Muhammad Ashad Azam explored the process of spontaneous parametric down conversion, a process by which a single photon produces two ‘entangled’ photons, which can then be used in single photon experiments. The process of type-II down conversion from a beta-barium borate crystal was studied in detail and down converted photons were successfully detected. A number of complementary experiments were done along the way such as measuring the dark counts, looking at characteristics of avalanche photodetectors and verifying Poissonian statistics of detected photons.Outcome: The work continues.