Abstract
By using quantum-chemistry approaches, the second-order nonlinear optical responses of molecules and two-dimensional molecular arrays containing the p-nitroaniline chromophore are evaluated in order to highlight key features of the simulation of the second-harmonic and sum-frequency generation spectra of organic layers. For the electronic component, which dominates the second-harmonic generation response and which constitutes the weakly frequency-dependent background contribution to the vibrational sum-frequency generation phenomenon, the time-dependent Hartree-Fock scheme based on the semi-empirical AM1 parameterization is suitable for predicting the microscopic responses as well as for accounting for the surrounding effects within a simple multiplicative scheme. For the vibrational resonant part of the sum-frequency generation response, ab initio density functional theory approaches turn out to be necessary for locating the resonances and estimating their intensities.
Original language | English |
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Pages (from-to) | 627-634 |
Number of pages | 8 |
Journal | Applied physics. B: Lasers and optics |
Volume | 74 |
Issue number | 7-8 |
DOIs | |
Publication status | Published - 1 May 2002 |