Reliable low loss guidance of ultraviolet and visible light in optical fibres has long been sought after for a wide range of applications. In solid glass fibres such guidance is limited primarily due to Rayleigh scattering and photodarkening effects caused by the UV itself. Hollow core fibres can avoid these limitations by confining light in their air-filled core by virtue of their microstructure cladding.
In Hollow Core Antiresonant Fibres, broadband guidance which covers both the UV and visible spectrum requires the fabrication of an internal microstructure with extremely slender capillaries. Producing long lengths of such a fibre with a uniform microstructure is technically challenging using current fabrication methods.
Greg Jackson and team have published a modified technique consisting of additional draw stages which is capable of simultaneously achieving slender capillaries and significantly longer lengths of fibres than the current state of the art. Additionally, this technique leverages existing fibre drawing tower infrastructure, allowing for immediate implementation. Experimental results have demonstrated a fibre with 167nm thick capillaries and a length of ~350m, with the potential of exceeding 2km.
More information can be found at: https://doi.org/10.1364/OE.507703
