双芯光纤偏振分束器是一类基于模式干涉的偏振分束器,是以双芯光纤作为定向耦合器,经过双芯光纤的耦合区域后实现的偏振选择性输出,因而其输入、输出端的形状和尺寸会影响光的输出功率及特性。基于椭圆双芯光纤,在分束器的输出消光比满足一定要求(大于20dB)的情况下,借助于RSOFT软件的Beamprop模块,研究双芯光纤偏振分束器输入、输出端口的形状和尺寸以及输入光的波长和线偏振角度对偏振选择特性的影响,及其可能的工作带宽和制作容差。结果表明,双芯光纤偏振分束器形状为S-Bend,X和Z方向的尺寸分别为40μm和4000μm的端口,输入光的工作带宽可以大于7.5nm,对应的耦合区长度较短,约为209.87mm。 The dual-core fiber polarization beam splitter is a type of polarization beam splitter based on mode interference. It is a polarization-selective output that is realized by the dual-core fiber as the directional coupler after passing through the coupling region of the dual-core fiber. Therefore, Shape and size will affect the light output power and characteristics. Based on the elliptical double-core fiber, with the help of the Beamprop module of RSOFT software, the shape and size of the input and output ports of the dual-fiber optical fiber polarization splitter are studied under the condition that the output extinction ratio of the beamsplitter satisfies a certain requirement (more than 20dB) The effect of input light wavelength and linear polarization on polarization selectivity and its possible operating bandwidth and fabrication tolerances. The results show that the shape of dual-fiber optical fiber polarization beam splitter is S-Bend, and the size of 40μm and 4000μm in X and Z directions respectively. The working bandwidth of input light can be larger than 7.5nm, and the length of corresponding coupling region is short 209.87mm.