Passive planar multibranch optical power divider: some design considerations.

Design analysis has been performed on a passive planar multibranch waveguide optical power divider in a z-cut LiNbO3 substrate. Specifically, 5- and 3-branch waveguide structures were investigated with the effective index and field matching methods, taking into account the phase changes in the branches at the branching interface. Conditions for equal power division were examined regarding the appropriate branching angle and the relative index distribution in the branches. Illustrative numerical examples are presented and discussed.