提出了一种新型的微结构纤芯的光子晶体光纤,在纤芯中引入10个呈矩形排列的小圆空气孔,包层空气孔呈阶梯渐增结构。采用全矢量有限元法,通过改变纤芯小圆空气孔的大小和二者之间的孔间距,研究了这种光纤的基模模场、双折射、限制损耗和色散特性。研究结果表明,当小圆半径r1=0.225μm,孔间距Λ2=1.30μm时,在波长1.55μm处,双折射为3.22×10-2,限制损耗低至4.92×10-8 dB/m,且在0.6~2.0μm之间可获得三个零色散点。另外,通过优化纤芯结构参数,在波长1.55μm处,双折射最大值可达3.45×10-2,损耗最低达2.88×10-9 dB/m。该设计为在光纤通信、光纤传感方面的应用提供了理论基础。 A new kind of photonic crystal fiber with micro-structure core is proposed. Ten small circular air holes with rectangular arrangement are introduced into the core, and the air hole of the cladding layer is gradually stepped. By using the full vector finite element method, the fundamental mode field, birefringence, limiting loss and dispersion characteristics of the fiber are studied by changing the size of the aperture of the small core and the distance between the two. The results show that the birefringence is 3.22 × 10-2 at a wavelength of 1.55μm and the limit loss is as low as 4.92 × 10-8 dB / m when the radius of small circle r1 = 0.225μm and the hole spacing Λ2 = 1.30μm, Between 0.6 ~ 2.0μm three zero-dispersion points are available. In addition, by optimizing the parameters of the core structure, the maximum birefringence can reach 3.45 × 10-2 at the wavelength of 1.55μm with the lowest loss of 2.88 × 10-9 dB / m. The design provides a theoretical basis for the application in optical fiber communication and optical fiber sensing.