SEZIONE DI FIRENZE Colloquium di Ulf Leonhardt
Optical materials such as glass or water appear to light as if they change the geometry of space. One sees this directly in optical illusions where inhomogeneous optical materials affect the perception of space. One see this theoretically from Fermat's principle of the shortest path: light travels along geodesics measured with respect to
the refractive index of the material. One sees this in full detail from Maxwell's equations in Einstein's general relativity that appear as Maxwell's equations in media. This connection between general relativity and optics in media has given rise to a new research area: transformation optics. Here the optical implementation of coordinate
transformations has inspired devices that might do the (almost)impossible such as invisibility cloaking and perfect imaging. In this lecture I will introduce transformation optics and discuss some of its exciting applications.