CONICET | Buscador de Institutos y Recursos Humanos

We analyse in detail the necessary conditions to obtain amplified reflection (AR) in isotropicinterfaces when a plane wave propagates from a transparent medium towards an active one.First, we demonstrate analytically that AR is not possible if a single interface is involved.Then, we study the conditions for AR in a very simple configuration: normal incidence on anactive slab immersed in transparent media. Finally, we develop an analysis in the complexplane in order to establish a geometrical method that not only describes the behaviour of activeslabs but also helps to simplify the calculus.