Monitoring and protection device for optical-fibre cables (fibre-optic cables)

• Main Authors: ONKELS, ECKEHARD., 6141 EINHAUSEN, DE, RUEHL, FALK., 5106 ROETGEN, DE
• Format: Patent
• Language: English; German
• Published: 03.11.1994
• Edition: 5
• Subjects: MEASURING; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; TESTING; TESTING STATIC OR DYNAMIC BALANCE OF MACHINES ORSTRUCTURES; TESTING STRUCTURES OR APPARATUS NOT OTHERWISE PROVIDED FOR

The subject-matter of the invention is a monitoring and protection device for optical-fibre cables which detects energy leakage from an optical-fibre cable or from an optical fibre as a result of an interference. Damage to the optical-fibre cable occurs by uncontrolled coupling-out (detection) of the laser beams at interference points of the optical fibres, for example due to the bending radius dropping slightly below the permissible value. In the device according to the invention, the optical-fibre cable is designed in such a manner that it has one or more optical fibres with in each case one or more fibre coatings (layers), in the case of which device at least one fibre coating is provided for transmitting radiation power (radiant power), and that the lost radiation leaking from the fibre coating or coatings transmitting the radiation power is coupled into a second fibre coating by means of elastic or inelastic diffusion (conversion) and is guided to a detector. The conversion of the lost radiation is in this case performed by a suitable preparation of the secondary coatings, for example by enriching it with diffusers, dyes or scintillators. In the simplest case the optical-fibre cable is surrounded by a protective sheath which is filled with a liquid or a gel-like dye or scintillator carrier. The device according to the invention has the advantage that an interference of the optical-fibre cable is recognised at an early stage, so that severe damage or total destruction of the optical waveguides by power reduction or switching off of ... Original abstract incomplete.