Collapsing a multitube assembly and subsequent optical fiber drawing in the same furnace

摘要

Embodiments of the invention include a method and apparatus for making a multiple overclad optical fiber preform. The method includes positioning a first overclad tube around a preform core rod, positioning at least one second overclad tube around the first overclad tube, and collectively heating the preform core and the overclad tubes under pressure to collapse the overclad tubes onto the preform core rod thus producing a multiple overclad optical fiber preform. The apparatus includes a preform core rod, a first overclad tube surrounding the preform core rod, and at least one second overclad tube surrounding the first overclad tube. A quartz disc with or without one or more quartz spacers is used for supporting the preform core rod and the first overclad tube within the additional overclad tubes.