DETECTION OF STRESS APPLIED TO AN OPTICAL FIBER

摘要

Shocks or sudden stresses caused by attempts to tap into an optical fibre network are detected by monitoring the "speckle pattern" produced by intermodal interference at the output of a multimode fibre (2). The fibre is a single mode optical fibre communication link through which a monitoring beam having a wavelength at which the fibre supports multiple propagation modes is also transmitted.