微结构光纤偏振拍长的宽带稳定性及传输特性

Broadband stability of polarization beat-length and transmission characteristics in microstructure fiber

针对一种包层空气孔呈外圆内方阵列分布的微结构光纤,仅在包层结构中引入一种非对称结构来调节偏振拍长的宽带稳定性.应用虚位移全矢量有限差分光束传播法分析了内层矩形空气孔阵列的长宽变化对双折射和偏振拍长色散特性的影响.研究结果表明:仅利用一种非对称结构也可以有效地抑制微结构光纤双折射的非线性变化,不仅使偏振拍长在较宽的波长范围内具有较好的稳定性,而且优化后的包层结构中仅有一种尺寸的圆形空气孔,空气孔分布阵列为规则的矩形和圆形阵列,降低了工艺制作的难度.

For a microstructure fiber with the cylindrical air holes array around the rectangle in cladding, the broadband stability of polarization beat length was adjusted and regulated by introducing only one asymmetrical structure in cladding. What birefringence and polarization beat length dispersion characteristics influenced by the inner rectangular array of air holes were analyzed with Imaginary Distance Full Vector Beam Propagation Method. The results show that only one asymmetric structure can effectively suppress non-linear change of the birefringence in microstrueture optical fiber. Not only has the polarization beat length a good stability over a wide wavelength range, but also there is only one size of the circular array of air holes distributed in the optimized packet layer structure. The arrays of air holes are regular arrays of rectangular and circular. It reduces the difficulty of the production process. The polarization beat length of the microstructure fiber changes between 59--63mm in the range of 1.2--1.7μm wavelength and the relative change rate of is about 6.3%. The operating bandwidth is up to 500nm covering 1310nm and 155Onto two common communication wavelength window. It is more suitable for making the fiber broadband wave plate.