Optical: systems and elements – Diffraction – Using fourier transform spatial filtering
Reexamination Certificate
2011-07-05
2011-07-05
Pritchett, Joshua L (Department: 2872)
Optical: systems and elements
Diffraction
Using fourier transform spatial filtering
C359S569000
Reexamination Certificate
active
07974010
ABSTRACT:
The present invention relates to pigments comprising or consisting of a layer made of a material with an index of refraction that is higher than the index of refraction of the adjacent material by at least 0.25; whereas said layer has a zero-order diffractive micro-structure; whereas said layer acts as an optical waveguide and whereas said layer has a thickness between 50 nm and 500 nm; to processes for its manufacture and to its use. These pigments show a color effect upon rotation and/or tilting, and it is believed that this color effect is based on zero-order diffraction.
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Stuck Alexander
Walter Harald
CSEM Centre Suisse d'Electrique et de Microtechnique SA—R
Marshall & Gerstein & Borun LLP
Pritchett Joshua L
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