Method for creating an overlength of optical fibres in a metallic protection tube and adapted production device

摘要

The method involves forming a metal strip into a tube, and then welding the sides of the tube in a sealed manner. At least one length of optical fibre is introduced into the tube, with a surplus length of fibre provided at the ends. The welded and drawn tube is subject to an ultimate stretching to a predetermined value by advancing each optical fibre in the tube at the linear drawing speed of the tube, then relaxing the drawing of the tube to obtain the desired surplus length of the fibre equal to the predetermined value in the relaxed tube.