Characterization of evolution of mode coupling in a graded-index polymer optical fiber by using Brillouin optical time-domain analysis

• Published in: Optics express Vol. 22; no. 22; pp. 26510 - 26516
• Main Authors: Dong, Yongkang, Xu, Pengbai, Zhang, Hongying, Lu, Zhiwei, Chen, Liang, Bao, Xiaoyi
• Format: Journal Article
• Language: English
• Published: United States 03.11.2014
• ISSN: 1094-4087; 1094-4087
• 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.