ABSTRACT
The branch ratio of multimode waveguide branching depends strongly on the mode excitation distribution. As a result, when the multimode waveguide branching device is connected to optical fibers, the branching ratio fluctuates depending on the temporal change of modal distribution in the fiber. In addition, it is difficult to design the branching ratio of cascaded branching waveguides. Mode scrambler is used to obtain a fixed modal distribution to stabilize the branching ratio of multimode waveguide branching devices. A zigzag waveguide pattern is used for step index multimode waveguide and a cascaded tapered waveguide is used for distributed index multimode waveguide.
