分析了保偏光纤偏振特性及其拍长和偏振消光比的基本测量原理,并根据单模保偏光纤基模的2个正交偏振模分量HF^x11与HE^y11间的相位差与波长的关系,推导出偏振拍长的测量关系式,提出了测量保偏光纤偏振特性的波长扫描调制法。采用此方法对熊猫型保偏光纤(YOFC-3367WY)的偏振特性进行了验证性实验研究。拍长和偏振消光比的测量结果表明,在该保偏光纤工作波长处试验结果与理论分析相当一致,说明该方法具有简单易行、测量精度高的优点。
We analyze the polarization properties of polarization maintaining fiber and its basic measurement principle. Accord ing to the dependence of the phase difference between the two orthogonally polarized modes HF^x11 and HF^x11 on the wavelength of the injected laser,the wavelength-sweeping modulation method is adopted to measure the beat length of the fiber. The beat length and polarization extinction ratio of the PANDA polarization maintaining fibers are investigated in detail. Theoretical and experimental results are consistent with each other and both of them indicate that this method has the ad vantage of high precision and it is easy to operate .