Research outline

Nanomaterials have been paid much attention recently due to their unique optical properties. For instance, gold nanoparticles exhibit vivid color originated from collective excitation of free electrons known as plasmons, while bulk gold do golden color. Plasmon confines optical fields spatially and temporarily and enhances optical fields substantially. The enhanced fields are promising for various applications such as chemical sensors, nano-optical devices, and photo-thermotherapy. To understand and design the plasmonic materials, spatio-temporal properties of plasmons should be visualized. However, spatial distribution of the plasmons is smaller than the spatial resolution of conventional optical microscope. Nanoscopic methods are indispensable for visualization of plasmons. We have developed various nanoscopic methods for that purpose and applied them to various nanomaterials to reveal the origin of the properties.