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Scanning Near-field Optical Microscope (scanning + near-field_optical_microscope)

Distribution by Scientific Domains
Physics and Astronomy50%

Selected Abstracts

Investigation of dyed human hair fibres using apertureless near-field scanning optical microscopy

JOURNAL OF MICROSCOPY, Issue 2 2006
F. FORMANEK
Summary We present the first studies of dyed human hair fibres performed with an apertureless scanning near-field optical microscope. Samples consisted of 5-µm-thick cross-sections, the hair fibres being bleached and then dyed before being cut. Hair dyed with two molecular probes diffusing deep inside the fibre or mainly spreading at its periphery were investigated at a wavelength of 655 nm. An optical resolution of about 50 nm was achieved, well below the diffraction limit; the images exhibited different optical contrasts in the cuticle region, depending on the nature of the dye. Our results suggest that the dye that remains confined at the hair periphery is mainly located at its surface and in the endocuticle. [source]

Low-temperature scanning system for near- and far-field optical investigations

JOURNAL OF MICROSCOPY, Issue 3 2003
D. V. Kazantsev
Summary 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 × 5 × 5 mm3 and the spatial resolution is in the range of 1.5 µm 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. [source]

Near-field probing of photonic crystal directional couplers

LASER PHYSICS LETTERS, Issue 6 2006
V. S. Volkov
Abstract We report the design, fabrication and characterization of a photonic crystal directional coupler with a size of ,20 × 20 µm2 fabricated in silicon-on-insulator material. Using a scanning near-field optical microscope we demonstrate a high coupling efficiency for TM polarized light at telecom wavelengths. By comparing the near-field optical images recorded in and after the directional coupler area, the features of light distribution are analyzed. Finally, the scanning near-field optical microscope observations are found to be in agreement with the transmission measurements conducted with the same sample. (© 2006 by Astro, Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA) [source]

Spatial mapping on surface light extraction from 2D photonic quasicrystals patterned GaN-based light emitters

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2007
ZhenSheng Zhang
Abstract We report the observations of surface light extraction enhancement from two-dimensional (2D) photonic crystal (PC) and Photonic Quasicrystal (PQC) patterns on electrical current injected GaN-based light emitters. Spatial mapping of the surface extraction was acquired by a microscopic electrical luminescence setup and a scanning near-field optical microscope (SNOM). Slight difference of mapping profile between twelve-fold PQC and regular triangular PC was obtained. It is shown that 12PQC was more efficient for light extraction. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Near-field characterization of photonic crystal Y-splitters

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2005
V. S. Volkov
Abstract A scanning near-field optical microscope (SNOM) is used to directly map the propagation of light in a specially designed 50/50 photonic crystal (PC) Y-splitter fabricated on silicon-on-insulator (SOI) wafers. SNOM images are obtained for TE- and TM-polarized light in the wavelength range 1425,1570 nm. The recorded intensity distributions exhibit highly wavelength (and polarization) dependent intensity variations along the propagation direction, especially around the fork and bend regions. By comparing the SNOM images recorded in and after the PC Y-splitter area, the features of light distribution are analysed for both polarizations. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]