UPWARD COLLAPSE PROCESS AND APPARATUS FOR MAKING GLASS PREFORMS

An apparatus and related process for producing large glass preforms with minimal clad to-core waveguide distortion from a glass body having a weight, an outer surface, core rods, and a cladding surrounding and separated from the core rods by a gap. The apparatus includes collars affixed to the top and bottom of the cladding; a spacer upon which the core rods rest; a first unit holding and supporting both the bottom collar and the spacer; a second unit holding and supporting the top collar; and a frame defining a heating zone having a heating element to heat the glass body, collapse the cladding onto the core rods, close the gap, and create the glass preform. The weight of the glass body above and below the molten glass in the heating zone is supported by the first and second units withoutcontacting the outer surface of the glass body. 本发明提供了种用于从玻璃体产生具有最小的包层-芯体波导畸变的大型玻璃预成型件的设备和相关工艺，所述玻璃体具有定重量、外表面、芯棒以及包层，所述包层包围所述芯棒并且与所述芯棒隔开定间隙。所述设备包括套环，所述套环附连至所述包层的顶部和底部；间隔物，所述芯棒搁置在所述间隔物上；第单元，所述第单元固持并支撑所述底部套环和所述间隔物两者；第二单元，所述第二单元