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Nano Research

Article Title

Active coherent control of nanoscale light confinement: Modulation of plasmonic modes and position of hotspots for surface-enhanced Raman scattering detection

Authors

Zhendong Zhu, Division of Nano Metrology and Materials Measurement, National Institute of Metrology, Beijing 100028, China State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China Tsinghua–Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China
Qixia Wang, State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
Fa Zeng, State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China Laser Fusion Research Center, China Academic of Engineering Physics, Sichuan 621900, China
Oubo You, State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
Sitian Gao, Division of Nano Metrology and Materials Measurement, National Institute of Metrology, Beijing 100028, China
Benfeng Bai, State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
Qiaofeng Tan, State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
Guofan Jin, State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China
Qunqing Li, Tsinghua–Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China
Shoushan Fan, Tsinghua–Foxconn Nanotechnology Research Center, Tsinghua University, Beijing 100084, China
Wei Li, Division of Nano Metrology and Materials Measurement, National Institute of Metrology, Beijing 100028, China
Yushu Shi, Division of Nano Metrology and Materials Measurement, National Institute of Metrology, Beijing 100028, China
Xueshen Wang, Division of Nano Metrology and Materials Measurement, National Institute of Metrology, Beijing 100028, China

Keywords

surface plasmons, mode hybridization, positioning hotspot, double-stacked nanocone (DSC) nanostructure, surface-enhanced Raman scattering (SERS)

Abstract

ABSTRACT Multistep plasmonic nanostructures can induce the deep modulation of electromagnetic-field interactions on the nanoscale for positioning hotspots, and this generation of enhanced fields is important in many optical applications. In this article, a new strategy is proposed for fabricating a plasmonic doublestacked nanocone (DSC) nanostructure. In the DSC structure, a tunable plasmonic hybrid mode proceeds from the strong coupling of the plasmonic resonance of a fundamental cavity mode with a localized surface plasmon gap mode. In the nanostructure, the far-field response is deeply modulated and the hottest spots can be effectively positioned on the top surface of the DSC nanostructure. A controllable and cost-effective mask-reconfiguration technique for manufacturing the multiscale nanostructure is developed, which guarantees the generation of the introduced crucial stage on the DSC nanostructure. To evaluate the features of the plasmonic resonance, the DSC nanostructure is used as a surface-enhanced Raman scattering (SERS) substrate for detecting 4-mercaptopyridine molecules under specific excitation conditions. Its good performance, with an average measured SERS enhancement factor as high as 108, demonstrates its strong plasmonic-mode hybridization and extreme field enhancement.

Graphical Abstract

Publisher

Tsinghua University Press

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