Optically active semiconductor quantum dots and defects in solids behave in many ways like artificial atoms. The ease with which they interact with optical fields has made possible a number of quantum optical investigations. In this talk I will discuss some of our recent experiments that explore how a semiconductor quantum-dot optical transition interacts with a resonant laser. We exploit this interaction to not only optically measure quantum-dot electron spin orientation, but also to generate ultra coherent single photons. Finally, I will discuss a second proof-of-principle experiment demonstrating the possibility of fluorescence lifetime imaging microscopy with a single nitrogen vacancy center in diamond. In our experiments we measure the local density of optical states of a proximal nanoscale optical antenna.