| 摘要 |
A strain sensor comprises an optical waveguide having a plurality of reflecting structure (Bragg grating) along its length. Each structure reflects light at a different characteristic wavelength (lambda1 to lambdan+1) which changes in dependence on a change of physical length of at least part of the reflecting structure. The reflectivity of reflecting structures which reflect at characteristic wavelengths which are adjacent to each other (lambda1 and lambda2 or lambdan and lambdan+1) are configured to be different such that the intensity of light reflected from adjacent structures can be used to discriminate between them. |
