Results 131 to 140 of about 87,657 (169)

Fresnel zone plate fabricated using a polyvinyl chloride gel

Optical Engineering: The Journal of SPIE, 2018
. Based on creep-induced deformation of a polyvinyl chloride (PVC) gel in an electric field, a Fresnel zone plate (FZP) is fabricated. The employed electrode is constructed with a series of concentric zones, and the soft PVC gel coated on the electrode ...
Pingping Huang, Zuowei Zhou, H. Ren
semanticscholar   +1 more source

Fizeau interferometer with binary phase Fresnel-zone plate reference for precision measurement of large convex lens

Optics and lasers in engineering, 2018
A method of obtaining precision transmission wavefront of large convex lens interferometrically using binary Fresnel zone plate (FZP) was presented. We present the results from a set of experiments that demonstrate the accuracy, flexibility, and the ...
Xiaohong Wei, Yuhang He, Zhengkun Liu, Kaiyuan Xu, Bo Gao, Qiang Li, L. Ang, Liqun Chai   +7 more
semanticscholar   +1 more source

Properties and Fabrication of Micro Fresnel Zone Plates

Applied Optics, 1973
Arrays of ~2-mm diam, f/9, diffraction-limited Fresnel zone plates are made and measured. Amplitude zone plates are fabricated by conventional photolithographic techniques, while a specially developed evaporation/etching technique is used for phase zone plates.
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Aberrations of curved zone plates and Fresnel lenses

Applied Optics, 1977
The generalization of zone plates and Fresnel lenses from the usual flat surfaces to curved surfaces is discussed. It is shown that, although Abbe's sine law applies to zone plates but not to Fresnel lenses, both can yield single-element aplanats if formed on a curved surface. Third-order aberration formulas are given.
openaire   +2 more sources

Fresnel zone plate antenna with hexagonal‐cut zones

Microwave and Optical Technology Letters, 2008
AbstractA novel Fresnel zone plate antenna (FZPA) with hexagonal‐cut zones is presented. This new structure was simulated at 30 GHz using a finite‐difference time‐domain software to study its gain and sidelobe levels in relation to the standard circular FZPA and the hexagonal FZPA. Several prototypes were built and tested to verify the simulations.
S. M. Stout‐Grandy, A. Petosa, I. V. Minin, O. V. Minin, J. S. Wight   +4 more
openaire   +1 more source

Comprehensive focusing analysis of various Fresnel zone plates

Journal of the Optical Society of America A, 2004
A series-form expression for the individual diffracted field of a general annular ring is derived from the Rayleigh-Sommerfeld diffraction integral. It can be used for the accurate and fast simulation of any diffractive focusing element composed of concentric transparent rings.
Qing, Cao, Jürgen, Jahns
openaire   +2 more sources

Fresnel Zone Plate array fabricated by maskless lithography

2015 30th Symposium on Microelectronics Technology and Devices (SBMicro), 2015
This work reports the fabrication of Fresnel Zone Plates (FZP) by employing a maskless lithography tool based on direct laser writing. The target application areas in this work are to use a micro lens array (MLA) in a wavefront sensor, for optical aberrations quantification in human eye diagnostics or adaptive optical system. This last one is essential
Barea, Luis A., Zuben, Antonio A., M-Brahim, Tayeb, Montagnoli, Arlindo N., Hospital, Michel, Frateschi, N., Cirino, Giuseppe A.   +6 more
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Synthesis of Fresnel Diffraction Patterns by Overlapping Zone Plates

Applied Optics, 1968
It has been shown previously that two overlapping circular zone plates will create the image of two separate zone plates, two circular dots of light, with the closeness of the dots proportional to the degree of overlap of the zone plates. It is shown here that more complicated patterns can be produced by superpositioning of zone plate sections if the ...
R L, Conger, L T, Long, J A, Parks
openaire   +2 more sources

Fresnel Zone-Plate Diffraction Patterns

Journal of the Optical Society of America, 1969
The diffraction patterns of the central aperture and the first 10 rings of the classical Fresnel zone plate are calculated in the principal focal plane for off-axis distances as large as the radius of the 10th ring. The zone-plate pattern is found by summation; near the axis it is compared with closed-form approximations.
openaire   +1 more source

Fresnel zone plate: Anomalous foci

American Journal of Physics, 1976
It is found that, when a zone plate is examined in practice, foci exist where there should be none. An approach is developed which reveals that the zone plate is a circular diffraction grating, which in turn explains how a hologram works in a very direct manner.
openaire   +3 more sources