Design concepts of a novel mode splitter for multimode communication systems

In this paper, design and optimization of a novel optical mode splitter in Silicon Nanowire by introducing a small slot is shown by using a full-vectorial finite element method. The authors report, for the first time, that by creating a slot in a waveguide; the ideal coupling length ratio of 1:2 between fundamental mode and the second higher order mode can be achieved. The overall power transfer between these modes have also been analyzed by using the least squares boundary residual method along with the calculation of the performance variation due to any possible fabrication tolerances.