Title
Theory of Molecular Nonlinear Optics
Abbreviated Journal Title
Adv. Opt. Photonics
Keywords
2ND HARMONIC-GENERATION; HYPER-RAYLEIGH-SCATTERING; NEMATISCHEN; KRISTALLINFLUSSIGEN PHASE; OXYGEN-OCTAHEDRA FERROELECTRICS; MOLEKULAR-STATISTISCHE THEORIE; CONJUGATED ORGANIC-MOLECULES; LANGMUIR-BLODGETT-FILMS; BOND-LENGTH ALTERNATION; POLED POLYMER-FILMS; PUSH-PULL POLYMERS; Optics
Abstract
The theory of molecular nonlinear optics based on the sum-over-states (SOS) model is reviewed. The interaction of radiation with a single wtpisolated molecule is treated by first-order perturbation theory, and expressions are derived for the linear (alpha(ij)) polarizability and nonlinear (beta(ijk), gamma(ijkl)) molecular hyperpolarizabilities in terms of the properties of the molecular states and the electric dipole transition moments for light-induced transitions between them. Scale invariance is used to estimate fundamental limits for these polarizabilities. The crucial role of the spatial symmetry of both the single molecules and their ordering in dense media, and the transition from the single molecule to the dense medium case (susceptibilities. chi((1))(ij), chi((2))(ijk), chi((3))(ijkl), is discussed. For example, for beta(ijk), symmetry determines whether amolecule can support second-order nonlinear processes or not. For asymmetric molecules, examples of the frequency dispersion based on a two-level model (ground state and one excited state) are the simplest possible for beta(ijk) and examples of the resulting frequency dispersion are given. The third-order susceptibility is too complicated to yield simple results in terms of symmetry properties. It will be shown that whereas a two-level model suffices for asymmetric molecules, symmetric molecules require a minimum of three levels in order to describe effects such as two-photon absorption. The frequency dispersion of the third-order susceptibility will be shown and the importance of one and two-photon transitions will be discussed. (C) 2013 Optical Society of America
Journal Title
Advances in Optics and Photonics
Volume
5
Issue/Number
1
Publication Date
1-1-2013
Document Type
Article
Language
English
First Page
4
Last Page
82
WOS Identifier
ISSN
1943-8206
Recommended Citation
"Theory of Molecular Nonlinear Optics" (2013). Faculty Bibliography 2010s. 4249.
https://stars.library.ucf.edu/facultybib2010/4249
Comments
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