Designing hollow core nested anti-resonant fiber with ultra-low loss using finite difference eigen mode solver

Abstract

We report an optimized design of six-ring nodeless antiresonant fiber (NARF) in both single and nested ring configurations in the visible wavelength regime. Proposed fibers exhibit a record low loss of 6.7 × 10−4 dB km−1 at 630 nm with less than 1 dB km−1 over a broad 330 nm bandwidth, achieved by the incorporation and optimization of nested elements in the primary cladding tubes. A comprehensive analysis, utilizing finite difference algorithm, to study the role of structural parameters of the hollow core fiber viz. tube thickness and gaps between the tubes on the loss spectrum is also presented. A comparative analysis of NARF designs using tube thickness in different anti-resonant bands is also included. The bend robustness, polarization analysis, dispersion, and fabrication tolerances are investigated. Proposed low-loss fibers in the visible wavelength regime can drastically bring down the cost and complexity of quantum communication systems.