Method of and device for fabricating optical-fibre preforms.

摘要

The diameter of the supporting-tube of the preform (TQ) can be kept constant by this method, notwithstanding the tube tendency to collapse owing to the high-temperature necessary to reactant synthesis reaction and raw-material deposition.
<??>The diameter is controlled by generating between the internal and the external tube surface a pressure difference variable in a way inversely proportional to the diameter of the tube itself and to the total gas flow at the input.
<??>The device (GP) allows the generation of the required pressure loss at the output and the separation of raw-material solid particles from residual gases.