Optical power splitters for integrated multimode photonics

In this work we propose, fabricate and test a new integrated platform for 1xN power splitters. Given an array of N coupled and non-equally spaced waveguides, any arbitrary 1xN splitting ratio is achieved by properly setting the array length and the dimension of the (N-1) nano-gaps between the N adjacent waveguides. We provide the first experimental demonstration of 1xN splitting with an arbitrary power ratio ratio for both the fundamental mode as well as higher-order modes. These results find direct application in the framework of the emerging on-chip multimode technology.