Plasma deposition process with removal of substrate tube

Patent metadata

Field	Value
Publication number	US-9816179-B2
Application number	US-201514985961-A
Country	US
Kind code	B2
Filing date	Dec 31, 2015
Priority date	Jul 1, 2013
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

Disclosed are methods for manufacturing a precursor for a primary preform for optical fibers via an internal plasma deposition process. An exemplary method includes creating a first plasma reaction zone having first reaction conditions in the interior of a hollow substrate tube to deposit non-vitrified silica layers on the inner surface of the hollow substrate tube, and subsequently creating a second plasma reaction zone having second reaction conditions in the interior of the hollow substrate tube to deposit vitrified silica layers on the deposited, non-vitrified silica layers. Thereafter, the hollow substrate tube is removed from the deposited, vitrified silica layers to yield a deposited tube.

First claim

The invention claimed is:

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

2. The method according to claim 1 , wherein step iii) comprises depositing doped vitrified silica layers on the non-vitrified silica layers deposited in step ii).

3. The method according to claim 2 , wherein the doped vitrified silica layers correspond to depressed-trench layers.

4. The method according to claim 2 , wherein the doped vitrified silica layers correspond to cladding layers.

5. The method according to claim 2 , wherein the doped vitrified silica layers correspond to core layers.

6. The method according to claim 1 , wherein step iii) comprises depositing doped and undoped vitrified silica layers on the non-vitrified silica layers deposited in step ii).

7. The method according to claim 1 , wherein step iv) comprises removing the non-vitrified silica layers deposited in step ii) from the vitrified silica layers deposited in step iii).

8. A method for manufacturing a precursor for a primary preform for trench-assisted, bend-insensitive optical fibers via an internal plasma deposition process, the method comprising the following steps:
i) providing a hollow substrate tube;
ii) creating a first plasma reaction zone having first reaction conditions in the interior of the hollow substrate tube by means of electromagnetic radiation to deposit non-vitrified silica layers on the inner surface of the hollow substrate tube;
iii) creating a second plasma reaction zone having second reaction conditions in the interior of the hollow substrate tube by means of electromagnetic radiation to deposit doped vitrified silica layers on the non-vitrified silica layers deposited in step ii), wherein the doped vitrified silica layers comprise depressed-trench layers; and
iv) removing the hollow substrate tube from the vitrified silica layers deposited in step iii) to obtain a deposited tube.

9. The method according to claim 8 , comprising an additional step v) of collapsing the deposited tube obtained in step iv) form a primary preform.

10. The method according to claim 9 , comprising an additional step vi) of externally providing the primary preform of step v) with an additional amount of glass.

11. The method according to claim 8 , comprising an additional step vi) of externally providing the deposited tube of step iv) with an additional amount of glass.

12. The method according to claim 8 , comprising the subsequent step of creating a plasma reaction zone having reaction conditions in the interior of the deposited tube by means of electromagnetic radiation to deposit vitrified silica layers on the inner surface of the deposited tube.

13. The method according to claim 8 , wherein the pressure of the first reaction conditions is between 30 millibar and 1000 millibar.

14. The method according to claim 8 , wherein the pressure of the second reaction conditions is between 1 and 25 millibar.

15. The method according to claim 8 , wherein hollow substrate tube provided in step i) is a non-quartz substrate tube.

16. The method according to claim 8 , wherein the total thickness of the non-vitrified silica layers deposited in step ii) is between 1 and 1000 micrometers.

17. The method according to claim 1 , comprising the subsequent step of creating a plasma reaction zone having reaction conditions in the interior of the deposited tube by means of electromagnetic radiation to deposit vitrified silica layers on the inner surface of the deposited tube.

18. The method according to claim 1 , wherein the pressure of the first reaction conditions is between 30 millibar and 1000 millibar.

19. The method according to claim 1 , wherein the pressure of the second reaction conditions is between 1 and 25 millibar.

20. The method according to claim 1 , wherein hollow substrate tube provided in step i) is a non-quartz substrate tube.

Assignees

• Draka Comteq Bv
• Draka Comteq Bv

Inventors

• Milicevic Igor
• Hartsuiker Johannes Antoon
• Van Stralen Mattheus Jacobus Nicolaas
• Krabshuis Gertjan

Classifications

• C23C16/01 Primary

  on temporary substrates, e.g. substrates subsequently removed by etching · CPC title

• C23C16/402

  Silicon dioxide · CPC title

• C03B37/0183 Primary

  for plasma within a tube substrate · CPC title

• C03B37/018 Primary

  by glass deposition on a glass substrate, e.g. by {inside-, modified-, plasma- or plasma modified-} chemical vapour deposition {[ICVD, MCVD, PCVD, PMCVD], i.e. by thin layer coating on the inside or outside of a glass tube or on a glass rod} (C03B37/016 takes precedence; surface treatment of glass by coating with glass C03C17/02) · CPC title