REVERSE SYMMETRY WAVEGUIDE FOR OPTICAL BIOSENSING

摘要

An optical waveguide sensor comprises a substrate material (208), having a refractive index n>s<, 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 n>F<, and a cover material (210) over the waveguide having a refractive index n>c<, 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 n>F< > n>S< > and n>F< > n>C< and n>C< > n>S<, and n>C< < 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.