Doubling the field of view in off-axis low-coherence interferometric imaging

AbstractWe describe recent progress with interferometric imaging using the Multiple Mirror Telescope (MMT). All six telescopes can now be phased over a wide field of view simultaneously resulting in a (u, v) plane coverage corresponding to that of a 686 cm aperture telescope. We describe the open-loop phasing control of the MMT for gravitational changes and we describe a concept of an internal cophasing/coalignment system for MMT type telescopes.

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Low-Coherence Shearing Interferometry With Constant Off-Axis Angle

Frontiers in Physics ◽

10.3389/fphy.2020.611679 ◽

2021 ◽

Vol 8 ◽

Author(s):

Rongli Guo ◽

Itay Barnea ◽

Natan T. Shaked

Keyword(s):

Human Sperm ◽

Optical Path Difference ◽

Wide Field ◽

Phase Imaging ◽

Single Shot ◽

Interferometric Imaging ◽

Coherent Noise ◽

Shearing Interferometry ◽

Quantitative Phase ◽

Low Coherence

We present a wide-field interferometric imaging module for biomedical and metrological measurements, employing shearing interferometry with constant off-axis angle (SICA) that can work, for the first time, with a low-coherence light source. In the SICA module, the shearing distance between the interfering beams can be fully controlled without a direct relation with the off-axis angle. In contrast to our previous SICA module, here we use a low-coherence illumination source, providing quantitative phase profiles with significantly lower spatial coherent noise. Although a low-coherence source is used, we obtain off-axis interference on the entire camera sensor, where the optical path difference between the two beams is compensated by using a glass window positioned in the confocal plane. This highly stable, common-path, low-coherence, single-shot interferometric module can be used as an add-on unit to a conventional bright-field microscope illuminated by a low-coherence source. We demonstrate the advantages of using the module by quantitative phase imaging of a polymer bead, fluctuations in a human white blood cell, and dynamics of human sperm cells.

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Very High Resolution Analysis of the Dynamics of a Coronal Plasmoid

International Astronomical Union Colloquium ◽

10.1017/s0252921100026117 ◽

1994 ◽

Vol 144 ◽

pp. 593-596

Author(s):

O. Bouchard ◽

S. Koutchmy ◽

L. November ◽

J.-C. Vial ◽

J. B. Zirker

Keyword(s):

High Resolution ◽

Solar Eclipse ◽

Total Solar Eclipse ◽

Field Of View ◽

Small Field ◽

High Resolution Analysis ◽

Ccd Observations ◽

Resolution Analysis ◽

Very High ◽

Small Field Of View

AbstractWe present the results of the analysis of a movie taken over a small field of view in the intermediate corona at a spatial resolution of 0.5“, a temporal resolution of 1 s and a spectral passband of 7 nm. These CCD observations were made at the prime focus of the 3.6 m aperture CFHT telescope during the 1991 total solar eclipse.

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Dynamic Scanning Electron Microscopy of Small Particles

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010011502x ◽

1975 ◽

Vol 33 ◽

pp. 280-281

Author(s):

W. Krakow ◽

W. C. Nixon

Keyword(s):

Electron Microscopy ◽

Low Noise ◽

Time Sequence ◽

Field Of View ◽

Video Tape ◽

Small Particles ◽

Polystyrene Spheres ◽

Field Distributions ◽

Dynamic Scanning ◽

Scanning Electron

The scanning electron microscope (SEM) can be run at television scanning rates and used with a video tape recorder to observe dynamic specimen changes. With a conventional tungsten source, a low noise TV image is obtained with a field of view sufficient to cover the area of the specimen to be recorded. Contrast and resolution considerations have been elucidated and many changing specimens have been studied at TV rates.To extend the work on measuring the magnitude of charge and field distributions of small particles in the SEM, we have investigated their motion and electrostatic interaction at TV rates. Fig. 1 shows a time sequence of polystyrene spheres on a conducting grating surface inclined to the microscope axis. In (la) there are four particles present in the field of view, while in (lb) a fifth particle has moved into view.

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STM studies of crystal growth

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100086179 ◽

1991 ◽

Vol 49 ◽

pp. 374-375

Author(s):

M. G. Lagally

Keyword(s):

Crystal Growth ◽

Molecular Beam ◽

Chemical Vapor ◽

Sputter Deposition ◽

Field Of View ◽

Scanning Tunneling ◽

Wide Field ◽

Tunneling Microscopy ◽

Wide Field Of View ◽

The One

It has been recognized since the earliest days of crystal growth that kinetic processes of all Kinds control the nature of the growth. As the technology of crystal growth has become ever more refined, with the advent of such atomistic processes as molecular beam epitaxy, chemical vapor deposition, sputter deposition, and plasma enhanced techniques for the creation of “crystals” as little as one or a few atomic layers thick, multilayer structures, and novel materials combinations, the need to understand the mechanisms controlling the growth process is becoming more critical. Unfortunately, available techniques have not lent themselves well to obtaining a truly microscopic picture of such processes. Because of its atomic resolution on the one hand, and the achievable wide field of view on the other (of the order of micrometers) scanning tunneling microscopy (STM) gives us this opportunity. In this talk, we briefly review the types of growth kinetics measurements that can be made using STM. The use of STM for studies of kinetics is one of the more recent applications of what is itself still a very young field.

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A High Resolution Scanning Microscope

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100101529 ◽

1968 ◽

Vol 26 ◽

pp. 356-357

Author(s):

A. V. Crewe ◽

J. Wall ◽

L. M. Welter

Keyword(s):

High Resolution ◽

Field Emission ◽

Spherical Aberration ◽

Focal Length ◽

Spot Size ◽

Emission Source ◽

Field Of View ◽

Scanning Microscope ◽

Magnetic Lens ◽

High Quality

A scanning microscope using a field emission source has been described elsewhere. This microscope has now been improved by replacing the single magnetic lens with a high quality lens of the type described by Ruska. This lens has a focal length of 1 mm and a spherical aberration coefficient of 0.5 mm. The final spot size, and therefore the microscope resolution, is limited by the aberration of this lens to about 6 Å.The lens has been constructed very carefully, maintaining a tolerance of + 1 μ on all critical surfaces. The gun is prealigned on the lens to form a compact unit. The only mechanical adjustments are those which control the specimen and the tip positions. The microscope can be used in two modes. With the lens off and the gun focused on the specimen, the resolution is 250 Å over an undistorted field of view of 2 mm. With the lens on,the resolution is 20 Å or better over a field of view of 40 microns. The magnification can be accurately varied by attenuating the raster current.

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