提出了一种高双折射多孔光纤几何结构，其包层气孔呈圆形晶格阵列。应用有限差分波束传播法对其双折射特性进行了数值模拟，分析了截面结构参数对双折射特性的影响，比较了圆形、四边形和八边形晶格阵列产生的双折射。研究结果表明，这种圆形晶格多孔光纤的模式双折射在1.7～2.0 μm波长范围内可达到10-2量级；在截面结构参数相同的情况下，圆形晶格多孔光纤比四边形和八边形晶格多孔光纤具有更高的双折射，其偏振拍长值在0.6～2.0 μm波长范围内都处于亚毫米量级。这种光纤适合于制作光纤偏振器件或偏振干涉型光纤传感器。

A high-birefringence holey fiber geometry is proposed, in which the cladding holes form a round lattice array. The birefringence properties are simulated by the finite difference beam propagation method. The influence of the cross-section structure parameters on birefringence is analyzed. The birefringence performances from round, quadrilateral and octagonal lattice arrays are compared. The results show that the modal birefringence of the holey fiber with round lattice can reach the order of 10-2 in 1.7~2.0 μm wavelength range. In the cross-section under the same structural parameters, the holey fiber with round lattice has a higher birefringence than those with quadrilateral and octagonal lattices. The polarization beat length is in sub-millimeter level in the 0.6~2.0 μm wavelength range. This fiber is suitable for making polarization interferometric fiber devices and sensors.