Process and apparatus for sintering a porous glass preform

摘要

Apparatus for sintering a porous glass preform (2) from which an optical fiber can be drawn. The sintering apparatus includes: a control unit (4) which can vary a condition for sintering the porous glass preform; and a furnace (12) which sinters the porous glass preform by heating the preform in an atmosphere of dehydration gas and inert gas (e.g. Cl2 and He). The control unit (4) includes a drive source (3) for supplying the porous glass preform to the furnace at various speeds. Optionally the control unit also includes a temperature control unit (15) for controlling the temperature of a heating source (9) provided in the furnace. A method by which the preform supply speed is varied during sintering of such a porous glass preform is also disclosed. The apparatus and method aim to solve the problem of core-clad eccentricity and roundness by providing a more uniform sintering of the porous preform.