image: (a) Images of the 3D printed preforms and subsequently filled cores; (b) Optical fiber drawing tower used in this experiment; (c) Temperature change of the fiber drawing process; (d) loss spectrum of the 3D printed single-core, and loss of seven cores fibers at 632.8 nm; (e) emission spectra of a single core fiber excited by the 830 nm and 980 nm lasers. view more
Credit: by Yushi Chu, Xinghu Fu, Yanhua Luo, John Canning, Jiaying Wang, Jing Ren, Jianzhong Zhang, and Gang-Ding Peng
3D printing of silica glasses and silica optical fiber preforms has recently been proved experimentally. One challenge of 3D printing silica optical fibers performance is how to extend the recent reports of small-scale glass “bulk or slice” printing from a few millimeters to centimeters.
Dr. Yushi Chu and Prof. Jianzhong Zhang of Harbin Engineering University (HEU), and Prof. Gang-Ding Peng of the University of New South Wales (UNSW) led a research team to extend small-scale glass printing by several orders of magnitude. The paper, titled “Additive Manufacturing Fiber Preforms for Structured Silica Fibers with Bismuth and Erbium Dopants,” proved that optical fiber preforms could be made through 3D printing.
The centimeter-scale optical fiber preform was successfully fabricated by DLP 3D printing technology, and single-mode and multi-mode optical fibers were obtained by controlling the parameters during fiber drawing. On this basis, the research group further extended this work, bismuth ions and erbium ions were co-doped into the single-core and seven-core fibers. They realized the fabrication of multi-component fibers and structured fibers.
It is essential to consider the capability of 3D printing technology to produce complex fiber structures. The ability to demonstrate these additive capabilities improved manufacturing processes by reducing separation and integration processes. The researchers also introduced dopants from five different elements. The elements were bismuth, erbium, germanium, titanium, and aluminum. Germanium, titanium, and aluminum formed waveguides and enriched the core glass network structure, conducive to luminescence. Bismuth and erbium provided the broadband luminescence-covered O-L band under a single wavelength excitation.
As part of their experiments, the researchers also discussed fiber loss, considered the most important property that restricts 3D printing optical fiber. They found that increasing the roundness of the core and cladding. It also reduced the moisture in the optical fiber, effectively reducing fiber loss. These can be achieved by carefully controlling the temperature and pressure during the fabrication process.
3D printing technology promises to revolutionize specialty optical fibers, providing opportunities for new applications. It is possible that society could see the creation of multicore fiber fan-in/fan-out or ideal mode coupling in space division multiplexing without optical fiber splicing.
Journal
Light: Advanced Manufacturing