Ultrasmall Power Splitters With Triangular Lattice Mosaic Patterns Designed by Bayesian DBS Method

Ultracompact power splitters based on triangular lattice mosaic structure are proposed. By employing the triangular lattice layout, the area of the mosaic region can be used effectively due to its larger filling ratio compared with the square lattice. Here, by using recently developed Bayesian direct binary search (DBS) method, mosaic-based triangular lattice
$1 \times 2$
power splitters with various splitting ratios are designed and fabricated, for the first time. The measured characteristics of the fabricated devices are in good agreement with the design, showing the proof-of-concept. The fabrication tolerance study explains well the relationship between theory and measurement. The use of triangular lattice layout for the mosaic-based devices gives an alternative option for design and fabrication, and is useful for other mosaic-based functional devices.