Results 231 to 240 of about 32,036 (281)
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Silica-based fibre Fresnel lens
Optics Communications, 2001A method of fabricating Fresnel lenses onto the tips of fibres is described and demonstrated. This involves a simple variant of standard fibre fabrication techniques that allows ultra-fine control of the dopant concentration profile. Conventional etching techniques allow fabrication of the Fresnel lens on the fibre tip.
John Canning +3 more
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Liquid crystal Fresnel lens display
Chinese Physics B, 2016A novel see-through display with a liquid crystal lens array was proposed. A liquid crystal Fresnel lens display (LCFLD) with a holographic screen was demonstrated. The proposed display system has high efficiency, simple fabrication, and low manufacturing cost due to the absence of a polarizer and color filter.
Wang, Xiaoqian +6 more
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Nonimaging Fresnel Lens Design
2001A Fresnel lens is essentially a chain of prisms. Each prism represents the slope of the lens surface, but without the material of the full body of the conventional singlet. The imaging Fresnel lens refracts light from an object and forms an image in the focal plane. Aberrations have an impact on the quality of the image; the imaging lens should be free
Ralf Leutz, Akio Suzuki
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IEE Proceedings - Microwaves, Antennas and Propagation, 1994
An analysis of the offset Fresnel lens antenna is presented using the vectorial Kirchhoff diffraction theory. Equations for predicting the copolarised and crosspolarised radiation patterns are given. Two approaches to evaluating the far-field integration are introduced.
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An analysis of the offset Fresnel lens antenna is presented using the vectorial Kirchhoff diffraction theory. Equations for predicting the copolarised and crosspolarised radiation patterns are given. Two approaches to evaluating the far-field integration are introduced.
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Journal of the Optical Society of America, 1961
In order to deform the wave surface passing through an optical system by the amount ϕ(u,v), it is suggested that a phase Fresnel lens be inserted in the pupil of the optical system. Assuming 0⩽ϕ(u,v)
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In order to deform the wave surface passing through an optical system by the amount ϕ(u,v), it is suggested that a phase Fresnel lens be inserted in the pupil of the optical system. Assuming 0⩽ϕ(u,v)
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Trifocal lens system with liquid crystal Fresnel lens
Japanese Journal of Applied Physics, 2018In this paper, we present the construction of a trifocal lens system by combining a liquid-crystal (LC) lens and an ordinary lens. The focusing properties of the proposed system can be controlled by changing the polarization state of the incident light wave.
Kohei Noda +7 more
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Linear Fresnel lens with polar tracking
Applied Optics, 1981The performance of coma and color corrected linear Fresnel lenses for solar concentration is evaluated for use in polar tracking systems. Effective concentrations of up to 90 at 75% efficiency were obtained.
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Comparison of lens and Fresnel null correctors
Applied Optics, 2001Fresnel null correctors are compared with classical Offner and Hindle null correctors for both optical performance and system sensitivities to errors of construction and placement in the test setup. Fresnel null correctors are closely related to circular diffractive null correctors, the main difference being that a Fresnel uses tilted grooves ...
A B, Meinel, M P, Meinel
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Wave-front analysis using Fresnel lens arrays
Optics Letters, 1995A compact wave-front sensor is implemented by an array of two-beam common path inversion interferometers. Each element of the array consists of two Fresnel lenses in a confocal configuration. The wave-front data can be extracted from a superposition of the zero-order undiffracted wave and the twice-diffracted first-order wave.
B, Spektor, J, Shamir
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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.
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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.
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