摘要 |
<p>An optical sensor 300 for sensing a measurand. The sensor comprises an optical waveguide with a D-shaped portion 10 having a D-shaped cross-section. The property of the D-shaped portion changes in response to a measurand which may be a strain, heat, electric field, magnetic field, or a response to a chemical. A layer 302 may be disposed on the flat surface of the D-shaped portion wherein the layer is sensitive to the measurand. The layer may strain the D-shaped portion in response to a change in the measurand or the refractive index of the layer may change in response to the measurand. A strain may also cause a change of polarisation of light propagating the waveguide. The sensor may be formed of two D-shaped portions (510, 511, fig. 5) and a thickness-changing layer (501, fig. 5) disposed between them. The D-shaped portions may have plurality of cores (612, 613, 614, 615 fig. 6).</p> |