| 摘要 |
A device for manufacturing an optical preform by means of an internal vapour deposition process, the device comprising an energy source and a hollow substrate tube, which hollow substrate tube has a supply side and a discharge side, the energy source being moveable along a length of the hollow substrate tube, the device further comprising an elongation tube connected to the hollow substrate tube at the discharge side thereof wherein the hollow substrate tube extends into an interior of the elongation tube and in that an internal diameter of the elongation tube is at least 0,5 millimeter larger than an external diameter of the hollow substrate tube. |
