An optical fiber structure having a holey fiber arranged in a holey outer support
structure made up of holey tubes encased in a thin walled outer jacket. The holey
fiber may have a solid core surrounded by a holey cladding having a plurality of
rings of holes. With the invention it is possible to produce robust, coated and
jacketed fibers with microstructured core features of micrometer size relatively
easily using existing fiber fabrication technology. This improvement is a result
of the outer holey structure which reduces the thermal mass of the supporting structure
and makes it possible to reliably and controllably retain small hole features during
the fiber fabrication process.