Toward a better understanding of light scattering in few-mode optical fibers

In this work, two experimental methods are proposed to quantify the contributions of the different light scattering mechanisms to the total attenuation of each guided-mode of two weakly-coupled FMF presenting different index profiles. The first approach is based on the analysis of the angular distribution of the light scattered by each mode of the two fibers whereas the second technique is based on bidirectional OTDR measurements also performed for each mode of the two fibers at different wavelengths. Some preliminary examples are reported and discussed for the fundamental mode and one higher order mode guided in a step-index and a trapezoidal index profile few-mode fiber.