Method of making optical fiber preform with pressed soot

Patent metadata

Field	Value
Publication number	US-10407337-B2
Application number	US-201715631808-A
Country	US
Kind code	B2
Filing date	Jun 23, 2017
Priority date	Jun 30, 2016
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

According to some embodiments method for making an optical fiber preform comprises the steps of: (i) placing a plurality of rods with an outer surface having a coefficient of friction 0.02≤COF≤0.3 into an inner cavity of an apparatus; (ii) placing particulate glass material in the inner cavity between the rods and an inner wall of the mold cavity; and (iii) applying pressure against the particulate glass material to press the particulate glass material against the plurality of rods.

First claim

What is claimed is:

1. A method for forming an optical fiber preform comprising the steps of:
(I) placing a plurality of rods into a mold cavity of an apparatus, wherein at least one of the plurality of rods is a metal or ceramic rod having a coating, the coating comprising at least one of: amorphous silicon (a-silicon), xylan flouropolymer, composites of xylan with other polymers, molydisulfide (molybdenum disulfide), tungsten disulfide, electroless nickel infused with Teflon, nickel infused with SiC;
(II) placing particulate glass material in the mold cavity between the rods and an inner wall of the mold cavity; and
(Ill) applying pressure against the particulate glass material to press the particulate glass material against the plurality of rods.

2. The method of claim 1 , wherein at least one of the plurality of rods has an outer surface with a coefficient of friction COF ≤0.3.

3. The method of claim 2 , wherein at least one of the plurality of rods has an outer surface with a coefficient of friction COF ≤0.15.

4. The method of claim 2 , wherein at least one of the plurality of rods has an outer surface with a coefficient of friction COF ≤0.1.

5. The method of claim 2 , wherein at least two of the plurality of rods are graphite rods, and wherein at least one of the plurality of rods is a core cane situated therebetween.

6. The method for making an optical fiber preform according to claim 1 , wherein the pressure is applied at least radially inwards against the particulate glass material to pressurize the particulate glass material against the plurality of rods.

7. The method of claim 1 , wherein prior to the step of applying pressure against the particulate glass material, the particulate glass material has an average density of from 0.1 to 0.5 grams per cubic centimeter and wherein subsequent to the step of applying pressure against the particulate glass material, the pressed particulate glass material has a density of from 0.6 to 1.2 grams per cubic centimeter.

8. The method of claim 1 , wherein the step of applying pressure against the particulate glass material comprises the step of applying radial pressure, and wherein prior to the step of applying pressure against the particulate glass material, the particulate glass material has an average density of from 0.1 to 0.5 grams per cubic centimeter and wherein subsequent to the step of applying a radial pressure against the particulate glass material, the pressed particulate glass material has a density of from 0.6 to 1.2 grams per cubic centimeter.

9. A method for making an optical fiber preform comprising the steps of:
placing a plurality of rods into a mold cavity of an apparatus, wherein at least two of the plurality of rods comprise an outer surface comprising at least one of the following coatings: amorphous silicon (a-silicon), Teflon, xylan flouropolymer, composites of xylan with other polymers, molydisulfide (molybdenum disulfide), tungsten disulfide, electroless nickel infused with Teflon, nickel infused with SiC;
placing particulate glass material in the mold cavity between the rods and an inner wall of the mold cavity; and
applying pressure against the particulate glass material to press the particulate glass material against the plurality of rods.

10. The method of claim 9 , wherein 0.05≤COF ≤0.3.

11. The method for making an optical fiber preform according to claim 9 , wherein the pressure is applied at least radially inwards against the particulate glass material to press the particulate glass material against the plurality of rods.

12. The method for making an optical fiber preform according to claim 9 , wherein the plurality of rods comprises: (i) at least one glass rod; and (ii) at least two mold rods; and said pressure is applied axially and/or radially.

13. The method for making an optical fiber preform according to claim 9 , wherein the apparatus comprises an outer wall, the outer wall surrounding the inner wall; the pressure is applied at least radially inwards, and the pressure has a magnitude from 25 psig to 250 psig.

14. The method of claim 9 , wherein at least one of the plurality of rods is a core cane situated along the axial center of the mold cavity.

15. The method of claim 9 , wherein at least one of the plurality of rods comprises a consolidated core cane surrounded by a porous soot clad layer and the core cane is situated along the axial center of said mold cavity.

16. The method of claim 9 , wherein prior to the step of applying a radial pressure against the particulate glass material, the particulate glass material has an average density of from 0.1 to 0.5 grams per cubic centimeter and wherein subsequent to the step of applying a radial pressure against the particulate glass material, the pressed particulate glass material has a density of from 0.6 to 1.2 grams per cubic centimeter.

17. The method of claim 9 wherein the plurality of rods are arranged co-linearly within the mold cavity.

18. A method of making an optical fiber, the method comprising the steps of:
(I) placing a plurality of rods into a mold cavity of an apparatus, wherein at least one of the plurality of rods is a metal or ceramic rod having a coating thereon, the coating comprising at least one of: amorphous silicon coating (a-silicon), xylan flouropolymer, composites of xylan with other polymers, molydisulfide (molybdenum disulfide), tungsten disulfide, electroless nickel infused with Teflon, nickel infused with SiC;
(II) placing particulate glass material in the mold cavity between the rods and inner wall of the mold cavity;
(Ill) forming a soot compact by applying pressure against the particulate glass material to press the particulate glass material against the plurality of rods;
(IV) removing the least one of said plurality of rods from the soot compact, thereby to format least one void within the soot compact;
(V) forming an optical fiber preform assembly by inserting at least one glass rod into the at least one void;
(VI) forming the optical fiber preform by sintering the optical fiber preform; and
(VII) drawing an optical fiber from the optical fiber preform.

19. A method of making an optical fiber, the method comprising the steps of:
(I) placing a plurality of rods into a mold cavity of an apparatus, wherein at least two of the plurality of rods comprise an outer surface comprising at least one of the following coatings: amorphous silicon (a-silicon), Teflon, xylan flouropolymer, composites of xylan with other polymers, molydisulfide (molybdenum disulfide), tungsten disulfide, electroless nickel infused with Teflon, nickel infused with SiC, wherein the outer surface has a coefficient of friction COF, and 0.02≤COF≤0.3;
(II) placing particulate glass material in the mold cavity between the rods and an the inner wall of the mold cavity;
(III) forming a soot compact by applying pressure against the particulate glass material to press the particulate glass material against the plurality of rods, and;
(IV) removing at least two of the plurality of rods from the soot compact to form at least two voids within the soot compact;
(V) forming an optical fiber preform assembly by inserting at glass rods into said voids;
(VI) forming the optical fiber preform by sintering the optical fiber preform assembly; and
(VII) drawing an optical fiber from the optical fiber preform.

20. A method of making an optical fiber, the method comprising the steps of:
(I) placing a plurality of rods into a mold cavity of an apparatus, wherein at least two of the plurality

Assignees

• Corning Inc

Inventors

• Boughton Daniel Robert
• Fagan James Gerard
• Hubbard Jr Larry Gleason
• Wang Ji

Classifications

• C03B2203/14

  Non-solid, i.e. hollow products, e.g. hollow clad or with core-clad interface · CPC title

• C03B37/01282

  by pressing or sintering, e.g. hot-pressing · CPC title

• C03B37/01222

  for making preforms of multiple core optical fibres (preforms of multifibres C03B37/01214) · CPC title

• C03B2203/30

  Polarisation maintaining [PM], i.e. birefringent products, e.g. with elliptical core, by use of stress rods, "PANDA" type fibres · CPC title

• C03B37/01217 Primary

  for making preforms of polarisation-maintaining optical fibres (polarisation-maintaining optical fibres per se G02B6/105) · CPC title