title: Experimental Validation of the Sensitivity of Waveguide Grating Based Refractometric (Bio)sensors.
abstract: Despite the fact that the theoretical foundations of the sensitivity of waveguide grating based (bio)sensors are well-known, understood and their implications anticipated by the scientific community since several decades, to our knowledge, no prior publication has experimentally confirmed waveguide sensitivity for multiple film thicknesses, wavelengths and polarization of the propagating light. In this paper, the bulk refractive index sensitivity versus waveguide thickness of said refractometric sensors is experimentally determined and compared with predictions based on established theory. The effective refractive indices and the corresponding sensitivity were determined via the sensors' coupling angles at different cover refractive indices for transverse electric as well as transverse magnetic polarized illumination at various wavelengths in the visible and near-infrared. The theoretical sensitivity was calculated by solving the mode equation for a three layer waveguide.
authors: CSEM Centre Suisse d'Electronique et de Microtechnique SA, Bahnhofstrasse 1, Landquart CH-7302, Switzerland. thomas.gartmann@csem.ch.
authors: Thomas E
authors: TE
authors: Gartmann
authors: CSEM Centre Suisse d'Electronique et de Microtechnique SA, Bahnhofstrasse 1, Landquart CH-7302, Switzerland. kehl@biomed.ee.ethz.ch.|Laboratory of Biosensors and Bioelectronics (LBB), Swiss Federal Institute of Technology ETH, Gloriastrasse 35, Zürich CH-8092, Switzerland. kehl@biomed.ee.ethz.ch.|Optics Balzers AG, Neugrüt 35, Balzers FL-9496, Liechtenstein. kehl@biomed.ee.ethz.ch.
authors: Florian
authors: F
authors: Kehl
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D008962:Models, Theoretical; D055096:Optical Devices; D055620:Optical Phenomena; D012031:Refractometry / Q000295:instrumentation*