Ultra-wideband dual-polarization silicon nitride power splitter based on modal engineered slot waveguides

Silicon nitride (SiN) waveguides provide a substantially lower index contrast, thermo-optic coefficient, and reduced. birefringence compared to silicon-on-insulator waveguides. These properties make SiN a prominent candidate for implementation of ultra-wideband dual-polarization photonics circuits with a great potential for datacom applications. State-of-the-art SiN power splitters are still hampered in terms of either bandwidth or single polarization operation. Here, we propose to overcome these limitations by exploiting modal and waveguide symmetry engineering in a single-mode slot waveguide. This topology prevents mode-beating, while granting symmetric power splitting for both polarizations. Experimental characterization of the fabricated device shows low loss ( <0.62 dB) and imbalance (<0.6 dB) within an unprecedented bandwidth of 420 nm (1.26-1.68 Am). (C) 2020 Optical Society of America