Single photon generation by pulsed excitation of a single dipole

The fluorescence of a single dipole excited by an intense light pulse can lead to the generation of another light pulse containing a single photon. The influence of the duration and energy of the excitation pulse on the number of photons in the fluorescence pulse is studied. The case of a two-level dipole with strongly damped coherences is considered. The presence of a metastable state leading to shelving is also investigated.Comment: 17 pages, 4 figures, submitted to PR

Fluorescence Correlation and Low Temperature Linewidth of Single Defect Centers in Diamond

Low temperature fluorescence excitation spectroscopy was carried out on single nitrogen vacancy defect centers. At temperatures below 90 K the fluorescence intensity of individual centers drastically diminishes because of the population of a metastable singlet state in near resonance with the optically excited state. Low temperature fluorescence excitation spectroscopy down to 5 K becomes possible via deshelving of this state with a second laser source. Surprisingly individual centers reveal low temperature fluorescence excitation line widths around 0.6 meV