Degree of polarization and quantum-mechanical purity H. Moya-Cessa, J.R. Moya-Cessa, J. E. A. Landgrave, G. Martínez-Niconoff, A. Pérez-Leija and A. T. Friberg J. Eur. Opt. Soc.-Rapid Publ., 3 (2008) 08014 Published online: 04 April 2008 DOI: 10.2971/jeos.2008.08014