Electro-optic wedge structure for beam steering and method of manufacture

An apparatus for steering a beam of light comprising:

• a volume of electro-optic, light transmissive nematic liquid crystal material having a predetermined geometric shape and positioned to intersect the beam of light so that the beam of light is directed into the material, said material having a first surface on which the beam of light is incident and a second surface opposite the first surface, the first and second surfaces defining a portion of the material therebetween having a thickness which varies, the beam of light passing through the portion of the material;
• a voltage source applying a potential difference across the portion of the material;
• a control circuit varying the magnitude of the potential difference applied to the portion of the material whereby the beam of light is deflected by an angle which is a function of the varying thickness of the portion of the material and the refractive index of the portion of the material as determined by the magnitude of the potential difference;
• and
• an alignment layer adjacent the first and second surfaces for aligning the molecules of the liquid crystal material to be substantially uniformly perpendicular to the first and second surfaces, respectively, when no potential difference is applied across the portion of the liquid crystal material whereby the alignment layer provides homeotropic alignment which enables proper optical position of the liquid crystal material when the potential difference is applied across the portion of the liquid crystal material.

An apparatus for steering a beam of light comprising:

• a volume of electro-optic, light transmissive material comprising a plurality of contiguous wedge-shaped bodies positioned to intersect the beam of light so that the beam of light passes through the material, the wedge-shaped bodies of material having first surfaces on which the beam of light is incident and second surfaces opposite the first surfaces, the first and second surfaces of each wedge-shaped body defining a wedge such that the material between the first and second surfaces has a thickness which varies, the wedge-shaped bodies being arranged such that the second surfaces of the material are parallel so that the volume is bounded by a plurality of contiguous wedge-shaped surfaces and being arranged such that a phase difference between the thickest part of each wedge-shaped body and the contiguous thinnest part of the next wedge-shaped body is a multiple of 2.pi. whereby destructive interference between adjacent wedge-shaped bodies is minimized;
• a voltage source applying a potential difference across the material;
• and
• a control circuit varying the magnitude of the potential difference applied to the material whereby the beam of light is deflected by an angle which is a function of the varying thickness of the material and the refractive index of the material as determined by the magnitude of the potential difference thereby steering the beam of light.

A method of manufacturing an apparatus for steering an image comprising a beam of light which defines the image in response to a variable potential difference, said method comprising the steps of:

• providing first and second substantially planar substrates;
• coating a surface of each substrate with one or more selected materials;
• positioning the substrates so that their coated surfaces face each other and so that the substrates define a portion therebetween having a thickness which varies;
• introducing a liquid crystal material between the positioned substrates;
• curing the liquid crystal material;
• and
• affixing means for applying a variable potential difference across the portion of varying thickness.

A method of manufacturing an apparatus for steering a beam of light in response to a variable potential difference, said method comprising the steps of:

• providing first and second substrates;
• coating a surface of each substrate with one or more selected materials;
• positioning the substrates nonparallel to each other so that their coated surfaces face each other and so that the substrates define a portion therebetween having a thickness which varies;
• introducing the liquid crystal material between the non-parallel substrates to form a wedge of the liquid crystal material;
• curing the liquid crystal material;
• and
• affixing means for applying a variable potential difference across the portion of varying thickness.