Abstract: A manufacturing apparatus of a porous glass base material is provided. The manufacturing apparatus includes a burner repeatedly moving back and forthreciprocating in a direction along a longitudinal direction of an axis-rotating base member glass rod, where the burner ejects and deposits glass particles onto the base member glass rod, and an exhaust hood positioned above a porous glass soot formed by the deposition of the glass particles, where the exhaust hood repeatedly moves back and forth reciprocates in a same direction as the burner in synchronization with the burner. Here, the exhaust hood surrounds a portion of the porous glass soot corresponding to an angle ? of 100° or more with respect to an axial centera central axis of the porous glass soot. To be more specific, the angle ? may be preferably 180° or more.

Abstract: A manufacturing apparatus of a porous glass base material is provided. The manufacturing apparatus includes a burner repeatedly moving back and forth reciprocating in a direction along a longitudinal direction of an axis-rotating base member glass rod, where the burner ejects and deposits glass particles onto the base member glass rod, and an exhaust hood positioned above a porous glass soot formed by the deposition of the glass particles, where the exhaust hood repeatedly moves back and forth reciprocates in a same direction as the burner in synchronization with the burner. Here, the exhaust hood surrounds a portion of the porous glass soot corresponding to an angle ? of 100° or more with respect to an axial centera central axis of the porous glass soot. To be more specific, the angle ? may be preferably 180° or more.

Abstract: There are provided a sintering method and a sintering apparatus of a porous glass base material for sintering a porous glass base material to be dehydrated and vitrified into a transparent glass without causing core displacement and cross-sectional shape deformation. In detail, an aspect of the present invention is a sintering method of a porous glass base material for sintering a rod-like porous glass base material by hanging and moving the rod-like porous glass base material though a heating furnace. Here, the porous glass base material is lowered into a heating furnace heated to a sintering temperature, and after every part of the porous glass base material is moved through a preheated region extending from an upper edge of an insulating member to an upper edge of a heater in a heating furnace body in 4.5 hours or longer, the porous glass base material is sintered by the heater to be vitrified into a transparent glass.

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: Apparatus (700) for sintering a glass base material (2) which is a base material for an optical fiber. The sintering apparatus (700) includes: a control unit which varies a condition for sintering the glass base material; and a furnace (12) which sinters the glass base material by heating the glass base material in an atmosphere of dehydration gas and inert gas. The control unit includes a drive source (3) which supplies the glass base material to the furnace at various speeds. The control unit includes a temperature control unit which controls the temperature of a heating source provided in the furnace.

Abstract: A method for sintering a porous-glass material to form a glass base material, which is a base material for an optical fiber, comprising: preparing a ring heater having an opening, through which the porous-glass material passes, for heating the porous-glass material; selecting the porous-glass material having an outer diameter (d) within a predetermined range, the predetermined range being determined based on an inner diameter (D) of the opening of the ring heater; and heating the porous-glass material in an atmosphere of dehydration gas and inert gas with the ring heater.

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.