Single-layer universal optical computing

Because of the potential advantages in data processing over the electrical counterpart, recent strategies for optical computing have received much attention. However, the tradeoff between the depth of the structures for optical computing and universality of their capability is hard to balance. In this work, we propose an optical computing strategy which can implement universal optical computing by a one-layer structure of the operation units. The proposal is based on the KAK decomposition of unitary matrices. We also present experimental validation of our proposal, showing the implementation of several operations. Moreover, it is pointed out that the proposal enables a resource-efficient implementation for certain operations, advancing the capability of performing the computation by light.