Results 21 to 30 of about 4,282 (222)

Optical elements for the extreme ultraviolet and soft X-ray range [PDF]

Biuletyn Wojskowej Akademii Technicznej, 2022
The article presents the physical basis and overview of optical elements for the rangeincluding extreme ultraviolet (EUV) and soft X-ray (SXR). The first chapter contains an introductionto the subject under review and physical fundamentals.
Martyna Wardzińska, Przemysław Wachulak   +1 more
doaj   +1 more source

Lensless imaging with a programmable Fresnel zone aperture. [PDF]

Sci Adv
Zhang X, Wang B, Li S, Liang K, Guan H, Chen Q, Zuo C.   +6 more
europepmc   +2 more sources

The Inverse Fresnel Beam XSP-CDP Stack Imaging in Crosswell Seismic

Frontiers in Earth Science, 2022
In order to overcome the shortcomings of serious arc drawing and low computational efficiency in the crosswell seismic migration method and the problems of the inaccurate velocity model and sparse distribution of reflection points in the traditional ...
Fei-Long Yang, Fei-Long Yang, Fei-Long Yang, Fei-Long Yang, Guang-Ying Ren, Feng-Ming Yao, Chong Zhao   +6 more
doaj   +1 more source

Investigation of Beam Width Shaping of a Ku-band Horn Antenna using a Diffractive Optic Element and an Electromagnetic Wave Absorber

Sakarya Üniversitesi Fen Bilimleri Enstitüsü Dergisi, 2020
The feasibility of beam-shaping of a Ku-Band horn as a transmitting (Tx) antenna by mounting two different versions of lenses which are kind of Fresnel Zone Plates (FZP) is studied.
Ahmet Teber
doaj   +1 more source

Expansion of Image Space in Enhanced-NA Fresnel Holographic Display

Applied Sciences, 2022
The enhanced-NA Fresnel hologram reconstructs a holographic image at a viewing angle larger than the diffraction angle of a hologram pixel. The image space is limited by the bandwidth of a digital hologram.
Byung Gyu Chae
doaj   +1 more source

Mathematical model of antenna with nonlinear characteristics for calculating the electromagnetic field in the Fresnel zone

Радіоелектронні і комп'ютерні системи, 2021
The paper presents a mathematical model of radio-electronic systems (RES), which include antennas and their excitation paths with nonlinear characteristics.
Дмитро Вячеславович Грецьких, Василь Олександрович Алєксєєв, Андрій Володимирович Гомозов, Віктор Олександрович Катрич, Михайло Васильович Нестеренко   +4 more
doaj   +1 more source

Comparison of Communication Viewsheds Derived from High-Resolution Digital Surface Models Using Line-of-Sight, 2D Fresnel Zone, and 3D Fresnel Zone Analysis

ISPRS International Journal of Geo-Information, 2018
We compared three methods for deriving communication viewsheds, which indicate the coverage areas for transmitter points from high-resolution digital surface models.
Jieun Baek, Yosoon Choi
doaj   +1 more source

Pinhole Zone Plate Lens for Ultrasound Focusing

Sensors, 2017
The focusing capabilities of a pinhole zone plate lens are presented and compared with those of a conventional Fresnel zone plate lens. The focusing properties are examined both experimentally and numerically.
Constanza Rubio, José Miguel Fuster, Sergio Castiñeira-Ibáñez, Antonio Uris, Francisco Belmar, Pilar Candelas   +5 more
doaj   +1 more source

Amplitude Zone Plate in Adaptive Optics: Proposal of the Principle

Photonics, 2022
One of the main elements in hardware-based adaptive optics systems is a deformable mirror. There is quite a large number of such mirrors based on different principles and exhibiting varying performance.
Vasily Matkivsky, Alexsandr Moiseev, Pavel Shilyagin, Grigory Gelikonov   +3 more
doaj   +1 more source

Design of Fresnel Lens-Type Multi-Trapping Acoustic Tweezers

Sensors, 2016
In this paper, acoustic tweezers which use beam forming performed by a Fresnel zone plate are proposed. The performance has been demonstrated by finite element analysis, including the acoustic intensity, acoustic pressure, acoustic potential energy ...
You-Lin Tu, Shih-Jui Chen, Yean-Ren Hwang   +2 more
doaj   +1 more source