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Probing confined fields with single molecules and vice versa
Author(s) -
Sick B.,
Hecht B.,
Wild U. P.,
Novotny L.
Publication year - 2001
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1046/j.1365-2818.2001.00795.x
Subject(s) - electric field , focus (optics) , optics , excitation , dipole , dielectric , field (mathematics) , aperture (computer memory) , materials science , numerical aperture , near and far field , absorption (acoustics) , physics , optoelectronics , acoustics , wavelength , mathematics , quantum mechanics , pure mathematics
Single dye molecules are used as local probes to map the spatial distribution of the squared electric field components in the focus of a high numerical aperture lens. Simulated field distributions are quantitatively verified by experimentally obtained fluorescence excitation maps. We show that annular illumination can be used to engineer the field distribution in the focus at a dielectric/air interface such that electric field components in all directions acquire comparable magnitudes. The 3D orientation of molecular absorption dipoles can be determined by comparing measured to simulated image patterns. The presence of longitudinal electric field components in a focus is of particular interest in tip‐enhanced scanning near‐field optical microscopy.