Degenerate 4-Dimensional Matrices with Semi-Group Structure and Polarization Optics

In polarization optics, an important role play Mueller matrices — real four-dimensional matrices which describe the effect of action of optical elements on the polarization state of the light, described by 4-dimensional Stokes vectors. An important issue is to classify possible classes of the Mueller matrices. In particular, of special interest are degenerate Mueller matrices with vanishing determinants. With the use of a special technique of parameterizing arbitrary 4-dimensional matrices in Dirac basis, a classification of degenerate 4-dimensional real matrices of rank 1, 2, 3. is elaborated. To separate possible classes of degenerate matrices we impose linear restrictions on 16 parameters of 4 × 4 matrices which are compatible with the group multiplication law.

polarization of the light, degenerate Mueller matrices, classification