Fiber Optics Group, Department of Physics, University of Ottawa, Ottawa, Canada K1N 6N5.
Opt Lett. 2010 Jan 15;35(2):193-5. doi: 10.1364/OL.35.000193.
We report on what we believe to be the first truly distributed birefringence measurement of polarization-maintaining fibers (PMFs) based on transient Brillouin grating (TBG). A TBG is created by two short pump pulses in the slow axis of the PMF, and then the birefringence-related TBG spectrum is mapped by scanning a probe pulse launched in the fast axis, where the local birefringence can be calculated using the birefringence induced frequency shift. Two types of widely used PMFs, bow-tie and panda, with a length of 8 m were measured at a spatial resolution of 20 cm, and the results show that the birefringence features a periodic variation, and their variation ranges are approximately 2.4x10(-6) and 1.3x10(-6) along the test fibers, respectively.
我们报告了基于瞬态布里渊光栅（TBG）的偏振保持光纤（PMF）的首次真正分布式双折射测量，这在业内尚属首次。在 PMF 的慢轴中使用两个短泵浦脉冲产生 TBG，然后通过扫描在快轴中发射的探测脉冲来绘制与双折射相关的 TBG 光谱，其中可以使用双折射引起的频率位移来计算局部双折射。我们对两种常用的 PMF（蝴蝶结型和熊猫型）进行了测量，每种 PMF 的长度均为 8 米，空间分辨率为 20 厘米，结果表明双折射具有周期性变化，其沿测试光纤的变化范围分别约为 2.4x10(-6)和 1.3x10(-6)。
