Results 21 to 30 of about 78,093 (245)

Spatial-energy characteristics of focused modes of a metal terahertz laser resonator [PDF]

Радиофизика и электроника, 2019
Subject and ppurpose. In this paper, the spatial-energy characteristics of laser beams with inhomogeneous spatial polarization with their moderate and sharp focusing are theoretically investigated.
S.A. Vlasenko, A.V. Degtyarev, M.M. Dubinin, V.A. Maslov   +3 more
doaj   +1 more source

CONTROL OVER HIGHER-ORDER TRANSVERSE MODES IN A WAVEGUIDE-BASED QUASI-OPTICAL RESONATOR [PDF]

Radio Physics and Radio Astronomy, 2022
Subject and Purpose. The problems under consideration concern selection and focusing of higher-order modes in a waveguide-based dielectric laser. The purpose is to clarify the physics underlying the behavior of, and permitting control over, continuous ...
A. V. Degtyarеv, M. M. Dubinin, O. V. Gurin, V. O. Maslov, K. I. Muntean, V. M. Ryabykh, V. S. Senyuta, O. O. Svystunov   +7 more
doaj   +1 more source

Light distribution in fat cell layers at physiological temperatures

Scientific Reports, 2023
Adipose tissue (AT) optical properties for physiological temperatures and in vivo conditions are still insufficiently studied. The AT is composed mainly of packed cells close to spherical shape.
Irina Yu. Yanina, Polina A. Dyachenko, Arkady S. Abdurashitov, Alexander S. Shalin, Igor V. Minin, Oleg V. Minin, Andrey D. Bulygin, Denis A. Vrazhnov, Yury V. Kistenev, Valery V. Tuchin   +9 more
doaj   +1 more source

Digital holographic microscopy and focusing methods based on image sharpness

Journal of Microscopy, 2014
SummaryDigital holographic microscope allows imaging of opaque and transparent specimens without staining. A digitally recorded hologram must be reconstructed numerically at the actual depth of the object to obtain a focused image. We have developed a high‐resolution digital holographic microscope for imaging amplitude and phase objects with ...
İlhan, Hazar Aytekin, Doğar, Mert, Özcan, Meriç   +2 more
openaire   +4 more sources

Sharp focusing of linearly polarized asymmetric Bessel beam

Computer Optics, 2015
We conduct the numerical and experimental study of sharp focusing of a linearly polarized asymmetric Bessel beam with topological charge n = 3 and a crescent-shaped transverse intensity pattern. Using the Debye integral, we show that in the focal plane of a high NA aplanatic lens (NA = 0.9 – 0.95) the intensity distribution is also crescent-shaped ...
V. Kotlyar, S. Stafeev, A. Porfirev
openaire   +1 more source

Congeneric predators fill discrete niches created by the relative abundances of their prey species

Journal of Avian Biology, 2022
To what degree is niche partitioning driven by underlying patterns in resources such as food, rather than by competition itself? Do discrete niches exist?
Eliot T. Miller, Oisin Mac Aodha, Emma I. Greig, David N. Bonter, Wesley M. Hochachka   +4 more
doaj   +1 more source

Adiabatic nano-focusing of plasmons by sharp metallic wedges [PDF]

Applied Physics B, 2006
In this paper, we demonstrate the possibility of efficient adiabatic nano-focusing of plasmons by a sharp triangular metal wedge. The geometrical optics approach and the approximation of continuous electrodynamics are used for the analysis. In particular, it is demonstrated that both the phase and group velocities of an incident anti-symmetric (with ...
Gramotnev, Dmitri, Vernon, Kristy
openaire   +2 more sources

Structurally Stable Astigmatic Vortex Beams with Super-High Orbital Angular Momentum (ABCD Matrix Approach)

Photonics, 2023
We have demonstrated efficiency of employing the ABCD matrix approach to transform higher-order structured Laguerre–Gaussian (sLG) beams into structurally stable astigmatic sLG (asLG) beams, highlighting their dynamics at propagating.
Alexander Volyar, Mikhail Bretsko, Server Khalilov, Yana Akimova   +3 more
doaj   +1 more source

Visualization Characteristics of a Sharp Focusing Schlieren Method.

Journal of the Visualization Society of Japan, 2000
A sharp focusing schlieren system gives a means for observing any cross section of a flow field, which is perpendicular to the test beam axis of the optical system. This is impossible for a conventional schlieren system. In this study, a sharp focusing schlieren system was designed with referring to the Weinsten's system to investigate visualization ...
Yutaka YAMAGUCHI, Masashi KASHITANI, Shinichi WADA, Teruo SAITO   +3 more
openaire   +2 more sources

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, Romero-Garcia, Vicent, Garcia-Raffi, Lluis Miquel, Camarena, Francisco, Staliunas, Kestutis   +4 more
openaire   +5 more sources