Simulation of the Structural Parameters of Anti-resonant Hollow-core Photonic Crystal Fibers

Anti-resonant hollow-core photonic crystal fiber (AR-HCF) has unique advantages, such as low nonlinearity and high damage threshold, which make it a promising candidate for high-power laser delivery at distances of tens of meters. However, due to the special structure, optical properties such as modefield profile and bending loss of hollow-core fibers are different from those of solid-core fibers. These differences have limited the widespread use of AR-HCF in practice. In this paper we conduct numerical analysis of AR-HCFs with different structural parameters, to analyze their influences on an AR-HCF???s optical properties. The simulation results show that with a 23-??m air-core diameter, the fundamental mode profile of an AR-HCF can well match that of the widely used Nufern???s 20/400 fiber, for nearlysingle-mode power delivery applications. Moreover, with the ratio of cladding capillary diameter to aircore diameter ranging from 0.6 to 0.7, the AR-HCF shows excellent optical characteristics, including low bending sensitivity while maintaining single-mode transmission at the same time. We believe these results lay the foundation for the application of AR-HCFs in the power delivery of high power fiber laser systems.