Development of near-field refection microspectroscope

2015 Fiscal Year Final Research Report

• Project/Area Number: 26620018
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Physical chemistry
• Research Institution: Waseda University
• Principal Investigator: Imura Kohei 早稲田大学, 理工学術院, 教授 (80342632)
• Project Period (FY): 2014-04-01 – 2016-03-31
• Keywords: ナノ分光法 / 反射分光法 / プラズモン

Outline of Final Research Achievements

Near-field optical microscope achieves a nanometer spatial resolution, and is of great use for studying optical properties of nanomaterials. However, the method is not fully compatible to conventional spectroscopic methods. For example, near-field reflection spectroscopy was not established because of large background light with respect to a tiny near-field signal. We proposed to extract near-field signal from the observed reflection by using phase-stepping technique. We developed near-field reflection microscope and applied it to study optical properties of a silver nanoplate. The microscope improves the signal to noise greatly and enables to recover a tiny signal from observed reflected light. Near-field reflection image of the plate shows periodic spatial oscillations attributable to plasmon modes. The microscope enables to study nanostructures not only on the transparent substrate but also on the opaque substrate, and has a great potential as a general analytical tool.

Free Research Field

物理化学