Results 61 to 70 of about 99,715 (244)

Chromatically-corrected, high-efficiency, multi-colour, multi-plane 3D imaging [PDF]

, 2012
It is shown that grisms, a grating and prism combination, are a simple way to achieve chromatic control in 3D multi-plane imaging. A pair of grisms, whose separation can be varied, provide a collimated beam with a tuneable chromatic shear from a ...
Dalgarno, Paul A, Feng, Yan, Greenaway, Alan H, Lee, David, Thomson, Robert R, Yang, Yi   +5 more
core   +1 more source

Hard X-ray nano-holotomography with a Fresnel zone plate.

Optics Express, 2020
X-ray phase contrast nanotomography enables imaging of a wide range of samples with high spatial resolution in 3D. Near-field holography, as one of the major phase contrast techniques, is often implemented using X-ray optics such as Kirkpatrick-Baez ...
S. Flenner, A. Kubec, C. David, M. Storm, Clemens F Schaber, F. Vollrath, M. Müller, I. Greving, J. Hagemann   +8 more
semanticscholar   +1 more source

Focusing Microwaves in the Fresnel Zone With a Cavity-Backed Holographic Metasurface

IEEE Access, 2018
We present the design and experimental demonstration of a cavity-backed, holographic metasurface capable of focusing microwaves in the Fresnel zone. The circular cavity consists of two stacked plates: microwaves are injected into the bottom plate via a ...
Vinay R. Gowda, Mohammadreza F. Imani, Timothy Sleasman, Okan Yurduseven, David R. Smith   +4 more
doaj   +1 more source

Analysis of Predistortion Techniques on Fresnel Zone Plates in Ultrasound Applications

Sensors, 2021
In this work, we analyze the effect of predistortion techniques on the focusing profile of Fresnel Zone Plates (FZPs) in ultrasound applications. This novel predistortion method is based on either increasing or decreasing the width of some of the FZP ...
José Miguel Fuster, Sergio Pérez-López, Francisco Belmar, Pilar Candelas   +3 more
doaj   +1 more source

Fresnel zone plate development for x-ray radiography of hydrodynamic instabilities at the National Ignition Facility.

Applied Optics, 2020
The study of Rayleigh-Taylor (RT) and Richtmyer-Meshkov (RM) instabilities in a planar geometry at high energy densities at the National Ignition Facility (NIF) requires high spatial resolution imaging. We demonstrate the potential of Fresnel zone plates
A. Do, L. Pickworth, B. Kozioziemski, A. Angulo, G. Hall, S. Nagel, D. Bradley, T. Mccarville, J. Ayers   +8 more
semanticscholar   +1 more source

Fresnel zone plate telescopes for X-ray imaging II: numerical simulations with parallel and diverging beams [PDF]

, 2009
We present the results of simulations of shadows cast by a zone plate telescope which may have one to four pairs of zone plates. From the shadows we reconstruct the images under various circumstances.
A. R. Rao, Anuj Nandi, Dipak Debnath, HH Barrett, JG Ables, RH Dicke, Sandip Kumar Chakrabarti, SK Chakrabarti, Sourav Palit, UD Desai, V. Girish, Vipin K. Yadav   +11 more
core   +1 more source

Investigation of Quadrate Fresnel Zone Plates Fabricated by Femtosecond Laser Direct Writing

Applied Sciences, 2022
The circular Fresnel zone plate (FZP) has been extensively used in micro-optics due to its outstanding focusing performance. Despite that, the curved edge of the circular zone has drawbacks limiting its use in terahertz imaging, array generator, and ...
Xiaoyan Sun, Fang Zhou, Lian Duan, Ji-an Duan   +3 more
doaj   +1 more source

Millimeter-wave offset fresnel zone plate lenses characterization [PDF]

, 2014
Fresnel Zone Plate Lenses (FZPLs) are transparent-opaque lenses that filter the desirable phase. The centred Fresnel lenses have a strong back radiation towards the feed. In order to solve this drawback, offset feeding or offset pointing lenses are used.
Hao, Yang, Herrán Ontañón, Luis Fernando, Las Heras Andrés, Fernando Luis, León Fernández, Germán, Muñoz, Max   +4 more
core   +2 more sources

Direct replication of a glass micro Fresnel zone plate array by laser irradiation using an infrared transmissive mold.

Optics Express, 2020
It is not yet possible to fabricate micrometer-scale, glass optical components with nanometer-scale precision. Glass thermal imprinting enhances production efficiency.
Runjia Han, Juho Lee, Baekcheon Seong, Ryung Shin, Donghyun Kim, Changsu Park, Jiseok Lim, C. Joo, Shinill Kang   +8 more
semanticscholar   +1 more source

Surface Passivation of HgTe Nanocrystals Enabling EG/2 Open‐Circuit Voltage and Their Coupling to Dielectric Cavity for Narrow Detection

Advanced Materials, EarlyView.
This article explores how the integration of a thin shell, combined with optimized surface chemistry, enables the design of photodiodes based on short‐wave infrared HgTe nanocrystals. These photodiodes achieve an open‐circuit voltage greater than half the optical bandgap, which drastically reduces dark current. The article also explores the integration
Albin Colle, Clement Gureghian, Dario Mastrippolito, Mariarosa Cavallo, Jiho Roh, Marco Paye, Tommaso Gemo, Diogo Almeida, Adrien Khalili, Yoann Prado, Xavier Lafosse, Sandrine Ithurria, Mathieu G. Silly, Pavel Dudin, James K. Utterback, José Avila, Debora Pierucci, Emmanuel Lhuillier   +17 more
wiley   +1 more source