▎ 摘　　要

An ultra-broadband polarization splitter based on graphene layer-filled dual-core photonic crystal fiber (GDC-PCF) that can work in a wavelength range from 1120 nm to 1730 nm is proposed in this paper. Through optimizing fiber configuration, the polarization splitter has an extinction ratio of -56.3 dB at 1.55 mu m with a fiber length of 4.8 mm. Compared with the photonic crystal fiber reported splitters, to our knowledge, the GDC-PCF splitter with the extinction ratio below 20 dB has a super wide bandwidth of 610 nm. Due to the excellent splitting characteristics, the GDC-PCF will be used in coherent optical communication systems in a wavelength range from infrared to mid-infraed.