Effective method for photonic jet shaping in reflection mode

We report an effective method to shape a photonic jet (PJ) generated by a dielectric cuboid scatterer on a hollow reflection screen. The study focuses on the shaping of PJ by hollow and cuboid geometries, including side length, depth, and position. The results show that all the geometric parameters can effectively shape the PJ in characteristic parameters of intensity, focal length (FL), and lateral size. The comparison shows that the present shaping method is much superior to the previously reported one based on a change of cuboid height, characterized by three times larger of the varying ranges of the PJ characteristic parameters. The shaping by the side length and depth of hollow and cuboid is explained from viewpoints of ray optics and electromagnetic field theory in terms of hollow-induced phase singularity in Poynting vector distribution. The hollow position mainly shapes the propagation trajectory of PJ. The deviation of the hollow position results in the curvature of the propagation trajectory of PJ, and the curvature is correlated with the asymmetric extent of the scattering system.