The state of mode coupling in bent and twisted step-index plastic-clad silica fibers is investigated in this article by the numerical solving of the time-independent power flow equation. The coupling length L c at which the equilibrium mode distribution is achieved and the length z s of the fiber required for achieving the steady-state mode distribution are obtained. It was found that the bent and twisted step-index plastic-clad silica fiber investigated in this work shows a much stronger mode coupling than the straight plastic-clad silica fiber. As a result, the coupling lengths where equilibrium mode distribution is achieved, and the lengths of fiber required for achieving a steady-state mode distribution for bent and twisted fibers, are much shorter than corresponding lengths for straight fibers.

中文翻译：

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弯曲和扭曲阶跃折射率包覆塑料石英纤维中的模式耦合

本文通过对时间无关的潮流方程进行数值求解，研究了弯曲和扭曲阶跃折射率包塑石英纤维中的模态耦合状态。获得达到平衡模式分布的耦合长度L c和实现稳态模式分布所需的光纤的长度zs。发现在这项工作中研究的弯曲和扭曲的阶跃折射率包层硅胶光纤显示出比笔直的包塑硅胶光纤更强的模式耦合。结果，在其中达到平衡模式分布的耦合长度，以及对于弯曲和加捻的纤维实现稳态模式分布所需的纤维长度，比直纤维的相应长度短得多。