Processes and devices for manufacturing optical fibres comprising periodic perturbations and optical fibres thus obtained

摘要

A device according to the invention comprises, in a known manner, a plunger 3 which is integrally attached to a nut 6 mounted on an endless screw 4 and which travels forward at constant speed pushing a tubular silica preform 1 towards a vertical melting furnace 2. Molten silica is drawn in the shape of a filament 7 which is wound onto a drum 8 driven by a motor 9. A device according to the invention comprises a piezoelectric component 14 which is inserted between the plunger 3 and the preform 1 and a source of sinusoidal voltage 15 which is connected to the electrodes of the piezoelectric component so that the rate of drawing of the fibre 7 is modulated periodically about an average rate. One application is the manufacture of optical fibres. IMAGE