Zinc oxide Au nanoclusters Nanocombs Nanowires Photoluminescence ZnO ZnO nanostructures Article Effective volume Energy gap Excitation sources Exciton photoluminescences Fabry-Perot Free-exciton emissions Fused silica Gold deposits Growth mechanisms Growth patterns Incident polarization Input polarization Intensity dependence Morphology changes Multiple reflections Nano-objects Nanotechnology Nonlinear excitation Nonlinear signals Partial pressure ratio Phase matching Phase matching conditions