Open AccessAnalyzing bowtie structures with sharp tips by a vertical mode expansion method
Author(s) -
HuaTian Shi,
Ya Yan Lu,
Qiang Du
Publication year - 2018
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.26.032346
Subject(s) - optics , field (mathematics) , boundary (topology) , mode (computer interface) , gravitational singularity , physics , materials science , computer science , mathematics , mathematical analysis , quantum mechanics , pure mathematics , operating system
Bowtie structures of metallic nanoparticles are very effective in producing strong local fields needed in many applications. Existing numerical studies on bowtie structures are limited to those with rounded tips. Due to the field singularities at sharp edges and corners, accurate numerical solutions for bowtie structures with mathematically sharp tips are difficult to obtain. Based on an improved vertical mode expansion method (VMEM) that incorporates boundary integral equation techniques for domains with corners, we analyze bowtie structures with truly sharp tips. Numerical results are presented to reveal the effects of a few key factors including the distance between the tips, the apex angle and the substrate.