48‐3: Light Field Display Using Virtual Imaging Mode

An electronic device has been constructed which manipulates the primary beam in the conventional transmission microscope to illuminate a specimen under a variety of virtual condenser aperture conditions. The device uses the existing tilt coils of the microscope, and modulates the D.C. signals to both x and y tilt directions simultaneously with various waveforms to produce Lissajous figures in the back-focal plane of the objective lens. Electron diffraction patterns can be recorded which reflect the manner in which the direct beam is tilted during exposure of a micrograph. The device has been utilized mainly for the hollow cone imaging mode where the device provides a microscope transfer function without zeros in all spatial directions and has produced high resolution images which are also free from the effect of chromatic aberration. A standard second condenser aperture is employed and the width of the cone annulus is readily controlled by defocusing the second condenser lens.

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Ultra high resolution SEM at high voltage images individual fab fragments applied as molecular label to cell surface receptors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015232x ◽

1989 ◽

Vol 47 ◽

pp. 70-71

Author(s):

Klaus-Ruediger Peters

Keyword(s):

High Resolution ◽

High Energy ◽

Metal Coating ◽

Beam Diameter ◽

Surface Receptors ◽

Surface Mobility ◽

Metal Atoms ◽

Shadowing Effect ◽

Imaging Mode ◽

Deposition Techniques

Topographic ultra high resolution can now routinely be established on bulk samples in cold field emission scanning electron microscopy with a second generation of microscopes (FSEM) designed to provide 0.5 nm probe diameters. If such small probes are used for high magnification imaging, topographic contrast is so high that remarkably fine details can be imaged on 2DMSO/osmium-impregnated specimens at ribosome surfaces even without a metal coating. On TCH/osmium-impregnated specimens topographic resolution can be increased further if the SE-I imaging mode is applied. This requires that beam diameter and metal coating thickness be made smaller than the SE range of ~1 nm and background signal contributions be reduced. Subnanometer small probes can be obtained (only) at high accelerating voltages. Subnanometer thin continuous metal films can be produced under the following conditions: self-shadowing effect between metal atoms must be reduced through appropriate deposition techniques and surface mobility of metal atoms must be diminished through high energy sputtering and/or specimen cooling.

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Quantification of gold labeled cell surface antigens by SEM: Current progress and remaining problems

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015770x ◽

1990 ◽

Vol 48 (3) ◽

pp. 34-35

Author(s):

Etienne de Harven ◽

Davide Soligo ◽

Roy McGroarty ◽

Hilary Christensen ◽

Richard Leung ◽

...

Keyword(s):

Cell Surface ◽

Immunogold Labeling ◽

Target Antigen ◽

Facs Analysis ◽

Becton Dickinson ◽

Cell Surface Antigens ◽

Human T Lymphocyte ◽

Backscattered Electron ◽

Imaging Mode ◽

Electron Imaging

Taking advantage of the high elemental contrast of particles of colloidal gold observed in the backscattered electron imaging(BEI) mode of the SEM (1,2), the human T lymphocyte was chosen as a model system to study the potential value of immunogold labeling for the quantification of cell surface expressed molecules. The CD3 antigen which is expressed on all human T lymphocytes and is readily identified by the LEU-4 murine monoclonal antibody (Becton Dickinson, Mountain View, CA) followed by a gold conjugated goat anti-mouse Ig polyclonal antibody was chosen as a model target antigen. When quantified by non-EM methods, using radio-iodinated probes or FACS analysis, approximately 30,000 to 50,000 copies of this antigen per cell are enumerated.The following observations were made while attempting to quantify the same molecule by SEM after specific immunogold labeling:Imaging in the SE vs BE mode: The numbers of gold markers counted in the secondary electron (SE) imaging mode are considerably lower than those counted on the same cells in the backscattered electron (BE) imaging mode.

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Optical characteristics of the hitachi HF-2000 cold field-emission TEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151210 ◽

1993 ◽

Vol 51 ◽

pp. 1076-1077

Author(s):

L. F. Allard ◽

E. Völkl ◽

T. A. Nolan

Keyword(s):

Field Emission ◽

Recent Literature ◽

Electron Gun ◽

High Brightness ◽

Condenser Lens ◽

Illumination System ◽

High Resolution Images ◽

Imaging Mode ◽

Better Than ◽

Illuminating System

The illumination system of the cold field emission (CFE) Hitachi HF-2000 TEM operates with a single condenser lens in normal imaging mode, and with a second condenser lens excited to give the ultra-fine 1 nm probe for microanalysis. The electron gun provides a guaranteed high brightness of better than 7×l08 A/cm2/sr, more than twice the guaranteed brightness of Schottky emission guns. There have been several articles in the recent literature (e.g. refs.) which claim that the geometry of this illumination system yields a total current which is so low that when the beam is spread at low magnifications (say 10 kX), the operator must “keep his eyes glued to the binoculars” in order to see the image. It is also claimed that this illuminating system produces an isoplanatic patch (the area over which image character does not vary significantly) at high magnification which is so small that the instrument is ineffective for recording high resolution images.

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The Impact of Light Polarisation on Light Field of Scenes with Multiple Reflections

Light & Engineering ◽

10.33383/2019-023 ◽

2020 ◽

pp. 108-115 ◽

Cited By ~ 1

Author(s):

Vladimir P. Budak ◽

Anton V. Grimaylo

Keyword(s):

Mathematical Model ◽

Light Field ◽

Global Illumination ◽

Multiple Reflections ◽

Software Environment ◽

The Monte Carlo Method ◽

Mueller Matrices ◽

Volume Integration ◽

The Impact

The article describes the role of polarisation in calculation of multiple reflections. A mathematical model of multiple reflections based on the Stokes vector for beam description and Mueller matrices for description of surface properties is presented. On the basis of this model, the global illumination equation is generalised for the polarisation case and is resolved into volume integration. This allows us to obtain an expression for the Monte Carlo method local estimates and to use them for evaluation of light distribution in the scene with consideration of polarisation. The obtained mathematical model was implemented in the software environment using the example of a scene with its surfaces having both diffuse and regular components of reflection. The results presented in the article show that the calculation difference may reach 30 % when polarisation is taken into consideration as compared to standard modelling.

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