Plasmonic structure on a tapered optical fiber for application as a surface‐enhanced Raman spectroscopy substrate

Abstract

AbstractA plasmonic structure using gold nanorods (GNRs) on the surface of a tapered fiber was developed. The structure was used to study the Raman spectra of Rhodamine 6G (R6G) and zinc oxide (ZnO) adsorbed on the tapered optical fiber covered with the GNRs, respectively. The tapered optical fiber was manufactured by a dynamic etching process. The tapered fiber had a tip diameter in the nanometer range. The optical tweezing phenomenon was used to develop the plasmonic structure along the length of the tapered fiber surface. The density of GNRs varied as the diameter of the fiber in the tapered region changed. Raman spectra for R6G and ZnO were recorded and analyzed at different fiber locations with and without GNRs. We could obtain the SERS spectrum of a R6G solution of concentration 10−7 M using the developed substrate.