| 摘要 |
The sensor comprises an optical waveguide layer (4) between an emitter (1) and receiver (2). Overall transmissivity is altered by concentration variation. The layer includes coupling areas (5,6) for light entry and exit, spaced along its path. Light entering is contained and propagated by multiple total internal reflection in the layer, leaving at the exit coupling (6). It is detected by the receiver. Preferred Features: The waveguide layer transmission characteristics vary with changes in concentrations of ions, atoms and/or molecules. The refractive index is altered. There is a main (e.g. thick) layer. On the surface away from the emitter, there is an (e.g. thin) sensor layer. Transmission characteristics of this layer, especially refractive index, are altered by concentration. The sensor layer changes in reflectivity on concentration changes. The side of the layer opposite the medium being monitored (3) is made reflective. The sensor has a casing and an appropriately-configured opaque body (15). Its sensor recesses (16,17) are filled by transparent material and overlapped by the optical waveguide layer. Where not overlapped, the transparent material is given an opaque covering (19). The emitter is a semiconductor diode chip, the receiver a photosensor semiconductor chip. The main body, injected recess fillings and covers are diverse, transparent and opaque plastics. Electrical connections are made through the casing.
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