TECHNIQUES FOR MULTI-LAYER LIQUID CRYSTAL ACTIVE LIGHT MODULATION
Various embodiments set forth optical patterning systems. In some embodiments, an optical patterning system includes multiple liquid crystal (LC) layers and a substrate including circuitry that is connected to each of the LC layers. Each LC layer is independently addressable, via connections to the circuitry in the substrate, to modulate a different degree of freedom (DOF) of light, such as an amplitude, a phase, a distinct polarization component, or an amplitude or a phase of a polarization component of the light. In addition, each LC layer can be configured to operate in a non-resonant mode, in which light passes through the LC layer a single time, or in a resonant mode, in which light bounces back and forth between reflective layers multiple times to enhance the interaction with the LC layer.
1 . An optical patterning system, comprising:
a plurality of liquid crystal layers; and
a substrate that includes circuitry,
wherein each liquid crystal layer included in the plurality of liquid crystal layers is controllable to modulate a different degree of freedom of light, and
wherein each liquid crystal layer included in the plurality of liquid crystal layers is connected to the circuitry included in the substrate.
2 . The optical patterning system of claim 1 , further comprising at least one microlens array.
3 . The optical patterning system of claim 1 , wherein each liquid crystal layer included in the plurality of liquid crystal layers is connected by a separate set of vias to the circuitry included in the substrate.
4 . The optical patterning system of claim 1 , wherein at least two of the plurality of liquid crystal layers share a common electrode.
5 . The optical patterning system of claim 1 , further comprising at least one polarizer.
6 . The optical patterning system of claim 1 , further comprising at least one of a high-reflection layer or a partial-reflection layer.
7 . The optical patterning system of claim 1 , wherein the substrate includes either a nontransparent material or a transparent material.
8 . The optical patterning system of claim 1 , wherein the plurality of liquid crystal layers is partitioned into rectangular or annular segments.
9 . The optical patterning system of claim 1 , wherein the optical patterning system is used in computer-generated holography.
10 . The optical patterning system of claim 1 , wherein the optical patterning system is included in a near eye display device.
11 . A method for fabricating an optical patterning system, the method comprising:
fabricating a first stack that includes a substrate, circuitry, and at least one of a high-reflection layer, a partial-reflection layer, or an anti-reflection layer;
etching through the first stack and depositing a first layer that includes electronic vias;
fabricating at least one cell above the first stack, wherein each cell includes a plurality of layers that are filled with sacrificial material;
etching through the at least one cell and depositing a second layer that includes electronic vias;
fabricating a third layer that includes one or more electrodes above the at least one cell;
etching away the sacrificial material within the plurality of layers; and
filling the plurality of layers with liquid crystals.
12 . The method of claim 11 , further comprising fabricating a cover layer that includes a microlens array above the third layer using a lithography technique.
13 . The method of claim 11 , further comprising laminating a cover layer that includes a microlens array above the third layer.
14 . The method of claim 11 , wherein each cell further includes a plurality of alignment layers adjacent to the plurality of layers.
15 . The method of claim 14 , wherein each of the plurality of alignment layers includes microstructure gratings that are fabricating using a lithography technique.
16 . The method of claim 11 , further comprising:
releasing the optical patterning system from the substrate; and
bonding the optical patterning system to a transparent substrate.
17 . The method of claim 16 , further comprising:
fabricating a cover layer that includes a microlens array above the third layer; and
fabricating a second cover layer that includes a microlens array below the transparent substrate.
18 . A computer-implemented method for modulating light, the method comprising:
determining states of a plurality of cells of an optical patterning system for at least one point in time;
driving each cell included in the plurality of cells based on a corresponding state, wherein driving the cell comprises:
driving, via a first connection to circuitry in a substrate, a section of a first liquid crystal layer to modulate at least a first degree of freedom of light, and
driving, via a second connection to the circuitry in the substrate, a section of a second liquid crystal layer to modulate at least a second degree of freedom of light; and
projecting a light beam that is incident on the plurality of cells.
19 . The computer-implemented method of claim 18 , further comprising passing the light beam through at least one microlens array.
20 . The computer-implemented method of claim 18 , further comprising passing the light beam through at least one polarizer.