Design Issues of Novel Hollow Core Optical Fibers
for Optical Communications
Abstract
This keynote talk presents a comprehensive analysis of the design challenges in developing novel hollow core optical fibers (HCs) for optical communications, focusing on fibers with record-low loss. Using numerical simulations with COMSOL Multiphysics, the authors evaluate the sensitivity of fiber performance to geometric variations, specifically core diameter, cladding tube sizes, strut thickness, and inter-tube gaps. The study demonstrates that even slight deviations in these parameters significantly affect leakage loss and bandwidth. In particular, reductions in the main cladding tube diameter and core size, or inconsistencies in the thickness of antiresonant elements, lead to an increase in leakage losses by orders of magnitude. These findings explain the variations in bandwidth observed between different sections of a recently reported high-performance HC fiber, despite similar overall attenuation levels. The research highlights those technological imperfections during fiber fabrication, such as variations along the fiber length, critically limit the usable bandwidth, a major consideration for wavelength-division-multiplexed systems. The work underscores the importance of strict geometric control in the manufacturing process and suggests that minimizing the core size without degrading performance remains a significant challenge.
Short Biography
Prof Belardi obtained a PhD at the ORC, University of Southampton, United Kingdom. He held an Excellence Research Chair in Photonics at the University of Lille, France. He was also the General Coordinator of the European Project GADEIRE. He joined the University of Parma, Italy, in late 2023. Prof. Belardi is one of the main pioneers in the field of hollow core antiresonant optical fibers, particularly with the very first theoretical conception, proposal, and fabrication, in 2013, of a novel structure of hollow core optical fiber, that became later the most important candidate for high-capacity data transmission with low latency and loss. Moreover, he has given major contributions to the development of simplified hollow core optical fibers for practical use in the mid-infrared spectral range.
