Abstract: A glass base material manufacturing apparatus for manufacturing a glass base material comprising: a plurality burners, arranged in a row at a predetermined intervals along the longitudinal direction of a starting base material of the glass base material, for forming a deposit, which is a base material of the glass base material by depositing glass soot on the starting base material while moving reciprocatory over a section of the entire length of the starting base material along the longitudinal direction of the starting base material; a plurality of flow rate regulators, at least one of which is connected to the plurality of burners, respectively, for regulating a flow rate of raw material gas of the glass soot, which is supplied to the plurality of burners; and a control unit connected to each of the plurality of flow rate regulators for controlling individually the plurality of flow rate regulators.

Abstract: A method for manufacturing a preform having a core and a multilayer clad, includes covering a circumference of a rod including at least the core and an inner clad layer with a first tube including at least a high viscosity clad layer, and unifying the rod and the first tube by heating and contracting the first tube.

Abstract: A glass base material manufacturing apparatus for manufacturing a glass base material comprising: a plurality burners, arranged in a row at a predetermined intervals along the longitudinal direction of a starting base material of the glass base material, for forming a deposit, which is a base material of the glass base material by depositing glass soot on the starting base material while moving reciprocatory over a section of the entire length of the starting base material along the longitudinal direction of the starting base material; a plurality of flow rate regulators, at least one of which is connected to the plurality of burners, respectively, for regulating a flow rate of raw material gas of the glass soot, which is supplied to the plurality of burners; and a control unit connected to each of the plurality of flow rate regulators for controlling individually the plurality of flow rate regulators.

Abstract: A glass base material manufacturing apparatus for manufacturing a glass base material comprising: a plurality burners, arranged in a row at a predetermined intervals along the longitudinal direction of a starting base material of the glass base material, for forming a deposit, which is a base material of the glass base material by depositing glass soot on the starting base material while moving reciprocatory over a section of the entire length of the starting base material along the longitudinal direction of the starting base material; a plurality of flow rate regulators, at least one of which is connected to the plurality of burners, respectively, for regulating a flow rate of raw material gas of the glass soot, which is supplied to the plurality of burners; and a control unit connected to each of the plurality of flow rate regulators for controlling individually the plurality of flow rate regulators.

Abstract: A method of packing a glass base material (10, 20, 30), which is a base material of an optical fiber comprising packing the glass base material (10, 20, 30) into a cylindrical container (16, 26, 36). The packing has: putting the glass base material (10, 20, 30) into a plastic bag (12, 22, 32); and packing the glass base material (10, 20, 30), which is put into the plastic bag (12, 22, 32), into the cylindrical container (16, 26, 36). The packing further has: wrapping the glass base material (10, 20, 30), which is put into the plastic bag (12, 22, 32), with air packing material (14, 24, 34), which contains air inside; and packing the glass base material (10, 20, 30) wrapped with the air packing material (14, 24, 34) into the cylindrical container (16, 26, 36).

Abstract: An apparatus for fabricating a soot preform for an optical fiber. The soot preform is fabricated by depositing glass particles on a starting rod capable of being rotated and pulled up. The apparatus comprises elements as follows. A reaction chamber is used for depositing the glass particles on the starting rod. An upper room is located above the reaction chamber for receiving the soot preform formed in the upper portion of the reaction chamber. At least one core burner is installed in the reaction chamber. A gas-supplying inlet is located in the top part of the sidewall of the reaction chamber closest to burner(s), and a gas-exhausting outlet is located in the top part of another sidewall opposite to the gas-supplying inlet. In addition, at least one cladding burner is installed in the reaction chamber.

Abstract: An apparatus for manufacturing a glass base material, which is a base material of an optical fiber, comprising: a base rod, around and along which said glass base material is formed; a burner that hydrolyzes and accumulates a gas material, which is a base material of said glass base material, around and along said base rod; a first burner-moving-unit that moves said burner in a direction parallel with a longitudinal direction of said base rod; and a second burner-moving-unit that moves said first burner-moving-unit in a same moving direction of said first burner-moving-unit.

Abstract: An apparatus for manufacturing a glass-base-material, which is a base material of an optical fiber, includes a driving unit that drives a glass rod around an axis of the glass rod; a burner for accumulating glass soot around outside surface of the glass rod, which is driven by the driving unit, to form the glass-base-material; a weight-deducting unit, on which the driving unit is mounted, for deducting a predetermined weight from a total weight of the driving unit and the glass-base-material formed by the burner; and a measuring unit provided under the weight-deducting unit for measuring the total weight, from which the predetermined weight is deducted by the weight-deducting unit.

Abstract: Even if an optical fiber obtained by drawing a preform is exposed to hydrogen atmosphere, an OH peak in the optical fiber at wavelength of about 1385 nm hardly rises regardless of the condition of drawing.

Abstract: An apparatus for fabricating a soot preform for an optical fiber. The soot preform is fabricated by depositing glass particles on a starting rod capable of being rotated and pulled up. The apparatus comprises elements as follows. A reaction chamber is used for depositing the glass particles on the starting rod. An upper room is located above the reaction chamber for receiving the soot preform formed in the upper portion of the reaction chamber. At least one core burner is installed in the reaction chamber. A gas-supplying inlet is located in the top part of the sidewall of the reaction chamber closest to burner(s), and a gas-exhausting outlet is located in the top part of another sidewall opposite to the gas-supplying inlet. In addition, at least one cladding burner is installed in the reaction chamber.

Abstract: An apparatus for manufacturing a glass-base-material, which is a base material of an optical fiber, includes a driving unit that drives a glass rod around an axis of the glass rod; a burner for accumulating glass soot around outside surface of the glass rod, which is driven by the driving unit, to form the glass-base-material; a weight-deducting unit, on which the driving unit is mounted, for deducting a predetermined weight from a total weight of the driving unit and the glass-base-material formed by the burner; and a measuring unit provided under the weight-deducting unit for measuring the total weight, from which the predetermined weight is deducted by the weight-deducting unit.

Abstract: A method for manufacturing a base material for an optical fiber, includes steps of: holding a bar material by a support member; and adjusting to reduce a difference between an axis of the bar material and a rotational axis of the support member. Furthermore, an optical fiber base material grasping apparatus for holding a bar material having an axis, includes: a support member having a center axis, the support member being rotatable around the center axis; and an adjusting mechanism for reducing a difference between the axis of the bar material and the central axis of the support member.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical-fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: An apparatus for manufacturing a glass-base-material, which is a base material of an optical fiber, includes a driving unit that drives a glass rod around an axis of the glass rod; a burner for accumulating glass soot around outside surface of the glass rod, which is driven by the driving unit, to form the glass-base-material; a weight-deducting unit, on which the driving unit is mounted, for deducting a predetermined weight from a total weight of the driving unit and the glass-base-material formed by the burner; and a measuring unit provided under the weight-deducting unit for measuring the total weight, from which the predetermined weight is deducted by the weight-deducting unit.

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method for manufacturing a glass base material for an optical fiber by forming a core rod having a core section and a portion of a clad, forming an additional clad by depositing glass particles on circumference of the core rod, and performing a sintering and vitrifying process on an obtained porous base material, includes the step of forming the core rod in order that the relation 3.75≦a/m≦6 is satisfied, where ‘a’ denotes an outer diameter of a section corresponding to the core rod, and ‘m’ denotes a mode field diameter at 1385 nm in wavelength with regard to the optical fiber obtained by drawing the glass base material.

Abstract: A method for manufacturing a glass rod (106), which is a parent material of an optical fiber (350), comprising: adjusting a vertical inclination of a standard rod (138) having a predetermined straightness; and heating and elongating a base material (102), which is a parent material of the glass rod (106), along an axis of the standard rod (138), the vertical inclination of which is adjusted, to generate the glass rod (106).

Abstract: A method for manufacturing an optical fiber comprises setting a heating condition for heating a glass rod, which is a parent material of the optical fiber, and an elongating speed of the glass rod based on a prescribed numerical value which changes with a progress of elongation of the glass rod; heating and elongating the glass rod to generate a preform based on the heating condition and the elongating speed which are set by the setting; and drawing the preform to a filament-like form by further heating the preform to generate the optical fiber.

Abstract: A method for manufacturing a glass rod (106), which is a parent material of an optical fiber (350), comprising: adjusting a vertical inclination of a standard rod (138) having a predetermined straightness; and heating and elongating a base material (102), which is a parent material of the glass rod (106), along an axis of the standard rod (138), the vertical inclination of which is adjusted, to generate the glass rod (106).

Abstract: A method for fusing an optical fiber preform comprises fusing the preform while blowing an oxidative gas against the preform to be fused from upper and lower directions of a fusing burner unit. An apparatus for carrying out the method includes a plurality of nozzles for preventing deposition of silica cloud, which are each set at an angle, &thgr;, of blowing the oxidative gas relative to the preform being drawn such 20°≦&thgr;≦60°.