Low loss double cladding nested hollow core antiresonant fiber

A double cladding nested antiresonant hollow core fiber is reported in this article. We demonstrated that the addition of nested elements in the second cladding ring and the proper optimization of structural parameters lead to the loss reduction by more than five orders. The numerical simulation exhibits a loss of less than ∼ 0.1 dB/km over the O, E, S, C, L telecom bands, with the minimum loss of 0.001 dB/km at 1.40 µm wavelength with a fiber core diameter of 33 µm. The fiber also shows a better performance in terms of bending loss as well as single modeness, and may have effective applications in a telecommunication system.