Inverse Design of Multi-Port Power Splitter with Arbitrary Ratio Based on Shape Optimization

Arbitrary ratio power splitters (APSs) play a crucial role in enhancing the flexibility of photonic integrated circuits (PICs) on the silicon-on-insulator (SOI) platform. However, most existing APSs are designed with two output channels, limiting their functionality. In this study, we present a shape optimization method to develop a multiport arbitrary ratio power splitter (MAPS) that enables arbitrary power distribution across three output channels within a compact footprint of 6 mu m x 2.7 mu m. To validate this approach, two MAPS designs were demonstrated with power ratios of 1:2:1 and 1:2:4. Across a bandwidth range from 1500 nm to 1600 nm, these designs matched the desired power distribution with excess losses (ELs) below 0.5 dB. Experimental results further confirmed the effectiveness of the splitters, with ELs below 1.3 dB over a bandwidth of 1500-1565 nm.