High-crosstalk polarization filter based on double-D photonic crystal fiber with amethyst and gold

Polarization filters based on surface plasmon resonance (SPR) have undergone rapid development in recent years. In this work, a dual D-type PCF polarization filter based on SPR is designed and analyzed. The filter improves the limiting loss of the core mode by gilding the semi-circular split ring and inlaying amethyst. The influence of the structural parameters of the filter on the filtering characteristics is analyzed by the finite element method. The results show that the core mode losses of the x and y polarized light are 32[Formula: see text]dB/cm and 910.56[Formula: see text]dB/cm at 1.55[Formula: see text][Formula: see text]m, respectively. For a fiber length of 1000[Formula: see text][Formula: see text]m, the crosstalk and bandwidth are 763.11[Formula: see text]dB and 700[Formula: see text]nm, respectively. In addition, the impact of manufacturing errors in the structural parameters on the filter performance is discussed. The filter has excellent filtering characteristics and large potential in optical communication and optical sensing.