Photonics Research, 2019, 7 (5): 05000526, Published Online: Apr. 15, 2019
Plasmonic tip internally excited via an azimuthal vector beam for surface enhanced Raman spectroscopy Download: 517次
Abstract
The synergy of a plasmonic tip and fiber-based structure light field excitation can provide a powerful tool for Raman examination. Here, we present a method of Raman spectrum enhancement with an Ag-nanoparticles (Ag-NPs)-coated fiber probe internally excited via an azimuthal vector beam (AVB), which is directly generated in a few-mode fiber by using an acoustically induced fiber grating. Theoretical analysis shows that gap mode can be effectively generated on the surface of the Ag-NPs-coated fiber probe excited via an AVB. The experimental result shows that the intensity of Raman signal obtained with analyte molecules of malachite green by exciting the Ag-NPs-coated fiber probe via an AVB is approximately eight times as strong as that via the linear polarization beam (LPB), and the activity of the AVB-excited fiber probe can reach 10 11 mol / L , which cannot be achieved by LPB excitation. Moreover, the time stability and reliability are also examined, respectively.
Min Liu, Wending Zhang, Fanfan Lu, Tianyang Xue, Xin Li, Lu Zhang, Dong Mao, Ligang Huang, Feng Gao, Ting Mei, Jianlin Zhao. Plasmonic tip internally excited via an azimuthal vector beam for surface enhanced Raman spectroscopy[J]. Photonics Research, 2019, 7(5): 05000526.