Enhanced birefringence in conventional and hybrid anti-resonant hollow-core fibers

A hollow-core anti-resonant fiber (HC-ARF) design based on hybrid silica/silicon cladding is proposed for single-polarization, single-mode and high birefringence. We show that by adding silicon layers in a semi-nested HC-ARF, one of the polarization states can be strongly suppressed while simultaneously maintaining low propagation loss other states, birefiringence. The optimized HC-ARF exhibits loss, birefringence, polarization-extinction ratio 0.05 dB/m, 0.5 × 10 −4 , >300 respectively y-polarization x-polarization >5 dB/m at 1064 nm. also has bend-loss thus coiled to small bend radii 5 cm having ≈0.06 loss.