OPTICAL SENSOR FOR DETECTING CHEMICAL SUBSTRATE

摘要

PURPOSE:To measure the degree of attenuation of light in a specific mode in an optical waveguide by constituting an optical sensor with a planar-shaped optical waveguide containing a thin film for waveguide and a coupler for incidence light and that for emission light provided on the optical waveguide. CONSTITUTION:Light from a light source 1 is guided within a thin film 2 for waveguide and is combined again by a prism coupler 4 when it is emitted and then emitted light intensity is measured by a photo detector 5. A chemical substance to be detected passes above the thin film 2, waveguide characteristics of the thin film 2 change, thus changing the emitted light intensity and hence detecting the change using the detector 5 and determining whether a chemical substance to be detected exists in a gas or a liquid or not.