A side-ported MMI based InP polarization beam splitter

Abstract

The design of a multimode interference coupler (MMI) based InP polarization beam splitter (PBS) at 1.3 μm wavelength is reported. When the input and output waveguides are placed on the side walls of the PBS MMIs, the PBS can be shortened effectively, while maintaining both low insertion loss (IL) and high extinction ratio (ER). The optimized PBS design is 299 μm in length which is less than 1/3 of the PBS with end ported access ports. At the same time, the ER of the side ported PBS is notably better than the ER of the long end ported PBS.