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arXiv · 1011.0251

High-Q exterior whispering gallery modes in a metal-coated microresonator

Yun-Feng Xiao·Chang-Ling Zou·Bei-Bei Li·Yan Li·Chun-Hua Dong·Zheng-Fu Han·Qihuang Gong
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Abstract

We propose a kind of plasmonic whispering gallery modes highly localized on the exterior surface of a metal-coated microresonator. This exterior (EX) surface mode possesses high quality factors at room temperature, and can be efficiently excited by a tapered fiber. The EX mode can couple to an interior (IN) mode and this coupling produces a strong anti-crossing behavior, which not only allows conversion of IN to EX modes, but also forms a long-lived anti-symmetric mode. As a potential application, the EX mode could be used for a biosensor with a sensitivity high up to 500 nm per refraction index unit, a large figure of merit, and a wide detection range.

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Yun-Feng Xiao, Chang-Ling Zou, Bei-Bei Li, Yan Li, Chun-Hua Dong, Zheng-Fu Han, Qihuang Gong. 2010-11-01. High-Q exterior whispering gallery modes in a metal-coated microresonator. https://doi.org/10.1103/physrevlett.105.153902

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