title: Horizontal slot waveguide channel for enhanced Raman scattering.
abstract: Herein we characterize and experimentally demonstrate a new type of a horizontal slot waveguide structure for remarkably enhanced Raman scattering detection in nanometer-scale void channels. As the measurement sensitivity is one of the key limiting factors in nanofluidic detection, it is essential to search advanced solutions for such detection. Combining an all dielectric resonance waveguide grating and a surface enhanced Raman scattering (SERS) substrate in a close proximity it is possible to create high electromagnetic field energy hot zones within an adjustable slot region. This results in a strong enhancement in Raman scattering. We show the theoretical principles and demonstrate, with rhodamine 6G molecules, an approximately 20-fold enhancement compared to a conventional SERS substrate within the corresponding slot arrangement. We foresee potential applications for the proposed approach in the fields of medical, biological and chemical sensing, where the high detection sensitivity is essential due to integration with nanofluidic devices.
authors.affiliation: University of Eastern Finland, Department of Physics and Mathematics, P.O. Box 111, 80101 Joensuu, Finland. jussi.rahomaki@uef.fi
authors.forename: Jussi
authors.initials: J
authors.lastname: Rahomäki
authors.forename: Tarmo
authors.initials: T
authors.lastname: Nuutinen
authors.forename: Lasse
authors.initials: L
authors.lastname: Karvonen
authors.forename: Seppo
authors.initials: S
authors.lastname: Honkanen
authors.forename: Pasi
authors.initials: P
authors.lastname: Vahimaa
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D036103:Nanotechnology / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*