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Infrared Images of Single Electrons
Apr. 22, 2013

Infrared Images of Single Electrons

Scattering-type near-field optical microscopy (s-SNOM) is a powerful technique to image nano objects. It can be employed in a broad spectral range, namely the complete infrared region spanning from the terahertz range up to the visible range. In this article we describe a system which utilizes a free-electron laser as a spectrally narrow and widely tunable source of infrared radiation. This system was employed to study electrons confined in self-assembled InAs quantum dots. We spatially resolved single quantum dots upon resonant excitation of transitions between discrete energy levels of the confined electrons.
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Targeted Subcellular Nanoanalysis
Apr. 16, 2013

Targeted Subcellular Nanoanalysis

We developed a new approach using cryo-correlative light and scanning transmission electron microscopy allowing analysis of targeted in situ intracellular ions and water measurements at the ultrastructural level within domains identified by examination of specific GFP-tagged proteins [1]. We illustrate the potential of this approach by investigating changes in water and ion content in nuclear domains identified by GFP-tagged proteins in cells stressed by Actinomycin D treatment and controls. more
Scanned LSFM with Confocal Detection
Apr. 08, 2013

Scanned LSFM with Confocal Detection

Light sheet fluorescence microscopy (LSFM) is a technique with a vivid development [1, 2]. In contrast to epi-illumination microscopy the sample is illuminated with a thin light sheet orthogonally to the detection path. Most often the sheet is formed by rapidly scanning a laser beam across the sample. This illumination yields intrinsic optical sectioning and reduction of photobleaching and phototoxicity since excitation is limited to fluorophores inside the observation plane. This is particularly beneficial for long term imaging in developmental biology and reduces image background [3-5].
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Molecularly Resolved Cellulose Nitrate
Apr. 02, 2013

Molecularly Resolved Cellulose Nitrate

The development of nanostructured lacquers and propellants needs to master the cellulose nitrate processing on the nanoscale. The challenge is the deposition of single cellulose nitrate molecules to image them with molecular resolution. We report on the effect of solvent, shaking duration and deposition techniques, from which the spray technique succeeded, for the first time to our knowledge, to image by Atomic Force Microscopy, individual molecular cellulose nitrate polymeric chains.
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Nano-FTIR - The Chemical Nanoscope
Mar. 25, 2013

Nano-FTIR - The Chemical Nanoscope

We show identification of chemical compounds and chemical maps at 20 nm resolution, enabled by a novel combination of infrared spectroscopy and near-field microscopy. Nano-FTIR returns the surface topography and simultaneously the local mid-infrared spectrum of the tiny volume (20 nm3) just below the probing tip thus allowing correlative topography/hyperspectral infrared images. In the case of molecular substances, comparison with common infrared databases enables local chemical recognition.
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Light Sheet Ultramicroscopy
Mar. 18, 2013

Light Sheet Ultramicroscopy

We developed a new ultramicroscopy design equipped with modified optics to achieve 3D-vizualizations of specimens with μm-resolution. The optical unit consists of elements with complex surface structures to create an ultra-thin light sheet. Diffraction and other unwanted optical effects are minimized, while the laser energy is used more efficiently. This enables us to obtain marked enhancements in resolving fine details of specimens (e.g. fruit-flies, entire mouse brains, and mouse hippocampi).
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Single Electron Events in TEM
Mar. 14, 2013

Single Electron Events in TEM

Single Electron Events (SEE) have been used to quantify the point spread function of several cameras for Transmission Electron Microscopy (TEM). The spatial resolution is measured by the Single Electron Modulation Transfer Function (MTFSEE) compared with the MTF generated by standard knife edge experiment. In addition, the sensitivity of the camera as a function of high tension has been measured, showing an excellent Signal-to-Noise Ratio (SNR) from 300 kV down to 8 kV.
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New Insights on Electron Channeling
Mar. 04, 2013

New Insights on Electron Channeling

Electron channeling contrast imaging (ECCI) is a powerful technique for the quantitative characterization of deformation structures in the SEM. The coupling of ECCI with EBSD provides an efficient method to attain enhanced diffraction contrast in the SEM. The EBSD-based ECCI set-up allows the imaging of dislocation and nano-twin substructures in the SEM. Some examples of quantitative microstructural characterization on structural materials are provided.
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