Extraordinary optical transmission and second harmonic generation in sub–10-nm plasmonic coaxial aperture

Nanophotonics

article

Jaehak Lee¹  Suyeon Yang¹  Jihye Lee⁴  Jun-Hyuk Choi⁴  Yong-Hee Lee¹  Jung H. Shin¹  Min-Kyo Seo¹ 

[1] Department of Physics, Korea Advanced Institute of Science and Technology;Division of National Supercomputing, Korea Institute of Science and Technology Information;Current address: Department of Physics, Wageningen University and Research Centre;Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials;Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology

关键词: plasmonics;    gap plasmon;    plasmonic coaxial aperture;    extraordinary optical transmission;    second harmonic generation;   

DOI  :  10.1515/nanoph-2020-0066

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Recent development in nanofabrication technology has enabled the fabrication of plasmonic nanoapertures that can provide strong field concentrations beyond the diffraction limit. Further utilization of plasmonic nanoaperture requires the broadband tuning of the operating wavelength and precise control of aperture geometry. Here, we present a novel plasmonic coaxial aperture that can support resonant extraordinary optical transmission (EOT) with a peak transmittance of ~10% and a wide tuning range over a few hundred nanometers. Because of the shadow deposition process, we could precisely control the gap size of the coaxial aperture down to the sub–10-nm scale. The plasmonic resonance of the SiN x /Au disk at the center of the coaxial aperture efficiently funnels the incident light into the sub–10-nm gap and allows strong electric field confinement for efficient second harmonic generation (SHG), as well as EOT. In addition to the experiment, we theoretically investigated the modal properties of the plasmonic coaxial aperture depending on the structural parameters and correlation between EOT and SHG through finite-difference time-domain simulations. We believe that our plasmonic coaxial apertures, which are readily fabricated by the nanoimprinting process, can be a versatile, practical platform for enhanced light–matter interaction and its nonlinear optical applications.

【 授权许可】

CC BY