Polarization Sensitive Multi-Hollow-Core Antiresonant Fiber

The recent expansion of interest to use hollow-core fibers for telecommunications, nonlinear studies, and beam delivery calls for fiber-based components for all-fiberized integration. Of particular interest is the development of an inline multicore polarization beam splitter. To this end, multicore fiber designs have been investigated, but mostly in simulation studies. Reports on experimental results are scarce and their performances have been limited. In this work, we present a design and fabrication of a polarization-dependent triple hollow-core anti-resonant fiber (PD-THC-ARF). Numerical simulations predict that the fiber design allows for polarization beam splitting with a polarization extinction ratio (PER) greater than 20 dB. Experimentally, the fabricated PD-THC-ARF achieves polarization beam splitting with a PER greater than 7.8 dB. This is the first experimental demonstration of polarization beam splitting in an antiresonant hollow-core fiber. The PER can be improved by refining fabrication to achieve better uniformity of the capillary glass wall thickness. Furthermore, the fabricated fiber can serve as a polarization filter, a polarization-dependent coupler, or a spectral comb filter, with PER of up to 23 dB. The results of this study encourage the development of various hollow multicore antiresonant fiber components, such as beam combiners, mode converters, and multicore fiber amplifiers.