Feng Ting, Shang Yanling, Wang Xichen, Wu Shengbao, Khomenko Anton, Chen Xiaojun, Yao X Steve
Opt Express. 2018 Oct 1;26(20):25989-26002. doi: 10.1364/OE.26.025989.
We describe a first distributed polarization analysis (DPA) system using binary polarization rotators in an optical frequency domain reflectormeter (OFDR) capable of measuring the variations of polarization states along a single-mode fiber (SMF). We demonstrate using such a DPA system to accurately measure the distance-resolved birefringence with 12 fiber loops of different radii with different birefringence values along a length of SMF and obtain a bending-induced birefringence coefficient (BBC) of 6.601 × 10 m, agreeing well with the theoretically estimated value of 5.334 × 10 m. To further verify the measurement accuracy, we obtain the birefringence values of the 12 fiber loops of different radii one at a time using a non-distributed polarization analysis system with an accuracy traceable to a birefringence standard made with a quartz crystal, and obtain a BBC value of 6.490 × 10 m, agreeing well with our distributed measurement with a relative error of only 1.68%. In addition, we measure the residual birefringence of the SMF with both distributed and non-distributed polarization analysis systems and obtain similar results with a relative error of only 0.59%. Our experiments not only validate the performances of our DPA system, but also the first to use DPA to experimentally obtain the accurate birefringence values along the SMF and verify the theory of bending-induced birefringence. Our work further proves that such an OFDR-based DPA system is a practical tool for optical component characterization, nondestructive optical material inspection, and distributed fiber optic transversal stress sensing.
我们描述了一种首个分布式偏振分析（DPA）系统，该系统在光频域反射仪（OFDR）中使用二元偏振旋转器，能够测量沿单模光纤（SMF）的偏振态变化。我们演示了使用这种DPA系统，沿着一段SMF，对具有不同双折射值的12个不同半径的光纤环进行距离分辨双折射的精确测量，并获得了弯曲诱导双折射系数（BBC）为6.601×10⁻⁶ m，与理论估计值5.334×10⁻⁶ m吻合良好。为了进一步验证测量精度，我们使用一个精度可追溯到由石英晶体制成的双折射标准的非分布式偏振分析系统，一次获取12个不同半径的光纤环的双折射值，得到的BBC值为6.490×10⁻⁶ m，与我们的分布式测量结果吻合良好，相对误差仅为1.68%。此外，我们使用分布式和非分布式偏振分析系统测量了SMF的残余双折射，得到了相似的结果，相对误差仅为0.59%。我们的实验不仅验证了我们DPA系统的性能，而且首次使用DPA通过实验获得了沿SMF的精确双折射值，并验证了弯曲诱导双折射理论。我们的工作进一步证明，这种基于OFDR的DPA系统是用于光学元件表征、无损光学材料检测和分布式光纤横向应力传感的实用工具。
