Simple scheme for rapid three-dimensional orientation determination of the emission dipole of single molecules

One of the unique features of single molecule absorption and emission is their anisotropy due to the well-defined transition dipole(s) for both processes allowing the determination of the molecule's orientation. While polarization-resolved techniques are usually capable of detecting only a projection of the transition dipole, several methods have been proposed in order to determine the full three-dimensional orientation. Here, we report on a detection scheme that allows for a shot-noise limited determination of the emission dipole orientation utilizing an annular mirror, a polarizing beam splitter in conjunction with three detectors in a scanning confocal optical microscope.