USE OF A LASER DIFFRACTION PATTERN TO STUDY SURFACE SELF‐DIFFUSION OF METALS

1967 ◽  
Vol 10 (9) ◽  
pp. 258-260 ◽  
Author(s):  
H. P. Bonzel ◽  
N. A. Gjostein
Keyword(s):  
Diffraction Pattern ◽  
Laser Diffraction ◽  
Self Diffusion ◽  
Laser Diffraction Pattern

Study on the Precise Alignment of Micro-Lenses in the Microcolumn by Using the Laser Diffraction Pattern

2007 ◽  
Vol 544-545 ◽  
pp. 845-848 ◽  
Author(s):  
Seung Joon Ahn ◽  
Dae Wook Kim ◽  
Ho Seob Kim ◽  
Chul Geun Park ◽  
Seung Joon Ahn
Keyword(s):  
Carbon Nanotubes ◽  
Diffraction Pattern ◽  
High Precision ◽  
Laser Diffraction ◽  
Image Resolution ◽  
Alignment Method ◽  
Critical Factors ◽  
Overall Performance ◽  
Laser Diffraction Pattern ◽  
Grid Mesh

The alignment precision of the electron lenses is one of the most critical factors that determine overall performance of the microcolumn system including the image resolution and aberration. Since the lens apertures are usually as small as 5 ~ 300 μm, the alignment is difficult to carry out, even if the expensive and complicated aligner is used. In this work, we have developed a novel alignment method using laser diffraction pattern, with which we can easily obtain high-precision alignment. The images of Cu grid (mesh# 1000) and carbon nanotubes (200-nm diameter) taken by the microcolumn fabricated by the new alignment scheme has confirmed that the new method was very simple and useful.

The Measurement of Liquid Surface Tension by Optical Technique

2012 ◽  
Vol 203 ◽  
pp. 108-110
Author(s):  
Peng Zhang ◽  
Dao Bin Luo ◽  
Jian Ke Liu
Keyword(s):  
Surface Tension ◽  
Diffraction Pattern ◽  
Liquid Surface ◽  
Laser Diffraction ◽  
Optical Technique ◽  
Laser Technique ◽  
Liquid Surface Tension ◽  
Diffraction Patterns ◽  
Liquid Surface Waves ◽  
Laser Diffraction Pattern

Based on the laser technique, a method of detecting liquid surface tension was proposed. The relation between the laser diffraction pattern and liquid surface tension is derived. In this experiment, laser diffraction patterns from liquid surface waves were collected .The experiment results show that the proposed way is feasible.

Fabrication and Precise Alignment of Electron Lenses in the Microcolumn Using the Laser Diffraction Pattern

2011 ◽  
Vol 695 ◽  
pp. 589-593
Author(s):  
Seong Joon Ahn ◽  
Ho Seob Kim ◽  
Seung Joon Ahn
Keyword(s):  
Diffraction Pattern ◽  
Laser Light ◽  
Beam Current ◽  
Laser Diffraction ◽  
Alignment Method ◽  
Semiconductor Processing ◽  
Processing Technologies ◽  
Airy Disk ◽  
Laser Diffraction Pattern

The quality of electron lenses and precision of their alignment are very important factors that determine the resolution of the microcolumn. In this work, we have fabricated the quality electron lenses using the semiconductor processing technologies and checked their circular shapes by using the laser diffraction pattern. The observed diffraction pattern by naked eyes was the circular Airy disk and the measured eccentricity of the lens aperture was found to be less than 0.02. We have also made precise alignment of the electron lenses by illuminating the laser beam through the roughly aligned electron lenses and adjusting the electron lenses while monitoring the diffraction pattern formed by the diffracted laser light from the lens apertures. This new method can replace the conventional alignment method where the expensive equipment like the aligner or the STM is required. We have also found the misalignment limit by measuring the e-beam current that came out from the microcolumn.

Analysis of electron-diffraction intensity profiles using a photodiode-array detection system

1983 ◽  
Vol 41 ◽  
pp. 322-323
Author(s):  
J. B. Warren
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Detection System ◽  
High Energy ◽  
Photographic Emulsion ◽  
Diffraction Intensity ◽  
Silicon Photodiode ◽  
Photodiode Array Detection ◽  
Analog To Digital ◽  
Photodiode Array

Electron diffraction intensity profiles have been used extensively in studies of polycrystalline and amorphous thin films. In previous work, diffraction intensity profiles were quantitized either by mechanically scanning the photographic emulsion with a densitometer or by using deflection coils to scan the diffraction pattern over a stationary detector. Such methods tend to be slow, and the intensities must still be converted from analog to digital form for quantitative analysis. The Instrumentation Division at Brookhaven has designed and constructed a electron diffractometer, based on a silicon photodiode array, that overcomes these disadvantages. The instrument is compact (Fig. 1), can be used with any unmodified electron microscope, and acquires the data in a form immediately accessible by microcomputer.Major components include a RETICON 1024 element photodiode array for the de tector, an Analog Devices MAS-1202 analog digital converter and a Digital Equipment LSI 11/2 microcomputer. The photodiode array cannot detect high energy electrons without damage so an f/1.4 lens is used to focus the phosphor screen image of the diffraction pattern on to the photodiode array.

Light Optical Diffraction Studies of Macromolecular Ultrastructure

1970 ◽  
Vol 28 ◽  
pp. 258-259
Author(s):  
Glen B. Haydon
Keyword(s):  
High Resolution ◽  
Diffraction Analysis ◽  
Diffraction Pattern ◽  
Electron Micrographs ◽  
Optical Diffraction ◽  
Electron Micrograph ◽  
Its Analysis ◽  
Resolution Electron ◽  
Diffraction Patterns

Analysis of light optical diffraction patterns produced by electron micrographs can easily lead to much nonsense. Such diffraction patterns are referred to as optical transforms and are compared with transforms produced by a variety of mathematical manipulations. In the use of light optical diffraction patterns to study periodicities in macromolecular ultrastructures, a number of potential pitfalls have been rediscovered. The limitations apply to the formation of the electron micrograph as well as its analysis.(1) The high resolution electron micrograph is itself a complex diffraction pattern resulting from the specimen, its stain, and its supporting substrate. Cowley and Moodie (Proc. Phys. Soc. B, LXX 497, 1957) demonstrated changing image patterns with changes in focus. Similar defocus images have been subjected to further light optical diffraction analysis.

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