Exploring the effect of the core boundary curvature in hollow antiresonant fibers

Through numerical simulations, we systematically study the leakage loss properties of a simplified novel hollow antiresonant fiber in which the core is surrounded by semi-elliptical elements. These studies lead to new insight into the effect of the curvature of the core boundary in antiresonant fibers. We observe in particular that in our design, there exists an optimum curvature of the elements—which we quantify simply through the aspect ratio of the ellipses—for which the fiber’s leakage loss is minimized. Furthermore, it is shown that elliptical elements can lead to orders of magnitude loss reduction as compared with similar fibers with circular ones