Lower order effects in nonlinear twohyphen; and threehyphen;photon resonance spectroscopies

摘要

A semiclassical description of the simultaneous processes of twohyphen;photon absorption, twohyphen;photon excitation, and second harmonic generation in noncentrosymmetric crystals is presented. The results are generalized to include threehyphen;photon processes and third harmonic generation in centrosymmetric media. Consequences for molecular crystal excitation spectroscopy are emphasized. Similar results and observations are made for thirdhyphen;order wave mixing in noncentrosymmetric crystals.