Method and apparatus for sintering porous optical fiber preforms

An improved method and apparatus is disclosed for sintering large, cylindrical, porous bodies used in the manufacture of high-quality optical fiber preforms. The apparatus has a compact, simplified structure, as compared to comparable apparatus of the prior art. The apparatus includes two separate support/slide assemblies that support the porous body throughout the sintering process. A first support/slide assembly engages a special handle for the porous body during a first stage of the process, in which the body is lowered into a furnace muffle. A second support/slide assembly then engages the porous body's handle during a second stage of the process, in which the body is controllably moved through a hot zone of the furnace, for dehydration and sintering of the body into a dense glass optical fiber preform. The body's handle is specially configured to allow both support/slide assemblies to be engaged with it simultaneously, whereby the sintering process can be carried out without the need for separate support structure during the switchover from the first support/slide assembly to the second support/slide assembly.