Glass base material, optical fiber, method for manufacturing thereof, and method for determining cause of defect thereof
AssigneeShin-Etsu Chemical Co., Ltd.
InventorHiroshi Oyamada
Life of this patent
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Abstract
A glass base material, which is a base material of an optical fiber, comprising: a core; and a clad surrounding the core; wherein: a rate of change in a relative-refractive-index-difference between the core and the clad in a longitudinal direction of the glass base material is substantially 6% or less.
Claims18
A glass base material, which is a base material of an optical fiber, comprising:
- a core;
- and
- a clad surrounding said core;
- wherein:
- a rate of change in a relative-refractive-index-difference between said core and said clad in a longitudinal direction of the glass base material is substantially 6% or less.
An optical fiber, comprising:
- a core;
- and
- a clad surrounding said core;
- wherein:
- a rate of change in a relative-refractive-index-difference between said core and said clad in a longitudinal direction of the optical fiber is substantially 6% or less.
An optical fiber, comprising:
- a core;
- and
- a clad surrounding said core;
- wherein:
- an absolute value of an amount of change in a backscattering-light-collect-coefficient |I(λ, z)| in a longitudinal direction of the optical fiber is substantially 0.1 dB or less.
A glass base material, which is a base material of an optical fiber, comprising:
- a core;
- and
- a clad surrounding said core;
- wherein:
- a rate of change in a diameter of said core in a longitudinal direction of the glass base material is substantially 7% or less.
An optical fiber, comprising:
- a core;
- and
- a clad surrounding said core;
- wherein:
- a rate of change in a diameter of said core in a longitudinal direction of the optical fiber is substantially 7% or less.
An optical fiber, comprising:
- a core;
- and
- a clad surrounding said core;
- wherein:
- an absolute value of an amount of change in a backscattering-light-collect-coefficient |I(λ, z)| in a longitudinal direction of the optical fiber is substantially 0.1 dB or less.
A method for determining a cause of defect in an unused optical fiber comprising:
- measuring backscattering-light-strengths S(λ1, z) and S(λ2, z) of said optical fiber for two wavelengths λ1 and λ2, where λ1<λ2 from both ends of said optical fiber;
- calculating an amount of change in a backscattering-light-collect-coefficient I(λ2, z) and I(λ1, z) for said two wavelength λ1 and λ2;
- comparing said amount of change in a backscattering-light-collect-coefficient I(λ1, z) and I(λ2, z) for said two wavelengths λ1 and λ2 to examine whether said amount of change in a backscattering-light-collect-coefficient I(λ1, z) and I(λ2, z) satisfy a predetermined relationship;
- and
- determining said cause of defect in said optical fiber according to said comparison.
A method for manufacturing a glass base material, which is a base material of an optical fiber, comprising:
- forming a clad around a core by accumulating glass particles on said core to form a porous-glass-base-material;
- sintering and dehydrating said porous-glass-base-material to form said glass base material;
- measuring a rate of change in a relative-refractive-index-difference between said core and said clad in a longitudinal direction of said glass base material;
- and
- removing said glass base material, said rate of change in a relative-refractive-index-difference of which is more than substantially 6%.
A method for manufacturing an optical fiber, comprising:
- drawing a glass base material, which is a base material of said optical fiber having a core and a clad that surrounds said core, to form said optical fiber;
- measuring a rate of change in a relative-refractive-index-difference between said core and said clad in a longitudinal direction of said optical fiber;
- and
- removing a part of said optical fiber, said rate of change in a relative-refractive-index-difference of which is more than substantially 6%.
A method for manufacturing a glass base material, which is a base material of an optical fiber, comprising:
- forming a clad around a core by accumulating glass particles on said core to form a porous-glass-base-material;
- sintering and dehydrating said porous-glass-base-material to form said glass base material;
- measuring a rate of change in a diameter of said core in a longitudinal direction of said glass base material;
- and
- removing said glass base material, said rate of change in said diameter of said core of which is more than substantially 7%.
A method for manufacturing an optical fiber, comprising:
- drawing a glass base material, which is a base material of said optical fiber having a core and a clad that surrounds said core, to form said optical fiber;
- measuring a rate of change in a core diameter in a longitudinal direction of said optical fiber;
- and
- removing a part of said optical fiber, said rate of change in said core diameter of which is more than substantially 7%.
A method for manufacturing an optical fiber, comprising:
- drawing a glass base material, which is a base material of said optical fiber having a core and a clad that surrounds said core, to form said optical fiber;
- measuring an amount of change in a backscattering-light-collect-coefficient in a longitudinal direction of the optical fiber;
- removing said optical fiber, in which an absolute value of said amount of change in a backscattering-light-collect-coefficient |I(λ, z)| is more than substantially 0.1 dB.
Dependencies are inferred from the claim text.