Patent ID: 8682115
Filing Date: 2014-03-25
Classification: G01N

Abstract:
1. An optical sensor for detecting a substance, the optical sensor comprising: a first waveguide; a second waveguide optically coupled to the first waveguide within a coupling path, thereby forming a directional coupler between the first waveguide and the second waveguide; and a functional surface near the directional coupler that is configured to accumulate or store a substance to be detected such that an intensity of a coupling between the first waveguide and the second waveguide can be changed by the substance accumulated or stored on the functional surface; wherein the first waveguide is guided in a vicinity of the coupling path such that a spacing between the first waveguide and the second waveguide is changeable there by a deformation or movement of the first waveguide or of a carrier of the first waveguide, and wherein at least the first waveguide extends in a freely floating manner over the coupling path covered by the directional coupler or rests there only on a swellable material absorbing the substance.