodynamical treatment of a high-order non linear optical effect. Specifically, a general temporal theory is developed to account for the second-harmonic intensity produced through phase-conjug ate six-wave mixing. The theory permits elucidation of the intensity of the second-harmonic radiation for arbitrary arrangements of the generating las er beams and molecular geometry. Several models are considered: a one-dimen sional model, linear geometry, and a planar geometry. A comparison is made between the results associated with these models and with those obtained fr om ultrafast experiments on dilute solutions of substituted stilbenes. We f ind that the off-axial components of the molecular polarizabilities are nec essary to properly describe the orientational dynamics of such molecules.