Spinors, matrix structures, and projective geometry in polarization   optics
  The paper discusses the role played by Mueller and Jones formalisms in polarization optics, by addressing the following aspects: restriction to the SU(2) symmetry, non-relativistic Stokes 3-vectors; Cartan 2-spinors in polarization optics; Jones 4-spinors for partially polarized light; the linear group SL(4,R) and the classification of 1-parametric Mueller matrices; semi-group structure and classification of degenerate Mueller matrices. 
E. Ovsiyuk, O. Veko, M. Neagu, V. Balan, V. Red'kov
physics.optics math-ph math.MP