Bisyarin M A, Kotov O I, Hartog A H, Liokumovich L B, Ushakov N A
Appl Opt. 2017 Jan 10;56(2):354-364. doi: 10.1364/AO.56.000354.
The Rayleigh backscattering produced by an incident fundamental mode in a multimode step-index optical fiber was analyzed using a recently developed diffraction technique. The complete set of backward propagating modes, both radial and azimuthal, was determined and regarded. For this type of fiber, normalized mode functions were constructed in an explicit form, thus providing a unified power scale to characterize the relationships between various excited modes. The dependencies of the mode excitation efficiencies on the technical parameters of the fiber and the frequency of the launched radiation were studied. A comparison of the mode excitation efficiencies was performed with those in the fiber with quadratic refractive index profiles.
利用最近开发的衍射技术分析了多模阶跃折射率光纤中入射基模产生的瑞利背散射。确定并考虑了所有向后传播的模式，包括径向模式和方位角模式。对于这种类型的光纤，以显式形式构建了归一化模式函数，从而提供了一个统一的功率尺度来表征各种激发模式之间的关系。研究了模式激发效率与光纤技术参数和发射辐射频率的依赖关系。将模式激发效率与具有二次折射率分布的光纤中的激发效率进行了比较。
