Journal of Optics
Active isotropic slabs: conditions for amplified reflection
Liliana Ines Perez, Claudia L. Matteo, J. I. Etcheverry, María Celeste Duplaá
Abstract
We analyse in detail the necessary conditions to obtain amplified reflection (AR) in isotropic interfaces 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 an active slab immersed in transparent media. Finally, we develop an analysis in the complex plane in order to establish a geometrical method that not only describes the behaviour of active slabs but also helps to simplify the calculus.