Agradecimentos: The authors thank F. Amrani and F. Delahaye with the GPPMM Group, XLIM Institute, University of Limoges, for contributing to fiber fabrication. This work was supported in part by the S & atilde;o Paulo Research Foundation (FAPESP) under Grant 2022/10584-9, in part by the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) under Grant 310650/2020-8, 309989/2021-3 and 305024/2023-0, and in part by the Minas Gerais Research Foundation (FAPEMIG) under Grant RED-00046-23 Ver menos

Abstract: The modulation efficiency of a tubular-lattice hollow-core fiber (HCF) employing flexural acoustic waves is investigated in detail for the first time. The main acousto-optic properties of the HCF are evaluated, using 2D and 3D models based on the finite element method. The induced coupling of the fundamental and first higher-order modes is simulated from 743 to 1355 nm. The most relevant acoustic (amplitude, period, strain, energy) and optical (effective index, beat length, birefringence, coupling coefficient) parameters are analyzed. The simulations are compared to experimental results and indicate higher modulation performance in HCFs compared to standard optical fibers. In addition, useful insights into the design and fabrication of all-fiber acousto-optic devices based on HCFs are provided, enabling potential application in tunable spectral filters and mode-locked fiber lasers Ver menos