title: Evanescent-wave excitation of surface-enhanced Raman scattering substrates by an optical-fiber taper.
abstract: We present a way of guiding light to planar surface-enhanced Raman scattering (SERS) substrates by using evanescent-wave coupling. Using nanostructured chalcogenide glass-based SERS substrates, we experimentally show the incident-angle dependence of plasmon resonances of the SERS substrates, demonstrating strong resonances at large incident angles. This allows the evanescent-wave excitation of SERS substrates through tapered optical fibers. Experiments show that fiber-taper-excited SERS substrates exhibit a significant enhancement of the Raman spectra of Rhodamine-6G analyte molecules. This configuration forms the basis of fiber-optic-based, reproducible, highly compact, and sensitive SERS systems.
authors.affiliation: Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK. ls431@cam.ac.uk
authors.forename: Lei
authors.initials: L
authors.lastname: Su
authors.forename: T H
authors.initials: TH
authors.lastname: Lee
authors.forename: S R
authors.initials: SR
authors.lastname: Elliott
mesh_terms: D018011:Chalcogens / Q000737:chemistry; D005336:Fiber Optic Technology; D005898:Glass; D008027:Light; D008855:Microscopy, Electron, Scanning / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry; D055095:Optics and Photonics; D012235:Rhodamines / Q000494:pharmacology; D012542:Scattering, Radiation; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013059:Spectrum Analysis, Raman / Q000379:methods*; D020349:Surface Plasmon Resonance / Q000379:methods
chemical_list: D018011:Chalcogens; D012235:Rhodamines; C026188:rhodamine 6G