| AVS 61st International Symposium & Exhibition | |
| Nanometer-scale Science and Technology | Thursday Sessions |
| Session NS-ThP |
| Session: | Nanoscience Division Poster Session |
| Presenter: | Jungseok Chae, National Institute of Standards and Technology |
| Authors: | J. Chae, National Institute of Standards and Technology B. Lahiri, National Institute of Standards and Technology G. Holland, National Institute of Standards and Technology A. Centrone, National Institute of Standards and Technology |
| Correspondent: | Click to Email |
Propagating light can interact efficiently with artificially fabricated metallic nanostructures through plasmonic excitations. In the infrared (IR) such light-matter interactions enables enhanced absorption in nanoscale volumes (“hot spots”), leading to sensitive IR detection. However, direct imaging of IR absorption hot spots is challenging because their size is several time smaller of the diffraction limit of the long IR wavelengths. Recently our group directly imaged and quantified the mid-IR absorption enhancement in polymer films coating asymmetric split ring resonators (ASSRs) using the photothermal induced resonance (PTIR) technique.[1] PTIR measures the transient thermal expansion caused by the absorption of light pulses in the sample with an atomic force microscope cantilever, leading to lateral resolution comparable to the AFM tip size P lasmonic arrays of different shapes (ASRR, C-shaped, crescent-shaped and U-shaped) and different lattices (square, hexagonal and rhombic) were fabricated by e-beam lithography on top of zinc selenide right angle prisms to enable PTIR characterization. Here I’ll show how the different shapes and arrangements of the resonators impact the shape, distribution and intensity of IR absorption hot spots in the near-field. The experimentally and directly measured enhancement factors in PMMA film coating the plasmonic structures will be compared for the different cases and with the enhancements measured for a single resonator of each shape.
[1]. B. Lahiri, G. Holland, V. Aksyuk and A. Centrone, NanoLetters. 13, 3218 (2013).