Investigation Of Second Order Nonlinear Optical Activity And Surface Second-Harmonic Generation In Chiral Media

Chiral material is a kind of dissymmetric matter that exists widely in nature. it is studied and applied in biology, chemistry, physics and pharmacology. As the chiral medium presents the second-order nonlinear optical effect, it is significative in theory and practice using nonlinear techniques to study the structure of molecules, explore the new functional material. Also it is of theoretical significance in enriching the nonlinear optics.In this thesis, first, the history and current situation of research on the second-order nonlinear optics in chiral media are summarized. The relationship between parameters of molecule and polarization of molecule are deduced by classical electrodynamics, presented the relationship between molecule susceptibility and medium susceptibility.Secondly, the intensity of reflected and transited light in second-harmonic generation is calculated by means of classical multipole radiation theory based on the two-coupled-oscillator model. The intensity of circular difference in second harmonic generation is derived too.The end, the influence of chiral molecule microcosmic structure on second-order susceptibility, polarization state of linearly polarized light on second-harmonic generation and microscopic parameters on circular dichroism are simulated under the above model. Otherwise, the effect of the molecule microscopic parameters on second-harmonic generation is simulated based on the one-electron model. When the appropriate date is given, we can make a comparison between the curve of theoretical calculation and the result of experiment in reference to prove our theoretical calculation which is correct.The connection of microscopic and macroscopic properties of chiral molecules in nonlinear process is established by our work, it is the theoretical basis for characterizing and detecting chirality. Also it is the instructing for synthesizing new material in the future.