Laser-drilled free-form silica fiber preforms for microstructured optical fibers

•We present a laser drilling technology for structuring solid glass preforms.•This technology offers the possibility to prepare complex preform designs.•Novel microstructured optical fibers can be realized now.•A fiber from such a preform is analyzed to demonstrate the feasibility.

We describe a laser drilling technology suitable for structuring solid glass preforms for microstructured optical fibers. This technology offers the possibility to prepare complex preform designs that cannot be easily managed by the stack-and-draw technology. As a proof of concept, we present a four-ring hexagonal hole structure drilled in a silica rod over a length of 80 mm. A fiber drawn from such a preform has been analyzed to demonstrate the feasibility of this concept.