Studying photon number distribution of NV-centre-emission in diamond

One key element in further development of quantum information processing systems is the ability to prepare single photon states, which in practice is still difficult. While attenuated lasers obey Poissonian statistics, current single photon sources are imperfect, because their second order correlation function g(2)(t = 0) is non-zero, implying residual multiphoton emission [1]. Various experimental method has been developed to analyse an unknown quantum state using i.e. photon number resolving detectors, quantum homodyne tomography as well as techniques based on e.g. the reconstruction of the optical density matrix providing information on the photon number distribution [2].