AM simplifies optical fibre production
Researchers at the University of Southampton’s Zepler Institute are set to investigate additive manufacturing techniques for fabricating optical fibre.
If successful, the process could help create complex fibres for high-power laser applications and the telecoms and medical industries.
The team aim to simplify the production of optical fibre performs from which a fibre is drawn, and creates intricate internal structures such as bandgaps. This is currently one of the most difficult stages in the production of optical fibres.
‘We hope our work will open up a route to manufacture novel fibre structures in silica and other glasses for a wide range of applications, covering telecommunications, sensing, lab-in-a-fibre, metamaterial fibre, and high-power lasers,’ said Professor Jayanta Sahu, part of the research team. ‘This is something that has never been tried before and we are excited about starting this project.’
‘We will design, fabricate and employ novel Multiple Materials Additive Manufacturing (MMAM) equipment to enable us to make optical fibre preforms – both in conventional and microstructured fibre geometries – in silica and other host glass materials,’ said Sahu. ‘Our proposed process can be utilised to produce complex preforms, which are otherwise too difficult, too time-consuming or currently impossible to be achieved by existing fabrication techniques.’
Current techniques used to produce optical fibre preforms give a consistent structure along the length of the preform but make it difficult to control the shape and composition of the fibre in 3D. This limits the degree of flexibility that engineers can exercise in the design of the fibre and as a consequence, the capabilities that the fibres can offer.
Currently, most microstructured fibres are made using the labour intensive ‘stack and draw’ process which involves stacking several smaller glass capillaries or canes together by hand to form the preform.
However, using the new additive manufacturing technique, the researchers will be able to form complex fibre structures from ultra-pure glass powder, layer-by-layer, gradually building up the shape to create a preform several tens of centimetres in lengths. There are numerous challenges including the high melting temperature of the glass; the need for precise control of dopants, refractive index profiles and waveguide geometry; and the need for transitions between the layers to be smooth, otherwise the properties of the resultant fibre will be altered.
As part of the project, funded by the Engineering and Physical Sciences Research Council (EPSRC), the researchers will be working with three companies: ES Technology (Oxford, UK), a provider of laser material processing systems; Fibercore (Southampton, UK) a supplier of specialty fibre; and SG Controls (Cambridge UK) a leading manufacturer of optical fibre equipment.