Search results for "Optical microscope"
showing 10 items of 157 documents
Rigid Rod Polymers Having Flexible Side Chains. 3. Structural Investigations on a Novel Layered Mesophase Formed by Thermotropic Poly(1,4-phenylene-2…
1987
A series of thermotropic poly(1,4-phenylene-2,5-di-n-alkoxy terephthalate)s with the length of the n-alkoxy side chains being varied between n = 2 and n = 18 carbon atoms has been examined by optic...
Effects of weathering on the performance of self-cleaning photocatalytic paints
2019
Abstract The use of photocatalytic products for the surface coating of buildings is spreading more and more, because of the reduction of atmospheric pollutants and the colour maintenance of the paints over time with reduction of the maintenance costs and the improvement of the aesthetic appearance. The study reports the evaluation of the effects of the atmospheric conditions on three commercial photocatalytic paints containing TiO2. In particular tests were carried out by using samples subjected to accelerated aging inside a climate chamber and naturally aged by exposure for two years to the external environment of the city of Palermo (representative of a coastal environment of the Mediterr…
Resolving Bio–Nano Interactions of E. coli Bacteria–Dragonfly Wing Interface with Helium Ion and 3D-Structured Illumination Microscopy to Understand …
2020
Obtaining a comprehensive understanding of the bactericidal mechanisms of natural nanotextured surfaces is crucial for the development of fabricated nanotextured surfaces with efficient bactericidal activity. However, the scale, nature, and speed of bacteria-nanotextured surface interactions make the characterization of the interaction a challenging task. There are currently several different opinions regarding the possible mechanisms by which bacterial membrane damage occurs upon interacting with nanotextured surfaces. Advanced imaging methods could clarify this by enabling visualization of the interaction. Charged particle microscopes can achieve the required nanoscale resolution but are …
An Evanescent Field Optical Microscope
1989
We present a new form of optical microscope. An evanescent field is produced in the lower index medium of an ATR system and modulated by a sample deposited on the hypotenuse of the prism. A sharpened fiber optic probes this field and gives information about the topography of the surface.
Shaded-mask filtering: novel strategy for improvement of resolution in radial-polarization scanning microscopy
2006
Radially polarized illumination produces, in combination with annular pupil filtering, the sharpest focal spot. However, the enhanced sidelobes produce an effective deterioration of spatial resolution. This study shows that if one substitutes the annular filter by one, adequately designed, shaded-mask filter, the sidelobes' strength is strongly reduced, and an important, effective improvement of resolution is achieved.
Super-Resolution Scanning Near-Field Optical Microscopy
2007
Scanning near-field optical microscopy (SNOM) is a method to obtain information about the optical properties of a sample at a lateral resolution below the diffraction limit of far-field microscopy. In SNOM, a light source of a dimension which is small compared to the wavelength of light and which is held at a small distance from the sample is scanned across the surface of the sample. The modulation by the sample of the light emitted from the source is recorded as a signal. As a general rule one may say that the size of the source and the distance to the sample limit the resolution of SNOM. A radiating self-emitting point dipole may be regarded as an idealized SNOM source. With such a source…
Upgrading a brightfield optical microscope into a robust numerically advanced interference-based phase imager
2019
The approach to convert a brightfield microscope into an interference-based versatile quantitative phase imaging unit is presented. It employs partially coherent illumination and diffraction grating. Enhanced interferogram bio-phase retrieval is performed by two-shot numerically-robust Hilbert-Huang method.
Characterization of the nanocomposite laminate structure occurring in fish scales from Arapaima Gigas
2008
In the present paper, the nanocomposite laminate structure of scales from the Amazonian fish Arapaima Gigas is investigated. The structure and composition of the scales were assessed by means of X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR). The theory of Fickian diffusion is used and discussed in order to rationalize the water absorption and desorption behavior of the scales. Morphology studies and fracture analysis of the native scales were carried out using Transmission Electron Microscopy (TEM), Light Optical Microscopy (LOM) and Scanning Electron Microscopy (SEM). A fibrous layer of collagen and a plywood-like structure were observed. In order to study the …
One-dimensional wavelength multiplexed microscope without objective lens
2009
A new approach aimed to achieve microscopic imaging without objective lenses and based on wavelength multiplexing of the spatial object information is presented. The proposed method is used to develop, construct and experimentally validate a new type of optical microscope having no objective lens and no numerical reconstruction algorithms to allow imaging process. In order to extract the collected spatial information we use a spectrometer as part of our microscope system. Preliminary results are presented while considering two different types of one-dimensional (1-D) objects.
Theory of Near‐field Optical Imaging with a Single Molecule as Light Source
2002
Scanning near-field optical microscopes (SNOM) illuminate a sample in the very near-field using a nanometer sized tip. Ideally, the light source should be point-like and many efforts have been made to optimize tip efficiency (see, for example, the article of Heimel et al in this issue). Very recently, Sandoghdar et al have realized a molecular probe tip in which a terrylene molecule inserted in a paraterphenyl microcrystal is attached at the extremity of the probe tip [1]. The excited molecule behaves as a point-like light source which is raster scanned over an aluminium patterned structure. We propose here an analysis of this experiment based on the field-susceptibility formalism (also cal…