All-Angle Self-Collimation-Based Invisibility Cloaking in 2D Square Lattice Photonic Crystals

Here, a two-dimensional (2D) hole-type square lattice photonic crystal is shown to achieve invisibility cloaking based on all-angle self-collimation. The proposed structure, which is composed of the high-refraction-index dielectric material PbTe (n_PbTe ≈ 6), is applicable in the mid-infrared (mid-IR) frequency range. The cloaking region is capable of hiding any object of any shape and size since the incoming wave does not interact with the cloaked object. The optimization process and the functionality of the proposed structure are investigated by equal frequency contour analysis and the finite difference time domain (FDTD) method.