Using the power flow equation, the state of mode coupling in step index multimode silica optical fiber with fluorinated thermoplastic polymer cladding is investigated in this work. Coupling coefficient is determined by employing our previously reported calculation method. The silica optical fiber with fluorinated thermoplastic polymer cladding shows much stronger mode coupling than the all plastic-clad silica fibers investigated in earlier works. Consequently, it takes much shorter fiber length for the equilibrium mode distribution or steady state distribution to develop (faster launch beam narrowing), which is of great interest in employing silica optical fiber with fluorinated thermoplastic polymer as a part of telecommunication, medical and sensory system.

利用功率流方程，研究了带折射率热塑性多金属包覆层的阶跃折射率多模石英光纤的模耦合状态。耦合系数是通过采用我们先前报道的计算方法确定的。具有氟化热塑性聚合物包层的二氧化硅光纤比早期研究中研究的所有塑料包覆的二氧化硅光纤具有更强的模式耦合。因此，需要很短的纤维长度才能达到平衡模式分布或稳态分布（更快的发射光束变窄），这在将石英纤维与氟化热塑性聚合物一起用作电信，医疗和传感系统的一部分时引起了极大的兴趣。 。