Dugas J, Sotom M, Martin L, Cariou J M
Appl Opt. 1987 Oct 1;26(19):4198-208. doi: 10.1364/AO.26.004198.
We describe an original technique that permits a specially accurate measurement of the variations of the transmittance of optical fibers vs the incidence of launched light. For large-diameter large-aperture fibers, which prefer light power transmission, the transmittance may be modeled using geometric optics. Taking into account the reflection losses at both ends, the core attenuation and a very weak lack of reflectivity at the core-cladding interface, good agreement is obtained between calculated variations and experimental results for the three kinds of fiber tested. The remaining difference has to be attributed to the mode coupling process which may be thus evaluated. The too high attenuation coefficient, which is attributed to the cladding to account for the losses at the core-cladding interface, characterizes in fact a thin perturbed layer where the materials contact. Thus, this method is a good means to evaluate separately the various processes contributing to the attenuation of open beams along the fibers and to determine which process should be worked on to improve the transmittance.
我们描述了一种原创技术，该技术能够特别精确地测量光纤透光率随入射光的变化。对于倾向于光功率传输的大直径大孔径光纤，其透光率可以用几何光学进行建模。考虑到两端的反射损耗、纤芯衰减以及纤芯 - 包层界面处非常微弱的反射率不足，对于所测试的三种光纤，计算得到的变化与实验结果之间取得了良好的一致性。剩余的差异必须归因于模式耦合过程，因此可以对该过程进行评估。过高的衰减系数归因于包层以解释纤芯 - 包层界面处的损耗，实际上它表征了材料接触的薄扰动层。因此，该方法是一种很好的手段，可分别评估导致沿光纤传播的开放光束衰减的各种过程，并确定应致力于改进哪个过程以提高透光率。
