Integrated optical sensor detecting change of refractive index - has monomode waveguide in substrate of optically transparent material

摘要

The waveguide (14) extends along the surface (24) of the substrate between two end faces (18, 19). A side housing boundary surface of the waveguide can be brought into contact with a measuring fluid. A coupling surface (16) can receive a light beam (82). A light detector (69), receives a measuring signal (73) by reflection or transmission from a corresp. coupling surface (17). The waveguide is double refractive. The incident light beam (82) can be linearly polarised and shifted in phase w.r.t. the optical axis (52) by a set angle by a polariser (70) in the plane of the end face (18). The light beam (73) penetrating the coupling surfaces (16 or 17) can be similarly polarised and phase shifted by a second polariser (71). ADVANTAGE - Highly sensitive with min. dependence on temp.