Ultra-low-loss anti-resonant hollow-core fiber with nested concentric circle structures

Abstract

In this paper, a novel nested concentric circle anti-resonant hollow-core fiber with double-layer cladding structure and an outer cladding ring is proposed. By optimizing the structural parameter of the novel fiber, its confinement loss reaches 0.0001 dB/km at the wavelength of 1.55 μm, which is one or two orders of magnitude lower than the conventional fiber loss, and the ratio of the lowest high-order mode loss to fundational mode loss also reaches a maximum of 60,000. In the range of 1.14–1.78 μm, its loss is less than 0.005 dB/km, indicating that its bandwidth is also wide. Its surface scattering loss is 0.0017 dB/km, and the bending loss is 0.0011 dB/km. Furthermore, we discuss the effect of the movement of the nested concentric circles and the rotation of the cladding structure on the fiber properties. Consequently, we believe that the designed fiber will lay a theoretical foundation for the fabrication and application of new hollow-core fibers.