Compact low loss 3dB curved directional coupler enabled by silicon columns in silicon-on-insulator

We propose a compact, low loss 3dB power splitter enabled by silicon columns. The proposed device consists of two curved waveguides and a group of silicon columns on coupling region, compatible with mature CMOS processes. The simulation results show that the device has the beam splitting of 0.5±0.05 in the wave band from 1270 to 1330nm. Moreover, the effective coupling length is only 11.9μm, and the excess loss is less than 0.04dB, which makes the proposed splitter full of potential to be applied in high-density photonic integrated chips.