Broadband low loss single-polarization single-mode hollow-core antiresonant fiber with hybrid cladding

A hollow-core antiresonant fiber (HC-ARF) using nested hybrid silica/silicon cladding is proposed for single-polarization single-mode (SPSM) and broadband. The HC-ARF design consists of four cladding tubes with nested tubes, and a cladding tube with an inner surface coated with silicon. Single-polarization guidance is realized by adjusting the thickness of the silicon layer to control the coupling between the y-polarization and cladding mode, and by optimizing the diameter of the nested tube, the high-order modes (HOMs) can be significantly suppressed. The simulation results show that the performance of SPSM can be improved by selecting appropriate structural parameters. The polarization extinction ratio (PER) is up to 139,804 and the y-polarization loss is 133 dB / m, the x-polarization loss is as low as 0.00095 dB / m at 1550 nm. Moreover, high-order mode extinction ratio (HOMER) between the HOMs and x-polarization, as high as 40,360, is obtained in proposed fiber with HOMs loss of 32.38 dB / m. Particularly, the proposed fiber also has a bandwidth of 230 nm (1450 to 1680 nm) with x-polarization mode loss <1 and 0.08 dB / m bending loss when the fiber is bent in the y-direction at a bending radius of 5 cm. The proposed fiber has potential applications in short-distance, polarization-sensitive fiber systems.