Ultrawide bandwidth dual sakura hollow-core antiresonant fiber polarization beam splitter

Abstract

A dual sakura hollow-core antiresonant fiber (DSHC-ARF) is proposed for developing an ultrawide-bandwidth polarization beam splitter (PBS). An air gap is introduced into the fiber between dual sakura hollow cores acting as a mode-coupling channel, which determines the implementation of a DSHC-ARF-based PBS. We demonstrate the wavelength dependence of coupling length can be reduced by introducing nested tubes and investigate their impact on single-mode operation further. Through optimizing the fiber, a high-performance PBS based on a 4.42 cm long DSHC-ARF can be obtained with an ultrawide bandwidth of 460 nm ranging from 1400 to 1860 nm, good single-mode operation with a higher-order mode extinction ratio above 100, and a low fundamental mode loss below 0.543 dB.