Invariant quantities of a nondepolarizing Mueller matrix

TL;DR

This paper identifies and interprets the invariant physical quantities of nondepolarizing Mueller matrices, enhancing understanding of the information they encode in polarization optics.

Contribution

It provides a detailed analysis of the invariant quantities under orthogonal transformations of nondepolarizing Mueller matrices, clarifying their physical significance.

Findings

Invariant quantities preserve degree of polarization and intensity.

Orthogonal transformations relate to retarders and polarization basis changes.

Enhanced understanding of information contained in Mueller matrices.

Abstract

Orthogonal Mueller matrices can be considered either as corresponding to retarders or to generalized transformations of the polarization basis for the representation of Stokes vectors, so that they constitute the only type of Mueller matrices that preserve the degree of polarization and the intensity of any partially-polarized input Stokes vector. The physical quantities which remain invariant when a nondepolarizing Mueller matrix is transformed through its product by different types of orthogonal Mueller matrices are identified and interpreted, providing a better knowledge of the information contained in a nondepolarizing Mueller matrix.