Rayleigh scattering in graded-index polymer optical fibers (GI-POF) is studied under the assumption that spherical scatterers are uniformly distributed within the layers of concentric ring structure. This approximation allows to describe typical imperfections occurring during the fabrication of GI-POFs. For the purpose of experimental characterization by side illumination, an analytical model of the light conversion into waveguide modes has been developed. This model describes the mode excitation by a multiplicative contribution of three different physical mechanisms. The corresponding experimental analysis of the light scattering has been performed and compared with numerical simulation results for the fibers with single-ring and multi-ring structures. Besides the application to GI-POFs, this article can be also applied to multi-step index fibers.

中文翻译：

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由于聚合物光纤中不完美的渐变折射率结构而散射成导模

在假设球形散射体均匀分布在同心环结构层内的情况下，研究了渐变折射率聚合物光纤 (GI-POF) 中的瑞利散射。这种近似允许描述在 GI-POF 制造过程中发生的典型缺陷。为了通过侧面照明进行实验表征，开发了光转换为波导模式的分析模型。该模型通过三种不同物理机制的乘法贡献来描述模式激发。对光散射进行了相应的实验分析，并与具有单环和多环结构的光纤的数值模拟结果进行了比较。除了应用于 GI-POFs 外，本文还可以应用于多阶折射率光纤。