Reduction of loss and improved long-term reliability of hollow core fibers

A system for fabricating a hollow core optical fiber, the system comprising:

• a preform mount for holding a preform;
• a noble gas supply system connected to an arrangement of gas conduits, wherein the arrangement of gas conduits includes channels with openings positioned where the openings of a hollow core and a plurality capillaries defining a plurality of voids of a preform would be positioned with a preform mounted in the preform mount, and wherein the noble gas supply system is configured to flow gas comprising a noble gas through the preform mounted in the preform mount;
• and
• a draw furnace which is configured to be heated to a temperature suitable for softening a material of the preform.

A method of fabricating a hollow core optical fiber, the method comprising:

• providing a preform comprising a transverse cross-sectional structure comprising a hollow core surrounded by a plurality of capillaries defining a plurality of voids encased by a tubular cladding, wherein the hollow core and the plurality of voids extend longitudinally along a length of the preform;
• purging the preform by flowing a gas comprising a noble gas through the hollow core and the plurality of voids, wherein purging the preform comprises evacuating the preform followed by flowing the noble gas through the hollow core and the plurality of voids;
• and
• subsequent to purging the preform, drawing a hollow core optical fiber by passing the purged preform through a draw furnace heated to a temperature suitable for softening a material of the preform.