Results 1 to 10 of about 87,657 (169)
Some of the next articles are maybe not open access.
Journal of Optics A: Pure and Applied Optics, 2009
The performance of Fresnel zone plates having a polygonal boundary between zones has been studied. The contribution of the complex amplitude of each zone is calculated analytically and numerically solved. The case of a continuous phase plate is considered as the limit case in performance for each polygonal shape.
Javier Alda, Francisco Javier González
openaire +1 more source
The performance of Fresnel zone plates having a polygonal boundary between zones has been studied. The contribution of the complex amplitude of each zone is calculated analytically and numerically solved. The case of a continuous phase plate is considered as the limit case in performance for each polygonal shape.
Javier Alda, Francisco Javier González
openaire +1 more source
Contrast optimization of Fresnel zone plate imaging
Review of Scientific Instruments, 2023Fresnel zone plates (FZPs) are circular diffractive elements that operate as a lens for x-rays. They have gained interest in the field of laser-plasma physics due to their ability to achieve higher spatial resolution than pinholes. Their design and implementation are complicated by the fact that a significant amount of the x-rays passing through the ...
D. Haberberger +4 more
openaire +2 more sources
A Millimeter-Wave Fabry–Pérot Cavity Antenna Using Fresnel Zone Plate Integrated PRS
IEEE Transactions on Antennas and Propagation, 2020This communication introduces a new structure of a partially reflective surface (PRS) to realize gain enhancement for a millimeter-wave Fabry–Pérot Cavity (FPC) antenna. It is the first attempt at applying a Fresnel zone plate (FZP) to a single-layer PRS,
Qing-Yi Guo, H. Wong
semanticscholar +1 more source
Journal of Applied Physics, 1992
We present a novel application of the Fresnel zone plate geometry in which the Mössbauer effect is used to focus nuclear-resonant x-ray photons and thereby to monochromatize synchrotron radiation. The calculated efficiency and energy bandpass of the Mössbauer–Fresnel zone plate monochromator compare well with those of other Mössbauer-effect ...
T. M. Mooney, E. E. Alp, W. B. Yun
openaire +1 more source
We present a novel application of the Fresnel zone plate geometry in which the Mössbauer effect is used to focus nuclear-resonant x-ray photons and thereby to monochromatize synchrotron radiation. The calculated efficiency and energy bandpass of the Mössbauer–Fresnel zone plate monochromator compare well with those of other Mössbauer-effect ...
T. M. Mooney, E. E. Alp, W. B. Yun
openaire +1 more source
IETE Journal of Research, 1968
ABSTRACTThe paper describes the design of a Fresnel zone plate suitable for use as an antenna in the centimetric or lower wavelength range. It has been shown that such antennas can be fabricated by using either metal or dielectric rings. Its properties have been analysed by employing the simple methods of electromagnetic diffraction.
G. S. Sanyal, Mahendra Singh
openaire +1 more source
ABSTRACTThe paper describes the design of a Fresnel zone plate suitable for use as an antenna in the centimetric or lower wavelength range. It has been shown that such antennas can be fabricated by using either metal or dielectric rings. Its properties have been analysed by employing the simple methods of electromagnetic diffraction.
G. S. Sanyal, Mahendra Singh
openaire +1 more source
, 2020
We present a simple and efficient method for generating focused acoustic vortices in air over a wide range of ultrasonic frequencies by means of an Active-Spiral Fresnel Zone Plate.
Ruben D. Muelas-Hurtado +2 more
semanticscholar +1 more source
We present a simple and efficient method for generating focused acoustic vortices in air over a wide range of ultrasonic frequencies by means of an Active-Spiral Fresnel Zone Plate.
Ruben D. Muelas-Hurtado +2 more
semanticscholar +1 more source
Array illumination of a Fresnel–Dammann zone plate
Applied Optics, 2016The traditional Dammann grating is a phase-only modulation, and its theoretical foundation is based on far-field diffraction. Here we extend the traditional Fresnel zone plate (FZP) into a Fresnel-Dammann zone plate (FDZP), which is, in essence, considered as a FZP with Dammann modulation.
Yayao, Ma +5 more
openaire +2 more sources
SPIE Proceedings, 1985
A description is given of the use of the Fresnel zone plate as a focusing or a frequency-filtering device at millimeter wavelengths. Sample design data are given, as well as references to prior results. A newer type of zone plate is discussed which employs two dielectrics of equal thickness to produce a flat zone plate.
openaire +1 more source
A description is given of the use of the Fresnel zone plate as a focusing or a frequency-filtering device at millimeter wavelengths. Sample design data are given, as well as references to prior results. A newer type of zone plate is discussed which employs two dielectrics of equal thickness to produce a flat zone plate.
openaire +1 more source
Optimization of modified volume Fresnel zone plates
Journal of the Optical Society of America A, 2009Modified volume Fresnel zone plates (MVFZPs) fabricated with laser direct writing were optimized for higher diffraction efficiencies. The Fresnel radii in each layer of a volume zone plate were iteratively adjusted by a simulation-based direct search optimization.
Srisungsitthisunti, Pornsak +2 more
openaire +3 more sources
Imaging and focusing of atoms by a fresnel zone plate
Physical Review Letters, 1991Focusing of and imaging with atoms by means of a spherical Fresnel zone plate has been observed for the first time. An intense beam of metastable helium atoms with atomic de Broglie wavelength ${\ensuremath{\lambda}}_{\mathrm{dB}}$=0.5--2.5 \AA{} is passed through either a single or a double slip with dimensions in the 10-\ensuremath{\mu}m range.
, Carnal +4 more
openaire +2 more sources