Two designs of optical switching elements for multistage interconnection networks were proposed in this paper based on the polarization of light beams. The optical switching elements can perform not only conventional go-straight and crossover switching but also upper and lower broadcasting. The first switch comprises polarizers, polarizing beam combiners, magneto-optic rotators, and polarizing beam splitters. The second switch utilizes polarization-selective birefringence holograms as beam splitters and lead lanthanum zirconated titanate as polarization rotators. The switch was integrated onto a silicon substrate with a planar configuration. A large multistage interconnection network can be built through a cascade of the 2 \times 2 switching elements using either design.