We put forward an experimentally feasible technique to generate engineered entangled states in d-dimensional Hilbert spaces in parametric down-conversion of photons. The scheme is based on the orbital angular momentum of light and translates the classical, topological information imprinted in the light beam that pumps the two-photon source into quantum information contained in the weights and phases of the quantum entangled two-photon states.
Juan P. Torres, Deyanova, Y., Torner, L., Molina-Terriza, G. Preparation of engineered two-photon entangled states for multidimensional quantum information. "Physical review A", Maig 2003, vol. 67, núm. 5, p. 052313-1-052313-5.