Comparision of splitting properties of various 1x16 splitters

Optical Access Networks (OAN) mostly use optical splitters to distribute the services from Optical Line Terminal (OLT) on the provider's side to the subscribers in Optical Network Unit (ONU). Optical splitters are the key components in such access networks as for example GPON and XG-PON by ITU-T. In this paper we investigate the optical properties of 1x16 Y-branch splitter and 1x16 MMI splitters based on different widths of multimode interference section and different lengths of the output ports. These two splitters were designed, simulated and the obtained results of both were studied and compared with each other. Additionally, we show that the used standard waveguide core size (usually 6x6 µm2 to match the diameter of the single mode input/output fibers, i.e. to keep the coupling loses as low as possible) supports not only propagation of the single mode but of the first mode too, leading to an asymmetric splitting ratio (increasing non-uniformity of split power over all the output waveguides). Decreasing waveguide core size, it is possible to suppress presence of the first mode and this way to reduce non-uniformity