Ultrafast Plasmonic Control of Second Harmonic Generation

作者：Davidson Roderick B II^*; Yanchenko Anna; Ziegler Jed I; Avanesyan Sergey M; Lawrie Benjamin J; Haglund Richard F Jr

来源：ACS Photonics, 2016, 3(8): 1477-1481.

DOI：10.1021/acsphotonics.6b00034

• nonlinear optics
• metasurfaces
• plasmonic enhancement
• intoferometry
• optical control

Efficient frequency conversion techniques are crucial to the development of plasmonic metasurfaces for information processing and signal modulation. In principle, nanoscale electric-field confinement in nonlinear materials enables higher harmonic conversion efficiencies per unit volume than those attainable in bulk materials. Here we demonstrate efficient second-harmonic generation (SHG) in a serrated nanogap plasmonic geometry that generates steep electric field gradients on a dielectric metasurface. An ultrafast control pulse is used to control plasmon-induced electric fields in a thin-film material with inversion symmetry that, without plasmonic enhancement, does not exhibit an even-order nonlinear optical response. The temporal evolution of the plasmonic near-field is characterized with 100 as resolution using a novel nonlinear interferometric technique. The serrated nanogap is a unique platform in which to investigate optically controlled, plasmonically enhanced harmonic generation in dielectric materials on an ultrafast time scale. This metamaterial geometry can also be readily extended to all-optical control of other nonlinear phenomena, such as four-wave mixing and sum- and difference-frequency generation, in a wide variety of dielectric materials.

• 出版日期2016-8