Reaching the Theoretical Resonance Quality Factor Limit in Coaxial Plasmonic Nanoresonators Fabricated by Helium Ion Lithography
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- 作者：M. Melli ; A. Polyakov ; D. Gargas ; C. Huynh ; L. Scipioni ; W. Bao ; D. F. Ogletree ; P. J. Schuck ; S. Cabrini ; A. Weber-Bargioni
- 刊名：Nano Letters
- 出版年：2013
- 出版时间：June 12, 2013
- 年：2013
- 卷：13
- 期：6
- 页码：2687-2691
- 全文大小：308K
- 年卷期：v.13,no.6(June 12, 2013)
- ISSN：1530-6992
文摘
Optical antenna structures have revolutionized the field of nano-optics by confining light to deep subwavelength dimensions for spectroscopy and sensing. In this work, we fabricated coaxial optical antennae with sub-10-nanometer critical dimensions using helium ion lithography (HIL). Wavelength dependent transmission measurements were used to determine the wavelength-dependent optical response. The quality factor of 11 achieved with our HIL fabricated structures matched the theoretically predicted quality factor for the idealized flawless gold resonators calculated by finite-difference time-domain (FDTD). For comparison, coaxial antennae with 30 nm critical dimensions were fabricated using both HIL and the more common Ga focus ion beam lithography (Ga-FIB). The quality factor of the Ga-FIB resonators was 60% of the ideal HIL results for the same design geometry due to limitations in the Ga-FIB fabrication process.