Low-loss coupling by injecting tapered solid-core fibers into the hollow-core of anti-resonant fibers

Anti-resonant hollow-core fibers (AR-HCFs) have attracted intensive attention. In order to realize low-loss coupling between anti-resonant hollow-core fibers and solid-core fibers, tapered solid-core fibers are injected into the hollow-core of AR-HCFs. For the ice-cream type anti-resonant hollow-core fibers whose mode field diameter are about 35μm, the coupling efficiency is over 85% when the tapered diameters are around 35~42μm, and the all-fiber structure is the tapered single-mode fibers (HI-1060) injecting into the hollow-core of AR-HCFs and the multi-mode fibers abutted on another end of AR-HCFs as output end. The experimental results show that the maximum coupling efficiency is 74.59%, which provides a feasible low-loss coupling scheme for AR-HCFs with large mode field diameters.