Reflective photonic hook achieved by a dielectric-coated concave hemicylindrical mirror

In this study,we propose a new design of a dielectric-coated concave hemicylindrical mirror for efficient generation of a reflective photonic hook (PH).Numerical approaches based on the finite-difference time-domain technique are used to investigate the physical mechanism of reflective PH formation. The field intensity distributions and photonic fluxes near the concave mirror are analyzed for working in the reflection mode. The asymmetric vortexes of Poynting vectors cause the reflective PHwith a large bending angle. By changing the refractive index of the dielectric film, the shape and curvature of the reflective PHcan be efficiently adjusted.Moreover, the narrow waist of the reflectivePHis obtained beyond half of the incident wavelength. This compact dielectric-coated concave mirror has proven its practicability for integrated photonic circuits in the reflection mode.