MicroStructure Element Method (MSEM): viscous flow model for the virtual draw of microstructured optical fibers

Abstract

Abstract:We propose a new method to accurately model the structural evolution of a microstructured fiber (MOF) during its drawing process, given its initial preform structure and draw conditions. The method, applicable to a broad range of MOFs with high air-filling fraction and thin glass membranes, is an extension of the Discrete Element Method; it determines forces on the nodes in the microstructure to progressively update their position along the neck-down region, until the fiber reaches a final frozen state. The model is validated through simulation of 6 Hollow Core Photonic Band Gap Fibers (HC-PBGFs) and is shown to predict accurately the final fiber dimensions and cross-sectional distortions. The model is vastly more capable than other state of the art models and allows fast exploration of wide drawing parameter spaces, eliminating the need for expensive and time-consuming empirical parameter scans.

Volume Manufacturing of Hollow Core Photonic Band Gap Fibers: Challenges and Opportunities

“…To predict the fiber draws in this study we used the MicroStructure Element Method (MSEM) [2]; a recent numerical model for the simulation of microstructured fiber draws that has been demonstrated to accurately reproduce the draw of an HC-PBGF fiber with hundreds of holes [3]. The MSEM discretizes the geometry and then it applies fluid forces (viscosity, pressure and surface tension) to evolve the structure through the draw.…”

“…If this technology is ever to replace conventional fibers in at least selected telecoms applications, the capacity to volume-produce HC-PBGFs in lengths exceeding 100km needs to be developed. In this paper we use a recently developed fluid dynamics model [2,3] to virtually study, for the very first time, the draw of fibers up to 500km long. The challenges to be faced in order to achieve a good microstructure, and therefore guidance properties, are discussed.…”

Demonstration of an 11km Hollow Core Photonic Bandgap Fiber for Broadband Low-latency Data Transmission

“…Note that previous reports of similarly extreme structures were characterized by high loss [8,9], and/or shorter lengths [10]. We employed optimization prior to fiber drawing using a novel fluid-dynamic model [11], capable of reproducing the complex HC-PBGF drawing process, Fig. 1a-c, in association with improved control of hole pressurization, in order to minimize any distortions of the core surround -a known problem at high expansion values that can lead to increased scattering loss [12] and to instability during the fiber draw.…”

Combined structural and optical modelling tool to optimise design and fabrication of hollow core photonic band gap fibres

“…Two models are used in this work: the MSEM -a fluid dynamics model that predicts the microstructure evolution through the draw from a given starting cane 3 , and a full vector FEM-based electromagnetics model that calculates the optical properties of each virtually simulated fibre 6 . The structure used by the FEM stage is interpreted from the MSEM output using mass conservation routines to distribute glass to the nodes, fillets and struts appropriately.…”

“…In this paper we present a modelling tool that combines a recently developed fluid dynamics model that can predict the geometry of fibres from their preform for any arbitrary draw parameter 3 , with electromagnetics simulations to predict their final optical properties. The toolset is validated by comparing its results with an older experimental draw 4 .…”