Optical fibre preform manufacture
AssigneeInternational Standard Electric Corporation
InventorsPhilip W. Black, John Irven
Life of this patent
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Abstract
A rod of silica 14 is inserted into a substrate tube 10 whose bore is lined with a layer 11 of material having a refractive index less than that of silica. This layer 11 is itself covered with a layer 12 of silica. The assembly of the rod and tube is drawn into fibre, or its components are fused together to form a solid cross-section optical fibre preform.
Claims13
A method of fabricating an optical fibre preform by utilizing a silica substrate tube having a first index of refraction comprising the steps of:
- coating said tube with a first layer of silica including a dopant sufficient to provide a cladding layer exhibiting an index of refraction less than that of said silica tube,
- coating said first layer with an inhibiting layer of substantially undoped silica to provide a barrier to prevent migration of said cladding layer dopant across said inhibiting layer,
- inserting a substantially undoped silica rod coaxially into said coated tube to provide a core of said optical fibre preform, and
- fusing together said coated tube and said rod to form a solid cross-section optical fibre preform.
A method of fabricating an optical fibre perform by utilizing a silica substrate tube having a first index of refraction comprising the steps of:
- coating said tube with a first layer of silica including a dopant sufficient to provide a cladding layer exhibiting an index of refraction less than that of said silica tube,
- coating said first layer with an inhibiting layer of substantially undoped silica to provide a barrier to prevent migration of said cladding layer dopant across said inhibiting layer,
- inserting a substantially undoped silica rod coaxially into said coated tube to provide a core of said optical fibre preform,
- holding said coated tube and said rod on a common axis, heating and collapsing and tube onto said rod, and fusing together said tube and said rod to form a solid cross-section optical fibre preform.
A method of fabricating an optical fibre by utilizing a silica substrate tube having a first index of refraction comprising the steps of:
- coating said tube with a first layer of silica including a dopant sufficient to provide a cladding layer exhibiting an index of refraction less than that of said silica tube, coating said first layer with an inhibiting layer
- of substantially undoped silica to provide a barrier to prevent migration of said cladding layer dopant across said inhibiting layer,
- inserting a substantially undoped silica rod coaxially into said coated tube to provide a core of said optical fibre preform,
- holding said coating tube and said rod on a common axis,
- heating and collapsing one end of said tube onto said rod,
- commencing with the collapsed end, introducing said tube and said rod coaxially into a furnace, causing progessive collapsing and fusing of said tube onto said rod, and
- drawing a solid cross-section optical fibre from an end of the fused tube and rod.
Dependencies are inferred from the claim text.