摘要 |
<p>A sensor includes a waveguide path (1) in which interrupts (3) are arranged at a plurality of places. At the interrupts the ends of the waveguide path can be simultaneously moved in relation to each other. The attenuation of light, injected from a light source (7) and propagating along the waveguide path, produced by the movement, is measured by a detector (9). Even if the movement at the interrupts is very small it can be measured due to the multiplying effect obtained by the fact that a plurality of interrupts are arranged. The waveguide path can be an optical fiber wound in large number of turns in a spiral or helical shape or so that it forms a coil.</p> |