Results 11 to 20 of about 663,427 (287)
Sharp acoustic vortex focusing by Fresnel-spiral zone plates [PDF]
Applied Physics Letters, 2018 We report the optimal focusing of acoustic vortex beams by using flat lenses based on a Fresnel-spiral diffraction grating. The flat lenses are designed by spiral-shaped Fresnel zone plates composed of one or several arms. The constructive and destructive interferences of the diffracted waves by the spiral grating result in sharp acoustic vortex beams,
Jiménez, Noé +4 more
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Physics of Fluids, 2023 Precise manipulation of fluids and objects on the microscale is seldom a simple task, but, nevertheless, crucial for many applications in life sciences and chemical engineering. We present a microfluidic chip fabricated in silicon–glass, featuring one or several pairs of acoustically excited sharp edges at side channels that drive a pumping flow ...
Alen Pavlic +4 more
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Компьютерная оптика, 2023 In this work, the sharp focusing of a laser beam whose initial polarization pattern is formed by superposition of a cylindrical mth-order vector beam and a homogeneous linearly polarized beam is considered theoretically and numerically.
V.V. Kotlyar, S.S. Stafeev, V.D. Zaitsev
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Компьютерная оптика, 2023 Features of the near-field diffraction of Gaussian beams and Laguerre-Gauss modes by silicon subwavelength optical elements with varying relief height were studied in this paper using a finite-difference time-domain method.
D.A. Savelyev
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Focusing of inhomogeneous polarized modes of a laser waveguide dielectric resonator [PDF]
Радиофизика и электроника, 2020 Subject and Purpose. In this paper, spatial power characteristics of laser beams with inhomogeneous spatial polarization are theoretically investigated depending on whether they have moderate or sharp focusing.
A.V. Degtyarev +3 more
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Calculation of the intensity at the sharp focus of a cylindrical vector beam by three methods
Компьютерная оптика, 2023 We conduct a comparative analysis of diffraction fields upon sharply focusing vortex and non-vortex incident beams, calculated using three non-paraxial methods. The methods employed are a finite difference time domain (FDTD) method, a Rayleigh–Sommerfeld
A.G. Nalimov +2 more
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Older yet Sharp: No General Age-Related Decline in Focusing Attention
Journal of Experimental Psychology: General, 2023 Attention is a multifaceted mechanism operating on space, features, and memory. Previous studies reported both decline and preservation of attention in aging. Yet, it is unclear if healthy aging differentially affects attentional selection in these domains. To address these inconsistencies, we evaluated the ability to focus attention in a battery of 11
Alessandra S. Souza +2 more
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Spin angular momentum density in the tight focus of a light field with phase and polarization singularities [PDF]
Компьютерная оптика, 2019 For a light field with both phase and polarization singularities at its center, expressions are obtained that describe the distribution of the spin angular momentum (SAM) density in the sharp focal spot of an aplanatic system.
Alexey Kovalev +2 more
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Sharp-focusing Bragg–Fresnel zone plate with Laue diffraction geometry [PDF]
Journal of Synchrotron Radiation, 2006 The impact of decreased zone height on the focal properties of hard X-ray Bragg-Fresnel zone plates has been studied by numerical simulation. Decreased zone height allows for smaller zone widths and, although the efficiency of the lens is decreased, the signal-to-background ratio in the focal plane of the lens remains at a comparatively high level ...
Levon, Haroutunyan, Gayane, Hovhannisyan
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New Journal of Physics, 2022 Metalens with broadband and high-efficiency focusing functionality is desired in various underwater acoustic applications such as sonar and oceanography.
Jun Mei, Lijuan Fan, Xiaobin Hong
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