We propose a novel method for observing and utilizing nanometrically fluctuating signals due to optical near-field interactions between a probe and target in nearfield optical microscopy. Based on a hierarchical structure of the interactions, it is possible to obtain signals that represent two-dimensional spatial patterns without requiring any scanning process. Such signals reveal individual features of each target, and these features, when appropriately extracted and defined, can be used in security applications-an approach that we call nanophotonic security. As an experimental demonstration, output signals due to interactions between a SiO2 probe and Al nanorods were observed by using near-field optical microscopy at a single readout point, and these signals were quantitatively evaluated using an algorithm that we developed for extracting and defining features that can be used for security applications.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Industrial and Manufacturing Engineering
- Metals and Alloys
- Materials Chemistry