Photon-pair source with at least 10 MHz pair-emission rate exists

High-efficiency photon-pair sources are developed that generate a sufficient number of photon pairs to generate images using Ghost Imaging in real time. To this end, nonlinear crystals with large transverse area and optimized optical coating to enhance the local density of the states in the crystal are explored.Finally, a photon pair source with at least 10 MHz pair rate will be available.