Single-Band 2-nm-Line-Width Plasmon Resonance in a Strongly Coupled Au Nanorod.

Wang, Pan; Wang, Yipei; Yang, Zongyin; Guo, Xin; Lin, Xing; Yu, Xiao-Chong; Xiao, Yun-Feng; Fang, Wei et al. · Nano Lett · 2015

basic_science · Level V

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Abstract

This paper reports a dramatic reduction in plasmon resonance line width of a single Au nanorod by coupling it to a whispering gallery cavity of a silica microfiber. With fiber diameter below 6 μm, strong coupling between the nanorod and the cavity occurs, leading to evident mode splitting and spectral narrowing. Using a 1.46-μm-diameter microfiber, we obtained single-band 2-nm-line-width plasmon resonance in an Au nanorod around a 655-nm-wavelength, with a quality factor up to 330 and extinction ratio of 30 dB. Compared to an uncoupled Au nanorod, the strongly coupled nanorod offers a 30-fold enhancement in the peak intensity of plasmonic resonant scattering.