title: Direct and accurate patterning of plasmonic nanostructures with ultrasmall gaps.
abstract: We report an improved method to directly and accurately fabricate plasmonic nanostructures with ultrasmall gaps. The fabrication is based on high-resolution focused ion beam milling with closely packed nanoring patterns. With fine and precise adjustment of the ion beam, elegant plasmonic nanostructures with ultrasmall dimensions down to 10 nm are achieved. We also show that the gap dimensions have a strong effect on the optical reflectance and transmittance of the plasmonic nanostructures. Measured results show reasonable agreement with finite-difference time-domain calculations. Our approach could find promising applications in plasmon-assisted sensing and surface-enhanced spectroscopy.
authors.affiliation: College of Information Science and Engineering, Northeastern University, Shenyang 110004, China.
authors.forename: Guangyuan
authors.initials: G
authors.lastname: Si
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jiangtao
authors.initials: J
authors.lastname: Lv
authors.forename: Fengwen
authors.initials: F
authors.lastname: Wang
authors.forename: Hailong
authors.initials: H
authors.lastname: Liu
authors.forename: Jinghua
authors.initials: J
authors.lastname: Teng
authors.forename: Yan Jun
authors.initials: YJ
authors.lastname: Liu