Methods for forming an overclad portion of an optical fiber from pelletized glass soot
AssigneeCorning Incorporated
InventorsRobert Brett Desorcie, Peter Joseph Ronco, Roger A. Rose, Pushkar Tandon
Life of this patent
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Abstract
Methods of forming an overclad portion of an optical fiber are described which include positioning a core cane member in an overclad tube to form a rod and tube assembly. Thereafter, glass soot pellets are positioned in the rod and tube assembly between the core cane member and an interior sidewall of the overclad tube. The rod and tube assembly is then redrawn under conditions effective to form the overclad tube and the glass soot pellets into a continuous, void-free glass layer surrounding the core cane member at a sintering time tsinter of at least 1800 seconds thereby forming an overclad portion of an optical fiber.
Claims14
A method of forming an overclad portion of an optical fiber comprising:
- forming a pelletized glass soot containing rod and tube assembly by positioning a core cane member in an overclad tube and positioning pelletized glass soot between the core cane member and an interior sidewall of the overclad tube, the pelletized glass soot comprising pellets having an average equivalent spherical diameter DP of at least 2.0 mm and formed from glass soot particles bound with a binder;
- and
- redrawing the pelletized glass soot containing rod and tube assembly under conditions effective to form the overclad tube and the pelletized glass soot into a glass layer surrounding the core cane member at a sintering time tsinter of at least 1800 seconds thereby forming an overclad portion of an optical fiber;
- and wherein the rod and tube assembly comprises gas or air in pores between pelletized glass soot and is redrawn at a redraw temperature Tredraw, that is above the softening point of the pelletized glass soot, and wherein the average equivalent spherical diameter DP, the sintering time tsinter, and the redraw temperature Tredraw satisfy the equation:
- t
- sinter
- ≥
- 2.5
-
- μ
-
-
- D
- p
- σ
- ,
- wherein:
- μ is a viscosity of the pelletized glass soot as a function of the redraw temperature Tredraw;
- and
- σ is a surface tension of the pelletized glass soot as a function of the redraw temperature Tredraw;
- and wherein a sintering rate of the pelletized glass soot containing rod and tube assembly is controlled based on the rate of escape of the gas or air in pores between pelletized glass soot before closure of the pores.
A method of forming an overclad portion of an optical fiber comprising:
- forming a pelletized glass soot containing rod and tube assembly by positioning a core cane member in an overclad tube and positioning pelletized glass soot between the core cane member and an interior sidewall of the overclad tube, wherein the pelletized glass soot comprises pellets with an average equivalent spherical diameter DP of at least 2.0 mm and formed from glass soot particles bound with a binder, wherein the rod and tube assembly comprises gas or air in pores between pelletized glass soot;
- and
- redrawing the pelletized glass soot containing rod and tube assembly at a sintering time tsinter of at least 1800 seconds at a redraw temperature Tredraw of at least 1700° C. such that the overclad tube and the pelletized glass soot form a continuous, void-free glass layer surrounding the core cane member;
- and wherein the average equivalent spherical diameter DP, the sintering time tsinter, and the redraw temperature Tredraw, satisfy the equation:
- t
- sinter
- ≥
- 2.5
-
- μ
-
-
- D
- p
- σ
- ,
- wherein:
- μ is a viscosity of the pelletized glass soot as a function of the redraw temperature Tredraw;
- and
- σ is a surface tension of the pelletized glass soot as a function of the redraw temperature Tredraw;
- and wherein a sintering rate of the pelletized glass soot containing rod and tube assembly is controlled based on the rate of escape of the gas or air in pores between pelletized glass soot before closure of the pores.
Dependencies are inferred from the claim text.