Highly Birefringent Anti-Resonant Hollow-Core Fiber With a Low Loss

In recent years, anti-resonant hollow-core fibers (known as AR-HCFs) have gradually become one of the research hotspots. However, their loss and birefringence properties are often difficult to reconcile. In this letter, a new structure of AR-HCF is proposed by analyzing the factors that affect their loss and birefringence. The fiber features a negative curvature core surround, double-layer structures, and two half-tubes containing nested tubes. Based on COMSOL Multiphysics, the designed AR-HCF has a high birefringence of $1.3\times 10 ^{-4}$ and a low confinement loss of 6.1 dB $\cdot $ km−1 at 1550 nm, a bandwidth of 40 nm, bending resistance and single-mode operation.