Plasma Deposition Process with Removal of Substrate Tube

摘要

The present invention relates to a method of removing a substrate tube from the deposited layer inside of said substrate tube. In other words, the present invention relates to a method for manufacturing a precursor for a primary preform for optical fibres by means of an internal plasma deposition process, which method comprises the steps of providing a hollow substrate tube; creating a first plasma reaction zone having first reaction conditions in the interior of said hollow substrate tube by means of electromagnetic radiation for effecting the deposition of non-vitrified silica layers on the inner surface of said hollow substrate tube, and subsequently creating a second plasma reaction zone having second reaction conditions in the interior of said hollow substrate tube by means of electromagnetic radiation for effecting the deposition of vitrified silica layers on the non-vitrified silica layers deposited in the previous step; and removing the hollow substrate tube from the vitrified silica layers and the non-vitrified silica layers to obtain a deposited tube.

主权项

1. A method for manufacturing a precursor for a primary preform for optical fibres by means of an internal plasma deposition process, which method comprises the steps of:
i) providing a hollow substrate tube; ii) creating a first plasma reaction zone having first reaction conditions in the interior of said hollow substrate tube by means of electromagnetic radiation for effecting the deposition of non-vitrified silica layers on the inner surface of said hollow substrate tube, and subsequently; iii) creating a second plasma reaction zone having second reaction conditions in the interior of said hollow substrate tube by means of electromagnetic radiation for effecting the deposition of vitrified silica layers on the non-vitrified silica layers deposited in step ii); iv) removing the hollow substrate tube from the vitrified silica layers deposited in step iii) and the non-vitrified silica layers deposited in step ii) to obtain a deposited tube.