The present paper proposes a novel design for achieving single-polarization single-mode (SPSM) operation at 1550 nm in photonic crystal fiber (PCF), using a rectangular-lattice PCF with two lines of three central air holes enlarged. The proposed PCF composed entirely of silica material is modeled by a full-vector finite element method with anisotropic perfectly matched layers. Simulations show that single-polarization operation within broad wavelength range can be easily realized with the proposed structure. The wide-band SPSM operation features, the low confinement losses, and the small effective mode area are the main advantages of the proposed PCF structure. A SPSM-PCF with confinement loss less than 0.1 dB/km within wavelength range from 1370 to 1610 nm and effective mode area about 4.7 micron2 at 1550 nm is numerically demonstrated.

应用全矢量有限元方法，分析了椭圆形高折射率芯Bragg光纤的偏振和色散特性，详细讨论了光纤结构参量对模式双折射的影响，结果发现：椭圆形高折射率芯Bragg光纤的模式双折射在10^－3量级，比传统保偏光纤高出一个量级，且随波长的增加而单调递增；模式双折射随包层低折射率材料填充比的增加而减小，但与包层周期的变化几乎无关．此外，提高椭圆率或材料间的折射率比可显著增强模式双折射．研究结果有助于设计高性能的一维微结构保偏光纤．