地 点：电子信息工程学院 102报告厅
Prof. Dr. Wenxin Wang earned his doctoral degree of Technical Physics in TU Ilmenau, Germany. Then he was introduced into Harbin Engineering University as the head of “Photonic Materials Group”, which devotes its research to designing, constructing photonic crystals and metasurfaces and utilize them into different applications.
Plasmonic metastructures based on localized surface plasmon resonances (LSPR) of individual metallic nanoparticles provide interesting optical properties. However, they suffer from complex fabrication processes and limited sample scaling when using conventional lithographic techniques. Here, we propose an elegant non-lithographic approach to achieve highly homogeneous arrays over centimeter-scale dimensions with ‘L’, ‘U’ or ‘O’ shaped unit nanoparticles. Our method is based on using ultrathin alumina membranes as a deposition mask in physical vapour deposition. We have characterized the structural quality of these metamaterials by investigating their linear and second-order nonlinear optical properties. Specifically, multiple resonant modes in the measured extinction spectra have been examined. The spatial fluctuations of the nonlinear emissions, including second harmonic generation (SHG) and two-photon luminescence (TPL) of individual nanoparticles haven been investigated. Narrow linewidths of their linear extinction spectra and a narrow Gaussian distribution of the nonlinear emission intensities from large areas of the array demonstrate the high-level uniformity of the fabricated arrays.