Directional coupler-type polarization beam splitter with dually bridged silicon wire waveguides for high polarization extinction ratio

초록

Integrated polarization diversity devices are being recognized as very important components in silicon-based photonic integrated circuits. Especially polarization beam splitters (PBSs) are essential elements in coherent optical detection systems [1]. Various types of planar waveguide PBSs based on directional coupler (DC), subwavelength grating structures, photonic crystal structures, interferometers, and hybrid plasmonic silicon waveguides have been reported. These PBSs have either a low polarization extinction ratio (PER) below 30 dB or a complicated device structure. In this paper, we present a new type of PBS based on a directional coupler with dually bridged wire waveguides on a silicon-on-insulator (SOI) platform for high PERs above 30 dB for both TE and TM modes.