Method for checking the correct installation of a. bend-insensitive optical cable and optical cable suitable for the method thereof

摘要

A method for detecting faulty laying down of an optical cable exhibiting a measured cut-off wavelength is described. The method comprises: providing an optical cable for transmitting optical signals including at least one single-mode optical fibre having an attenuation equal to or larger than a first threshold value as measured when wound for one turn around a bending radius equal to or smaller than 5 mm at at least one predetermined test wavelength, the test wavelength being smaller than the measured cut-off wavelength, and an attenuation smaller than a second threshold value as measured when wound for one turn around a bending radius equal to at least a minimum bending radius at an operative wavelength equal to or larger than the measured cut-off wavelength; laying the optical cable, and measuring the attenuation in the at least one optical fibre at the predetermined test wavelength. An optical cable is also described which exhibits single-mode transmission and is bend- insensitive at wavelengths equal to or higher than a measured cut-off wavelength after propagation over a cable length. Preferably, the measured cut-off wavelength is 1260 nm. The optical cable comprises at least one optical fibre that is bend sensitive at a predetermined test wavelength not larger than the measured cut-off wavelength and is bend insensitive at an operative wavelength larger than the measured cut-off wavelength, where the cable operates in single-mode regime.