Abstract:Photonic crystal optical fiber is made of high-purity quartz glass, which offers the advantages of low bending loss and robust environmental adaptability. It is particularly well-suited for high-stability optical fiber gyroscopes in demanding application environments. The internal micropores of traditional photonic crystal fibers occupy a significant amount of space, leading to a large fiber diameter. The primary operating band is 1550nm, which does not meet the demands for miniaturization and high precision in fiber gyroscopes. This paper proposes a double-layer air hole structure to reduce the diameter of the optical fiber, minimize optical fiber loss, and control polarization correlation. A sample of Φ 60 / 100 μ m photonic crystal fiber was prepared using the "stacking-pull" method. The fiber loss was measured at 6.5dB / km@850nm, and the polarization crosstalk was -15dB@100m.