Angular Schmidt spectrum of entangled photons derivation of an exact formula and experimental characterization for non-collinear phase matching
Dr. Deepika Choudhury, Dr. Mukesh Kumar, Prof. P. K. Raina, Dr. Pushpendra P. Singh, Dr. Rajesh V. Nair, L. Taneja, S. Aarav, A. K. Jha , 
Phys. Rev. A 97, 063846