Сибирский федеральный университет

Тип публикации: статья из журнала

Год издания: 1988

Аннотация: A theory of the nonlinear optical properties of fractals (fractal clusters) is developed. Giantenhancement of the nonlinear susceptibilities are predicted for impurities bound to fractals. Thisenhancement is implemented by excitation with radiation in the intrinsic-absorption band of thefractal. The giant optical nonlinearities are due to the existence of strong local fields at theimpurity centers. The enhancement of the local fields is due to the inhomogeneously broadenedcharacter of the fractal spectrum (partial preservation of the individuality of the monomers), andis proportional to the Q factor of the monomer treated as a resonator. The effects of coherent anti-Stokes Raman scattering (CARS) and of the phase conjugation are much more enhanced thangeneration of higher harmonics. In the general case, the nonlinear susceptibility of higher orderwill be enhanced to the utmost if the frequency of at least one strong field enters in thesusceptibility with a minus sign. On the contrary, higher-harmonic generation is minimallyenhanced. The dependence of the susceptibility on the type of effect is due to the influence of thefluctuations of its phase when averaged over an ensemble of fractals. The gain dependssubstantially on the fractal (Hausdorff) dimensionality and decreases when the latter tends tobecome trivial. The observed phenomena yield information on the spectra of the impurityparticles as well as of the fractal. It is predicted that the CARS spectra of impurity centers willexhibit a system ofnarrow lines typical of a fractal isolated monomer.

Журнал: Журнал экспериментальной и теоретической физики

Выпуск журнала: Т. 94, № 1

Номера страниц: 107-124

ISSN журнала: 00444510

Место издания: Москва

Издатель: Издательство "Наука"

• Бутенко А.В.
• Шалаев В.М.
• Штокман М.И. (Сибирский федеральный университет)

• Ядро РИНЦ (eLIBRARY.RU)
• Список ВАК