Nanoscale optical mapping of meta-atoms in metal-insulator-metal metasurfaces in the infrared spectrum

This is the authors' abstract. We don't add key points for this paper.

Metamaterials are of significant use in a wide variety of potential applications. Their optical properties are determined not only by their constituent materials but also by their individual constituent configuration. Metal-insulator-metal (MIM) metasurfaces, for instance, can be engineered to achieve near-unity absorption at specific frequencies. In this study, we investigate the unit MIM structure that constitutes the metasurface using Photo-Induced Force Microscopy (PiFM) and Near-field Scanning Optical Microscopy (NSOM). We probe its near-field optical response in the infrared (IR) range. Our results highlight the predominant influence of dipole-dipole interactions and vertically oriented photo-induced forces, providing critical insights into nanoscale light-matter interactions and facilitating the development of MIM-based photonic devices in the IR range.