title: Low-temperature scanning system for near- and far-field optical investigations.
abstract: A combined system for far- and near-field optical spectroscopy consisting of a compact scanning near-field optical microscope and a dedicated spectrometer was realized. The set-up allows the optical investigation of samples at temperatures from 10 to 300 K. The sample positioning range is as large as 5 x 5 x 5 mm3 and the spatial resolution is in the range of 1.5 micro m in the far-field optical microscopy mode at low temperatures. In the scanning near-field optical microscope mode the resolution is defined by the microfabricated cantilever probe, which is placed in the focus of a double-mirror objective. The tip-to-sample distance in the scanning near-field optical microscope is controlled by a beam deflection system in dynamic scanning force microscopy mode. After a description of the apparatus, scanning force topography images of self-assembled InAs quantum dots on a GaAs substrate with a density of less than one dot per square micrometre are shown, followed by the first spectroscopic investigations of such a sample. The presented results demonstrate the potential of the system.
authors.affiliation: Physikalisch-Technische Bundesanstalt (PTB), Bundesallee 100, 38116 Braunschweig, Germany.
authors.forename: D V
authors.initials: DV
authors.lastname: Kazantsev
authors.forename: C
authors.initials: C
authors.lastname: Dal Savio
authors.forename: K
authors.initials: K
authors.lastname: Pierz
authors.forename: B
authors.initials: B
authors.lastname: Güttler
authors.forename: H-U
authors.initials: HU
authors.lastname: Danzebrink
mesh_terms: D001152:Arsenicals / Q000032:analysis / Q000737:chemistry; D003080:Cold Temperature; D005708:Gallium / Q000032:analysis / Q000737:chemistry; D006371:Helium / Q000737:chemistry; D007204:Indium / Q000032:analysis / Q000737:chemistry; D008027:Light; D018613:Microscopy, Confocal / Q000295:instrumentation / Q000379:methods; D020527:Microscopy, Scanning Probe / Q000295:instrumentation / Q000379:methods*; D008961:Models, Structural; D013050:Spectrometry, Fluorescence; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D001152:Arsenicals; D007204:Indium; D006371:Helium; C043055:gallium arsenide; D005708:Gallium; C076773:indium arsenide