02 Jul 2015
Scientists at Zepler Institute say method will enable "previously impossible" fiber structures and applications.
The scientists say this entirely new way of making fiber “could pave the way for more complex structures capable of unlocking applications in a wide range of industries, from biotechnology to aerospace and telecommunications”.
Current techniques used to produce optical fiber preforms give a consistent structure along its length but make it difficult to control the shape and composition of the fiber in 3D. This limits the degree of flexibility that 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, together with his 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.
'Making possible the impossible'
Professor Sahu commented, “We will develop novel Multiple Materials Additive Manufacturing (MMAM) equipment to make optical fiber preforms both in conventional and microstructured fiber geometries in silica and other host glass materials. 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.”
The making of the preform is one of the most challenging stages of optical fiber manufacturing, especially when it has a complex internal structure, such as in photonic bandgap fiber - a new type of microstructured fiber, which Southampton anticipates will “revolutionize the telecoms and datacoms industries in particular”.
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 expect to 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.
Professor Sahu added, “There are numerous challenges including the high melting temperature of the glass, which is 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 UK’s Engineering and Physical Sciences Research Council to the tune of £700,000 ($1.1 million), 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 fiber; and SG Controls (Cambridge UK) a leading manufacturer of optical fiber equipment.
Professor Sahu concluded, “We hope our work will open up a route to manufacture novel fiber structures in silica and other glasses for a wide range of applications, covering telecommunications, sensing, lab-in-a-fiber, metamaterial fiber, and high-power lasers. This is something that has never been tried before and we are excited about starting this project.”
About the Author
Matthew Peach is a contributing editor to optics.org.