Optimal design of a silicon nitride waveguide structure composed of resonant nanoantennas for efficient light coupling with interlayer exciton emitters in a MoSe${}_2$–WSe${}_2$ heterostructure is proposed. Numerical simulations demonstrate up to eight times coupling efficiency improvement and twelve times Purcell effect enhancement in comparison with a conventional strip waveguide. Achieved results can be beneficial for development of on-chip non-classical light sources.

The concept and design optimization of a polarization-independent dielectric metasurface for the spatial separation of scalar light beams with different values of the orbital angular momentum are discussed. The metasurface is based on an array of Mie resonant nanodisks. The geometrical parameters of a structure working at a wavelength of 810 nm are obtained and the displacement of beams with different orbital angular momenta with respect to the axis of the optical system is numerically demonstrated.