Polarization-preserving optical fiber
AssigneeBell Telephone Laboratories, Incorporated
InventorsWilliam Pleibel, Rogers H. Stolen
Life of this patent
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Abstract
A method of making a polarization-preserving optical fiber is disclosed having a first step of fabricating a substrate tube to have a wall of nonuniform thickness, the nonuniformity in thickness being arranged about the wall of the substrate tube so that maxima and minima in wall thickness lie in planes which are substantially orthogonal. This first step is followed by deposition of cladding layers and a core layer within the substrate tube. The substrate is then collapsed and the fiber drawn therefrom. The nonuniform wall thickness of the substrate tube operates together with differential thermal contraction of the layers to produce stress-induced birefringence in the fiber, which birefringence provides a polarization-preserving optical fiber.
Claims14
A method of making an optical fiber comprising the steps of:
- fabricating a substrate tube having a wall with an outer surface and an inner surface of predetermined shape, the distance between said outer surface and said inner surface being the thickness of said wall,
- depositing at least one cladding layer on the interior of said substrate tube by a vapor deposition process.
- depositing a core layer on the interior of said at least one cladding layer by a vapor deposition process,
- radially collapsing said substrate tube by a heating process to form an optical preform, and
- drawing an optical fiber from said preform,
- characterized in that said step of fabricating causes the thickness of the wall of said substrate tube to be substantially nonuniform in thickness, said nonuniformity in thickness being arranged about said wall so that maxima and minima of said thickness lie in planes which are substantially orthogonal, whereby said steps of collapsing said substrate tube and drawing an optical fiber from said preform form a polarization-preserving optical fiber.
A method of making a polarization-preserving optical fiber from a substrate tube having a wall with an outer surface comprising the steps of:
- shaping said wall of said substrate tube to be substantially nonuniform in thickness, said nonuniformity in thickness being arranged about said wall so that maxima and minima of said thickness be in planes which are substantially orthogonal;
- depositing at least one cladding layer on the interior or said substrate tube by a vapor deposition process;
- depositing a core layer on the interior of said cladding layers by a vapor deposition process;
- radially collapsing said substrate tube by a heating process to form an optical preform;
- and
- drawing an optical fiber from said preform.
A method of making an optical fiber comprising the steps of:
- fabricating a substrate tube having a wall with an outer surface and an inner surface of predetermined shape, the distance between said outer surface and said inner surface being the thickness of said wall,
- depositing at least one cladding layer on the interior of said substrate tube by a vapor deposition process,
- depositing a core layer on the interior of said at least one cladding layer by a vapor deposition process,
- radially collapsing said substrate tube by a heating process to form an optical preform, and
- drawing an optical fiber from said preform, characterized in that said step of fabricating causes the thickness of the wall of said substrate tube to be substantially nonuniform in thickness, said nonuniformity in thickness being asymmetrically arranged about said wall, whereby said steps of collapsing said substrate tube and drawing an optical fiber from said preform form a polarization-preserving optical fiber.
Dependencies are inferred from the claim text.