Veda Narayana Koraganji presented his work, titled ‘Effects of 3D Printed Preform Annealing on Structural and Optical Properties of Fibers’, on Aug 4th 2020 at the Pacific Rim Conference on Lasers and Electro-Optics (CLEO PR 2020), which was held virtually this year from Aug 3rd to Aug 5th. This work was done in collaboration with Camila Faccini de Lima, Merve Gkce Kurtoglu and Mengxin Zheng.
Recent developments in additive manufacturing has enabled the 3D printing of polymer preforms with complex internal geometry , which can be thermally drawn into fibers while retaining their cross-sectional geometry. Several works have explored this concept and applied 3D printing of preforms to produce multimaterial fibers and step-index fibers [2, 3]. However, the effects of anisotropic porosity and anisotropic thermal conduction in the preform – which are inherent to 3D printing processes – are rarely considered. These aspects influence the deformation of the fiber during the draw process, as well as its optical properties. Here, we report a novel approach to reduce these factors and improve fiber performance by introducing an annealing step between the preform 3D printing and its draw into a fiber.
Our investigation of the effects of annealing on 3D printed preforms revealed two things. Firstly, annealing helps in preserving the cross section of the fiber drawn from 3D printed preforms and secondly, even though annealing makes the 3D printed preforms optically transparent, due to the undesired introduction of the metal during the 3D printing process the attenuation is increased in annealed fibers.
 P.M. Toal et al. “Microstructured monofilament via thermal drawing of additively manufactured preforms,” Additive Manufacturing, Volume 16, 2017, Pages 12-23, ISSN 2214-8604, https://doi.org/10.1016/j.addma.2017.03.009
 Kevin Cook et al. "Step-index optical fiber drawn from 3D printed preforms," Opt. Lett. 41, 4554-4557 (2016)
 J. Kaufman, et al. “3D Printing Preforms for Fiber Drawing and Structured Functional Particle Production,” in Photonics and Fiber Technology 2016 (ACOFT, BGPP, NP), OSA Technical Digest (online) (Optical Society of America, 2016), paper AW4C.1.