title: Orientational imaging of single molecules by annular illumination
abstract: The absorption dipole orientation of single fluorescent molecules is determined by mapping the spatial distribution of the squared electric field components in a high-numerical-aperture laser focus. Annular illumination geometry and the vicinity of a plane dielectric/air interface strongly enhance the longitudinal field component and the transverse fields perpendicular to the polarization direction. As a result, all three excitation field components in the focus are of comparable magnitude. The scheme holds promise to monitor rotational diffusion of single molecules in complex environments.
authors.affiliation: Physical Chemistry Laboratory, Swiss Federal Institute of Technology, ETH-Z, CH-8092 Zurich, Switzerland.
authors.initials: B
authors.lastname: Sick
authors.initials: B
authors.lastname: Hecht
authors.initials: L
authors.lastname: Novotny