Dong Yongkang, Xu Pengbai, Zhang Hongying, Lu Zhiwei, Chen Liang, Bao Xiaoyi
Opt Express. 2014 Nov 3;22(22):26510-6. doi: 10.1364/OE.22.026510.
A narrow bandwidth (2GHz) π-phase-shift flattop fiber Bragg grating (FBG) is proposed to achieve Brillouin optical time-domain analysis (BOTDA) for perfluorinated graded-index polymer optical fibers (GI-POFs) for the first time to best of our knowledge. Using the technique of BOTDA, we explore the evolution of mode coupling in perfluorinated GI-POFs by analyzing the Brillouin frequency shift (BFS) variation along the whole fiber, and compare them with that of silica graded index multimode fibers (GI-MMFs). The characteristics of mode coupling of GI-POFs and GI-MMFs were also investigated in terms of the speckle patterns at the output face of the two fibers. The results show that compared with silica GI-MMFs, GI-POFs exhibit more efficient mode coupling and the excellent ablility of mode scrambling regardless of alignment conditions.
据我们所知，首次提出了一种窄带宽（2GHz）的π相移平顶光纤布拉格光栅（FBG），以实现对全氟渐变折射率聚合物光纤（GI-POF）的布里渊光时域分析（BOTDA）。利用BOTDA技术，我们通过分析沿整个光纤的布里渊频移（BFS）变化，探索了全氟GI-POF中模式耦合的演变，并将其与石英渐变折射率多模光纤（GI-MMF）的进行比较。还根据两种光纤输出面的散斑图案研究了GI-POF和GI-MMF的模式耦合特性。结果表明，与石英GI-MMF相比，GI-POF表现出更有效的模式耦合，并且无论对准条件如何，都具有出色的模式扰频能力。
