Gradient index liquid crystal devices and method of fabrication thereof
First Claim
1. Apparatus for shaping the profile of an optical beam of given wavelength which is directed along a path, which comprises at least one liquid crystal device intercepting said beam, said device having a first and a second substrate respectively having first and second surfaces opposed to each other, a liquid crystal material between said surfaces and having a chirality providing a structure of molecules of a given pitch P0 so as to provide a selective reflection band having a peak wavelength where λ
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0, the peak wavelength in said band being essentially equal to said given wavelength and equal to the product of P0 and nav, the average of the extraordinary and ordinary indexes of refraction of said material at λ
0 and measured at temperatures at which said apparatus is operating, and said first and second surfaces defining weak anchoring sites for said molecules.
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Accused Products
Abstract
Laser beam apodizers using cholesteric liquid crystals provides soft edge profile by use of two separate cholesteric liquid crystal mixtures with different selective reflection bands which in an overlap region have a gradient index where reflectivity changes as a function of position. The apodizers can be configured as a one-dimensional beam apod
The U.S. government has rights in the invention under Contract No. DE-FC03-85DP40200 between the University of Rochester and the Department of Energy.
47 Citations
23 Claims
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1. Apparatus for shaping the profile of an optical beam of given wavelength which is directed along a path, which comprises at least one liquid crystal device intercepting said beam, said device having a first and a second substrate respectively having first and second surfaces opposed to each other, a liquid crystal material between said surfaces and having a chirality providing a structure of molecules of a given pitch P0 so as to provide a selective reflection band having a peak wavelength where λ
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0, the peak wavelength in said band being essentially equal to said given wavelength and equal to the product of P0 and nav, the average of the extraordinary and ordinary indexes of refraction of said material at λ
0 and measured at temperatures at which said apparatus is operating, and said first and second surfaces defining weak anchoring sites for said molecules. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
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0, the peak wavelength in said band being essentially equal to said given wavelength and equal to the product of P0 and nav, the average of the extraordinary and ordinary indexes of refraction of said material at λ
- 19. The method of fabricating a device for shaping the profile of a laser beam which comprises the steps of preparing mixtures of liquid crystal materials of different chirality to provide first and second mixtures each having different pitch, containing said mixtures in a gap between surfaces of substrates so that a region is formed having a gradient pitch.
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