On the basis of an extended configuration-interaction description of the lowest singlet excited states, we investigate the third-order nonlinear optical response of the Β-carotene molecule by means of the sum-over-states approach. We first uncover the nature of the electronic states contributing primarily to the cubic molecular polarizabilities. From this starting point, we apply a simplified model to evaluate the frequency-dependent third-harmonic generation (THG) and electroabsorption (EA) spectra; the vibronic structure of the spectra is described by taking into account Franck-Condon factors calculated in a displaced oscillator model. For both the THG and EA processes, we obtain good agreement between the theoretical simulations and the experimental data, which underlines the general character of our model.
|Original language||English (US)|
|Number of pages||12|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - 1997|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics