Precise asymmetric power-splitter (1.7:1) by using nano-pixel waveguide

Power-splitter is one of the fundamental elements for photonic integrated circuits. Y-junction, multi-mode-interference (MMI), and directional coupler may have been widely used as power splitter; however, the design theory to realize precise asymmetric splitting ratio is not well established. In addition, the device length is relatively long and less robustness in general. To realize a power splitter with a desired splitting ratio, the authors used a nano-pixel structure. Nano-pixel structures consist of an array of pixels in which the rectangular waveguide region is divided into many nano-scale regions. The implemented devices were realized in an area of 3.2 mu m x 3.4 mu m. The device exhibited precise asymmetric splitting of 1.7:1 successfully at 1550 nm.