scholarly journals Colourful imaging and self-reconstruction properties of modified single-focus fractal zone plates

2020 ◽  
Vol 28 (25) ◽  
pp. 37827
Author(s):  
Tian Xia ◽  
Shubo Cheng ◽  
Shaohua Tao ◽  
Weixing Yu
Keyword(s):  
Zone Plates ◽  
Single Focus

Single-focus spiral zone plates

2017 ◽  
Vol 42 (13) ◽  
pp. 2663 ◽  
Author(s):  
Yonghao Liang ◽  
Enliang Wang ◽  
Yilei Hua ◽  
Changqing Xie ◽  
Tianchun Ye
Keyword(s):  
Zone Plates ◽  
Single Focus

Mirror-rotation-symmetrical single-focus spiral zone plates

2018 ◽  
Vol 43 (13) ◽  
pp. 3116 ◽  
Author(s):  
Zhen-Nan Tian ◽  
Qi-Dai Chen ◽  
Zhi-Yong Hu ◽  
Yi-Ke Sun ◽  
Yan-Hao Yu ◽  
...  
Keyword(s):  
Zone Plates ◽  
Single Focus

THE EFFECTS OF MANUFACTURING INACCURACIES ON THE IMAGING PROPERTIES OF ZONE PLATES

1984 ◽  
Vol 45 (C2) ◽  
pp. C2-93-C2-96
Author(s):  
M. J. Simpson ◽  
M. T. Browne ◽  
R. E. Burge ◽  
P. Charalambous ◽  
P. J. Duke ◽  
...  
Keyword(s):  
Zone Plates ◽  
Imaging Properties

scholarly journals Analysis of Predistortion Techniques on Fresnel Zone Plates in Ultrasound Applications

Sensors ◽  
2021 ◽  
Vol 21 (15) ◽  
pp. 5066
Author(s):  
José Miguel Fuster ◽  
Sergio Pérez-López ◽  
Francisco Belmar ◽  
Pilar Candelas
Keyword(s):  
Intensity Distribution ◽  
Fresnel Zone ◽  
Focal Depth ◽  
Acoustic Intensity ◽  
Fresnel Zone Plates ◽  
Therapeutic Applications ◽  
Zone Plates ◽  
Ultrasound Applications

In this work, we analyze the effect of predistortion techniques on the focusing profile of Fresnel Zone Plates (FZPs) in ultrasound applications. This novel predistortion method is based on either increasing or decreasing the width of some of the FZP Fresnel rings by a certain amount. We investigate how the magnitude of the predistortion, as well as the number and location of the predistorted rings, influences the lens focusing profile. This focusing profile can be affected in different ways depending on the area of the lens where the predistortion is applied. It is shown that when the inner area of the lens, closer to its center, is predistorted, this technique allows the control of the focal depth at the main focus. However, when the predistortion is applied to an area farther from the center of the lens, the acoustic intensity distribution among the main focus and the closest adjacent secondary foci can be tailored at a certain degree. This predistortion technique shows great potential and can be used to control, modify and shape the FZP focusing profile in both industrial and therapeutic applications.

Mesotheliomas and Proliferative Lesions of the Testicular Mesothelium Produced in Fischer, Sprague-Dawley and Buffalo Rats by Methyl(acetoxymethyl)nitrosamine (DMN-OAc)

1979 ◽  
Vol 16 (5) ◽  
pp. 574-582 ◽  
Author(s):  
J. J. Berman ◽  
J. M. Rice
Keyword(s):  
Body Weight ◽  
Tumor Cells ◽  
Mesothelial Cells ◽  
Male Rats ◽  
Sprague Dawley ◽  
Colloidal Iron ◽  
Microscopic Appearance ◽  
Intraperitoneal Dose ◽  
Single Focus

A single intraperitoneal dose of methyl(acetoxymethyl)nitrosamine (13 mg/kg body weight) given to 78 5-week-old male rats induced 25 mesotheliomas; two mesotheliomas were found in 67 control rats. All mesotheliomas arose from the peritesticular mesothelium and had a typical microscopic appearance of branching papillary fronds with a collagenous core covered by one or many layers of plump tumor cells. Cytoplasm of tumor cells contained material that reacted positively to a colloidal iron stain and was labile to hyaluronidase. In addition to frank mesotheliomas, 16 lesions, which we called atypical mesothelial proliferations. were found. These consisted of a single focus of plump mesothelial cells overlying an area of thick stroma. Often these foci included short, non-branched papillary projections above the surface of adjacent normal mesothelium. Twelve of the 16 lesions occurred in methyl(acetoxymethyl)nitrosamine-treated rats.

scholarly journals On a cassegrain reflector with corrected field

1913 ◽  
Vol 88 (602) ◽  
pp. 188-191
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Straightforward Manner ◽  
Flat Field ◽  
Convex Mirror ◽  
Solution Proceeds ◽  
Characteristic Features ◽  
Working Out ◽  
Essential Problem ◽  
Single Focus

The purpose of this memoir is to discover an optical appliance which shall correct in a practical manner the faults in the field of a Cassegrain reflector, while leaving unimpaired its achromatism and the characteristic features of its design, which gives a focal length much greater than the length of the instrument, combined with a convenient position of the observer. The question touches an investigation by Schwarzschild as to what can be done with two curved mirrors the figures of which are not necessarily spherical. With these be corrects spherical aberration and coma, but in order to secure a flat field he is led to a construction in which the second mirror, which is between the great mirror and its principal focus, is concave, and therefore shortens the effective focal length, in place of increasing it. The deformations from spherical figures are also so great, especially for the great mirror, as to leave it doubtful whether the construction discussed could ever be the model for practicable instruments. If we keep to the Cassegrain form, spherical aberration and coma may equally be corrected by deformations of the mirrors which through large, are less extreme, but there remains a pronounced curvature of the field. For this reason I am led, in the present memoir, to consider more complicated systems produced by the interposition of systems of lenses, achromatism can be preserved completely for a single focus if there are three lenses of focal length determined when their position are given, and if all are made of the same glass. One of these lenses, which I call the reverser, is silvered at the back and replaces the convex mirror; the other two are placed close together in the way of the outcoming beam, about one third of the distance from the great mirror to the reverser; the members of this pair, which I call the corrector, are of nearly equal but opposite focal lengths, introducing very little deviation in the ray but an arbitrary amount of aberration, according to the distribution of curvatures between the two faces of each lens. All the surfaces are supposed spherical except that of the great mirror, The essential problem is to bring the necessary work into a form that will allow unknown quantities which express the distribution of curvature between the faces of each lens to be carried forward algebraically. The methods employed are those of a recent memoir by the author,* and a part of the paper is occupied in working out expressions to which this theory leads, for thin lenses, systems of thin lenses, mirrors, reversers and the like, and it may be regarded as an expansion and working illustration of that memoir. Ibis part does not lend itself to summary, When the expressions are obtained the solution proceeds in a straightforward manner, by approximation, which is somewhat complicated owing to the number of considerations which it is necessary to keep in view, but is not otherwise difficult. The solution is completed at the stage where the unextinguished aberrations are considered negligible.

scholarly journals Thermal stability of tungsten zone plates for focusing hard x-ray free-electron laser radiation

2012 ◽  
Vol 14 (4) ◽  
pp. 043010 ◽  
Author(s):  
D Nilsson ◽  
F Uhlén ◽  
J Reinspach ◽  
H M Hertz ◽  
A Holmberg ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Laser Radiation ◽  
Free Electron ◽  
Free Electron Laser ◽  
X Ray ◽  
Zone Plates ◽  
Thermal Stability Of

Spiral zone plates with arbitrary diameter of the dark spot in the centre of their focal point

1995 ◽  
Vol 114 (1-2) ◽  
pp. 1-8 ◽  
Author(s):  
Z Jaroszewicz ◽  
A Kolodziejczyk ◽  
D Mouriz ◽  
C Gomez-Reino
Keyword(s):  
Focal Point ◽  
Dark Spot ◽  
Zone Plates
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