A Hollow-Core Fiber with High Birefringence in the Near-Infrared Band

We propose a highly birefringent hollow-core fiber in the near-infrared band (1.75-2.25 μm). The confinement loss of the fiber is less than 0.8 dB/m and the birefringence is greater than 1.2×10
⁻⁴
in the range from 1.75 μm to 2.25 μm, and the confinement loss of the lowest x-pol fundamental mode is 0.034 dB/m at 2.05 μm and the lowest y-pol fundamental mode is 0.041 dB/m at 1.87 μm, and the max birefringence value is 1.66 × 10
⁻⁴
at 1.75 μm. The effect of semicircular tube spacing z and anti-resonance ring on the transmission performance of the fiber is also investigated. The stable 10–
⁴
birefringence indicates that the proposed fiber has potential applications in fiber gyroscopes, fiber sensors, and fiber lasers.