Air-like plasmonics with ultralow-refractive-index silica aerogels
SCIE
SCOPUS
- Title
- Air-like plasmonics with ultralow-refractive-index silica aerogels
- Authors
- Kim, Yeonhong; Baek, Seunghwa; Gupta, Prince; Kim, Changwook; Chang, Kiseok; Ryu, Sung-Pil; Kang, Hansaem; Kim, Wook Sung; KIM, WOOKSUNG; Myoung, Jaemin; Park, Wounjhang; Kim, Kyoungsik
- Date Issued
- 2019-02
- Publisher
- NATURE PUBLISHING GROUP
- Abstract
- The coupling of the surface plasmon near-field into the sensing medium is key to the sensitivity of surface plasmon-based sensing devices. A low-index dielectric is necessary for the sensing medium to support a highly-penetrating surface plasmon evanescent field that extends well into the dielectric medium. The air-like refractive index, n, of an aerogel substrate provides another dimension for ultralow-index plasmonic devices. In this paper, we experimentally observed an angular surface plasmon resonance dip at 74° with the ultralow-index aerogel substrate, as was expected from theory. We also demonstrated the comparatively high-sensitivity surface plasmon resonance wavelength, λ, while the change in Δλ/Δn with different substrates was studied in detail. A 740 nm-period metal grating was imprinted on aerogel (n = 1.08) and polydimethylsiloxane (PDMS; n = 1.4) substrates. The ultraviolet-visible-near-infrared spectra were observed in the reflection mode on the grating, resulting in sensitivities of 740.2 and 655.9 nm/RIU for the aerogel and PDMS substrates, respectively. Numerical simulations were performed to understand the near-field of the surface plasmon, which demonstrated resonances well correlated with the experimentally observed results. The near-field due to excitation of the surface plasmon polaritons is observed to be more confined and to penetrate deeper into the sensing medium when a low-index substrate is used.
- URI
- https://oasis.postech.ac.kr/handle/2014.oak/94898
- DOI
- 10.1038/s41598-019-38859-2
- ISSN
- 2045-2322
- Article Type
- Article
- Citation
- Scientific Reports, vol. 9, page. 1 - 9, 2019-02
- Files in This Item:
-
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.