Diffraction-grating interferometer for testing aspheric concave mirrors with optimization of fringe visibility

2004 ◽  
Vol 43 (9) ◽  
pp. 2124
Author(s):  
Tae-Joon Hwang
Keyword(s):  
Diffraction Grating ◽  
Fringe Visibility ◽  
Grating Interferometer

scholarly journals Performance and optimization of X-ray grating interferometry

2014 ◽  
Vol 372 (2010) ◽  
pp. 20130027 ◽  
Author(s):  
T. Thuering ◽  
M. Stampanoni
Keyword(s):  
Interference Fringe ◽  
Refraction Angle ◽  
Fringe Visibility ◽  
X Ray ◽  
Analytical Formulae ◽  
Grating Interferometer ◽  
Differential Phase Contrast ◽  
Energy Dependent ◽  
Application Specific ◽  
Contrast Image

The monochromatic and polychromatic performance of a grating interferometer is theoretically analysed. The smallest detectable refraction angle is used as a metric for the efficiency in acquiring a differential phase-contrast image. Analytical formulae for the visibility and the smallest detectable refraction angle are derived for Talbot-type and Talbot–Lau-type interferometers, respectively, providing a framework for the optimization of the geometry. The polychromatic performance of a grating interferometer is investigated analytically by calculating the energy-dependent interference fringe visibility, the spectral acceptance and the polychromatic interference fringe visibility. The optimization of grating interferometry is a crucial step for the design of application-specific systems with maximum performance.

The Use of an Improved Diffraction Grating Interferometer

1969 ◽  
Vol 8 (11) ◽  
pp. 2191 ◽  
Author(s):  
A. R. Maddox ◽  
R. C. Binder
Keyword(s):  
Diffraction Grating ◽  
Grating Interferometer

Diffraction grating interferometer for the accurate measurement of rotational quantities

Measurement ◽  
1995 ◽  
Vol 16 (2) ◽  
pp. 71-80 ◽  
Author(s):  
Angelika Täubner ◽  
Hans-Jürgen von Martens
Keyword(s):  
Diffraction Grating ◽  
Grating Interferometer

scholarly journals Boosting phase contrast with a grating Bonse–Hart interferometer of 200 nanometre grating period

2014 ◽  
Vol 372 (2010) ◽  
pp. 20130028 ◽  
Author(s):  
Han Wen ◽  
Andrew A. Gomella ◽  
Ajay Patel ◽  
Douglas E. Wolfe ◽  
Susanna K. Lynch ◽  
...  
Keyword(s):  
Diffraction Grating ◽  
Phase Contrast ◽  
Incident Angle ◽  
Incident Beam ◽  
Grating Period ◽  
X Rays ◽  
Contrast Imaging ◽  
Phase Images ◽  
Large Phase ◽  
Grating Interferometer

We report on a grating Bonse–Hart interferometer for phase-contrast imaging with hard X-rays. The method overcomes limitations in the level of sensitivity that can be achieved with the well-known Talbot grating interferometer, and without the stringent spectral filtering at any given incident angle imposed by the classic Bonse–Hart interferometer. The device operates in the far-field regime, where an incident beam is split by a diffraction grating into two widely separated beams, which are redirected by a second diffraction grating to merge at a third grating, where they coherently interfere. The wide separation of the interfering beams results in large phase contrast, and in some cases absolute phase images are obtained. Imaging experiments were performed using diffraction gratings of 200 nm period, at 22.5 keV and 1.5% spectral bandwidth on a bending-magnetic beamline. Novel design and fabrication process were used to achieve the small grating period. Using a slitted incident beam, we acquired absolute and differential phase images of lightly absorbing samples. An advantage of this method is that it uses only phase modulating gratings, which are easier to fabricate than absorption gratings of the same periods.

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