Axially Symmetric Diffraction Grating on Substrate in Dielectric Waveguide

Author(s):  
Maxim Legenkiy
2021 ◽  
Vol 11 (21) ◽  
pp. 10381
Author(s):  
Yuriy Sirenko ◽  
Seil Sautbekov ◽  
Merey Sautbekova ◽  
Nataliya Yashina ◽  
Nursaule Burambayeva ◽  
...  

The paper is focused on reliable modeling and analysis of axially symmetric radiators with a very narrow (throat) funnel-shaped radiation pattern. When such a diagram is formed, a wave analogue of Smith–Purcell coherent radiation is realized—the surface wave of a radial dielectric waveguide ‘sweeps out’ with its exponentially decaying part a concentric periodic grating, the fundamental spatial harmonic of which, propagating without attenuation in a direction close to the symmetry axis of the structure, generates a radiation field with the required characteristics.


2016 ◽  
Vol 10 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Oleksandr P. Kusaykin ◽  
Peter N. Melezhik ◽  
Anatolij E. Poyedinchuk ◽  
Sergey A. Provalov ◽  
Dmitrij G. Seleznyov

2000 ◽  
Vol 179 ◽  
pp. 379-380
Author(s):  
Gaetano Belvedere ◽  
Kirill Kuzanyan ◽  
Dmitry Sokoloff

Extended abstractHere we outline how asymptotic models may contribute to the investigation of mean field dynamos applied to the solar convective zone. We calculate here a spatial 2-D structure of the mean magnetic field, adopting real profiles of the solar internal rotation (the Ω-effect) and an extended prescription of the turbulent α-effect. In our model assumptions we do not prescribe any meridional flow that might seriously affect the resulting generated magnetic fields. We do not assume apriori any region or layer as a preferred site for the dynamo action (such as the overshoot zone), but the location of the α- and Ω-effects results in the propagation of dynamo waves deep in the convection zone. We consider an axially symmetric magnetic field dynamo model in a differentially rotating spherical shell. The main assumption, when using asymptotic WKB methods, is that the absolute value of the dynamo number (regeneration rate) |D| is large, i.e., the spatial scale of the solution is small. Following the general idea of an asymptotic solution for dynamo waves (e.g., Kuzanyan & Sokoloff 1995), we search for a solution in the form of a power series with respect to the small parameter |D|–1/3(short wavelength scale). This solution is of the order of magnitude of exp(i|D|1/3S), where S is a scalar function of position.


Author(s):  
Godfrey C. Hoskins ◽  
V. Williams ◽  
V. Allison

The method demonstrated is an adaptation of a proven procedure for accurately determining the magnification of light photomicrographs. Because of the stability of modern electrical lenses, the method is shown to be directly applicable for providing precise reproducibility of magnification in various models of electron microscopes.A readily recognizable area of a carbon replica of a crossed-line diffraction grating is used as a standard. The same area of the standard was photographed in Phillips EM 200, Hitachi HU-11B2, and RCA EMU 3F electron microscopes at taps representative of the range of magnification of each. Negatives from one microscope were selected as guides and printed at convenient magnifications; then negatives from each of the other microscopes were projected to register with these prints. By deferring measurement to the print rather than comparing negatives, correspondence of magnification of the specimen in the three microscopes could be brought to within 2%.


2001 ◽  
Vol 7 (2s) ◽  
pp. 19-25
Author(s):  
A.A. Loginov ◽  
◽  
Yu.I. Samoilenko ◽  
V.A. Tkachenko ◽  
◽  
...  
Keyword(s):  
Mhd Flow ◽  

2014 ◽  
Vol E97.C (10) ◽  
pp. 1036-1040 ◽  
Author(s):  
Junichi NAKAYAMA ◽  
Yasuhiko TAMURA

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