Ultralow loss hollow-core negative curvature fibers with nested elliptical antiresonance tubes

TL;DR

This paper introduces new nested elliptical antiresonant hollow-core fibers with record low transmission loss and improved bending resistance, advancing the development of ultra-low loss fibers for near-infrared applications.

Contribution

The study proposes and compares three novel nested tube structures for hollow-core negative curvature fibers, achieving record low loss and enhanced bending performance.

Findings

Nested elliptical antiresonant fiber 1 has the lowest transmission loss.

Transmission loss as low as 6.45×10⁻⁶ dB/km at 1.06 μm.

Bending loss below 2.99×10⁻² dB/km at 5 cm radius.

Abstract

Hollow-core negative curvature fibers can confine light within air core and have small nonlinearity and dispersion and high damage threshold, thereby attracting a great deal of interest in the field of hollow core fibers. However, reducing the loss of hollow-core negative curvature fibers is a serious problem. On this basis, three new types of fibers with different nested tube structures are proposed in the near-infrared spectral regions and compared in detail with a previously proposed hollow-core negative curvature fiber. We used finite-element method for numerical simulation studies of their transmission loss, bending loss, and single-mode performance, and then the transmission performance of various structural fibers is compared. We found that the nested elliptical antiresonant fiber 1 has better transmission performance than that of the three other types of fibers in the spectral range of 0.72-1.6 {\mu}m. Results show that the transmission loss of the LP01 mode is as low as 6.45*10-6 dB/km at {\lambda} = 1.06 {\mu}m. To the best of our knowledge, the record low level of transmission loss of hollow-core antiresonant fibers with nested tube structures was created. In addition, the nested elliptical antiresonant fiber 1 has better bending resistance, and its bending loss was below 2.99*10-2 dB/km at 5 cm bending radius.