scholarly journals Двумерные брэгговские резонаторы на основе планарных диэлектрических волноводов (от теории к модельному тестированию)

2019 ◽  
Vol 53 (10) ◽  
pp. 1315
Author(s):  
Н.С. Гинзбург ◽  
Н.Ю. Песков ◽  
В.Ю. Заславский ◽  
Е.Р. Кочаровская ◽  
А.М. Малкин ◽  
...  
Keyword(s):  
Narrow Band ◽  
Bragg Reflection ◽  
Dielectric Waveguides ◽  
Wavelength Band ◽  
Reflection Band ◽  
Millimeter Wavelength ◽  
Bragg Structures ◽  
Significant Interest ◽  
Simulation Results ◽  
Analytical Approaches

Using analytical approaches and CST Microwave Studio 3D simulations, we have undertaken a theoretical analysis of electrodynamical characteristics of 2D Bragg structures based on planar oversized dielectric waveguides with double-periodical corrugation. Such structures are of significant interest for obtaining directed narrow-band radiation in heterolasers with large dimensions of an active area. Modeling electrodynamical experiments on 'cold' testing of such structures in millimeter wavelength band were conducted. Fine agreement between the experimental results and the simulation results was demonstrated which includes the presence of the highest-quality mode inside the Bragg reflection band in absence of the periodicity defects.

scholarly journals Theoretical and experimental studies of highly selective planar two-dimensional Bragg structures based on dielectric waveguides in the terahertz frequency range

2019 ◽  
Vol 30 ◽  
pp. 07009
Author(s):  
Naum Ginzburg ◽  
Nikolay Peskov ◽  
Vladislav Zaslavsky ◽  
Ekaterina Kocharovskaya ◽  
Andrey Malkin ◽  
...  
Keyword(s):  
Bragg Reflection ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Dielectric Waveguides ◽  
Two Dimensional ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Frequency Range ◽  
Three Dimensional Modeling ◽  
Bragg Structures

Based on theoretical approach and three-dimensional modeling using the CST Microwave Studio code, planar dielectric two-dimensional Bragg structures in terahertz frequency range were developed and manufactured. Proof-of-principle electrodynamic experiments on the “cold” testing of these structures were carried out. It is shown that the experimental results are in good agreement with the theoretical predicts, including the existence of the highest Q mode inside the Bragg reflection band in the absence of periodicity defects.

Diamond channel-cut crystals for high-heat-load beam-multiplexing narrow-band X-ray monochromators

2021 ◽  
Vol 28 (6) ◽  
Author(s):  
Yuri Shvyd'ko ◽  
Sergey Terentyev ◽  
Vladimir Blank ◽  
Tomasz Kolodziej
Keyword(s):  
Heat Load ◽  
Narrow Band ◽  
Bragg Reflection ◽  
High Heat ◽  
High Repetition Rate ◽  
X Rays ◽  
Ray Optics ◽  
X Ray ◽  
Load Beam ◽  
High Heat Load

Next-generation high-brilliance X-ray photon sources call for new X-ray optics. Here we demonstrate the possibility of using monolithic diamond channel-cut crystals as high-heat-load beam-multiplexing narrow-band mechanically stable X-ray monochromators with high-power X-ray beams at cutting-edge high-repetition-rate X-ray free-electron laser (XFEL) facilities. The diamond channel-cut crystals fabricated and characterized in these studies are designed as two-bounce Bragg reflection monochromators directing 14.4 or 12.4 keV X-rays within a 15 meV bandwidth to 57Fe or 45Sc nuclear resonant scattering experiments, respectively. The crystal design allows out-of-band X-rays transmitted with minimal losses to alternative simultaneous experiments. Only ≲2% of the incident ∼100 W X-ray beam is absorbed in the 50 µm-thick first diamond crystal reflector, ensuring that the monochromator crystal is highly stable. Other X-ray optics applications of diamond channel-cut crystals are anticipated.

WAVELENGTH SELECTIVE BOLOMETER DESIGN

2008 ◽  
Vol 18 (03) ◽  
pp. 569-574 ◽  
Author(s):  
SANGWOOK HAN ◽  
JOO-YUN JUNG ◽  
DEAN P. NEIKIRK
Keyword(s):  
Narrow Band ◽  
Wavelength Band ◽  
Common Plane ◽  
Wavelength Selectivity

Multi-color narrow-band Salisbury Screen and Jaumann Absorbers combined with optimized thick Si 3 N 4 support layers are designed for wavelength selectivity in 7~14µm wavelength band. The Jaumann Absorbers are adopted as a vertically ‘stacked’ pixel structure to save space and enhance resolution compared against ‘tiled’ structure (pixels lying in a common plane).

Planar orotron experiments in the millimeter-wavelength band

1988 ◽  
Vol 16 (2) ◽  
pp. 199-205 ◽  
Author(s):  
E.M. Marshall ◽  
P.M. Phillips ◽  
J.E. Walsh
Keyword(s):  
Wavelength Band ◽  
Millimeter Wavelength

Dynamic biped robot locomotion on less structured surfaces

Robotica ◽  
2000 ◽  
Vol 18 (2) ◽  
pp. 163-170 ◽  
Author(s):  
M.-Y. Cheng ◽  
C.-S. Lin
Keyword(s):  
Design Method ◽  
Control Design ◽  
Biped Robot ◽  
Control Parameters ◽  
Surface Slope ◽  
Structured Surfaces ◽  
Robot Locomotion ◽  
The Past ◽  
Simulation Results ◽  
Analytical Approaches

Most studies in the past on the control of biped locomotion considered only level surfaces. However, in the real world the ground is rarely completely flat. More research on locomotion on less structured surfaces is needed. In this study, we investigated a control design method that searches for suitable control and trajectory parameters using a Genetic Algorithm (GA). Many sets of parameters are generated through the search and the best set is selected based on a robustness measure developed from the linearized Poincaré map. This technique reduces tedious analysis and is favorably applicable to the design for locomotion on unstructured surfaces, for which analytical approaches are less appropriate. Simulations have been performed. Control parameters for different slopes were obtained and stored in a database. During the control, the control parameters suitable for the current surface slope were retrieved and the trajectory for a level surface was modified according to the surface slope. The control parameters changed values according to the terrain. Simulation results were promising.

Image Segmentation Arithmetic Based on Narrow Band C-V

2010 ◽  
Vol 108-111 ◽  
pp. 1338-1343
Author(s):  
Xiao Hu Lv ◽  
Yong Xin Liu
Keyword(s):  
Image Segmentation ◽  
Level Set ◽  
Narrow Band ◽  
Segmentation Algorithm ◽  
Computational Method ◽  
Computation Complexity ◽  
Iterative Computation ◽  
Iterative Calculation ◽  
Simulation Results

The characters of C-V model are analyzed in this paper. Using the C-V technique to segment objects from an image, every pixel of whole image needed to be updated in each iterative calculation. The amount of iterative calculation is very large. So a computational method combine C-V model with the narrow band of level set is proposed. The segmentation iterative computation is defined on a narrow band, so the computation complexity is gotten lower. This segmentation algorithm is simulated in MATLAB. The simulation results shows that this segment arithmetic is efficiency, constringency fast and can get object integrally.

Polarization independent narrow band Bragg reflection gratings made with silica‐on‐silicon waveguides

1992 ◽  
Vol 60 (15) ◽  
pp. 1779-1781 ◽  
Author(s):  
R. Adar ◽  
C. H. Henry ◽  
R. C. Kistler ◽  
R. F. Kazarinov
Keyword(s):  
Narrow Band ◽  
Bragg Reflection ◽  
Silicon Waveguides ◽  
Reflection Gratings ◽  
Polarization Independent
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