Studying the limits of production rate and yield for the volume manufacturing of hollow core photonic band gap fibers.

Hollow core photonic band gap fibers have great potential in low latency data transmission and power delivery applications, but they are currently only fabricated in research scale fabrication facilities, with km-scale lengths. To drive cost reduction and volume manufacturing it is essential to be able to upscale the preform size, but before embarking on costly experimental attempts it is useful to apply fluid dynamics models to study how the fiber drawing dynamics would be affected by such a change. In this work we use a fluid dynamics model to virtually draw increasingly longer lengths of the same fiber from preforms of identical length but different diameters. Taking advantage of our fast numerical model we explore the physical dynamics of the draw process. We discover that the draw tension is the key thermodynamic parameter and that an upper length limit exists beyond which undesirable distortions in the microstructure become difficult to control. These mechanisms are identified and possible mitigation methods described which could allow the fabrication of over 200 km fiber from a single preform.