【研究成果】2016年-

研究成果101

Highly efficient plasmonic tip design for plasmon nanofocusing in near-field optical microscopy
Takayuki Umakoshi, Yuika Saito & Prabhat Verma
Nanoscale, 8, 5634 (2016) | DOI: 10.1039/c5nr08548a

Near-field scanning optical microscopy (NSOM) combined with plasmon nanofocusing is a powerful nano-analytical tool due to its attractive feature of efficient background suppression as well as light energy compression to the nanoscale. In plasmon nanofocusing-based NSOM, the metallic tip plays an important role in inducing plasmon nanofocusing. Here, the authors proposed an efficient tip design and fabrication which enable one to actively control plasmonic properties for efficient plasmon nanofocusing. Almost 100% reproducibility in plasmon nanofocusing was achieved in the experiments. This new approach of tip fabrication makes plasmon nanofocusing-based NSOM practical and reliable, and opens doors for many scientists working in related fields.


(a) Schematic of the tip structure for plasmon nanofocusing (a dielectric pyramidal structure and a metallic thin layer on its surface). By illuminating the grating with a laser, plasmon nanofocusing is induced to generate near-field light at the apex. (b) An intensity map of FDTD simulation of electric field in the vicinity of the tip apex during plasmon nanofocusing (c) SEM image of a fabricated tip. (inset: an enlarged image of the tip, where a grating structure was fabricated on the thin and smooth silver layer)