A glass body manufacturing apparatus includes: a first heating furnace including a furnace core tube accommodating the soot and a first heater, to supply a dehydration gas into the furnace core tube and heat the soot at a first treatment temperature lower than a softening point of the porous portion by the first heater; a second heating furnace including a structural body accommodating the soot and a second heater, to heat the soot at a second treatment temperature equal to or higher than the softening point by the second heater; and a conveyance container, connectable to each of the first and second heating furnaces while keeping airtightness with respect to the atmosphere, to accommodate and hold the soot, and convey the soot between the first and second heating furnaces.

The invention relates to a method and a device for producing a preform for glass fiber production. The method comprises the steps of providing a carrier gas with a desired, precisely adjusted temperature, loading the carrier gas with halide vapor, mixing the loaded carrier gas with additional gases, and producing the preform in a reaction chamber with substrate.

An apparatus for optical fiber manufacturing process is provided, including a raw material providing structure, a dopant providing structure, and a preform forming substrate tube. The dopant providing structure is disposed at a downstream side of the raw material providing structure and in communication with the raw material providing structure. The dopant providing structure includes an outer tube, a first inner tube, a first dopant providing container, a second inner tube, and a second dopant providing container. The first inner tube is disposed in the outer tube. The first dopant providing container is disposed in the first inner tube. The second inner tube is disposed in the outer tube at a downstream of the first inner tube. The second dopant providing container is disposed in the second inner tube. The preform forming substrate tube is disposed at a downstream side of the dopant providing structure.

An apparatus for optical fiber manufacturing process is provided, including a raw material providing structure, a dopant providing structure, and a preform forming substrate tube. The dopant providing structure is disposed at a downstream side of the raw material providing structure and in communication with the raw material providing structure. The dopant providing structure includes an outer tube, a first inner tube, a first dopant providing container, a second inner tube, and a second dopant providing container. The first inner tube is disposed in the outer tube. The first dopant providing container is disposed in the first inner tube. The second inner tube is disposed in the outer tube at a downstream of the first inner tube. The second dopant providing container is disposed in the second inner tube. The preform forming substrate tube is disposed at a downstream side of the dopant providing structure.

A device for manufacturing an optical preform by means of an internal vapour deposition process including an energy source, a hollow substrate tube having a supply side and a discharge side and the energy source being moveable along a length of the hollow substrate tube, and an elongation tube connected to the hollow substrate tube at the discharge side thereof, wherein the hollow substrate tube extends into an interior of the elongation tube and an internal diameter of the elongation tube is at least 0.5 millimeters larger than an external diameter of the hollow substrate tube.

The present invention relates to a method of forming an optical fiber precursor including: forming an alkali metal doped tube; inserting an optical fiber core rod within the alkali metal doped tube; forming a cladding jacket around the alkali metal doped tube; and diffusing an alkali metal from the alkali metal doped tube through a surface of the optical fiber core rod. The present invention further relates to an optical fiber preform having: an optical fiber core rod; an alkali metal doped tube surrounding the optical fiber core rod; and a cladding jacket surrounding the alkali metal doped tube.

Preparation of halogen-doped silica is described. The preparation includes doping silica with high halogen concentration, sintering halogen-doped silica to a closed-pore state, and subjecting the closed-pore silica body to a thermal treatment process and/or a pressure treatment process. The temperature of thermal treatment is sufficiently high to facilitate reaction of unreacted doping precursor trapped in voids or interstices of the glass structure, but is below temperatures conducive to foaming. Core canes or fibers drawn from halogen-doped silica subjected to the thermal treatment and/or pressure treatment show improved optical quality and possess fewer defects. The thermal treatment and/or pressure treatment is particularly advantageous when used for silica doped with high concentrations of halogen.

A method for manufacturing a glass fine particle deposit includes: emitting a siloxane gas, a carrier gas, and a combustion gas from a burner; setting volume concentration of a supply volume amount of the siloxane gas per unit time with respect to the sum of the supply volume amount of the siloxane gas per unit time and a supply volume amount of the carrier gas per unit time (C1) to 10.6 volume %<C1<20.0 volume %; and setting volume concentration of the supply volume amount of the siloxane gas per unit time with respect to the sum of the supply volume amount of the siloxane gas per unit time, the supply volume amount of the carrier gas per unit time, and a supply volume amount of the seal gas per unit time (C2) to 5.8 volume %<C2<10.0 volume %.

The present invention relates to a method of manufacturing an optical fiber preform for obtaining an optical fiber with low transmission loss. A core preform included in the optical fiber preform comprises three or more core portions, which are each produced by a rod-in-collapse method, and in which both their alkali metal element concentration and chlorine concentration are independently controlled. In two or more manufacturing steps of the manufacturing steps for each of the three or more core portions, an alkali metal element is added. As a result, the mean alkali metal element concentration in the whole core preform is controlled to 7 atomic ppm or more and 70 atomic ppm or less.

The invention relates to a method and a device for producing a preform for glass fiber production. The method comprises the steps of providing a carrier gas with a desired, precisely adjusted temperature, loading the carrier gas with halide vapor, mixing the loaded carrier gas with additional gases, and producing the preform in a reaction chamber with substrate.