In a new paper with Kostas, Ivor and Andre, we demonstrate how a dielectric medium can be made invisible for certain incoming beams when a suitable spatial distribution of gain and loss is added to the medium’s permittivity. (See highlight in Optica top downloads.)
![](https://rottergroup.itp.tuwien.ac.at/wp-content/uploads/2020/05/osa-optica-1.jpg)