Conformal cloaks from a function composition

Abstract

Since the beginning of transformation optics, invisibility cloaks have been attracting lots of attention, most of which however are usually too complex to realize. Here we propose a conformal cloak by using two mappings in a function composition. The required isotropic refractive index distribution is optimized to a range from 0 to 7.55, which is more feasible than previous designs. Numerical calculations have been performed to verify the cloaking effect.