Photonic Chips: multi-port beam splitter based on silicon nitrite waveguides.
Photonic Chips are micrometer-scale optical integrated circuit devices capable of confining and manipulating light. Compatible with CMOS technology, they provide a good platform for implementing many operations on a single device. Photonic beam splitters based on waveguides in silicon nitride and silicon oxide are an interesting platform to implement unitary operations, encoded in longitudinal momentum (paths), where each path represents a level of the system, which they can be used to process quantum information protocols. Therefore, this work is dedicated to the study of photonic multi-port beam splitters, capable of implementing quantum information protocols based on qudits. Applying the coupled mode theory, we found the unitaries that describe the operations for dimensions 3 and 4. We implemented electromagnetic simulations in finite-difference time-domain (FDTD) for our design of multi-port beam splitters with 3 and 4 guides, obtaining good results between simulations and theory. This is the first step towards developing high-dimensional photonic chips that will be capable of implementing d-level quantum information protocols.