A MULTIMODE PLANAR POWER SPLITTER

A novel scheme for multimode 1 x 2 and 1 x 4 splitters is proposed. Th ese devices differ from conventional 1 x 2 and 1 x 4 multimode interfe rence splitters, as they do not rely on the interference between the e xcited modes propagating in the multimode region. Instead, their funct ionality is based on the principle that in an asymmetric multipronged splitter, the power in each excited mode can be directed unambiguously into one of the single-mode output channels with minimal crosstalk be tween channels. The geometry and relative position of the single-mode input waveguide of the 1 x 2 and 1 x 4 splitters is optimized to split the input power as evenly as possible between the two and four output channels, respectively, and to minimize the excess loss of the device . A simple low-power single-mode tap, based on the same principle, is also investigated and its excess loss and wavelength dependence determ ined.