C Hettich | PubMed Health

PubMed2001

Diamond colour centres as a nanoscopic light source for scanning near-field optical microscopy.

Recently it was shown that a single molecule at cryogenic temperatures could be used as a local light source for illumination of a sample in the near field. Conventional light-emitting systems such as dye molecules and semiconductor quantum dots could also be used for this purpose, but they suffer from lack of photostability. However, colour centres in diamond have been found to be remarkably stable against bleaching and blinking effects. Here we present the first SNOM images taken with nanoscopic diamond crystals as a light source.

Journal Article↗

PubMed2000

Optical microscopy using a single-molecule light source

Rapid progress in science on nanoscopic scales has promoted increasing interest in techniques of ultrahigh-resolution optical microscopy. The diffraction limit can be surpassed by illuminating an object in the near field through a sub-wavelength aperture at the end of a sharp metallic probe. Proposed modifications of this technique involve replacing the physical aperture by a nanoscopic active light source. Advances in the spatial and spectral detection of individual fluorescent molecules, using near-field and far-field methods, suggest the possibility of using a single molecule as the illumination source. Here we present optical images taken with a single molecule as a point-like source of illumination, by combining fluorescence excitation spectroscopy with shear-force microscopy. Our single-molecule probe has potential for achieving molecular resolution in optical microscopy; it should also facilitate controlled studies of nanometre-scale phenomena (such as resonant energy transfer) with improved lateral and axial spatial resolution.

Journal Article↗