Researchers test new fiber 3D printing technique

Southampton, Hampshire, England - Researchers at the University of Southampton will investigate using 3D printing, or additive manufacturing, techniques in the fabrication of optical fiber. This entirely new way of making fiber could pave the way for more complex structures capable of unlocking a host of applications in a wide range of industries.

Currently, the piece of glass from which an optical fiber is drawn gives a consistent structure along the length of the preform, but makes it difficult to control the shape and composition of the fiber in 3D. This limits the flexibility engineers can exercise in the design of the fiber and the capabilities that the fibers can offer.

The new technique, being developed by Professor Jayanta Sahu and colleagues from the University of Southampton’s Zepler Institute and co-investigator Dr. Shoufeng Yang from the Faculty of Engineering and Environment, will allow 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 fiber preforms (both in conventional and microstructured fiber geometries) in silica and other host glass materials,” says Professor Sahu. “Our proposed process can be utilized to produce complex preforms, which are otherwise too difficult, too time-consuming, or currently impossible to be achieved by existing fabrication techniques.”

Currently, most microstructured fibers are made using the labor 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 fiber structures from ultra-pure glass powder, layer by layer, gradually building up the shape to create a preform several tens of centimeters in length. There are numerous 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 fiber 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, Oxfordshire, England), a provider of laser material processing systems; Fibercore (Southampton); and SG Controls (Cambridge, Cambridgeshire, England).