TY - JOUR
T1 - Characterization of overlapped plasmon modes in a gold hexagonal plate revealed by three-dimensional near-field optical microscopy
AU - Matsuura, Takuya
AU - Imaeda, Keisuke
AU - Hasegawa, Seiju
AU - Suzuki, Hiromasa
AU - Imura, Kohei
N1 - Funding Information:
This work was supported in part by JSPS KAKENHI Grant Nos. JP26107001, JP26107003, JP15K21725, JP16K13939, and JP16H04100 in Scientific Research on Innovative Areas “Photosynergetics” from the Japan Society for the Promotion of Science.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/2/21
Y1 - 2019/2/21
N2 - A detailed characterization of plasmon modes is important not only for a deeper understanding of plasmons but also for their practical applications. In this study, we investigated the three-dimensional near-field characteristics of high-order plasmon modes excited in a gold hexagonal nanoplate. From the near-field spectroscopic images, we found that both in-plane and out-of-plane plasmon modes observed near 900 nm were spectrally and spatially overlapped. We performed three-dimensional near-field measurement to reveal the optical characteristics of the overlapped modes in detail. We found that the steric near-field distribution near the nanoplate strongly depended on the plasmon mode, and the out-of-plane mode confines electromagnetic fields more tightly than the in-plane mode. We also found that the in-plane mode was dominantly visualized as the probe tip-sample distance increased. These findings demonstrate that the three-dimensional near-field technique enables selective visualization of a single plasmon mode even if multiple modes are spatially and spectrally overlapped.
AB - A detailed characterization of plasmon modes is important not only for a deeper understanding of plasmons but also for their practical applications. In this study, we investigated the three-dimensional near-field characteristics of high-order plasmon modes excited in a gold hexagonal nanoplate. From the near-field spectroscopic images, we found that both in-plane and out-of-plane plasmon modes observed near 900 nm were spectrally and spatially overlapped. We performed three-dimensional near-field measurement to reveal the optical characteristics of the overlapped modes in detail. We found that the steric near-field distribution near the nanoplate strongly depended on the plasmon mode, and the out-of-plane mode confines electromagnetic fields more tightly than the in-plane mode. We also found that the in-plane mode was dominantly visualized as the probe tip-sample distance increased. These findings demonstrate that the three-dimensional near-field technique enables selective visualization of a single plasmon mode even if multiple modes are spatially and spectrally overlapped.
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U2 - 10.1021/acs.jpclett.8b03578
DO - 10.1021/acs.jpclett.8b03578
M3 - Article
C2 - 30735394
AN - SCOPUS:85061542932
VL - 10
SP - 819
EP - 824
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
SN - 1948-7185
IS - 4
ER -