Multimode reverse-symmetry waveguide sensor for broad-range refractometry.
A sensor design that uses a grating-coupled multimode planar optical waveguide for absolute detection of the refractive indices of liquids or gases is presented. The waveguide consists of a simple 50-microm-thick, free-standing glass plate with air beneath it and the sample to be analyzed on top of it. This design offers a simple alternative to the well-known monomode waveguides, and, owing to its so-called reverse-symmetry configuration, a large detection range can be obtained.
Skivesen
Nina
N
Optics and Fluid Dynamics Department, Risø National Laboratory, DK-4000 Roskilde, Denmark. nina.skivesen@risoe.dk
Horvath
Robert
R
Pedersen
Henrik C
HC