Microstructured Optical Fiber Draw Method with In-Situ Vacuum Assisted Preform Consolidation

摘要

A method and apparatus for making a substantially void-free microstructured optical fiber using a one-step process is provided. A preform for the optical fiber is prepared, comprising an outer jacket made of solid glass, a cladding having a plurality of microtubes and/or microcanes arranged in a desired pattern within the jacket, and a core which may be solid or hollow, with the cladding and the core extending above the top of the outer jacket. The thus-prepared preform is placed into a fiber draw tower. As the fiber is drawn, negative gas pressure is applied to draw the canes together and consolidate the interfacial voids between the canes while positive gas pressure is applied to the preform to keep the holes of the microcanes open during the fiber drawing. The apparatus includes a jig having support tubes that are connected to a vacuum pump for application of the negative gas pressure and a vent tube connected to a gas supply for application of the positive gas pressure. The interfaces between the support tube and the outer jacket and between the vent tube and the cladding are sealed to ensure that the appropriate application of negative or positive pressure during the draw step is obtained. The preforms according to the present invention can include one or more components fabricated from specialty non-silica glass.