Whereas the basic features of stimulated emission are easily seen to hold true for ensembles of dipoles, the same is not always true for a single dipole system. For example, symmetry requires that well localized, bound dipoles emit a dipole field which is isotropic in the plane defined by the dipole vector. Indeed, for this case, nothing in the interaction between the dipole and the field conta...

Advances in bioimaging have revolutionized our ability to study life phenomena at a microscopic scale. In particular, the stimulated emission process, a universal mechanism that competes with spontaneous emission, has emerged as a powerful driving force for advancing light microscopy. The present review summarizes and compares three related techniques that each measure a different physical quan...