title: Experimental characterization of a silicon photonic biosensor consisting of two cascaded ring resonators based on the Vernier-effect and introduction of a curve fitting method for an improved detection limit.
abstract: We studied a refractive index sensor that consists of two cascaded ring resonators and that works analogously to a Vernier-scale. We implemented it in silicon-on-insulator and experimentally determined its sensitivity to be as high as 2169 nm/RIU in aqueous environment. We derived formulas describing the sensor's operation, and introduced a fitting procedure that allows to accurately detect changes in the sensor response. We determined the detection limit of this first prototype to be 8.310(-6)RIU.
authors.affiliation: Photonics Research Group, Department of Information Technology Ghent University - imec, Sint-Pietersnieuwstraat 41, 9000 Gent, Belgium. tom.claes@intec.ugent.be
authors.forename: Tom
authors.initials: T
authors.lastname: Claes
authors.forename: Wim
authors.initials: W
authors.lastname: Bogaerts
authors.forename: Peter
authors.initials: P
authors.lastname: Bienstman
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods*; D057230:Limit of Detection; D017785:Photons; D012031:Refractometry; D012825:Silicon / Q000737:chemistry*; D013057:Spectrum Analysis
chemical_list: D012825:Silicon