Preform for optical fiber and manufacturing method of optical fiber
AssigneeKohoku Kogyo Co., Ltd.
InventorsKatsuhiro Iwasaki, Qiuyue Piao, Yusuke Kinoshita
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Abstract
A preform for optical fiber made of a quartz glass sintered body which is made from quartz glass powder as a main raw material, in which at least a portion of the quartz glass sintered body is an opaque body, the opaque body has a visible light transmittance of 90% or less at a length of 5 mm or less in one direction, and the opaque body has a bulk density of 2.1 g/cm3 or more, or the opaque body has a visible light transmittance of 90% or less at a length of 5 mm or less in one direction, and the opaque body has an open porosity of 3.5% or less.
Claims13
A method of manufacturing a preform for optical fiber made of a quartz glass sintered body, the method comprising:
- a step of mixing a glass raw material solution containing a quartz glass powder, a solvent, a dispersant, and a hardening resin to blend a slurry;
- a step of hardening a mixture of the slurry and a hardener in a molding die to form a molded body;
- a step of removing the molding die from the molded body;
- a step of drying the molded body;
- a step of degreasing the molded body after the step of drying;
- a step of sintering the molded body after the step of degreasing to obtain the quartz glass sintered body, wherein:
- (a) at least a portion of the quartz glass sintered body is an opaque body, the opaque body has a visible light transmittance of 90% or less at a length of 5 mm or less in one direction, and the opaque body has a bulk density of 2.1 g/cm3 or more;
- (b) at least a portion of the quartz glass sintered body is an opaque body, the opaque body has a visible light transmittance of 90% or less at a length of 5 mm or less in one direction, and the opaque body has an open porosity of 3.5% or less;
- or
- (c) at least a portion of the quartz glass sintered body is an opaque body, the opaque body has a visible light transmittance of 2.5% or more and 90% or less at a length of 5 mm or less in one direction.
A preform for optical fiber made of a columnar quartz glass sintered body which is made from quartz glass powder as a main raw material, wherein:
- (a) the preform includes a portion having a ratio of outer roundness of a difference between a maximum outer diameter and a minimum outer diameter of the columnar quartz glass sintered body to outer diameter of the columnar quartz glass sintered body of 0.5% or less and a bulk density of 2.1 g/cm3 or more;
- (b) the preform includes a portion having the ratio of outer roundness to the outer diameter of 0.5% or less and an open porosity of 3.5% or less;
- or
- (c) the preform includes a portion having the ratio of outer roundness to the outer diameter of 0.5% or less.
A method of manufacturing a preform for optical fiber made of a quartz glass sintered body, the method comprising:
- a step of mixing a glass raw material solution containing a quartz glass powder, a solvent, a dispersant, and a hardening resin to blend a slurry;
- a step of hardening a mixture of the slurry and a hardener in a molding die to form a molded body;
- a step of removing the molding die from the molded body;
- a step of drying the molded body;
- a step of degreasing the molded body after the step of drying;
- a step of sintering the molded body after the step of degreasing to obtain the quartz glass sintered body, wherein:
- (a) the preform includes a portion having a ratio of outer roundness of a difference between a maximum outer diameter and a minimum outer diameter of the columnar quartz glass sintered body to outer diameter of the columnar quartz glass sintered body of 0.5% or less and a bulk density of 2.1 g/cm3 or more;
- (b) the preform includes a portion having the ratio of outer roundness to the outer diameter of 0.5% or less and an open porosity of 3.5% or less;
- or
- (c) the preform includes a portion having the ratio of outer roundness to the outer diameter of 0.5% or less.
Dependencies are inferred from the claim text.