单偏振单模微结构聚合物光纤理论设计

Theoretical design of single polarization single mode microstructured polymer optical fibers

采用全矢量有限元法并结合完美匹配边界条件,设计实现了一种新型结构的单偏振单模(single polarization single mode,SPSM)微结构光纤(Microstructured optical fibers,MOFs),以聚合物聚甲基丙烯酸甲酯(polymethyl methacrylate,PMMA)为基材,对其偏振模场、快轴模和慢轴模截至波长和约束损耗进行了研究。结果发现,通过改变光纤结构参数,可以使光纤基模两个正交偏振态截止波长不同,光纤中只能传输基模的一个偏振态(慢轴模)。若调整光纤单偏振单模工作区在聚合物光纤通信窗口650nm附近,该光纤传输慢轴模的约束损耗低于0.06 dB/m。该研究为本体聚合技术制备单偏振单模微结构聚合物光纤提供了理论依据。

A new structure of single polarization single mode（SPSM） microstructured polymer optical fibers（MPOFs） is proposed and numerically analyzed by using a full vector finite element method with anisotropic perfectly matched layers.The polarization mode fields,the cutoff wavelength of fast-axis modes and slows-axis modes,and the confinement loss were theoretically studied based on polymethyl methacrylate（PMMA）.From the numerical results,it is confirmed that the cutoff wavelength of two-orthogonal polarized states can be adjusted by varying the structure parameters of the proposed fibers,and one polarized states of fundamental mode（slow-axis mode） is transmitted only.If the wavelength region of SPSM is tuned at communication wavelength of polymer optical fiber（POF） of 650 nm,the confinement loss of slow-axis mode was less than 0.06 dB/m.This result is a theoretical foundation to fabricate SPSM-MPOFs by adopting chemical in situ monomer polymerization technology.