Beam steering device
First Claim
1. A device for steering a beam of light, the device comprising an array of elements, said beam of light being incident upon said array of elements, each element having a reflective back electrode and a front electrode, the back and front electrodes being disposed respectively behind and in front of a liquid crystal layer, the back electrodes being spaced apart to define said array, and a reflective layer disposed behind the back electrodes to reflect light incident in the spaces between the back electrodes substantially in phase with the light reflected from the back electrodes.
1 Assignment
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Accused Products
Abstract
A beam steering device uses a liquid crystal with an array of back electrodes. Voltages are applied to the array to cause a desired phase distribution across the array, the distribution being selected to steer a beam incident upon the array into a desired direction. Reflective elements are disposed to reflect light incident in the spaces between the electrodes to reduce losses and to smooth the transitions in phase between adjacent electrodes.
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Citations
22 Claims
- 1. A device for steering a beam of light, the device comprising an array of elements, said beam of light being incident upon said array of elements, each element having a reflective back electrode and a front electrode, the back and front electrodes being disposed respectively behind and in front of a liquid crystal layer, the back electrodes being spaced apart to define said array, and a reflective layer disposed behind the back electrodes to reflect light incident in the spaces between the back electrodes substantially in phase with the light reflected from the back electrodes.
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16. A method of steering light having a first direction to a desired second direction, the method comprising:
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causing a beam of said light to be incident upon a reflective liquid crystal device;
selecting a desired spatial phase modulation characteristic for said liquid crystal device thereby to provide a deflection from said first direction to said second direction; and
providing a spatial distribution of phase levels across said liquid crystal device to at least approximate to said desired characteristic;
wherein the step of providing a spatial distribution of phase levels comprises driving said liquid crystal at sequential spaced driving locations to produce rising discrete phase levels; and
smoothing transitions in phase between said spaced driving locations by providing further locations between said spaced driving locations, and reflecting said light through said liquid crystal in said further locations. - View Dependent Claims (17, 18, 19, 20, 21)
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Specification