Method for optical fiber fabrication including deuterium/hydrogen exchange

Claim 2

Method for fabrication of an optical fiber preform comprising silica-based glassy material, the method comprising (a) chemically reacting at least some of the constituents of a moving stream of gas mixture comprising at least one glass-forming precursor compound and an oxidizing medium, the reaction resulting in the formation of a glassy silica-based reaction product, (b) forming a body by depositing at least a part of the reaction product on a substrate, at least part of the material of the body containing hydrogen bonded to oxygen, and (c) consolidating at least part of the deposited product by means of a hot zone produced by a heat source external to the body, characterized in that the method further comprises (d) replacing at least part of the hydrogen bonded to oxygen with deuterium in a deuterium/hydrogen exchange step carried out subsequent to step (b).

Claim 3

Method of claim 1, wherein step (d) comprises (a) contacting at least a part of the body with an atmosphere having a partial pressure of at least about 10 Torr of deuterium, and (b) maintaining at least substantially the part of the body at a temperature greater than about 300 degrees C.

Claim 4

Method for fabrication of an optical fiber preform comprising glassy silica-based material, the method comprising (a) forming a tubular body by depositing silica-based glassy material in substantially porous, unconsolidated form on the inside surface of a tube comprising silica, at least part of the material of the tubular body containing hydrogen bonded to oxygen, and (b) consolidating the deposited material by means of a hot zone produced by a heat source external to the tube, characterized in that the method further comprises (c) replacing at least part of the hydrogen bonded to oxygen with deuterium in a deuterium/hydrogen exchange step carried out sbsequent to step (a).

Claim 5

Method for fabrication of an optical fiber preform comprising glassy silica-based material, the method comprising (a) forming a tubular body by depositing silica-based glassy material in substantially porous, unconsolidated form on the inside surface of a tube comprising silica, at least part of the material of the tubular body containing hydrogen bonded to oxygen, and (b) consolidating the deposited material by means of a hot zone produced by a heat source external to the tube, characterized in that the method further comprises (c) replacing at least part of the hydrogen bonded to oxygen with deuterium in a deuterium/hydrogen exchange step carried out sbsequent to step (a).

Claim 6

Method of claim 3 where step (c) comprises contacting at least part of the interior surface of the tubular body with an atmosphere having a partial pressure of at least about 10 Torr of deuterium, and maintaining at least substantially the part of the surface at a temperature above 300 degrees C. for a period sufficient to result in substantial diffusion of deuterium into the tubular body.

Claim 7

Method of claim 4 wherein the atmosphere further comprises at least one glass-forming precursor compound.

Claim 8

Method of claim 4 wherein steps (a), (b), and (c) of claim 4 are carried out more than once in succession.

Claim 9

Method for fabrication of an optical fiber comprising glassy silica-based material, the method comprising (a) forming a tubular body by depositing silica-based glassy material in substantially porous, unconsolidated form on the inside surface of a tube comprising silica, at least part of the material of the tubular body containing hydrogen bonded to oxygen, (b) consolidating the deposited material by means of a hot zone produced by a heat source external to the tubular body, (c) drawing the optical fiber from a preform formed from the consolidated tubular body, characterized in that the method further comprises (d) exposing, prior to carrying out step (a), at least a part of the tube to an atmosphere having a partial pressure of at least about 10 Torr of deuterium, and maintaining at least substantially the part of the tube at a temperature above about 300 degrees C. for a period sufficient to result in substantial deuterium/hydrogen exchange in at least some of the material of the tube.

Claim 10

Method for fabrication of an optical fiber comprising glassy silica-based material, the method comprising (a) forming a tubular body by depositing silica-based glassy material in substantially porous, unconsolidated form on the inside surface of a tube comprising silica, at least part of the material of the tubular body containing hydrogen bonded to oxygen, (b) consolidating the deposited material by means of a hot zone produced by a heat source external to the tubular body, (c) drawing the optical fiber from a preform formed from the consolidated tubular body, characterized in that the method further comprises (d) exposing, prior to carrying out step (a), at least a part of the tube to an atmosphere having a partial pressure of at least about 10 Torr of deuterium, and maintaining at least substantially the part of the tube at a temperature above about 300 degrees C. for a period sufficient to result in substantial deuterium/hydrogen exchange in at least some of the material of the tube.