In this paper, an asymmetric photonic crystal fiber (PCF) polarization filter near the gold-clad hole based on surface plasmon resonance (SPR) is proposed. The outer walls of the two air holes in the y-direction are coated with a gold film, and the two kinds of cladding air holes are introduced near the coated holes to increase the difference in the coupling strength of x and y polarization modes and SPP modes, thus separating the two polarization states. The finite element method is used to study the characteristics of the polarization filter, and the result shows that the polarization loss in the y-direction is as high as 1565.98 dB/cm at $1.55\mathrm{\mu }\mathrm{m}$, while the loss in the x-direction is relatively small. When the fiber length is 1 mm, the crosstalk peak reaches 1322.7 dB. From $1\mathrm{\mu }\mathrm{m}$ to $2\mathrm{\mu }\mathrm{m}$ (range: 1000 nm), the crosstalk is always greater than 20 dB. If four kinds of pores with different sizes are used in the cladding layer, the symmetry around the gold-coated holes will be destroyed, and a better filtering effect can be obtained. The excellent performance of the proposed polarization filter makes it a good candidate material for broadband polarization filters.

本文提出了一种基于表面等离子体共振（SPR）的包金孔附近的非对称光子晶体光纤（PCF）偏振滤波器。在y方向上的两个气孔的外壁涂有金膜，并在涂覆的孔附近引入了两种包层气孔，以增加x和y偏振模与SPP的耦合强度之差。模式，从而将两个极化状态分开。用有限元方法研究了偏振滤波器的特性，结果表明，在y方向上的偏振损耗高达1565.98 dB / cm。$\mathrm{1个}。55\mathrm{\mu }\mathrm{米}$，而沿x方向的损耗则相对较小。当光纤长度为1 mm时，串扰峰值达到1322.7 dB。从$\mathrm{1个}\mathrm{\mu }\mathrm{米}$ 到 $2\mathrm{\mu }\mathrm{米}$（范围：1000 nm），串扰始终大于20 dB。如果在覆层中使用四种不同尺寸的孔，则金孔周围的对称性将被破坏，并且可以获得更好的过滤效果。所提出的偏振滤波器的优异性能使其成为宽带偏振滤波器的良好候选材料。