Techniques for complex wavefront modulation
Various embodiments set forth optical patterning systems. Each pixel of the optical patterning systems includes an amplitude-modulating cell that is in line with a phase-modulating cell. The amplitude-modulating cell includes a liquid crystal and a drive method for modulating at least the amplitude of a wavefront of light that passes through the amplitude-modulating cell. The phase-modulating cell includes a liquid crystal and a drive method for modulating at least the phase of a wavefront of light that passes through the phase-modulating cell. In some embodiments, the amplitude-modulating cell shares a common ground with the phase-modulating cell. The amplitude-modulating cell and the phase-modulating cell can be used to independently control the amplitude change and phase delay imparted by the pixel, enabling complex wavefront modulation.
1. An optical patterning system, comprising:
a plurality of pixels, each of the pixels comprising:
a first liquid crystal cell that modulates at least an amplitude of light; and
a second liquid crystal cell that modulates at least a phase of the light,
wherein the first liquid crystal cell is in line with the second liquid crystal cell, and
wherein the first liquid crystal cell and the second liquid crystal cell share a transparent ground.
2. The optical patterning system of claim 1 , wherein the first liquid crystal cell comprises a twisted nematic liquid crystal and a transparent electrode.
3. The optical patterning system of claim 1 , wherein the second liquid crystal cell comprises a vertically-aligned liquid crystal and a transparent electrode.
4. The optical patterning system of claim 1 , wherein the first liquid crystal cell comprises a linear polarizer.
5. The optical patterning system of claim 1 , wherein the first liquid crystal cell comprises a first linear polarizer and a second linear polarizer, and the first linear polarizer is cross-polarized with respect to the second linear polarizer.
6. The optical patterning system of claim 1 , wherein the second liquid crystal cell comprises a reflective substrate, and the first liquid crystal cell is driven via a voltage based on a square root of a target level of brightness.
7. The optical patterning system of claim 1 , wherein the second liquid crystal cell comprises a transmissive substrate, and the first liquid crystal cell is driven via a voltage based on a target level of brightness.
8. The optical patterning system of claim 1 , wherein the optical patterning system is used in computer-generated holography.
9. The optical patterning system of claim 1 , wherein the optical patterning system is included in a near eye display device.
10. A cell, comprising:
a first liquid crystal cell that modulates at least an amplitude of light; and
a second liquid crystal cell that is in line with the first liquid crystal cell and modulates at least a phase of the light,
wherein the first liquid crystal cell and the second liquid crystal cell share a transparent ground.
11. The cell of claim 10 , wherein the first liquid crystal cell comprises a twisted nematic liquid crystal, a transparent electrode layered on a substrate, and at least one linear polarizer.
12. The cell of claim 11 , wherein the at least one linear polarizer comprises a first linear polarizer that is cross-polarized with respect to a second linear polarizer.
13. The cell of claim 10 , wherein the second liquid crystal cell comprises a vertically-aligned liquid crystal and a transparent electrode layered on a substrate.
14. The cell of claim 13 , wherein the substrate is transparent.
15. The cell of claim 13 , wherein the substrate is either reflective or transflective.