Southampton University researchers have developed a new technique in the optical fibre fabrication using additive manufacturing, which could help more complex structures with a wide range of industrial applications from biotechnology to aerospace and telecommunications.
The current fabrication techniques for optical fibre preform has the limitation that it is difficult to control the shape and composition of the fibre in 3D. But the new technique allows engineers to manufacture preforms with far more complex structures and different features along their lengths.
“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,” says Professor Jayanta Sahu who developed the new technique together with his colleagues from the University’s Zepler Institute and co-investigator Dr Shoufeng Yang from the Faculty of Engineering and Environment.
Preform formation is one of the most challenging stages, especially when it has a complex internal structure as in photonic bandgap fibre, which is a new type of microstructured fibre extensively anticipated to revolutionise the telecom and datacom industries in particular.
Most of the microstructured fibres are made by stacking several smaller glass capillaries or canes together by hand to form the preform. However, the new technique involves additive manufacturing using ultra-pure glass powder, gradually building up the shape to create a preform several tens of centimetres in length. There are many challenges, including the high melting temperature of the glass (over 2000˚C in case of silica); 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.
The project is funded by the Engineering and Physical Sciences Research Council (EPSRC) which also involves the researchers 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.