Imaging second-harmonic radiation and scattering patterns in zinc oxide micro/nanostructures.

摘要

The optical characteristics of ZnO nanostructures have recently garnered interest due to the inclusion of these structures in many nanoscale optical and optoelectronic devices. This thesis will address several characteristics involving second harmonic generation and scattering in ZnO nano- and microstructures. A method will be presented for determining the nonlinear coefficients of the second order susceptibility in a single ZnO rod. This method uses transmission geometry where previous methods have employed back-reflected irradiation. The nonlinear coefficients found using this new technique were consistent with previous data from similar structures.;Models will be presented for predicting the second harmonic scattering patterns from both ZnO tetrapods and joined rods. The models are based on infinitely thin finite dipoles. The model for two joined rods showed good agreement with experimental data, while the model for the tetrapod showed only minor agreement.