Compact Inverse Designed Integrated 1 x 3 Silicon Nitride Balanced Optical Power Splitter

We designed a compact integrated Silicon Nitride 1 x 3 balanced optical power splitter using density-based topology optimization with built-in fabrication constraints. We experimentally validate our design on a commercial foundry process with a splitting ratio of 30-36-33 % and an insertion loss of 2.48 dB across two wafers.