Perturbation theory of the non-linear optical polarization of an isolated system

B. J. Orr, J. F. Ward

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The non-linear optical polarization of an isolated atom or molecule is treated, giving careful consideration to secular and resonant terms in the perturbation expansion. The Method of Averages introduced by Bogoliubov and Mitropolsky is used. The case where resonance-induced excited state populations are negligible, which is relevant to a wide range of non-linear optical experiments, is examined in detail for polarizations through third order in the perturbing fields. This yields concise expressions which are valid for any combination of applied field frequencies, including static fields.

Original languageEnglish
Pages (from-to)513-526
Number of pages14
JournalMolecular Physics
Issue number3
Publication statusPublished - 1971
Externally publishedYes


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