提出了一种新型的四排短轴渐减椭圆空气孔阵列的单模单偏振光子晶体光纤结构，并以完美匹配层为边界条件采用全矢量有限元方法研究了该光纤的各种特性及其各种参量随入射波长变化规律。研究表明，提出的光子晶体光纤结构是实现更宽带宽、色散平坦、单模单偏振运用的有效方案；在入射光波长为1.550 μm时，单模单偏振光子晶体光纤的模式双折射高达2.752×10-3，拍长为0.564 mm；x偏振模的限制损耗为0.139 dB/km，y偏振模的限制损耗是16.890 dB/km；对比x偏振模损耗情况，y偏振模可以在较短的光纤中被衰减掉，从而实现单模单偏振运用；x偏振模的数值孔径为0.415，有效模场面积为3.667 μm2, 非线性系数为28.740 (W·km)-1。入射光波长在1.347~1.691 μm的范围内，该光纤呈现出色散平坦特性，使其在超连续谱产生、脉冲传输等领域具有广阔应用前景；该光纤能够在入射光波长600 nm较宽范围内实现单模单偏振运用。

A novel single-polarization single-mode photonic crystal fiber (SPSM-PCF) design with two arrays of four lines of semiminor-axis-decreasing elliptical air-holes is proposed. The proposed SPSM-PCF characteristics are investigated by using a full-vector finite element method (FEM) with perfect matched layer (PML) boundary conditions. The modal birefringence of the proposed SPSM-PCF is as high as 2.752×10-3 at the wavelength of 1.550 μm and the beat length is 0.564 mm. The confinement loss of the x-polarization mode is as low as 0.139 dB/km, whereas the loss of the y-polarization mode is as large as 16.890 dB/km. Compared with the case of x-polarization mode, the y-polarization mode can be suppressed with a shorter fiber length. The numerical aperture is 0.415, the effective mode-field area is 3.667 μm2, and the nonlinear coefficient is 28.740 (W·km)-1 at the wavelength of 1.550 μm. The total dispersion profile of the SPSM-PCF is dispersion-flattened with the wavelength range from 1.347 to 1.691 μm. This dispersion property makes the proposed SPSM-PCF useful for various applications such as supercontinuum spectrum generation and pulse transmission. The spectral region of input light for SPSM operation is as wide as 600 nm. It indicates that this is a good solution to realize broadband dispersion-flattened SPSM operation.