Unidirectional coupling of a quantum emitter to a subwavelength grating waveguide with an engineered stationary inflection point

In this work, we propose an approach for the design of a waveguide structure that allows efficient and highly asymmetric coupling quantum sources with circularly polarized transition dipole moments to guided mode structure. The is based on mixing two quasi-degenerate modes periodic auxiliary single-mode leading formation dispersion stationary inflection point consequently high efficiency source. We show distribution field polarization inside relatively homogeneous maintaining circular in large area. Consequently, leads degree tolerance asymmetry strength position emitter. believe, our results will extend variety designs chiral nanophotonic interfaces planar semiconductor nanostructures.