Reverse symmetry waveguide for optical biosensing

摘要

An optical waveguide sensor comprises a substrate material (208), having a refractive index ns, typically an air containing groove (208) in the surface of a polymer structural substrate (205), an optical waveguide film (207) on the substrate material having a refractive index nF, and a cover material (210) over the waveguide having a refractive index nc, a light source (204) optically coupled to said waveguide, and a detector (209) for detecting evanescent wave interaction between said light and said cover material, wherein nF nS and nF nC and nC nS, and nC 1.45. The low refractive index of the substrate enables sensing of material in the cover further from the waveguide than would conventionally be possible.