Sub-wavelength visualization of near-field scattering mode of plasmonic nano-cavity in the far-field

Jin, X. et al. (2023) Sub-wavelength visualization of near-field scattering mode of plasmonic nano-cavity in the far-field. Nanophotonics, 12(2), pp. 297-305. (doi: 10.1515/nanoph-2022-0679)

Abstract

Spatial visualization of mode distribution of light scattering from plasmonic nanostructures is of vital importance for understanding the scattering mechanism and applications based on these plasmonic nanostructures. A long unanswered question in how the spatial information of scattered light from a single plasmonic nanostructure can be recovered in the far-field, under the constraints of the diffraction limit of the detection or imaging optical system. In this paper, we reported a theoretical model on retrieving local spatial information of scattered light by plasmonic nanostructures in a far-field optical imaging system. In the far-field parametric sin δ images, singularity points corresponding to near-field hot spots of the edge mode and the gap mode were resolved for gold ring and split rings with subwavelength diameters and feature sizes. The experimental results were verified with Finite Difference Time Domain (FDTD) simulation in the near-field and far-field, for the edge mode and the gap mode at 566 nm and 534 nm, respectively. In sin δ image of split-ring, two singularity points associated with near-field hot spots were visualized and resolved with the characteristic size of 90 and 100 nm, which is far below the diffraction limit. The reported results indicate the feasibility of characterizing the spatial distribution of scattering light in the far-field and with sub-wavelength resolution for single plasmonic nanostructures with sub-wavelength feature sizes.

• Item Type: Articles
• Additional Information: This work was supported by National Major Scientific Instruments and Equipment Development Project (No. 61827814), Beijing Natural Science Foundation (No. Z190018), National Natural Science Foundation of China (No. 61627802), Fundamental Research Funds for the Central Universities (No. 30920010011), Ministry of Education collaborative project (B17023), UK Engineering and Physical Sciences Research Council (EP/R042578/1), Nanjing University of Science and Technology.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hou, Dr Lianping and Cheng, Weiqing and Marsh, Professor John and Ye, Dr Shengwei
• Authors: Jin, X., Ye, S., Cheng, W., Hou, J. J., Jin, W., Sheng, T., Hou, L., Marsh, J. H., Yu, Y., Sun, M., Ni, B., Liu, X., and Xiong, J.
• College/School: College of Science and Engineering > School of Engineering; College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• Journal Name: Nanophotonics
• Publisher: De Gruyter
• ISSN: 2192-8606
• ISSN (Online): 2192-8614
• Published Online: 16 January 2023
• Copyright Holders: Copyright © 2023 The Authors
• First Published: First published in Nanophotonics 12(2): 297-305
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
302617		Optically controlled THz phased array antennas	John Marsh	Engineering and Physical Sciences Research Council (EPSRC)	EP/R042578/1	ENG - Electronics & Nanoscale Engineering