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US 6,587,180 B2Granted
Adjustable liquid crystal blazed grating deflector
AssigneeCalifornia Institute of Technology
InventorsXu Wang, Demetri Psaltis
Life of this patent
Estimating the term…
Abstract
A system of beam steering using electrical operation. A first system provides a grating and a liquid crystal material. When the liquid crystal is unenergized, there is a mismatch between the liquid crystal and the grating, causing the grating to diffract the light in a specified direction. The liquid crystal is energized to match its index of refraction to the grating. Then, the light is not diffracted by the grating, and hence travels in a different direction then it would when the liquid crystal was not energized. Another, finer system, forms electrically generated gratings using a liquid crystal material.
Claims31
A system, comprising:
- a first composite membrane including a grating, and an electrically controllable element, controlling a refraction of said grating;
- a second, composite membrane, including a grating and an electrically controllable element, controlling a refraction of said grating;
- and
- a control device, controlling said first and second composite membranes to control the direction of steering of an incoming beam based on controlling both said first composite membrane and said second composite membrane, wherein said first composite membrane has a grating with a first period, and said second composite membrane has a grating with a second period which is double said first period.
1 more element
A system, comprising:
- a first composite membrane including a grating, and an electrically controllable element, controlling a refraction of said grating;
- a second, composite membrane, including a grating and an electrically controllable element, controlling a refraction of said grating;
- and
- a control device, controlling said first and second composite membranes to control the direction of steering of an incoming beam based on controlling both said first composite membrane and said second composite membrane wherein said first composite membrane has a grating with a first period, and said second composite membrane has a grating with a second period which is double said first period, wherein said electrically controllable element in said first and second composite membranes includes a liquid crystal material, an electrically generated grating, coupled to one of said first and second composite membranes, to form additional steering directions.
1 more element
A system, comprising:
- an optically transparent substrate with an electrode, patterned thereon;
- a liquid crystal material, in contact with said electrode, and controlled by a voltage on said electrode between first and second states;
- and
- a plurality of gratings, in contact with said liquid crystal material, said plurality of gratings respectively providing a plurality of steering directions to incoming optical light based on a state of said liquid crystal material as controlled by said voltage, wherein said plurality of gratings are formed of an etchable material and one of said gratings has double the period of another of said gratings.
1 more element
A method, comprising:
- applying incoming optical light to an interface between a liquid crystal material and a grating;
- and controlling properties of the liquid crystal material to either match or mismatch to properties of the grating to control a direction of an outgoing light beam, wherein said controlling comprises controlling a plurality of layers of liquid crystal material and grating to provide a plurality of different beam steering directions and wherein one of the gratings has double the period of another of said gratings.
A method, comprising:
- applying incoming optical light to an interface between a liquid crystal material and a grating;
- controlling properties of the liquid crystal material to either match or mismatch to properties of the grating to control a direction of an outgoing light beam wherein said controlling comprises controlling a plurality of layers of liquid crystal material and grating to provide a plurality of different beam steering directions and wherein one of the gratings has double the period of another of said gratings, and
- providing an electrically generated grating to provide additional but finer beam steering control.
A system, comprising:
- a first layer, including a first grating having a first period, a liquid crystal material in contact with said first grating, and first and second control electrodes, positioned to control a refraction property of said liquid crystal material between said first and second control electrodes;
- a second layer, optically in series with said first layer, and including a second grating having a second period which is different than said first period, and a liquid crystal material in contact with said second grating, and third and fourth control electrodes, positioned to control a refraction property of said liquid crystal material between said third and fourth control electrodes;
- a control element, operating to control said first, second, third and fourth control electrodes between first and second control states, said first control state being one in which said liquid crystal material has an index of refraction which substantially matches a refraction of said grating, and said second control state being one in which said liquid crystal material has an index of refraction which mismatch is a refraction of said grating and
- a third layer, optically in series with said first and second layers, and including a liquid crystal material therein which is selectively electrically controlled to produce one of a plurality of different virtual gratings therein.
1 more element
Dependencies are inferred from the claim text.