Spatial Schmidt modes generated in parametric down-conversion F.M. Miatto, H. Di Lorenzo Pires, S.M. Barnett and M.P. van Exter Eur. Phys. J. D, 66 10 (2012) 263 Published online: 18 October 2012 DOI: 10.1140/epjd/e2012-30035-3