Broadband directional cloaking using graded index structures

We propose broadband two-dimensional cloaking designs based on isotropic and all dielectric lossless materials. The photonic structures are created by implementing artificially generated graded index (GRIN) media. The desired refractive index distribution is achieved with effective medium theory. Directional graded index cloaking structure shows unique characteristics such as low-loss, large bandwidth and scalable to other frequency regions in the electromagnetic spectrum. We numerically demonstrate feasibility of hiding arbitrary shaped large objects from the incident light. The unique features of GRIN medium tailoring the light propagation allow designing advanced configurations that enable cloaking under the oblique incidence cases.