Low-loss polarization filter at 1.55 μm based on photonic crystal fiber

In this paper, a photonic crystal fiber with the gold layer is simulated by finite element method. Due to birefringence, surface plasmon resonance only occurs in the y-polarization direction. The loss of y-polarization mode is much larger than that of x-polarization mode. The photonic crystal fiber is suitable for the polarization filter. The polarization filter has the short length and high extinction ratio. Furthermore, the insertion loss of the x-polarization mode is only 0.07 dB, which is the smallest as far as we know.