| 摘要 |
<p>A micro-optical method and a corresponding sensor for detecting chemical substances in a sample. The sample is brought into contact with the waveguiding layer of an optical planar waveguide. Coherent light is coupled into the waveguiding layer, guided therein as a light wave, and the latter is coupled out once again from the layer. Coupling in and out of the light wave guided in the layer waveguide is performed with the aid of a multidiffraction grating coupler located in the plane of the layer, that is to say a grating structure whose frequency spectrum has a plurality of fundamental components. The multidiffractive grating coupler causes a directional separation of coupled-out light from reflected, transmitted, or directly deflected partial beams. This enables light guided in the waveguiding layer to be detected free of background after coupling out, although the regions on the waveguiding layer in which the coupling in and out of the guided light wave take place partially overlap.</p> |
