title: Three-dimensional nanoscopy of colloidal crystals.
abstract: We demonstrate the direct three-dimensional imaging of densely packed colloidal nanostructures using stimulated emission depletion microscopy. A combination of two de-excitation patterns yields a resolution of 43 nm in the lateral and 125 nm in the axial direction and an effective focal volume that is by 126-fold smaller than that of a corresponding confocal microscope. The mapping of a model system of spheres organized by confined convective assembly unambiguously identified face-centered cubic, hexagonal close-packed, random hexagonal close-packed, and body-centered cubic structures.
authors.affiliation: Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Harke
authors.forename: Chaitanya K
authors.initials: CK
authors.lastname: Ullal
authors.forename: Jan
authors.initials: J
authors.lastname: Keller
authors.forename: Stefan W
authors.initials: SW
authors.lastname: Hell
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008422:Materials Testing / Q000379:methods; D008856:Microscopy, Fluorescence / Q000379:methods*; D049329:Nanostructures / Q000737:chemistry / Q000648:ultrastructure*
chemical_list: D003102:Colloids