This invention pertains to a hollow core photonic band gap chalcogenide optical
glass fiber and to a fabrication method for making the fiber. The fiber, which
is 80-1000 microns in outside diameter, is characterized by a solid glass circumferential
region and a structured region disposed centrally within the solid region, the
structured region includes a hollow core of 1 micron to several hundreds of microns
in diameter surrounded by a plurality of parallel hollow capillaries extending
parallel to the core, the core being centrally and longitudinally located within
the fiber. Ratio of open space to glass in the structured region is 30-99%. The
fabrication method includes the steps of providing a mold, placing chalcogenide
micro-tubes around the mold, stacking chalcogenide micro-canes around the stacked
micro-tubes, fusing the micro-tubes and the micro-canes to form a preform, removing
the mold and drawing the preform to obtain the fiber. In an alternative fabrication
method, the fiber is made by extruding flowing chalcogenide glass through suitably
made plate to form a preform and then drawing the preform to form the fiber.