Métrica de despolarización escalar Q(M) como criterio para identificar sistemas retardadores o desfasadores puros

Abstract

The trace criterion or theorem of Gil-Bernabeu is a neccesary and sufficient condition for a Jones matrix to be derivable from a Mueller matrix associated to passive optical systems. The matrix obtained in this way is named Mueller-Jones or pure Mueller matrix. In this work, several examples are shown of physical systems, diattenuating and non-diattenuating, which fulfill the theorem of Gil-Bernabeu or equivalently take on the upper limit for the depolarization index. This means that this criterion can provide only information about the non-depolarizing character of light by systems, but it is unable to distinguish the diattenuating character associated to the systems and consequently it cannot distinguish a polarizer from a retarder. It is shown the upper limit of $Q(M)$ can be employed as a criterion to identity uniquely non-diattenuating Jones matrices; that is, systems associated to pure retarders or dephasers.