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In this paper, the spectral characteristics formed by a double-grating transmission scheme are discussed based on the scalar diffraction theory. First, considering two different grating periods, the angular spectrum at the back of the second grating is obtained. Then, the spectral characteristics are discussed with three different periodic conditions, while it is proved that the spatial distribution and spacing of the spectrum are absolutely determined by the grating constants and angles. The theoretical results manifest that the spatial distribution range of the spectrum becomes larger as the angle increases, unlike the spectral points, which are distributed on a single line when the grating lines of the two gratings are parallel. Finally, for the sake of proving that our theoretical analysis is correct and reasonable, three sets of experiments are conducted with three different combinations of Ronchi gratings. As expected, the experimental and theoretical results are in perfect agreement. In a word, the involved results could be useful for expanding the application of moiré deflectometry.
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http://dx.doi.org/10.1364/JOSAA.531295 | DOI Listing |
This paper introduces a full-metal millimeter-wave leaky-wave antenna (LWA) with filtering response and enhanced frequency-scanning capabilities. The proposed LWA is constituted of a transmission line and a radiator array. The transmission line achieves an integrated filtering function by incorporating spoof surface plasmon polariton (SSPP) blocks within a double-grating waveguide (DGWG).
View Article and Find Full Text PDFJ Opt Soc Am A Opt Image Sci Vis
November 2024
In this paper, the spectral characteristics formed by a double-grating transmission scheme are discussed based on the scalar diffraction theory. First, considering two different grating periods, the angular spectrum at the back of the second grating is obtained. Then, the spectral characteristics are discussed with three different periodic conditions, while it is proved that the spatial distribution and spacing of the spectrum are absolutely determined by the grating constants and angles.
View Article and Find Full Text PDFAPL Bioeng
March 2018
Biomaterials Science Center, University of Basel, 4123 Allschwil, Switzerland.
Visualizing the internal architecture of large soft tissue specimens within the laboratory environment in a label-free manner is challenging, as the conventional absorption-contrast tomography yields a poor contrast. In this communication, we present the integration of an X-ray double-grating interferometer (XDGI) into an advanced, commercially available micro computed tomography system nanotom m with a transmission X-ray source and a micrometer-sized focal spot. The performance of the interferometer is demonstrated by comparing the registered three-dimensional images of a human knee joint sample in phase- and conventional absorption-contrast modes.
View Article and Find Full Text PDFOpt Lett
March 2013
Faculty of Physics, University of Warsaw, Warsaw, Poland.