Results 231 to 240 of about 22,341 (248)

Diffractive components: holographic optical elements

1993
Besides refractive and reflective components, planar diffractive optical elements are promising for free space optical interconnects. The content of this chapter is focused on holographic optical elements (HOEs), which are diffractive elements fabricated by recording the interference pattern of an object and a reference wave in a photosensitive ...
Hans Peter Herzig, René Dändliker
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Photovoltaic concentrator using a holographic optical element

Applied Optics, 1988
A photovoltaic concentrator is proposed that uses equatorial tracking (the rotation axis of a concentrator points to the North Star), so that the change of the sun's altitude angle is minimized. The solar concentrator consists of a Fresnel lens (objective), a holographic optical element made on photoresist with 90% diffraction efficiency, and a field ...
Y W, Zhang, C S, Ih, H F, Yan, M J, Chang   +3 more
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Computer-Generated Holographic Optical Elements

2017
In earlier chapters, designs of simple binary, multilevel, and blazed DOEs using basic diffraction equations were presented. The proposed techniques were suitable for design of DOEs only for simple applications such as array generation, focusing, etc. On the other hand, DOEs generating arbitrary intensity profiles at the Fourier plane can be designed ...
A. Vijayakumar, Shanti Bhattacharya
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Curved holographic elements for optical coordinate transformations

Optics Letters, 1991
A new method for performing optical coordinate transformation is presented. It is based on a curved holographic element on which the interference pattern of two perpendicular plane waves is recorded. The design procedures and results for two curved elements that perform a one-dimensional logarithmic coordinate transformation and a Gaussian-to-uniform ...
N, Davidson, A A, Friesem, E, Hasman, I, Shariv   +3 more
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Optical Interconnects with Reflection Holographic Optical Elements

Topical Meeting on Holography, 1986
The increasing demands on micrelectronic circuits for small size and high data rates has pushed electronic interconnection technology to its limit. New techniques are being sought to circumvent these difficulties. Among them are optical interconnections.
R.K. Kostuk, J. W. Goodman, L. Hesselink
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Achromatic optical interconnects using holographic optical elements

1994 Conference on Lasers and Electro-Optics Europe, 1994
Diffractive optical elements as deflectors for optical free-space interconnects have been proposed by several authors.1,2 Unfortunately, the high flexibility of such elements is in many cases outweighed by the strong chromatic aberrations. Surface relief gratings have commonly a rather low carrier frequency (due to the limited resolution of the ...
J. Schwider, R. Volkel, S. Junger
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Phase holographic optical elements and geometrical optics

Journal of the Optical Society of America A, 1997
In the framework of geometrical optics, we show that the general ray-tracing formula for finding the direction of the diffracted rays for thin phase holographic optical elements located on any arbitrary continuous surface can be derived in a form similar to Fermat's principle.
P. J. Twardowski, J. Harthong
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Holographic optical elements recorded in silver halide sensitized gelatin emulsions Part I Transmission holographic optical elements

Applied Optics, 2001
Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOE's). The drawback of DCG is its low sensitivity and limited spectral response.
J M, Kim, B S, Choi, S I, Kim, J M, Kim, H I, Bjelkhagen, N J, Phillips   +5 more
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Designing and constructing thick holographic optical elements

Applied Optics, 1978
Previously, holographic optical elements have been constructed with two spherical waves. Better image quality and efficiency can be achieved by constructing thick HOE's with spherically aberrated wavefronts. We include an exact lens equivalent for a HOE to allow computer optimization of such systems. The effect of changes in the index of refraction and
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Optical System Design Using Holographic Optical Elements

SPIE Proceedings, 1985
Holographic Optical Elements (HOEs) are being currently used in an increasing number of applications as components of optical systems, although their use is still relatively rare. HOEs are invaluable for selected optical system applications, inappropriate for most, and potentially useful for others.
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