Two ultra-broadband polarization filters based on Structure 1 and Structure 2 are reported and characterized in terms of attenuation, crosstalk, bandwidth, and polarization filtering properties by the finite element method. Structure 1 is formed by introducing partial elliptical air holes in the first layer of the square-lattice gold-filled photonic crystal fiber. Based on the design solution of Structure 1, Structure 2 is arranged by using circular air holes with the changed transverse pitch to replace elliptical ones. Numerical results show that high resonance intensities of 2265.07 and 1831.83 dB/cm for y polarization, together with the corresponding x polarization losses of 0.50 and 0.18 dB/cm at respective communication wavelengths of 1.55 and 1.31 μm can be achieved by varying the gold film thickness for Structure 1.Moreover, the design of Structure 2 with all circle holes can also realize a high resonance loss of 1942.54 dB/cm for y polarization with a low loss of 0.43 dB/cm for x polarization at 1.55 μm. Structure 1 and Structure 2 with the fixed fiber length of 300 μm can obtain the crosstalk values of −590.09 and −506.07 dB at 1.55 μm, together with the bandwidths of 1500 and 900 nm, respectively. Additionally, two types of designs represent good produce tolerances. These results show a high potential of the suggested fiber for application in polarization-dependent filtering and other polarizing devices.

报告了两个基于结构1和结构2的超宽带偏振滤波器，并通过有限元方法对衰减，串扰，带宽和偏振滤波特性进行了表征。通过在方格形金填充光子晶体光纤的第一层中引入部分椭圆形气孔来形成结构1。根据结构1的设计方案，结构2通过使用具有改变的横向间距的圆形气孔代替椭圆形气孔来布置。数值结果表明，y极化的高共振强度为2265.07和1831.83 dB / cm ，以及相应的 x 通过改变结构1的金膜厚度，可以在1.55和1.31μm的相应通信波长下实现0.50和0.18 dB / cm的极化损耗，此外，具有全圆孔的结构2的设计还可以实现高的谐振损耗y极化为1942.54 dB / cm，x 极化在1.55μm时具有0.43 dB / cm的低损耗 。光纤长度固定为300μm的结构1和结构2在1.55μm处可获得的串扰值为-590.09和-506.07 dB，带宽分别为1500和900 nm。另外，两种类型的设计代表了良好的产品公差。这些结果表明，所建议的光纤在偏振相关滤波和其他偏振设备中的应用具有很高的潜力。