Conformal Singularities and Topological Defects from Inverse Transformation Optics

The conventional approach in transformation optics (TO) starts with a virtual space and determines a complicated material profile in physical space to achieve unconventional phenomena, such as invisibility cloaks. We demonstrate that complicated materials can be effectively fabricated by virtual space based on the reversed process of TO in two dimensions. We first show that a conformal singularity of a refractive-index profile, with either zero …