TY - JOUR
T1 - Flexibly tunable surface plasmon resonance by strong mode coupling using a random metal nanohemisphere on mirror
AU - Okamoto, Koichi
AU - Okura, Kota
AU - Wang, Pangpang
AU - Ryuzaki, Sou
AU - Tamada, Kaoru
N1 - Funding Information:
The authors wish to thank Professors K. Wada and T. Matsuyama at the Osaka Prefecture University and Professors Y. Kawakami and M. Funato at the Kyoto University for valuable discussions and support. This work was supported by the JSPS KAKENHI S (15H05732), S (19H05627) and KAKENHI B (18H01903).
Funding Information:
Research funding : This work was supported by the JSPS KAKENHI S (15H05732), S (19H05627) and KAKENHI B (18H01903).
Publisher Copyright:
© 2020 Koichi Okamoto et al., published by De Gruyter, Berlin/Boston 2020.
PY - 2020/9/1
Y1 - 2020/9/1
N2 - We propose a unique random metal nanohemisphere on mirror (NHoM) structure to tune the surface plasmon (SP) resonance in a flexible manner. The SP resonance peak was split into two peaks owing to the strong coupling between the SP mode in the metal nanohemisphere and the mirror image mode generated in the metal substrate. This phenomenon is based on the fact that the strong coupling and the induced electromagnetic effects are similar to those pertaining to the Rabi splitting, Fano resonance, and electromagnetically induced transparency, thus providing quantum effect analogies. These phenomena have recently attracted increased attention and have been studied with nanocavities fabricated with top-down nanotechnologies. Compared with previous reports, NHoM structures can be fabricated in a much easier manner and are tunable in rather wider wavelength regions without nanofabrication technologies. The SP resonance peaks were enhanced, sharpened dramatically, and tuned flexibly, based on the optimization of the thickness of the spacer layer between the metal hemisphere and metal substrate. Experimental results were reproduced and were explained based on finite difference time domain (FDTD) simulations. These phenomena have never been observed previously on similar nanosphere on mirror (NSoM) because nanohemispherical structures were required. The NHoM nanocavity structure has a quality factor >200 that is surprisingly high for the localized SP mode of nanoparticles. Flexible tuning of the SP resonance with the use of NHoM is envisaged to lead to the development of new applications and technologies in the field of plasmonics and nanophotonics.
AB - We propose a unique random metal nanohemisphere on mirror (NHoM) structure to tune the surface plasmon (SP) resonance in a flexible manner. The SP resonance peak was split into two peaks owing to the strong coupling between the SP mode in the metal nanohemisphere and the mirror image mode generated in the metal substrate. This phenomenon is based on the fact that the strong coupling and the induced electromagnetic effects are similar to those pertaining to the Rabi splitting, Fano resonance, and electromagnetically induced transparency, thus providing quantum effect analogies. These phenomena have recently attracted increased attention and have been studied with nanocavities fabricated with top-down nanotechnologies. Compared with previous reports, NHoM structures can be fabricated in a much easier manner and are tunable in rather wider wavelength regions without nanofabrication technologies. The SP resonance peaks were enhanced, sharpened dramatically, and tuned flexibly, based on the optimization of the thickness of the spacer layer between the metal hemisphere and metal substrate. Experimental results were reproduced and were explained based on finite difference time domain (FDTD) simulations. These phenomena have never been observed previously on similar nanosphere on mirror (NSoM) because nanohemispherical structures were required. The NHoM nanocavity structure has a quality factor >200 that is surprisingly high for the localized SP mode of nanoparticles. Flexible tuning of the SP resonance with the use of NHoM is envisaged to lead to the development of new applications and technologies in the field of plasmonics and nanophotonics.
UR - http://www.scopus.com/inward/record.url?scp=85088382628&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85088382628&partnerID=8YFLogxK
U2 - 10.1515/nanoph-2020-0118
DO - 10.1515/nanoph-2020-0118
M3 - Article
AN - SCOPUS:85088382628
SN - 2192-8606
VL - 9
SP - 3409
EP - 3418
JO - Nanophotonics
JF - Nanophotonics
IS - 10
ER -