  Triangular cross-section color center photonics in silicon carbide is a
leading candidate for scalable implementation of quantum hardware. Within this
geometry, we model low-loss beam splitters for applications in key quantum
optical operations such as entanglement and single-photon interferometry. We
consider triangular cross-section single-mode waveguides for the design of a
directional coupler. We optimize parameters for a 50:50 beam splitter. Finally,
we test the experimental feasibility of the designs by fabricating triangular
waveguides in an ion beam etching process and identify suitable designs for
short-term implementation.
