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Fresnel zone

About: Fresnel zone is a research topic. Over the lifetime, 2337 publications have been published within this topic receiving 37650 citations.


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Journal ArticleDOI
TL;DR: In this paper, an amplitude photon sieve is designed using vector diffractive theory to improve the focusing ability of photon sieves from short, visible or long-wavelength light.
Abstract: Photon sieve is a novel nanostructure element with an array of pinholes. After structural optimization of pinholes, it has good focusing ability from short, visible or long-wavelength light. The resolution of the photon sieve depends on the diameter of the outermost pinholes. To improve the resolution, the diameter of the outmost pinholes decreases. At present, the design theory commonly adopted is scalar diffractive theory. But it is well known that scalar diffractive theory is no longer valid for designing of photon sieves when the diameter of pinholes is less than the wavelength of the incidence light. In this paper, an amplitude photon sieve is designed using vector diffractive theory. The detailed design procedures are described. To compare the imaging performance, we analyze the Fresnel zone plates and photon sieves using numerical simulation. The results show that photon sieves have better focusing performance than Fresnel zone plates, but the diffractive efficiency is lower than Fresnel zone plates. The results also provide a theoretical foundation for the application of photon sieves. To improve the diffractive efficiency, future work will focus on structural amelioration of photon sieves, e.g., phase photon sieves. We also provide two potential structures of phase photon sieves.

3 citations

Proceedings ArticleDOI
09 Dec 2002
TL;DR: In this paper, the results of an analysis of an infrared signal based upon wavelet transforms and filtering are presented, focusing on the detection of a detectable signature frequency of the variation in signal intensity that is based upon the Fresnel zone size.
Abstract: An infrared or optical signal propagating along a line-of-sight horizontal path near the earth's surface can encounter substantial perturbations There are two prominent factors which can generate fluctuations: first, refractive distortions are low-frequency modulations which can amplify or reduce a signal, and second, scintillation is a higher frequency fluctuation in signal intensity We will discuss models developed to predict these effects, and associated field test efforts to corroborate and correct the model predictions The field efforts include tests along horizontal near-surface paths over land and over the coastal ocean surface Previous transmission field tests have revealed that slow-scale refractive effects can create very pronounced changes in the recorded one-minute average intensity of a source We will show the results of an analysis of this signal based upon wavelet transforms and filtering We focus on the detection of a detectable signature frequency of the variations in signal intensity that is based upon the Fresnel zone size This Fresnel frequency is correlated with the location of the Kolmogorov power law scaling

3 citations

Journal ArticleDOI
TL;DR: In this article, a study of focusing and imaging properties of two Fresnel zone plates (ZP) system for hard X-rays is presented, where a phenomenon is demonstrated for the first time of focusing by two ZP located at significant distance from each other.
Abstract: Study of focusing and imaging properties of two Fresnel zone plates (ZP) system for hard X-rays is presented. A phenomenon is demonstrated for the first time of focusing by two ZP located at significant distance from each other. Peculiarities of intensity distribution at the focal plane during a scan by second ZP normally to the optical axis of the system as well as along the optical axis both theoretically and experimentally is investigated. A registration is realized experimentally on the beam line BM-5 ESRF (Grenoble, France) at E =9.4 keV of the focused image of the object. Computer program is elaborated for optical properties simulation using convolution of transmission function and Kirchhoff propagator in paraxial approximation by Fast Fourier Transform (FFT).

3 citations

Proceedings ArticleDOI
14 Sep 2011
TL;DR: The development of the theory of Fresnel Sections, the application and the practical implementation on modern computing architectures are presented.
Abstract: This paper presents the development of the theory of Fresnel Sections, the application and the practical implementation on modern computing architectures. The theory of Fresnel Sections and the term Fresnelabschnitte has been introduced with processing of seismic data. Fresnel Sections are the further stage development from the simple concept of Fresnel Zones which are only valid in non‐slanted environments and mostly cannot be used for real underground structures. Fresnel Sections handling slanted structures have been used with wave theory and optical phenomena. Using highly performant computing resources Fresnel Sections and derivates can be calculated for huge data sets as well as for sophisticated application scenarios.

3 citations

Book ChapterDOI
01 Jan 1980
TL;DR: Both experimental results obtained in the laboratory and clinical results are developed, trying to correlate these results and quantify the medical requirements of B echographic real time imaging.
Abstract: This is a progress report on the Fresnel imaging research that we presented at the 7 th symposium 1,2,3. At this time we had developed both B and C echographic experiments. During these last eighteen months we have built a few machines duplicated from our real time B echographic array and adapted to a permanent clinical use so that we have a better knowledge of the clinical potentiality of the Fresnel focusing technique. These 120 mm arrays have 160 elements and are acted at a recurrent frequency of 4 kHz to furnish a 160 line image in 40 ms. We shall develop here both experimental results obtained in the laboratory and clinical results, trying to correlate these results and quantify the medical requirements of B echographic real time imaging.

3 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202326
202249
202137
202052
201965
201878